Just a week after giving birth, women who exclusively breastfeed produce, on average, more than 500 milliliters of milk per day.  In parlor measurements, that’s about a pint of liquid.  At 6 weeks, this amount has typically increased by about 50%; in some highly productive women, it can even double.  For women with an abundant supply, excess milk can be drawn out with an electric pump and stored for future consumption (by baby, or in London, by high-paying ice cream connoisseurs.)

In an interview with the Daily Mail, the London parlor’s proprietor played up the novelty of his new flavor, but his description of its taste (‘creamy and rich’) was comfortably familiar.  Flavor-wise, how does milk from humans compare to milk from cows? Can you even taste a difference?  I don’t live in London, but I do have an ice cream maker.  It’s in my freezer, right next to 2 liters of frozen breast milk.

Continue reading at 3quarksdaily.com

15 years ago, General Motors debuted the first fully electric vehicle for lease in the United States.  The EV1 was silent, fast, and as aerodynamic as an F-16 fighter jet; but most importantly, it could run between 70 and 150 miles on a single charge. (Toyota’s Prius Plug-in Hybrid, for comparison, has an all-electric range of 13 miles.)  Between 1996 and 1999, more than 1000 EV1s were manufactured.  800 were leased out in Arizona and California, and, according to the brand manager at GM, inspired “maniacal loyalty” in their drivers.

Four years later, despite pleas from drivers, and a waiting list of interested customers, GM declared the electric-car program a money loser, and ordered the car’s destruction.  Existing EV1s were taken from their drivers, transported to the desert (in some cases, under police protection), and crushed. (Today, a few can be found in museums, but they’ve been disabled so as to never drive again.)

Continue reading at 3quarksdaily.com

(Originally posted June 20, 2011)

Last year, while doing our taxes, my husband and I were surprised to discover that we weren’t as poor as we thought we were.  As lowly graduate students making a combined income of about $50,000 per year, I had assumed we were on the penny-pinching side of the national pay scale.  But when I compared our income to the median income in the country, I found that we were sitting comfortably in the center.  We had made it; we were officially smack-dab in the middle class.  I thought it would feel different.

In the United States, nearly 25% of the population makes less than $25,000 per year.  At this bottom level, a few households squeak by the poverty threshold, but just barely: in 2010 it’s estimated at just $22,314 for a family of four.

This year, 16 million children will be born into poverty (1 out of every 5 children born in the US).  The lives of these children often follow a common stagnant storyline: poor nutrition, delayed mental and emotional development, academic deterioration, criminal activity, and frequently, early parenthood. As young parents, they are more likely to be unwed, more likely to drop out of high school, and more likely to stay impoverished.  The cycle is vicious, and unrelenting.  But is it possible to escape?   How early is the influence of our environment engraved into the patterns of our development?

Continue reading at 3quarksdaily.com

(Originally published January 24, 2011)

Last year, at Christmas dinner with my husband’s family, I was stumped by a seemingly simple question: “What was the biggest scientific discovery of 2009?” “That’s a great question,” I remember thinking, as the papers and news I’d read over the past year churned through my mind, struggling to bubble up to consciousness.

For a biology graduate student, it should have been easy; I should have been able to come up with something (anything!) that was a notable scientific achievement, yet also engaging enough to be of interest to my in-laws.

I fumbled for a long minute, and exchanged a blank glance with my husband (who was also a grad student) – he too was at a loss. (After all, not all research comes with the headline-grabbing, NASA-approved stamp of extra-terrestrial life.*) One of us eventually bumbled towards an answer (I think it was the Mars rover’s discovery of water), but I vowed to be better prepared in 2010.

So today, I present you with three science-y things from 2010 that you can talk about around the dinner table. Some were striking enough for me to remember on my own, others were featured in ScienceNOW’s excellent compilation of the most popular stories of the year, or Nature magazine’s top science articles of 2010. All have two things in common: 1. They make great conversation starters. 2. You don’t have to be a scientist to understand them.

#3. Men with good dance moves attract women.

The Gist: What exactly is a ‘good’ dance move? When attempting to quantify a woman’s perception of a man’s dancing ability, it’s nearly impossible to control for the appearance of the dancer.  His height, clothing, body shape, and facial features can all influence her impression of his skills.  Researchers at Northumbria University in the UK got around this problem and identified the essential elements of a man’s good moves by devising a way to separate the attractiveness of the dancer from the attractiveness of the dance.

To remove these confounding factors, the authors in the study used 3D motion-capture technology to create computer-generated avatars. Each dancing male wore 38 reflective markers distributed from his wrists to his neck to his ankles, and danced to a 30-second clip of music in front of a camera that recorded every shake, twist, bump, and grind. Videos were played for women, and researchers analyzed body position, movements, and speed.

The Controversy: No real controversy (or surprises) here. Heterosexual women prefer men (or at least purple gender-neutral computer avatars) who can dance. The authors speculated that good dance moves could signify important qualities in a potential mate (such as coordination, health, vigor, and athletic prowess).

Don’t fret if you’re a badly dancing heterosexual male though; this study offers instructional advice. My favorite tip? Get that right knee moving. According to the study’s authors, it was one of the most important signs of dance quality.

Why I like it: It may not be ‘the greatest scientific discovery of 2010’, but it’s worth watching the videos of good and bad dancing avatars on YouTube. (I’m not the only one who likes them; combined, the videos have nearly 740,000 hits- not bad for a scientific article.) There’s no word yet on whether the ‘good’ moves have sparked a new dance craze, but I’m holding out hope.

#2. Barefoot runners generate less impact force than their shod counterparts.

The Gist: In the 2008 Beijing Olympics, Kenya won 5 gold medals in track and field. All of their golds were for mid- or long-distance events, and all of their winning runners were from the Rift Valley Province. Kenyans from the Rift Valley are known for their incredible endurance, which has been attributed to everything from an automobile-free lifestyle (they run to and from school), to homeland geography (they live and run at altitude), to genetics. Oh, and they grow up running barefoot.

At the beginning of 2010, runner and Harvard human evolutionary biologist, Daniel Lieberman, published a long awaited study that sought to answer a simple question: Do runners with shoes run differently than those without? Lieberman’s group compared the foot-strike patterns and forces of 5 different sets of runners, including athletes from the Rift Valley and the US.

His team of researchers found that barefoot runners tended to strike the ground with their fore- or mid-foot, whereas shod runners typically hit with their heel. Why does this matter? Lieberman showed that forefoot striking reduces foot-to-ground collision forces nearly 3-fold.

If running shoes enable rear-foot striking, and rear-foot striking increases impact forces on the body, what’s the point of wearing shoes? It’s a good question (some would say revolutionary), and likely part of the reason Lieberman’s study made the cover of Nature magazine.

The Controversy: Lieberman’s paper was met with disbelief and derision on one side (podiatrists and running shoe companies decried the implied invalidation of their trades) and joyful righteousness on the other (barefoot running devotees basked in the vindication of their sport.) In the 11 months since the paper has been published, sales of minimal or ‘barefoot-style’ footwear have boomed (as have new barefoot-related running injuries).

So should you ditch your running shoes completely? Podiatrists and barefoot runners agree on one thing: any attempt to change running style should be done gradually. In an interview with Runner’s World magazine (which has remained thick with running shoe advertisements), Lieberman is careful to note that their study does not make any connection between running shoes and injuries, or advocate going shoeless. (Though you may see him running barefoot through Cambridge.)

Why I like it: I love when conventional wisdom (i.e. running shoes = good) is turned on its head. Running shoes came into popularity in the 70s, and, despite little supporting evidence, have been considered an athletic necessity ever since. For some people, running shoes may be necessary, but for others, they could be making things worse.

This year, I started running in minimal shoes. From heel to toe, the soles of my running shoes are 4mm thick; a typical running shoe heel is about 24mm (~1 inch). Admittedly, my sample size is small, but after years of struggling with plantar fasciitis, I was ready to try almost anything. Today, my foot injuries are gone, and it’s hard not to root for the barefoot runners.

#1. Biologists create first bacterium with synthetic genome.

The Gist: In May 2010, researchers at the J. Craig Venter Institute announced they had created “the first self-replicating species on the planet whose parent is a computer.” The claim, though slightly hyperbolic, sparked intense philosophical debate about the definition of life, and the ethics of creating it. Venter’s Institute synthesized and stitched together large swaths of DNA (more than a million base pairs total), and inserted the assembled chromosome into a bacterial cell whose own DNA had been removed.

The artificially generated genome was based on the sequence of the Mycoplasma mycoides (a bacterial parasite that causes lung disease in cows), and implanted into the empty husk of close relative, Mycoplasma capricolum. When the M. mycoides/M. capricolum hybrid grew and replicated, only the synthetic M. mycoides remained: thus, according to Venter, a new species was born.

The Controversy: Craig Venter’s announcement was hailed as the first demonstration of “synthetic life,” the first man-made species. Technically, this isn’t completely accurate. Though the genome was synthesized from scratch, it was copied from a previously existing life form (M. mycoides) and transplanted into a living (albeit vacant) cell. Without the M. capricolum shell, the naked artificial chromosome would have been homeless, forever unprotected and inanimate.

And the ethics of creating this life form? Is it, as Venter said, “perhaps a giant philosophical change in how we view life”? Or is it just the next, inevitable step in the evolution of a science that will eventually tailor different bacterial genomes to different biological tasks?

Why I like it: Time magazine has called him the ‘Gene Maverick’. To Forbes.com, he’s a ‘Gene Celebrity’. To me, Craig Venter is an irresistible mixture of unabashed ego and scientific diva that’s hard not to appreciate. I like him. I can’t help it.

In 2007, the J. Craig Venter Institute sequenced the first complete genome of an individual human being. The DNA source? Craig Venter. The name of the completed sequence? HumanReference, or HuRef (in other words, they christened Venter’s genome the reference sequence for humankind).

To differentiate between synthetic vs. natural bacterial DNA in their artificial life form, Venter’s team inserted their coded names, and a quote from James Joyce into the synthetic bacterium’s genome: “To live, to err, to fall, to triumph, to recreate life out of life.” Bold words, Dr. Venter. I can’t wait to see what’s next.

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

*Footnote: Earlier this month, NASA announced the discovery of a life form that could substitute arsenic for phosphorus as an essential component of DNA. They called it an “astrobiology finding that will impact the search for evidence of extraterrestrial life.” Despite the splashy claims, the original publishers of this research (Science magazine) didn’t include it in their ‘breakthroughs of 2010’. In their words, because “the paper ran late in the year, we feel it is prudent to allow for further analysis before giving it a nod.”

This post was originally published on December 27th at http://www.3quarksdaily.com.

The average lifespan for a man in the US is 76 years. Women tend to live about 5 years longer. Good nutrition, advanced medicine, and end-of-life care can extend our bodies’ reach into old age, but like many mammals with long life expectancies, our brains don’t always make the journey with us. In humans and captive mammals (which generally live longer than animals in the wild) the aging brain is remarkably similar, yet frustratingly mysterious.

Two things stand out:

1. Aging can impair several cognitive functions at once (memory, learning, and reaction time, to name a few).

2. Aging affects everyone differently (a group of 80 year old women can have a wide range of mental defects, and some may have none at all).

What determines whether we retain our brainpower or gradually submit to the ravages of age? Can we learn anything from other organisms, or are our brains too complicated to compare to our insect and animal counterparts?

Though invertebrates (like fruit flies and mosquitoes) have long been used to study human physiology, complex cognitive questions have generally been considered beyond their mental capabilities.

But our brains may be less complicated than we think.  Last week PLoS ONE reported a study that found surprising similarities between the brains of old honeybees and the brains of elderly humans.

Do honeybees have the mental skills to qualify as models for human aging? Dr. Amdam’s lab thinks so.  Honeybees are the intellectual heavyweights of the insect world: they’re navigational experts, can calculate distance from a hive (and convey the info to their hive mates), and can recognize complex visual patterns (like different human faces).

As with humans, these skills tended to fade with age. Dr. Amdam’s lab found that older honeybees had trouble forming new memories, and extinguishing (or forgetting) old ones. The ability to forget old memories is a critical part of normal human behavior; it’s the reason many elderly people can’t remember where their new home is, but have no trouble finding their old one.

Researchers changed hive locations to test the ability of the old bees to forget their previous homes

So, from honeybee to human, are we all marching towards an inevitable decline? Not necessarily. Like humans, elderly honeybees fit into a broad spectrum of mental abilities. The researchers even found some old bees that “performed excellently.”

Now the question is: how do we make it into that population?

PLoS ONE article:

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0013504#s4

I’m 131 pages into Origins, but was hooked after the first chapter.  Annie Murphy Paul has written a book that every woman (expectant or not), father-to-be, scientist, science buff, and lover of babies will want to read.  (As a female scientist who adores babies, you can see why it appealed to me.)  Paul compiles and distills much of what is known about the environment’s effect on the embryo and relates it to her own experience navigating the murky, ever-changing waters of prenatal care.  We follow her, month by month, as she explores the science behind each stage of fetal development.

At the beginning of the book, Paul has just discovered she’s pregnant with her second child; she’s 7 weeks along and only beginning to remember (and worry about) the transformation her life is about to undergo.  No drinking, no smoking, no hot baths. (I hadn’t heard of this restriction before, but prolonged exposure to high temperatures early in pregnancy can cause birth defects.)  Even the grocery store is fraught with potential hazards.  At times, the litany of purported pitfalls makes one marvel that so many babies are born healthy.  But Paul’s focus is not so much the dangers a pregnant woman should avoid, but the positive impact a new mother can have on her unborn baby’s life.

She cites one study that investigated the baby-protecting effects of feeding pregnant mice cruciferous vegetables (like broccoli, cabbage, and cauliflower).  The researchers were testing the idea that eating certain foods during pregnancy could defend offspring from diseases.  They were surprised to find that pups of veggie-eating mouse mothers avoided cancer, even late into life.

Paul delves into the research behind many popular pregnancy truisms, and debunks the ones not rooted in science.  (A couple of glasses of wine per week, for example, are not associated with fetal alcohol syndrome, and cocaine may actually be less harmful than cigarettes). Paul acknowledges that many maternal choices are based in fear, not facts, and promotes the idea that expectant mothers who understand the environment’s in utero impact will be better equipped to make decisions that benefit their children.

Though heavily peppered with experimental data, Origins is approachable, sincere, and endlessly fascinating. Even readers with only a casual interest in human development will appreciate the link between the lives we lead now and the forces that shaped our physical and mental development in the first 9 months of life.  I can’t wait to finish.

There’s supposed to be a worldwide shortage of onions this year, but I don’t think anyone told my garden. This spring, onions were one of the only plants to survive in my slug-besieged community plot at the Experimental College. We had luck with garlic, chives, and arugula too, but our red onions were the standout. Originally, we put them in as a pest deterrent; now, they line the perimeter of each bed like a green picket fence.

An easy-to-thwart fence, it would seem. Leafless kale, skeletal collards, mowed-down brussels sprouts: within days newly planted greens were devoured. The interiors of our beds looked like the “before” picture in a pesticide commercial. One day, my husband picked slugs off seedlings for half an hour—he lost count after 70.  We eventually erected fully enclosed bed-coverings out of wood and mosquito netting, but our onions survived the gastrapodian onslaught cage-free. They thrived, along with every other pungent smelling, peppery tasting plant in the garden.

Garlic (Allium sativum) and chives (Allium schoenoprasum) belong to the same lachrymal inducing, chemical-producing taxonomic family as onions (Allium cepa). This family’s volatile sulfur-containing compounds act as a potent defense system—they convince pesky herbivores to dine elsewhere, and impart the onion’s characteristic smell and taste. When an onion’s cells are damaged (say, by a sharp knife, or a slug’s mouth), enzymes called alliinases escape and convert odorless precursors to pungent aromatics.

Wondering how to avoid tears? The main strategies fall into two categories: 1. Reduce gas-to-eye exposure. (Chopping onions underwater can help, as can wearing protective eyewear. If you Google “onion goggles” the first hit is a pair from Amazon. It’s described as “stylish and comfortable.” You be the judge.) 2. Reduce alliinase activity. (Alliinases are less active when cold, so cooling the onion before cutting results in less gas formation.) Onions, however, are able to stymie more than garden slugs and teary-eyed chefs. Recent research suggests that they might be able to keep bacteria at bay as well.

Scientists at the University of Barcelona tested the antimicrobial activities of three different varieties of onions against a panel of pathogenic microorganisms that cause food spoilage. They chopped, freeze-dried, then ground white and yellow onions to a fine powder, extracted the non water-soluble portion, and added the extract to six common strains of food borne bacteria. Why the non water-soluble part? The researchers wanted to isolate the onions’ flavonoids, an anti-oxidantcontaining class of plant compounds that has gained commercial notoriety due to one of its more popular members: quercetin.

You can buy quercetin in the form of a supplement (confession: we have a bottle at home—my husband couldn’t resist), or a Lance Armstrong-endorsed energy drink (FRS: Free Radical Scavenger. Tagline: “Healthy Energy.”’ Only $35.75 for 15 cans.), but if you eat berries, grapes, leafy greens, or onions, (among other fruits and vegetables) you’re already getting it in your diet.  What’s all the hype about? Flavonoids have long been reported to have a slew of beneficial healtheffects, from antiallergenic to anticarcinogenic to cardioprotective.

Antibacterial and antifungal properties are also among their arsenal of purported tricks.  Indeed, the University of Barcelona scientists confirmed that flavonoid-containing onion extract prevented growth of several strains of bacteria.  Not surprisingly, varieties with higher levels of flavonoids were able to inhibit a wider variety of bacteria. (Red onions weren’t tested in this study, but they’re also thought to be a rich source of flavonoids.)

So, good news for people who cook with onions: It’s likely that you’re getting protection for your leftovers, and maybe even protection for your body (not to mention a free dose of “Healthy Energy”).  Other common kitchen spices have also been implicated in food preservation.  Cloves, cinnamon, oregano, and thyme all contain flavonoids or other antimicrobial compounds that allow them to act as so-called “botanical bacteriocides.” These natural preservatives could serve as an alternative to artificial means of food preservation.  As for my garden, I’m starting to think attempting to grow greens was the wrong approach to winter food
production; next year I’m planting rows and rows of onions…maybe I can sell them to Lance.

It’s two o’clock on a damp Saturday afternoon, and I’m in the production building of Putah Creek Winery; in one hand I have a notepad, in the other, a glass of 2009 Chardonnay, fresh from the barrel.

The lemon-lime colored wine is hazily translucent, and has a bright, tropical flavor- it’s only about 6 months old, but to me, it already tastes good.  Could it be an award winner?  I don’t know, but Gene Glaeser and Jeremy Bivins do.  And they’re not telling.

Gene and his wife Cathy are the owners of Putah Creek Winery, a South Davis based operation that sits amid 20 acres of sustainably farmed vineyards. Up the dirt road a bit, near the family’s house, are 35 additional acres of the Glaeser’s grapes.  The vineyards, originally used to produce grape vine cuttings, were planted in the late 70s, but Jeremy, Putah Creek Winery’s resident vintner, suspects many in Davis don’t know they exist.

“People didn’t think grapes from our region could make a decent wine,” Gene says.  “But you can’t just tell people your wine is good, they have to taste it.”  If their slew of recent prizes is any indication, Gene won’t need to do much convincing.

In 2009, the San Francisco Chronicle Wine Competition awarded Putah Creek Winery a silver medal for their 2006 Tannat (a tannic red often used in blends).  This year Gene and Jeremy walked away with two medals: a silver (for the 2007 Cabernet Sauvignon) and a bronze (for the 2007 Barbera).  Gene gestures to the vineyards behind me; the Barbera vines are grown right outside the door, about 50 feet from where we’re standing.

The winery, a small, unobtrusive building with corrugated metal walls, a peaked roof, and exposed cement floors, overlooks a landscape lush with grass, grapevines and oak trees.  (“You should see it in the spring,” Gene says.) Inside, wooden barrels of wine stacked on racks three high tower above us (nearly all of them are full). In the back, one of Gene’s four employees operates a small device loaded with a thick roll of labels; each bottle is filled, corked, and labeled by hand.

Today’s job involves tasting through the 2008s; not bad work for a Saturday, but as Gene likes to say, “it’s a full-time job on the side.”

I set my glass of chardonnay on a table next to a heavy-looking piece of red equipment.  It’s slightly larger than a sewing machine with a long handled lever attached to the right side: a capsule spinner, Gene tells me.  I watch as he places a cylindrical tin sheath (the capsule) on a corked bottle of wine, inserts the head, and pulls the lever.  The machine whirs and rumbles, and in seconds the capsule is shrunk around the top and neck of the bottle.  When production time comes, they repeat the process, one by one, for every bottle of wine.

“It doesn’t get any more boutique than this,” Gene chuckles. Recently, they’ve been fine-tuning conditions for their white wines: experimenting with yeast types, fermentation techniques, and aging times.  The goal, though, is to keep the process natural, and the style fruit-focused.

“It takes more effort,” Jeremy says, but he works to intervene as little as possible.  “It’s important for the whites to express everything in the environment.”

We taste our chardonnay again, and, for a moment, Jeremy considers the flavor. “It’s still evolving,” he says,  “If you had tried it a month ago, it would have tasted very different.  There are still a lot of immature flavors.”

So, how will they know when it’s done?  To Jeremy, it’s simple: “When it has a flavor profile we like.”

Is it really so straight-forward?  “Some winemakers like to tinker with their wines, but the real secret is patience,” Jeremy explains. Gene nods in agreement.

I’m curious about what he means by ‘tinkering’, so Jeremy rummages through a cabinet and brings out a small, ziplock-sized bag of powdered potassium carbonate.  It’s completely full, with an opening just large enough for Jeremy to extract a pinch. He sprinkles it into my wine, mixes it, then hands the glass to me.

The chemically modified chardonnay tastes completely different- less sweet, less tropical, not as good.

“It’s one way to tweak the flavor, but the downside is you lose some of the fruit.”  Jeremy continues, with a wry smile, “Minimalist style is better for a reason.”

It’s a philosophy Gene shares, and one reason their partnership works so well. Gene and Jeremy have been making wine together since 2006, but Gene has been farming for decades.  He was drawn to grapes because he believed he could differentiate himself from other farmers through his growing practices.

“If you’re growing corn or soybean, the only thing that counts is the harvest yield,” he says, “No matter how good of a farmer you are, there’s no feed back- the bottom line is quantity, and it doesn’t matter how you achieve that.”

“But with grapes you can taste the difference from one crop to the next, so you really learn how to become a better grower.  Finish, fruit-forward, mouth-feel- all those terms became absolute to me when I started making my own wines.”

Jeremy brings out three new glasses – we’re moving on to our second barrel tasting: the 2008 Syrah.  After we sample, Gene shakes his head and takes my glass, warming the bowl in his hands.  “It tastes so much better a few degrees warmer,” he explains.  And he’s right.  To Jeremy, the Syrah’s flavor is fruit and sweet oak, but there’s a touch of concentrated bitterness that he hopes will soften over the next few months.

“We’re still hunting for that elusive gold,” he grins.  I ask if they know when they have a medal-winner on their hands.

“Oh yeah,” Gene nods sagely, “We know.”  Two of their new wines are showing promise, but when I ask which, they exchange coy glances.  “ We don’t want to let it out of the bag just yet,” Gene smiles.  “It’s going to be a surprise.”

Twice a year Putah Creek Winery hosts an open house that showcases their wine and vineyards.  The next event is May 8^th, 2010; they will be pouring twelve different varieties of wine and serving hors d’oeuvres. Tickets are $10, or free for their wine club members.

My favorite radio game show has contestants listen to three unbelievable news stories and figure out which one is true.  The name of the game is  “Bluff the Listener”, but separating reality from fiction is harder than it sounds.  You can’t rely on choosing the oddest story, or what seems to be the most obvious, because, more often than not, the weirdest tales are real.  (A hamster hotel for people? True.  Bed-warming humans for hire?  Also true.)

If you listen carefully, though, sometimes you can catch the give-away: the one detail that reveals a story to be a sham.

Recently, one of the game’s players described a news story in which a raging fire consumed an entire garage and the 1967 Mustang convertible inside it.  What started the blaze?  According to the narrator, a flaming stash of marshmallow Peeps.

Absurd?  Yes.  Untrue?  I wasn’t sure until the storyteller described the Peeps as “3-to-a-pack.”

“Well, that story is obviously wrong,” I remember thinking, “Peeps come five to a package.”

I was right.  The story was in fact, false, but that knowledge didn’t come for free.  It was earned through years of dedicated Peep-eating.  And I think there may be a price to pay.

According to a new study in Cell Metabolism, a diet high in sugar can cut lifespan by as much as 20%.  The lifespan of a nematode, that is.  These hearty little roundworms (called C. elegans) are short (about 1mm long), tube-shaped, and like to hang out with humans- or, more specifically, human garbage.  C. elegans eat the bacteria that break down discarded bits of fruits and vegetables.

Though the worms are visible (barely) to the naked eye, they’re also transparent.  So, while you may have a hard time finding one in your compost pile, C. elegans’ sheer skin allows researchers to see the inner workings of their bodies- from end to end.

They’re also cheap, short-lived, easy to work with, freezable, and believe it or not, amazingly similar to humans. (In one classic experiment, Michigan scientists showed that C. elegans could become addicted to nicotine, and, like people who quit smoking, experience symptoms of withdrawal.)

There’s much to learn from these worms’ short (and, in the case of our Cell Metabolism study, sweet) lives that can be applied to humans.

The study’s authors found that feeding worms a diet constantly supplemented with sugar knocked about 4 days off their lives.  (The worms’ lives, not the researchers.)  4 days may not sound like much, but when your lifespan is measured in weeks, it’s a big deal.  We can scale this up to a human timeframe:  an average woman in the US lives to be 75; an equivalent reduction in longevity would shorten her life by 15 years.  What’s true in worms isn’t always true in humans, but it’s enough to make me wonder.

Let’s get back to the Peeps.

The average American eats 90 grams of processed sugar daily- that’s roughly the equivalent of two and a half packages of Peeps.  Every day.  But, unless we’re talking about me around Easter time, it’s unlikely that this surplus of dietary sugar comes from marshmallows.  So, where does it come from?

Not surprisingly, much of American sugar consumption is in the form of soda, which, at 39 grams per 12 oz can, is one of the densest forms of processed sugar a person can ingest.  To put it into Peep perspective, there’s about one package crammed into every can.

It’s enough to make my mouth water.

I looked up the sugar content of various sweet treats for something, anything, that could rival soda for sugar content.  A Hershey’s chocolate bar?  Nope- only 24 grams of sugar.  A Cadbury crème egg? Not even close. These candies (chocolate shells filled with gooey faux-yolk interiors) –ok, I’ll admit it, they’re my favorite- have 25 grams of sugar apiece. The only food item I could find that beat soda for sugar amount was nearly pure sugar itself: cotton candy.

So, how much soda does it take to match the sugar in one cone of the spun pink stuff?  About a can and a half.

It’s not completely clear how a high-sugar diet affects aging in humans, but I might think twice about what goes in the Easter baskets this year.

On the other hand, this looks pretty tempting:

I have a good nose for scents.

I think it’s something I inherited from my mother, a woman who can sniff out mysterious odors like a bloodhound.  When I was growing up it was not uncommon for her to freeze mid-conversation, tilt her head back, and ask, with voice hushed and nostrils flared, “Do you smell that?” My sister and I never could, but we liked to tiptoe behind her on the hunt.  She’d prowl from room to room, wafting air to nose silently, as if the offending odor was an animal we had to be careful not to spook.

Of the entire household, my father had the worst sense of smell.  Whereas my mother could pinpoint the precise location of an errant sliver of orange peel from two rooms away, Dad was better at detecting more distinct aromas.  He was able to determine, for instance, when the cat left a puddle on his side of the bedspread (the visual clue may have helped).

Since then, my sense of smell has matured, and I’ve noticed the gender-specific olfactory divide in my own marriage.  This difference between male and female noses seems especially apparent when it comes to food: leftovers in particular.

Most people use scent as a first line of defense against possible food spoilage. When bacteria and fungi start colonizing the tupperware-clad remnants of meals past, the telltale signs are usually smelly. Microorganisms snip the connections that hold our food together, breaking it into bite-sized bacterial pieces, and releasing odiferous compounds in the process. Though these tidy clean-up crews can turn a piece of leftover lasagna into a microbial metropolis, like any booming population, they leave behind the garbage of their growth. And this is what can make us sick.

Humans have learned to associate the smells of decaying food with the hazards of microbial waste; we generally avoid eating anything that causes our noses to wrinkle.  Well, most of us do.

Shortly into our relationship, I discovered that my husband has never met a leftover that didn’t smell fine to him.  He considers my periodic purges of the fridge a waste of good food; I draw the line at leftovers that hint at malodor. (There’s a reason why married men live longer than their single peers.)

Although women usually outperform men in tests of odor detection and identity, on the mammalian scale of scent sensitivity, humans rank near the bottom. We’re not the worst though: dolphins and whales are believed to have no sense of smell at all.

Differences in mammalian nasal architecture contribute to this wide spectrum of olfactory abilities.  In all smelling mammals, odor receptors (which detect and respond to specific scents- like citrus or urine, for example) are part of specialized nasal tissues that line the inside of the nose.

Dogs have about 100 square centimeters of this smell-sensing tissue  (about the size of a dollar bill); humans have only 10 (that’s less area than a stick of gum).  Clearly, not all noses are created equally.

But, it’s not just a matter of olfactory receptor real estate: even mice have more sensitive noses than we do. In fact, the nasal tissue of dogs, cats, rats, and mice is densely packed with an assortment of odor receptors.  Humans also have the genes that encode these receptors, but many have mutated or lost sections, and the remnants are no longer functional.

If the genes that encode odor receptors were cars, dogs would have a parking garage full of well-oiled, finely tuned models.  We’d have a more modest lot of vehicles, but most would have flat tires or broken-down engines.

Why have we lost so many of the genes necessary for a good sense of smell?   And what are other mammals smelling that we’re not?

Germs.  Pathogens, to be precise.  Diseases.  Using just their noses, mice can detect potentially harmful sicknesses. It’s a clever tool for avoiding illness, and can be helpful in selecting a healthy mate.  In fact, mice are known to use smell to steer clear of prospective paramours harboring parasites, though until this summer, no one understood how.

In May, Swiss scientists reported in Nature the discovery of a new family of mouse smell receptors that not only senses microorganisms, but also the odorants produced by infection-fighting immune systems.

Though the ability to sniff out sickness and bacteria via these new health-sensing odor receptors was first described in mice, there’s mounting evidence that dogs have similar talents.

In a 2006 study in Northern California, 5 dogs were trained to identify breath samples from cancer patients.  The clinic then presented the dogs with 169 different samples (86 from patients diagnosed with lung or breast cancer, 83 from healthy volunteers) and tested their ability to distinguish between the two groups.  The dogs were 99 percent accurate.

It’s likely that sensitivity to smell helps certain animals avoid dangerous contamination (which can come in the form of bodily sickness or spoiled food).

Fortunately, humans have developed another way to determine food safety: trichromatic vision.  In primates (us included), the loss of odor receptors coincides with the capacity to see in full color.  In other words, what we’ve lost in smell, we’ve made up in the ability to detect blue-hued bits of mold.  Our canine counterparts have not.

As humans, our sense of smell may be dulled, but, paired with superior vision, it’s sufficient to alert us to potential hazards lurking in our tupperware.

It’s not uncommon for human males, however, to have some degree of color blindness. After all, more than 95% of all variations in human color vision occur in the eyes of men.  According to my husband, he can fully differentiate between colors.  Based on his leftover preferences, I have my doubts.

For more on cancer-sniffing dogs and dog training, click here and here.