Spider Acts Like Ruthless Carnivore, Is Really Flexitarian

Even deadly predators crave a salad sometimes. Certain orb-weaver spiders—apparent full-time carnivores who eat by trapping prey, covering it with digestive juices, and then slurping it down like an insect smoothie—have been secretly taking their meals with a plant-based side dish. Namely, pollen.

Orb weavers are a family of spiders common all across the world; they're the ones that weave the classic concentric-circle webs you see in picture books. Earlier studies have shown that those webs can collect a lot of pollen on their sticky strands, and that the spiders are willing to eat pollen in the lab. Benjamin Eggs, a graduate student at the University of Bern in Switzerland, and ecologist Dirk Sanders studied two kinds of orb weavers to see what truth there was to this rumor.

For the first part of the experiment, Eggs gathered 20 young Aculepeira ceropegia spiders from outdoors in the spring and brought them into the lab. He coaxed each spider to build its nest inside a cardboard box, where he supplied it with several fruit flies per week. Eggs also sprinkled half the spiderwebs with birch pollen, as they might be in the wild.

After a month, Eggs broke down the spiders' bodies and examined the carbon and nitrogen isotopes inside them. Isotopes, if it's been a while since your last chemistry class, are different forms of the same element. For example, most carbon atoms in the world have 6 protons plus 6 neutrons in their nuclei, making them carbon-12. But a small percentage of carbon atoms, called carbon-13, have an extra neutron. Animals incorporate the atoms they eat into their bodies. So by comparing the ratio of lighter to heavier isotopes in spiders' bodies to the signature ratios of their various foods, the researchers could see what the spiders were eating.

In the lab, orb weavers supplied with pollen had a different isotope ratio than their neighbors who only received fruit flies. This told Eggs that his spiders were, in fact, eating the pollen. But would they do it in the wild?

He returned outdoors and gathered young Araneus diadematus spiders, another orb-weaver species, from the trees. He used nets and bug vacuums to gather as many other insects from the area as possible—the spiders' potential prey. And he collected samples of pollen from neighboring trees.

Eggs analyzed the carbon and nitrogen isotopes in the outdoor spiders, along with all the insects and pollen that might be on their menu. Based on those ratios, he calculated that pollen made up 25 percent of the orb weavers' diet.

It's convenient for orb weavers to eat pollen, because they frequently dismantle and eat their webs in order to recycle the silk proteins. As long as they're at it, they may as well suck down the vegetables trapped there. Eggs points out, though, that the pollen grains he found in his study are too big for spiders to swallow accidentally. So his orb weavers must have deliberately eaten pollen grains by first covering them in digestive enzymes, then slurping them up.

Eating pollen might be most practical in the spring, when young spiders have just hatched and built webs, but insects are still hard to find. The spiders in this study were all juveniles. Yet Eggs, who carried out this research for his undergraduate thesis, thinks there's no reason adult spiders wouldn't eat pollen too. He says, "The anatomy of araneids does not change dramatically when they reach maturity." (He adds intriguingly, "Exception: genitals.")

It's even possible that other kinds of spiders nibble on pollen too. "There is evidence that other web-building spiders like the sheet weavers (Linyphiidae) also feed on pollen," Eggs says, "although they don’t eat their own web." Every diet needs a cheat day, after all.


Photo by Dirk Sanders.

Eggs B, & Sanders D (2013). Herbivory in spiders: the importance of pollen for orb-weavers. PloS one, 8 (11) PMID: 24312430

Cooler Than Your Environmental Club: An Interview with My Little Sister about the Adirondack Youth Climate Summit

Teenagers who want to cause a disruption don't have to ride a skateboard anymore; these days they can do it on a bike generator. Earlier this November a crowd of students came together in Upstate New York to share ideas about greening their schools and addressing climate change on a small and large scale.  My youngest sister, Leigh, is a senior in high school and was at the conference for her second year. I asked her what they did there, and she told me about energy efficiency, celeriac soup, and how her generation is going to do things differently. (I never did get a straight answer about some Facebook photos, though.)

*****************

Hi Leigh! So who attends the Adirondack Youth Climate Summit?

There were about 150 students representing 27 colleges and high schools around New York, mostly from the Adirondack region. Each school could send 5 to 6 students along with a teacher chaperone. Students at my school had to write an essay explaining why they wanted to go to the summit and what interest they had in climate change. (Most students I talked to were shocked that my school had been so selective because their schools just brought their entire environmental club.)

By the way, I hope email is OK. Would I have more generational cred with you right now if I were conducting this interview via SnapChat or something?

I have to say, I much prefer the transfer of information through text bubbles containing less than 140 characters attached to a picture I can only view for 10 seconds on a 4-inch screen...but I guess this will do.

What kinds of workshops did you go to?

I got to attend three different workshops of my choice on the first day, splitting up with my school group so that we could cover more ground. I attended the three that were geared towards successfully sustaining a school garden and implementing younger students into climate action, because that's what I've been focused on at school the past couple years. The rest of my team attended workshops about composting, green teams, energy efficiency, biofuels, and recycling.

I hear the food was a highlight.

The food was absolutely delicious! All the meals and snacks were provided by local farms and vendors. They had vegetarian, vegan and gluten-free options, and Ben & Jerry's (a major sponsor of the summit) provided ice cream the second day. I caught myself enjoying kale chips and even tried parsnip and celeriac for the first time in a delicious soup that a Culinary Arts professor from Paul Smith's College made. (See recipe below.)

As weird as it sounds, I think the presence of wholesome, fresh, unprocessed food really boosted everyone's brain power for a few days.

And there were speakers too?

Brian Stillwell of Alliance for Climate Education kicked off the summit with a catchy, motivating presentation about climate change and the science behind it, followed by Brother Yusef Burgess of Youth Ed-Venture and the Children & Nature Network, who spoke about using the power of nature to transform and educate youth. Later in the afternoon Dr. Susan Powers, the Associate Director for Sustainability at Clarkson University, presented to us the outcomes of climate change in both our best and worst case scenarios.

Mark and Kristin Kimball, who own Essex Farm in the Adirondacks, hosted the dance party, fed us freshly harvested carrots, and encouraged our generation to be the driving force of the climate movement—and, more importantly, to have fun doing it. They made the point that these days, things like smoking cigarettes or dumping gasoline into a lake are considered "socially unacceptable," but that took time. Now, it is our time to make not caring about the environment be socially unacceptable.

Was it valuable just interacting with the other kids there, from different kinds of schools? Were you learning and getting ideas from each other?

YES. The second day, there was a 2-hour poster session where all the schools displayed posters of their current "green" efforts and plans for the future. I had a chance to talk to so many different schools and share ideas about outdoors clubs, gardening problems, recycling efforts and cafeteria food. I had conversations with a high school that was having trouble even starting an environmental club due to the lack of support from administration, and on the other end of the spectrum, I talked to a school that had livestock and taught all their science classes on a farm.

We also had the amazing opportunity to Skype with Finland, where they were holding a similar youth climate summit modeled after ours in the Adirondacks. Despite the sound lag and language barrier, it was still inspiring to see that kids our age halfway around the globe are facing the same problems we are.

It looks like you guys had a lot of fun at this dance party. In your Facebook photos I observed electric guitar, someone crowdsurfing, a guy in a sailor hat juggling fire, and what appeared to be people using ropes to move a large rock. Are these the elements of a good party for the young environmentalist crowd?

I think these are the elements of any good party, actually. Moving the rock could have been a metaphor for how teamwork can move the world or something, but it was really just for the fun of moving a rock. We were told that our generation will make it through this difficult time in climate change only if we have fun in the process.

What sorts of ideas or projects did you bring back from the summit to use at school?

The second day of the summit, all the teams were given 2 hours to create their school's "Climate Action Plan" and a detailed timeline to present to the rest of the schools at the end of the day. Our team decided to focus on 4 major projects in the coming year: improving the school garden, building a bike generator for the lobby, holding a bi-annual school-wide locker clean-out to donate gently used school supplies and teach proper recycling, and finding places to cut the school's phantom energy usage (a.k.a. the wattage used by electronics when they're turned off but still plugged in).

You may not know this, but back when I was at your school I belonged to an "environmental club" too. This meant that a couple of us would go to all the classrooms after school and pull trash out of the blue bins, because otherwise the maintenance guys refused to recycle. Is it fair to say things have come a long way?

Simply put, yes. We have a recycling bin in every classroom, our cafeteria serves vegetables from a number of local farms, quarterly grades and comments are now only available online, our drinking fountains are now water-bottle filling stations, and we have a garden that brings vegetables to the salad bar. We have solar panels on one building and another LEED-qualified building, with another one in the construction phase.

I think we're also a little cooler than your environmental club, because now we are the "Green Avengers," equipped with a logo and a Facebook page.

Are you optimistic about climate change? Do you come back from an event like this feeling like you're part of a group of people who will actually make a difference, whether it's through school-level projects now, or after college as policy makers? Or are we pretty much screwed?

Both times going to the summit I came back incredibly high in motivation, but I knew if I didn't write down all my ideas and get acting quickly, I would lose my energy. Spending time around so many like-minded people definitely makes me excited to get out there and make change.

It also reminds me we have to be able to work on our own and not rely on the work of others because that's part of the attitude that brought us to this predicament in the first place. As Dr. Powers told us, even in the earth's "best-case scenario," we'll still experience rising global temperatures. It's just up to my generation to slow the acceleration of carbon dioxide emissions and provide the optimistic attitude.

Celeriac and Parsnip Soup
Yields 18-24 servings (reduce if you're not feeding a youth summit)

Ingredients:
5 pounds cubed celeriac root
5 pounds chopped parsnip
6 tablespoons olive oil
15 cups vegetable stock
1 bundle thyme
1/2 teaspoon salt
1/2 teaspoon ground black pepper

Preparation:
Preheat the over to 400°F. Toss the celeriac and parsnip with the olive oil. Arrange the vegetables in a single layer on a foil-covered baking sheet. Roast them 35-45 minutes, flipping once, until they are tender and golden brown. Combine the caramelized vegetables with the stock and other ingredients in a pot over medium-high heat. After bringing to a boil, let the soup simmer for 15 minutes. Put all the food through a blender or food processor until smooth and serve hot.

Images: The Wild Center (top); Leigh Preston (bottom).

The Shambulance: Put Down the Bananas! There's No Such Thing as a Mono Meal

The Shambulance is an occasional series addressing bogus products and overhyped health claims. The chief tactical officer onboard is Steven Swoap.

While you're enjoying a full Thanksgiving plate this Thursday, you might take a moment to be thankful that your meal isn't a single melon with a spoon stuck in it. Or a stack of plain lettuce. People who eat "mono meals" insist that having only one type of raw fruit or vegetable per mealtime makes their digestive process more natural and virtuous. In reality, it just takes the fun out of salad.

Not to be confused with the noodle soup eaten by college students who are sick with mono, a mono meal is something eaten by healthy people who can afford to buy a lot of produce every week. It's an especially orthodox version of the "high carb raw vegan" diet—or maybe it's a sect of the "80/10/10" diet (which dictates that 80 percent of one's calories should come from carbs, and 10 percent each from fat and protein).

However the eating style evolved, Buzzfeed recently claimed mono meals are a "new diet trend." While it's hard to tell how many mono mealers are out there—they're hardly mainstream—it's true you can search Instagram, Pinterest or Twitter and find photographs of people's thirteen-tangerine breakfasts with a side of hashtags (#801010 #monomeal #fruit!).

An especially zealous group of high-carb raw vegans populates a website called 30 Bananas a Day, although some of them choose to eat their fruits and veggies mixed together, rather than individually. (I spent some time on this site looking for answers about what motivates the mono diet, and instead found several surreal items: a claim that the flavor of raw okra is delicious; a suggestion to blend dates into "dateorade"; a GIF of someone's stomach bloating and un-bloating, mesmerizingly.)

Other sites are more explicit about the point of mono-ing your meals. It's all about simplifying digestion, they say. "If too much activity is happening in the digestive tract," according to Carla Golden Wellness, "enzymes can cancel each other out causing food to rot...With so many different kinds of foods going in at one sitting, our body can get VERY tired trying to sort out the different enzymes and digestion times for all these various foods."

When I sent these claims to Steven Swoap, a physiologist at Williams College, he was pretty efficient about tearing them down.

"You can't have too much activity in the digestive tract," he says flatly. Our bodies use different enzymes to digest proteins, carbohydrates and fats, and "there is no canceling each other out." These processes have evolved to happen at the same time with no stress to our organs—not the stomach or intestine, where digestion occurs, and not the pancreas, which cranks out the enzymes. "The pancreas multi-tasks as well as the best of them," Swoap says.

Mono meal advocates say it's healthier to make things easy on your digestive system by eating just one thing. "When only one food is eaten at a time at a meal, the process of digestion is made to be extremely efficient," says the website Nature's Pilgrim. "The body must only focus on breaking down and absorbing one particular compound."

"Not only is this garbage, it can actually be critically wrong," Swoap counters. Eating a heap of bananas for dinner doesn't make digestion happen faster—and we wouldn't want it to. "Nutritionists agree that taking a longer time is much better for you," he says. Absorbing carbohydrates quickly causes a spike in blood sugar, followed by a spike in insulin. The more sharply a meal raises your blood sugar, the higher its "glycemic index" (GI), a score given by nutritionists.

A plain baked potato, for instance, has a high GI because we can very easily break down its starches into sugars and absorb them. But there's a way to slow things down and avoid the blood sugar spike: add some fat or protein. A dollop of sour cream or butter slashes the GI of that baked potato.

So a mono mealer's goal of mainlining carbs is actually a bad idea. Eating a lot of high-GI foods has been linked to diabetes and heart disease. Luckily, though, a pile of fruit doesn't fit the bill.

"If you each just one naturally occurring food (like a banana or a green pepper or a cucumber)," Swoap says, "this is inherently a meal that is mixed—mixed with carbs, protein, and fats." Every living cell contains fats in its outer membrane and proteins that drive its activities. Additionally, something like an apple or banana has plenty of fiber that slows down your body's absorption of its sugars.

That pile of kiwi fruits, then, won't make anybody's digestion quicker or cleaner than usual. And that's a good thing; your body is happier with slow-and-steady. (A meal that does have a high glycemic index? Juice.)

If you enjoy cantaloupe or plain vegetables enough to eat them exclusively for your meal, it probably won't hurt you. If you really enjoy them, you might become like 30 Bananas a Day user Jared Six. "I have NEVER enjoyed the taste of food more than I do now after 6 months of eating this way," he gushes. "People look at me like there is something seriously wrong for me for being so happy eating something like a meal of just lettuce."

Just make sure those 30 bananas a day don't turn into 36 bananas in one sitting, because that's enough to cause dangerously high potassium levels in your blood—something for which you won't feel thankful.


Image: Elaine Vigneault (via Flickr)

Why Yellowstone's Grizzlies Should Be Grateful for Wolves

There's only one time a giant domino chain isn't fun: when you're a domino. Humans are great knockers-down of ecosystem domino chains, and sometimes we don't even know which species we've felled until we start propping things back up. When we knocked every last wolf out of Yellowstone National Park, for example, we didn't know how we were hitting bears at the other end of the chain.

When Yellowstone was first created, visitors were free to kill the animals. Then in the early 20th century, government "predator control" efforts gradually finished the job of wiping out the park's wolves. The last ones were killed in 1926. Wolves remained absent from Yellowstone until the mid-1990s, when officials lugged pens of them into the park and set them free.

William Ripple, an ecologist at Oregon State University, and his colleagues investigated how the return of wolves affected grizzly bears in Yellowstone. They compared data from old studies of bear scat to data collected after the wolves came back. Specifically, they wanted to know how many berries bears had been eating.

What do wolves have to do with berries? Nothing. But wolves kill elk—and elk eat all kinds of plants, including berry shrubs that bears would otherwise dine on.

For a few decades after wolves were wiped out of Yellowstone, the booming elk population was culled to keep it under control. But the elk culling ended in the 1960s. Ripple found that in the late 1960s, while the elk population was still low, bears had a relatively high percentage of fruit in their dung. Over the next 20 years, as the elk population more than tripled, the grizzlies' berry diet dropped to almost nothing. And in the late 2000s, after wolves had reestablished themselves in the park and elk numbers had dropped, a hearty helping of berries returned to bear diets.

The researchers also looked at berries themselves, choosing a representative plant called serviceberry. They saw that plants in fenced-off areas (where elk and other grazers can't reach them) had been growing for decades. Outside the fences, though, the berry plants were young—they had all sprung up after wolf reintroduction. The evidence all pointed the same way: more wolves means fewer elk, which means more berries, which means better-fed bears.

Berries are good for a grizzly's diet, the authors explain, because bears use them to fatten up before entering hibernation. Female bears will give birth during their winter doze, so having enough energy stored is crucial to the population's survival.

Ripple says there's not yet any evidence that having more berries in their diets is actually helping bears—his study didn't ask that question. But he is optimistic about the future of grizzlies in Yellowstone. "It is good to see that the bears can at times get significant calories from...the berries," he says. Berries made up as much as 39% of female grizzlies' diets in recent years.

Other studies have shown that beaver and bison numbers both increased after wolves came back to the park. This might be, the authors write, because herbivores have less competition now from the once-ubiquitous elk. All the species that were knocked down while the wolves were gone can now stand back up and give them a thank-you.

Images: Grizzly bear and wolf at Yellowstone from YellowstoneNPS (via Flickr); diagram from Ripple et al.; bear hug card from OldEnglishCo on Etsy (available for $4.71!).

William J. Ripple, Robert L. Beschta, Jennifer K. Fortin, & Charles T. Robbins (2013). Trophic cascades from wolves to grizzly bears in Yellowstone Journal of Animal Ecology DOI: 10.1111/1365-2656.12123

Your Bird Feeder Could Be Bad for Birds

A free meal might seem like just the thing for your bird friends in winter, especially if that meal takes place in front of your picture window. But your feeder could be harming some bird species more than it's helping them. Even if it's a squirrel-proof seed tube or a pinecone rolled in peanut butter, there's still no such thing as a free lunch.

"We are really only in the early stages of understanding exactly what effects bird feeding is having on our wild bird populations," says Kate Plummer, an ecologist at the British Trust for Ornithology. Britons love to feed the birds. The BTO says that about half of everyone in the United Kingdom does it.

To find out how extra food during the winter months might affect wild birds, Plummer and her colleagues used populations of blue tits (Cyanistes caeruleus) that had never set eyes on a bird feeder. The birds lived at nine different sites in the woods. Researchers set up feeders to provide six bird groups with food (either straight fat, or fat plus vitamin E) while the other three got nothing. Over the course of three years, they rotated which bird populations were fed so they could better compare the results.

The scientists weren't interested in how extra food affected the birds eating it—they wanted to know what happened in the next generation. In nest boxes the following spring, they found that birds that had eaten at feeders hatched smaller chicks. Ultimately, fewer of these chicks grew up and left the nest.

Plummer says there are a few possible explanations. The fatty diet, for one, may have made birds nutritionally unbalanced by the time it came to egg-laying season. An earlier study that fed blue tits peanuts instead of straight fat found that it was beneficial to the next generation (though there were other differences between the studies too).

Feeders might also allow weaker birds to survive the winter, eventually hatching scrawnier chicks and bringing the whole population's average down. Or extra food in winter might encourage birds to invest resources in egg-laying, only to find come spring that their nests aren't in a great spot for food after all. The real answer may be a combination of factors, Plummer says.

Two other recent studies of woodland tits found that supplementing their food over the winter led to fewer chicks raised in the spring. But a similar study in woodpeckers found just the opposite. Bird feeders might be helpful for some species and harmful for others, possibly due to their different nutritional needs.

There may also be "winners and losers of bird feeding," Plummer says, that depend on the combination of species sharing a feeder. Dominant species might outcompete other birds, for example. Birds at feeders might also share diseases while they're pecking at the same seeds.

"People shouldn't stop bird feeding," Plummer says, at least not yet. It's too early to assume that feeding birds is always harmful. So go ahead and fatten up your feathered friends this winter. That is, as long as you can live with the possibility that the scene through your picture window isn't doing them any favors.

Image: David Lewis (via Flickr)

K. E. Plummer, S. Bearhop, D. I. Leech, D. E. Chamberlain, & J. D. Blount (2013). Winter food provisioning reduces future breeding performance in a wild bird Scientific Reports DOI: 10.1038/srep02002

Now Available: A Chastity Belt for Your Mouth

Is your main problem with dieting that you have a whorish mouth? Instead of saving itself for the truly worthy suitors—the poached lean proteins and steamed vegetables with dressing on the side—does it open up for every corn chip and chicken wing that passes by?

Good news, tramp-trap! For only $2,000 plus airfare to Los Angeles, you can have a patch of spiky plastic mesh stitched onto your tongue.

Doctor Paul Chugay promises the procedure is quick and easy. You’ll be back at work the next day. And instead of snacking at your desk, you’ll be sipping a new all-liquid diet, because your lingual chastity garment makes it too painful to consume solid foods.

Patients can expect to lose 20 to 30 pounds in a month on his 800-calorie-a-day “liquid beverage plan,” Chugay says in a video* on his site, or as much as 50 pounds in two months. After that, according to a Time article, the patch will have to be removed; otherwise it may be absorbed into the flesh permanently. That tongue just can’t control itself.

Image: www.drchugay.com

*Website NSFW, thanks to perky plastic-surgery “after” photos everywhere.

Everyone Underestimates Fast-Food Calories (But Especially at Subway)

At a McDonald's shareholder meeting last week, a nine-year-old girl accused CEO Don Thompson of sneaky advertising. Stop "tricking kids into eating your food," she demanded, saying that McDonald's ads tell kids to "keep bugging their parents" until they get that Happy Meal. In the world of fast-food chains, though, the golden arches may not be the sneakiest purveyor of excess calories. Diners in all kinds of fast-food restaurants underestimate the calories they're taking in—and the most dramatic underestimation happens at Subway.

Thompson may not have been swayed, but Jason Block of Harvard Medical School and a group of other researchers writing in BMJ do care what consumers think about their fast food. Specifically, they care how many calories people think they're eating. To find out, they went into the trenches: 80 fast-food restaurants in New England cities.

Researchers stood outside their chosen dining establishments (which included McDonald's, Burger King, Subway, Wendy's, KFC, and Dunkin' Donuts) in 2010 and 2011. They asked customers on their way in whether they'd be willing to save their receipts and answer a few questions when they came back out. (Only a few restaurants kicked the researchers off the premises.) At dinnertime, they targeted adults, either eating on their own or with kids. At lunchtime and after school let out, they went to fast-food places within a mile of a school and talked to adolescents.

In all, more than 3,000 people participated. Across all the restaurant chains, the average dinnertime meal for adults was 836 calories, and the average afternoon meal for adolescents was 756 calories. Yet when asked how many calories they thought their meals held, people consistently guessed too low. And the bigger their meals were, the more severely they underestimated.

The researchers also asked subjects whether they'd noticed any calorie information indoors. "All of [the chains] provide information in some way," says Block—"on a wall poster, on napkins/cups, on sandwich wrappers and tray liners, and on 'special menus' that might present items that are below a certain number of calories."

Yet less than a quarter of adults said they'd even noticed this information. Those people didn't do any better at estimating their calories than others. Did they use the information to help them make menu choices? Only five percent of all adults said yes. Of adolescents, two percent.

Block says it's easy for diners to miss the calorie information provided by fast-food chains today. But soon, as part of the Affordable Care Act, all chain restaurants with more than 20 locations will have to post calorie information in a standard format. "The menu labeling regulation will require the calories to be up front and highly recognizable," Block says.

Even this kind of prominent labeling has had mixed results in past studies. However, Block adds, the new law will also require menus to post an "anchoring statement" pointing out that people only need about 2000 calories a day. This might make, say, the 970 calories in a Wendy's Baconator more meaningful to a customer.

Anchoring was effective in at least one small study, Block says. Other studies have looked at "traffic light" labeling (in red, yellow, or green), or listing calories in terms of how much exercise you'd need to burn them back off. "We'll be in a position to know much more after the federal law is implemented," Block says. His group is collecting data this year and next year to see how well the new labeling works.

If people do start noticing how many calories their favorite chains are offering, they may be surprised. When researchers broke down their results by restaurant chain, they found that people underestimated their calories more dramatically at some restaurants than others. At McDonald's, adults guessed too low by an average of 100 calories, and adolescents by a little more than 200. The guesses were off by a bit more, on average, at Burger King and Wendy's. At Subway, the errors were most extreme: adults underestimated their calories by an average of about 350, adolescents by close to 500.

Five hundred calories is equivalent to all the bread in a 12-inch sub (or, if you opt for multigrain, all the bread plus four American-cheese triangles). It's a lot not to know you're eating. This mistake, the authors write, may happen because people view Subway with a "health halo." After seeing TV ads featuring fresh vegetables, smiling Olympians, and Jared's old pants, consumers may think they're making a healthier choice than they are.

The new calorie labeling could help most in places like this. A fast-food chain that brands itself as healthy is even sneakier than someplace like McDonald's, which even little girls know is bad for you.


Image: by Jeremy Brooks (via Flickr)

Block, J., Condon, S., Kleinman, K., Mullen, J., Linakis, S., Rifas-Shiman, S., & Gillman, M. (2013). Consumers' estimation of calorie content at fast food restaurants: cross sectional observational study BMJ, 346 (may23 3) DOI: 10.1136/bmj.f2907

Scientists Unsure Why Female Flies Expel Sperm and Eat It

She's apparently a picky mater but not a picky eater. The female of a certain fly species, after mating with a male, dumps his ejaculate back out of her body and onto the ground. Then she gobbles it up. Despite new hints that this behavior may help the female choose which partner fertilizes her eggs, or keep her healthy in times of famine, scientists are still a little perplexed by it.

Various female insects, spiders, and birds are known to expel the male ejaculate from their bodies after the deed is done. In some cases, it seems to let them decide which male's sperm reaches their eggs. Females don't always choose who mates with them, but that doesn't mean they have no choice in their progeny's fatherhood. (This kind of female choosiness about sperm can lead to evolutionary arms races between males and females. The "copulatory plug" is a popular tool among male insects, spiders, reptiles, and even some mammals.)

Eating the ejaculate, as Euxesta bilimeki does, is less popular. This fly lives on agave plants and mates pretty much all the time. "Females can be observed escaping male advances in chases that can last more than an hour," write Christian Luis Rodriguez-Enriquez and his coauthors from the Instituto de Ecología in Veracruz, Mexico. Using videocameras and careful meal planning, they tried to divine a reason for the female flies' behavior.

Out of 74 females that the researchers recorded mating, every one expelled and ate the ejaculate afterward. The researchers then killed the females and pulled them apart with tweezers to look for sperm inside their various storage locations. They found that three-quarters of the females had kept some sperm from their male partner, while one-quarter had expelled it all.

There was no obvious rule to which sperm the females kept. There were some patterns, though. For example, females that mated with larger males, then waited longer before expelling the sperm, were more likely to keep some. Since the female's behavior doesn't seem random—and since it's possible for her to keep no sperm at all—the authors think she may be choosing between mates after the fact.

This could explain why the female expels the sperm, but not why she eats it. In another experiment, researchers fed female flies various diets and measured whether supplementing those diets with ejaculate made them healthier. When female flies were starved entirely, the extra snack did help them live longer—but under normal circumstances there was no difference. The authors report their results in Behavioral Ecology and Sociobiology.

"Our study appears to have raised more questions than provided answers," the authors admit. They expected there would be some clear nutritional benefit to justify the females' tastes.

Rodriguez-Enriquez and his coauthors speculate that the ejaculate-as-meal habit may have evolved as a "nuptial gift." This is an edible present that male insects sometimes give to females as part of their courtship. Usually it's nutritious—a nicely wrapped dead bug, say—but in some cases it's just an empty sac. The ejaculate may be, like these gifts, just an edible empty gesture.

(The above is a video of Euxesta bilimeki flies mating. It doesn't look any different from what you're imagining, but the soundtrack is a nice twist.)

Rodriguez-Enriquez, C., Tadeo, E., & Rull, J. (2013). Elucidating the function of ejaculate expulsion and consumption after copulation by female Euxesta bilimeki Behavioral Ecology and Sociobiology DOI: 10.1007/s00265-013-1518-5

Image and video: Rodriguez-Enriquez et al.

Google Promises We'll Feel Better in the Summer

Shakespeare wasn't kidding about the "winter of our discontent." In the colder and darker months, people do more internet searches for mental health terms, from anxiety and ADHD all the way to suicide. Search patterns also promise that like a refreshed browser window, better times are due to arrive soon.

John Ayers, of the Center for Behavioral Epidemiology and Community Health in San Diego, and other researchers dove into Google Trends to explore whether certain searches vary by season. "Seasonal affective disorder is one of the most studied phenomena in mental health," Ayers says, "with many individuals suffering mood changes from summer to winter due to changes in solar intensity." He wanted to find out whether any other mental health complaints changed with the seasons, as some studies had hinted.

Since Google Trends breaks down searches by category, the researchers started in the "mental health" section. Looking at all mental health searches in the United States between 2006 and 2011, they saw a consistent cycle with peaks in the winter and troughs in the summer. (If you do this search yourself, you'll see that there's also a dip around the December holidays—but the curve reliably bottoms out in July of each year.)

The team did some statistical smoothing and found that mental health searches overall were about 14% higher in the winter than in the summer. To confirm that the difference was due to the season, they ran the same analysis on data from Australia. Searches cycled in the same way—about 11%  higher in winter than summer—but the peaks in the southern-hemisphere country were almost exactly 6 months out of sync with the United States.

When the scientists broke down searches by specific symptoms or illnesses, the seasonal cycle remained—and in some cases got much stronger. "We were very surprised" to see this, Ayers says. Searches including the terms ADHD, anxiety, bipolar, depression, anorexia or bulimia, OCD, schizophrenia, and suicide all rose in the winter and fell in the summer.

One of the most dramatically cycling search terms was schizophrenia, at 37% higher in the winter. Eating disorder terms varied just as strongly. (The smallest seasonal difference was for anxiety, which was just 7% higher in the winter in the United States, and 15% in Australia.)

Some of this seasonality might be due to the schedule of the school year, Ayers points out. Referrals for kids with ADHD and eating disorders may come from their schools.

Other explanations involve winter itself. The effect of shorter days on our circadian rhythms and hormone levels might be a factor, the authors write, as in seasonal affective disorder. They speculate that a lack of vitamin D (which we make using sunlight) in the winter might contribute. Even omega 3 fatty acids might matter: we consume less of them in winter, and omega 3 deficiency has been linked to some mental illnesses.

There's also the question of what we're doing all season. People hunkered indoors during the colder months may have fewer chances for socializing, which is "a well-known health emollient," the authors write. The same goes for physical activity.

"There is a lot more we need to learn about mental health and seasonality," Ayers says. "For instance, is there a universal mechanism that impacts our mental health?"

Of course, sometimes our malaise isn't about the season.

Whatever portion of mental health is predictable, though, doctors would love to know about it and use that information to help.

This study doesn't reveal much about low-income or elderly populations who aren't online. And knowing what people are searching for isn't exactly the same as knowing what symptoms they're experiencing. "We are actively working to address these limitations," Ayers says. Working with Google.org, the charitable branch of Google, he hopes to develop systems similar to Google Flu Trends that can track a population's mental health.

"Intuition suggests that these results are reflective of an important link between the seasons and mental health," Ayers says. For now, we have the reassurance of computer algorithms that skies will be clearer soon.


Ayers, J., Althouse, B., Allem, J., Rosenquist, J., & Ford, D. (2013). Seasonality in Seeking Mental Health Information on Google American Journal of Preventive Medicine, 44 (5), 520-525 DOI: 10.1016/j.amepre.2013.01.012

Image: Skaneateles, NY, by me.

Good Coot Parents Let Kids Starve, Make It Up to Them Later

Too many mouths to feed? Just make your babies fight each other to the death! That's a strategy some bird parents have been using since even before The Hunger Games was popular. It means the strongest chicks get stronger while the weakest ones conveniently stop showing up to the table.

One type of bird takes this family drama a step further: after letting the biggest chicks bully their siblings for a while, parents suddenly decide the runts are their favorites and begin beating up the older chicks themselves. Authors looking for the next dystopian mega-hit, take note.

"Many species of birds show 'hatching asynchrony,'" says Daizaburo Shizuka of the University of Nebraska, Lincoln. This means they stagger the hatching of the eggs within a nest. When some chicks emerge from their eggs days later than others, the younger birds are doomed to be outweighed and outcompeted by their older siblings. Blue-footed boobies, for example, produce two mismatched chicks; one may peck the other to death or shove it out of the nest. (If you think that's horrifying, you haven't heard about sand tiger sharks, which eat each other inside their mother's womb.)

The polite way to say "letting half your babies die" is "brood reduction." Why hatch a runty egg at all? Parents may allow more siblings to live if food is plentiful. Or a second egg might be a kind of insurance in case the first doesn't hatch.

American coots are waterbirds that lay large clutches of eggs and may space out their hatching over a week or more. This means some siblings end up much heftier than others. At first, young coots follow their parents around, relying on their parents to feed them insects and plant material they find by diving. Siblings don't physically attack each other, but older birds easily out-jostle smaller ones for food. Half of all chicks die of starvation.

Over several years, Shizuka and Bruce Lyon, an ecologist at the University of California, Santa Cruz, monitored 75 American coot families on a lake in British Columbia. They snuck every new chick away as it hatched to give it a color-coded tag. Spying on these families while their chicks ate or starved, the researchers discovered a highly unusual system at work.

During the first 10 days after hatching, younger coot chicks often died of starvation. But any runty chicks who survived this period saw their luck turn around. Parents suddenly started playing favorites. Each coot parent picked one preferred chick out of those who'd hatched last, and gave that chick the most food. Heightening the drama, moms and dads each chose a different favorite.

To discourage bigger siblings from asking for so much food, the parents spent more time "tousling" these birds. In humans this means "affectionately messing up someone's hair," but in birds it means "grabbing your baby by the head and shaking it." As you might imagine, it's pretty convincing. The beefy siblings backed off.

Once parents switched to spoiling the runts and beating up the bigger kids, late hatchers became just as likely to survive as their siblings. The youngest chicks even grew slightly larger than their older brothers and sisters.

This system may be a way "for parents to try to get the best of both worlds," Shizuka says. First, coot parents allow brood reduction to happen, watching their chicks compete to the death. Once the family reaches its optimal size, he says, "parents can take matters into their own hands to make sure that the youngest chicks that are still surviving end up getting enough."

Don't throw out your parenting books yet. Although this method seems to work for the coots, scientists still aren't sure why so many birds have evolved elaborate strategies that require siblings to murder each other—or why chicks go along with it. Shizuka says, "It's safe to say the matter is not resolved."


Shizuka, D., & Lyon, B. (2013). Family dynamics through time: brood reduction followed by parental compensation with aggression and favouritism Ecology Letters, 16 (3), 315-322 DOI: 10.1111/ele.12040

Image: Bruce E. Lyon

The Shambulance: Enough Already with the Juice Cleanses

The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. Helping me chart a course are Steven Swoap and Daniel Lynch. 

Before I learned that it costs $65 to $90 to starve yourself for a day, I considered trying one day's worth of "juice cleansing" to put myself into the proper cranky fog for writing this piece. But if I'm going to eat no calories, I prefer to spend no dollars. 

What did I give up by fueling myself on solid foods instead of liquefied produce? Really, one day would have been merely dipping a toe into the celery water. If I were a serious client of a juice cleanse company, I would pay for anywhere from three to ten days' worth of bottled juices, delivered to my doorstep in a cooler every morning. 

The first few days of deprivation would, in theory, "cleanse the blood" and release toxins from my tissues that have been slowing me down and making me sick. I'd give my colon a break while "sweeping" it out. The latter days would boost my immune system and "fight off degenerative diseases." After all that detoxifying and boosting, I would feel energized and restored. I might even have lost a few pounds—but it's about health, not weight.

In the midst of my cleanse, I could experience unpleasant symptoms. "Don't Panic," the website for BluePrintCleanse would reassure me, "It's Just A Healing Crisis!" Apparently, a body that's becoming healthier looks a lot like one that's unwell. Symptoms of detox may include fatigue, headaches, nausea, hives, decreased bowel movements, increased bowel movements, strangely colored bowel movements ("Did you just drink some of our beet juice?"), dry mouth, runny nose, and canker sores. I should ignore those symptoms, drink herbal tea, and be reassured that I'll soon be skinnier. Sorry, healthier.

I sent some promotional materials on juice cleansing to Steven Swoap and Daniel Lynch, both biologists at Williams College. "Where to start?" Swoap said.

The subject of "cleansing" has been covered on this site ad nauseam (not to mention ad headache, ad fatigue and ad canker sores). But to recap, your body does its own cleansing via your kidneys and liver. The wastes and unwanted materials those organs filter out leave you via the toilet—not through your sweat glands or the soles of your feet or water blasted up your colon. And depriving yourself of calories doesn't make the process go any faster.

If anything, it's the opposite, because fasting slows your metabolism. BluePrintCleanse claims that the energy you save on digestion by not eating any real food gets diverted to "other metabolic processes." But Swoap says this is false. Your whole metabolism will slow at once, not just the tasks attached to digesting food. This will make it harder to lose weight. 

The same website reassures users that they won't feel light-headed during a cleanse: "On the contrary, one's mind becomes clearer and one's ability to solve problems enhances." All the blood and oxygen you would normally use to process your food, it explains, get sent to your brain instead.

"Wrong," Swoap says. "The same amount of blood and oxygen is delivered to the brain under nearly all conditions." Reducing your calories won't send more blood to your head. Actually, fasting can make your blood pressure drop, which is the one circumstance in which less blood will reach your brain. 

So much for that clearer mind. In an article from the Boston Globe on juice cleansing companies, registered dietician Marjorie Nolan Cohn says that after a few days of fasting, "you become lightheaded and dizzy, and that euphoric feeling starts to come on." She adds, "I work with a lot of anorexics, and they feel euphoria, too."

Company websites are quick to insist that juice cleansing isn't fasting, even though their plans may provide under a thousand calories a day. And of course it's not about the weight loss—unless you're a bride-to-be. In that case BluePrintCleanse encourages you to "Drink your way to your best shape ever" before walking down the aisle. 

The company offers bridal packages ranging from six to thirty-six days of juice. Elsewhere on its website, it recommends you consult with your doctor before spending more than ten days on a cleanse. But when I emailed to ask how many solid food breaks are in a thirty-six-day juice program, a representative replied that I could schedule my days however I liked. "If you don't use all the juice days before your wedding, you can save them for after your honeymoon," she said. But I'm also free to schedule five consecutive weeks of fasting through the site. 

"Congratulations!" the representative wrote. By the way, that package would be $2,415.00. 

"In reality, for a healthy person to blow a bunch of money to purchase the juices and drink them over a couple days is probably not harmful," Daniel Lynch says. (The operative words being "a couple days.") "And if it serves as some motivational tool to eat better, etc., it is fine." But if your goal is to give your digestive system a rest, he adds, "why not go with an IV bag of dextrose?"

And if you're looking to empty your colon, Lynch points out, a cheap laxative will do the trick in about six hours. "Why spend loads of money and suffer through days of drinking liquified kale?" He sounds a little cranky. Maybe he missed a meal.

Image: Food Thinkers (via Flickr)

Cold and Hungry? Scientists Suggest Remembering Soup

Regrettably, and despite what the Breatharians will tell you, a person can't live on a diet of air. But you can keep hunger pangs at bay, scientists say, simply with the power of memory. And feelings of nostalgia can help you withstand cold, according to another group of scientists. Now that winter is settling in, it might be a good time for all of us to start collecting some really good soup experiences.

Researchers studied the effect of nostalgia on body temperature in a series of experiments reported in the journal Emotion. People may describe their fond thoughts of the past as "warm feelings," but do they really mean it?

In one experiment, 64 subjects individually sat in a room kept at a cool 16 degrees C (60 F). They were asked to recall either a memory that made them nostalgic or an "ordinary autobiographical event." After taking some time to reflect on the memory and record their feelings, subjects estimated the temperature of the room. The ordinary-memory people guessed about 17 C (63 F). But the nostalgic ones put the temperature higher, at around 20 C (a comfortable 68 F).

Another group of 80 volunteers reflected on a nostalgic or non-nostalgic memory, like the earlier group had. Afterward, they had to plunge one hand into a bowl of ice-cold water and hold it there for as long as they could. The non-nostalgic subjects lasted about 20 seconds before yanking their hands out of the bowl. Those fortified by warm, nostalgic memories, though, stuck it out for an average of 26 seconds.

A separate study, published this week in PLOS ONE, looked at how memory affects hunger. Patients with severe memory problems, the authors note, sometimes eat one full meal right after another—without recalling what they've eaten, they apparently don't feel full. For people with intact memories, does hunger also depend on our memory of our last meal?

To find out, researchers at the University of Bristol relied on a trick soup bowl. A hidden pump in the bowl's base, connected to a tube under the table, let scientists sneakily refill or drain the bowl while subjects were eating (surely this is the plot of a Greek myth I'm forgetting).

Researchers gave 100 subjects a bowl of "creamed tomato" soup that initially held either 500 ml (about 2 cups) or 300 ml (1 1/4 cups). Half the subjects were allowed to eat their soup with no funny business. A quarter of them saw a bowl holding the larger amount of soup but only ate the smaller amount as their bowls were secretly drained. And the final group saw a small bowl of soup but ate a larger portion as it refilled.

Over the next three hours, subjects rated how hungry they felt. By the end, people who had seen a small portion of soup felt significantly hungrier than those who had seen a large portion—regardless of the amount they'd actually eaten.

This suggests, the authors write, that appetite is closely tied to our memory of what we've eaten recently. We take visual hints from our food about how full it will make us feel, and those hints can override the information coming from our stomachs.

If you don't have a magic soup bowl, you might still be able to use your memory to your advantage by paying attention to what you eat. Previous research has shown that watching TV, or otherwise distracting ourselves during meals, can make us hungrier later on. Taking in all the visual information from our plates, so we remember it later, can keep us feeling fuller. And, of course, recalling fond memories might make us warmer. Maybe all that time Eliza Doolittle spent standing on the street and singing about "warm face, warm 'ands, warm feet!" would have been better spent looking to the past.


Zhou, X., Wildschut, T., Sedikides, C., Chen, X., & Vingerhoets, A. (2012). Heartwarming memories: Nostalgia maintains physiological comfort. Emotion, 12 (4), 678-684 DOI: 10.1037/a0027236

Brunstrom, J., Burn, J., Sell, N., Collingwood, J., Rogers, P., Wilkinson, L., Hinton, E., Maynard, O., & Ferriday, D. (2012). Episodic Memory and Appetite Regulation in Humans PLoS ONE, 7 (12) DOI: 10.1371/journal.pone.0050707

Image: Maria Pontikis (Flickr)

The Shambulance: Copying Roger Clemens Won't Help You Lose Holiday Pounds

The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. With me at the wheel of the Shambulance are Steven Swoap and Daniel Lynch.

The injections he'd been receiving in the buttocks during his major-league baseball career, pitcher Roger Clemens explained to a jury this summer, were not steroids. They were perfectly legal and innocent shots of vitamin B12. The jury acquitted him, lifting the weight of a felony perjury charge from his shoulders. You, too, can use B12 to put some spring back into your step—at least, if you believe the companies that market the injections for weight loss, energy, and general well-being. In reality, this is not a performance enhancer.

B12 is a quirky vitamin that you can't get from plants. It's manufactured by bacteria that provide their services to some animals by living in their guts. Humans mainly get B12 from meat, eggs, and dairy. Of course, this means vegan humans have to find the vitamin elsewhere, such as in fortified breakfast cereals or Flintstones chewables. (They might also ingest B12 from soil bacteria on vegetables that haven't been washed well.)

"Healthy individuals have a six-year supply of B12 stored in their liver," says Daniel Lynch, a biochemist at Williams College. So even a temporary shortage in your diet shouldn't harm you. Long-term vegans, though, can become deficient in B12. Some older adults and gastric-bypass patients who can't absorb enough B12 from their food need to get it from an outside source. And patients who suffer from a disorder called (oddly) "pernicious anemia" need B12 supplements.

B12 deficiency causes weakness and fatigue, and an injection of the vitamin reverses those symptoms. This has apparently led some people to conclude that healthy, non-deficient folks will also get stronger and more energetic by taking B12. Why settle for normal functioning when you could be a vitamin-powered superhuman?

"[Weekly] vitamin B12 injections are intended to crank up the metabolism and boost energy levels to increase daily activity and help weight loss even when the body is at rest," says one Chicago weight-loss center.  An "anti-aging" clinic asserts that "B12 injections are...an effective means of boosting the body's metabolism for those looking to lose weight."

You'll start by shedding weight in the wallet region: a 3-month course of shots from that office will relieve you of nearly $500.

It's true that vitamin B12 is involved in metabolism. However, according to the National Institutes of Health, "Vitamin B12 supplementation appears to have no beneficial effect on performance in the absence of a nutritional deficit."

In other words? "Basically, for any healthy person this is a sham," Lynch says. "Any excess B12 is peed out anyway."

Non-human animals store B12 in the liver, just as humans do. "So you could get the same effect of the injection by munching on liver," says Steven Swoap, a physiologist who's also at Williams College. "This is how they 'cured' vitamin B12 deficiency a hundred years ago."

If you still feel a craving for B12 but don't care for liver sandwiches, you can buy bottles of B12 pills—and they'll run you about five cents a tablet. "It begs the question as to why anyone would stick a needle in themselves when you can buy this stuff as a pill at the local drugstore," Swoap says. Maybe we can find a Hall-of-Fame-nominated baseball player to explain it.

Image: Craig Strachan (Flickr)

Caffeine Helps Us Recognize Positive Words

Does anyone still say "full of beans"? The phrase is supposed to describe someone who's upbeat and energetic. Maybe we can revive the expression by attaching it specifically to coffee beans, as in, "I just had a double-shot cappuccino and boy, oh boy am I full of beans!"

Caffeine lovers know the feeling of finishing a well-timed cup of coffee or tea: positive, alert, ready to go. (And maybe ready to go to the bathroom.) New research suggests that our brains also process language differently after having caffeine. We're quicker and more accurate at recognizing words—but only if those words have positive connotations.

Lars Kuchinke and Vanessa Lux, researchers at Ruhr University Bochum in Germany, studied the effect of caffeine on a word recognition challenge. To start, they recruited 66 subjects with a range of personal caffeine habits.

Leading up to the experiment, subjects abstained from coffee (and nicotine and alcohol) for at least 12 hours. Thirty minutes before the experiment started, each subject took a pill that contained either sugar or 200 mg of caffeine. That's the equivalent of 2 to 3 standard cups of coffee, or a bit less than 1 tall coffee at Starbucks. Subjects didn't know which pill they'd taken.

Then subjects sat facing a screen with their chins on a chin rest. While they focused on a spot in the center of the screen, words flashed briefly on one side or the other. Half the time, these were emotionally positive, negative, or neutral German words. The other half the time, they were nonsense words that looked similar to German ones. Subjects pressed a button indicating whether the word they'd just seen was real or not.

On the whole, people performed better on this task when the words flashed in front of their right eyes. This was expected, based on previous experiments and the fact that the right eye connects to the left hemisphere, the brain's language headquarters. What was more interesting was that on left-hemisphere trials, people who had taken a caffeine pill were significantly better at recognizing positive words than neutral or negative ones.

The researchers think the effect is down to dopamine. In addition to waking you up and making you quicker and more accurate at cognitive tasks, caffeine increases the activity of dopamine, a signaling molecule in the brain. (This may also be why caffeine drinkers say it improves their mood.)

Previous studies found that the brain is a little better at recognizing positive words (and happy faces) in general. Adding caffeine—and therefore dopamine—exaggerated this effect. Kuchinke and Lux think this is because dopamine interacts with the brain's language centers to make us quicker at processing positive words. They haven't yet studied how caffeine affects our understanding of outdated idioms.


Kuchinke, L., & Lux, V. (2012). Caffeine Improves Left Hemisphere Processing of Positive Words PLoS ONE, 7 (11) DOI: 10.1371/journal.pone.0048487

Image: Dan Barbus (Flickr)

The Shambulance: Zero-Calorie Noodles?

(The Shambulance is an occasional series in which I try to find the truth about overhyped health products. My Shambulance co-captains this week are Steven Swoap and Daniel Lynch, both of Williams College.)

It could almost be a Zen question: What do you call a food with no food in it? In Japan they're called shirataki noodles, and are made from the root of the konjac plant. In the United States they're called "Miracle Noodles" or a "healthier alternative to pasta" and promise "NO calories...NO net carbs...NO GUILT!!!"

The konjac root's contribution to the noodle is straight dietary fiber, in a form called glucomannan. Since the noodles are made of nothing but fiber and water, the idea goes, they'll hurry right through you without leaving any calories behind. This is attractive to American dieters who would like to be able to eat a whole plate of food without actually eating any food. A dinner of pasta topped with marinara sauce becomes a dinner of marinara sauce topped with time on the toilet.

The Chicago-based brand "NoOodles" displays a set of nutrition facts with zeros nearly all the way down, like a perfect report card. However, "Don't be mistaken," says Williams College physiologist Steven Swoap. "These noodles have calories!"

Insoluble fiber, Swoap explains, does pass through our bodies untouched and make up the bulk of our feces. But glucomannan is a soluble fiber. This means it's dissolvable in water; it's also digestible by the bacteria living in our guts. The bacteria break down soluble fiber into products that we absorb as calories. (They also make methane, which, as Swoap points out, "we don't absorb but rather share with our surroundings.")

The key to the zero-calorie claim made by NoOodles might lie in that 1.6-ounce serving size at the top of the label. The FDA permits calories under 5 to be rounded to 0. If each of those dainty servings really has 4 calories, a whole package—which would fill a plate—has about 20. It's hardly a calorie count that will ruin anyone's diet. But zero, in this case, doesn't really mean zero.

Shirataki noodles have a distinctly non-zero amount of offensive odor, as I discovered when I tried some NoOodles for myself. (They're in the refrigerator aisle, which I only mention in case you want to buy your own and also want to avoid having this conversation with two different grocery store clerks: "I'm looking for a product called noodles?")

The product's website describes the smell, caused by the calcium hydroxide, as "a little odd." I would have used different words, like maybe "neglected fish." But the odor rinses away with water. The rectangular shape of the package is harder to dispel.

I followed directions and heated my NoOodles in a dry nonstick pan until all the water had evaporated, though they looked otherwise the same. At this point it's recommended that you cook the NoOodles with some sort of sauce (or eggs or ice cream), but I wanted to try them in their unadulterated form. As promised, they tasted like nothing at all. They had a texture, though, that I was deeply not okay with, like biting through rubber bands. I managed one mouthful followed by a lot of water.

The water is recommended too, because soluble fiber sucks up water in your body. In 2010, Health Canada issued an advisory about the importance of drinking a full glass of water when taking pills or powders containing glucomannan. It also urged consumers not to use glucomannan supplements right before bed, because the stuff can swell up and cause choking or blockages in the intestine while you sleep. The health advisory didn't address shirataki noodles.

The water that NoOodles absorb makes the material passing through your gut especially slippery, so your small intestine can't absorb nutrients (which is to say, calories) as easily. Their website claims this makes the rest of your meal less caloric too, as everything slides through you along with the NoOodles. But Swoap says that experiments have shown this simply isn't true. "The small intestine is still long enough to get all of the calories from your food."

Among several other promises, NoOodles makers also say their product makes you feel fuller, so that "one tends to eat less when NoOodle is part of the meal." It's certainly possible, though it's also possible that one tends to make up those calories at one's next meal, when one is starving because one only ate marinara sauce for dinner. "The key word that gets them off the hook is 'tends,'" Swoap says. "Otherwise the FDA would have a major problem with this."

Not all the claims made about glucomannan noodles are spurious. The product does let dieters eat more food for fewer calories. And some studies have found that glucomannan can lower cholesterol, both in healthy and diabetic subjects.

So is an all-fiber noodle really a "healthier alternative?"

"The 'benefits' are in comparison to refined wheat flour that is used to make breads, pastas, etc. Most everyone acknowledges that is not good in excess," says Daniel Lynch, a biochemist who's also at Williams College. "But moderation is the key." He adds, "You might as well just have a glass of Metamucil or Citracel as a pre-dinner cocktail and then enjoy real food in smaller portions!"

Swoap says, "I don’t think this is necessarily bad for you. I would just prefer to get my fiber with vegetables that also bring along a lot of micronutrients." In other words, if you want to bulk up your meal with a low-calorie fiber source, there are less rubbery and more vitamin-filled ways to do it.

If you're still tempted to try a food-free plate of pasta, go for it. Just remember to drink water.


Arvill A, & Bodin L (1995). Effect of short-term ingestion of konjac glucomannan on serum cholesterol in healthy men. The American journal of clinical nutrition, 61 (3), 585-9 PMID: 7872224

Chen HL, Sheu WH, Tai TS, Liaw YP, & Chen YC (2003). Konjac supplement alleviated hypercholesterolemia and hyperglycemia in type 2 diabetic subjects--a randomized double-blind trial. Journal of the American College of Nutrition, 22 (1), 36-42 PMID: 12569112

Thanks to Chris F. for the tip! If you want to summon the Shambulance to the site of an emergency, leave a comment or send me an email at the address above.