The Brunch Table

Every couple years, it seems, the New York Times puts out a big feature summing up the current scientific views on food and health. For me, the biggest surprise from the latest one is the idea that discussing diet in terms of nutrients, rather than foods, is a political compromise that’s hurting public health.

“It was in the 1980s that food began disappearing from the American supermarket, gradually to be replaced by ‘nutrients,’ which are not the same thing…Nutrients themselves had been around, as a concept, since the early 19th century, when the English doctor and chemist William Prout identified what came to be called the ‘macronutrients’: protein, fat and carbohydrates. It was thought that that was pretty much all there was going on in food, until doctors noticed that an adequate supply of the big three did not necessarily keep people nourished…”

Apparently, the Reagan-era National Academy of Sciences was harrassed by accusations that it favored particular sectors of the food industry over others. (It was producing research suggesting people should eat less meat.) Talking exclusively about nutrients was a way to avoid crossing powerful special interests while keeping their findings honest–or so people thought.

The problem is that our current understanding of nutrients is very limited compared to our understanding of foods as a whole. You can take a solid piece of advice regarding a whole food, try to break it down into what individual nutrients are doing, and get the explanation utterly wrong–because our concept of what’s going on in there biochemically is still rapidly evolving.

Circadiana is a new blog about sleep written by someone who seems to be a sleep researcher. The first substantive entry, while a bit rambling, is the most informative thing I’ve read on sleep since Wide Awake at 3:00 A.M.. He claims that there is a natural biological variation in sleep patterns, from “larks”, who are early to bed and early to rise, to “owls” (me). It’s better for you to conform to your natural sleep cycle if possible, he says, but he also has advice on how to shift it:

The best way to shift a clock is by using bright light. Instead of buying a $500 light-box, you can, for much less money, build your own for a fraction of that money. You need a piece of board, 3-4 strong neon lightbulbs, balasts, a switch, a plug, and some wires. An hour of fun, and you have an apparatus that is just as good and effective as the hifallutin corporate gizmo. Use the light box at appropriate times (dawn for owls, dusk for [larks]). If you are an extreme owl, when you first get up in the morning, immediately go out in the sunlight (that is thousands of lux of light energy, compared to hundreds from a lightbox) for a jog with your dog. If you do not have a dog, buy one - that will force you to go for a walk early in the morning. Well-scheduled meals also help.

Do not take anti-depressants. They tend to not work for circadian-based depression and may just mask the symptoms (i.e., you “feel” good while your body is falling apart). Do not use melatonin supplements. Do not use alcohol - it may make you fall asleep fast, but the sleep will be shallow and erratic and you will wake up feeling lousy instead of rested. Caffeinated drinks are fine, except during the last 2-3 hours before your intended bedtime, at which time a warm glass of milk may be better.

Make a routine in the evening. The last 2-3 hours before bedtime stay out of the bedroom (bedroom is only for sleep and sex), and switch off all the screens: no TV, no computer, no gameboy. Reading a book while sitting in an armchair in the living room is fine. Just sitting on the porch and thinking will help you wind down. As the evening progresses gradually turn down the lights. Once the bedtime arrives, go to the bedroom, go to bed, switch off the light (pitch darkness) and go to sleep if you can. If you cannot, get up for a few minutes, but keep your lights dim, still no screens, no caffein, no food.

The part about the light rings true to me—I wake up much more easily in a room with lots of natural light than I do in rooms with small covered windows. I’ll have to try the “reading in the living room” bit. Anyway, that’s only a small excerpt of the full entry.

BBC’s got a series of audio lectures by neurologist Vilayanur Ramachandran on how brains work.

It’s a dark day for believin’ in humankind’s essential goodness. There was an upset last week in the UK’s 20th Anniversary Iterated Prisoner’s Dilemma Competition–an AI contest in which programs try to either work together to earn points in small quantities, or exploit each other by stealing points in large quantities. Until now, it was a bit of consolation in an otherwise-cruel world that, given enough turns to take effect, an altruistic strategy (cooperating with everyone who cooperates with you, while remembering and countering those who don’t) would invariably win the game in the end. Straight exploitation, while providing some great initial gains, accumulates too much risk over time.

But if I understand right, this year’s winners finally dethroned the nice guys with a new, unwholesome strategy–basically, the Mafia. In successive rounds of the game, the highest-scoring programs are allowed to “reproduce,” fielding more copies of themselves. The Mafia “master” was designed to execute a signature series of moves that its clones would recognize. The clones then became kamikazes, taking the aggressive exploitation strategy and trying to amass as many short-term points as possible, without regard for their own long-term survival. They would then conspire to lose repeatedly to the master program, which would just sit back and rake in the points.

Oh well.

What a wonderful find (and this is a genuine, first-hand excavated link; I didn’t get it from Boing-Boing or nothin’). It’s a video lecture from Jared Diamond on the origins of human geographic variation (aka “race”).

His core argument is beautifully simple. Three selective forces shape species. The first, and most famous, is natural selection–the external forces that make for many ways of being dead and only a few ways of being alive. Then there’s sexual selection–the fact that offspring resemble their parents, and therefore successful mates will cause the general population to look more like them. And, last, there’s neutral selection–features that neither help nor hurt an organism, and therefore gradually grow more different, like fingerprints.

He says that 19th-century eugenics pegged geographic variation as a result of natural selection, claiming that people near the equator developed dark skin to protect against the sun, and people near the poles developed light skin to compensate for a deficiency in sunlight. (Right away, insidiously, this theory gives us an inexorable division in the human species.) Diamond throws this out on two counts–first of all, skin cancer and vitamin-D deficiencies tend to kill us long after we’ve reached reproductive age, if at all, so they’re very weak selection factors, especially when you consider the short life expectancies of early humans. And second, we don’t actually see a consistent distribution of the darkest-skinned people near the equator and the lightest-skinned at the poles–although the assumption has been repeated so often for the past few hundred years that most of us assume it’s true.

Instead, he argues that our variation comes from sexual selection–when people spread geographically, the small first wave of people that settled in each new territory (”The first people across the Bering Strait, the first people across the English Channel”) exercised an outsized influence over the superficial appearance of their descendants. Sexual selection is the opposite of natural selection; instead of producing functional differences that help us survive, it’s the preservation of arbitrary differences in successful survivors. (After all, says Diamond, “Nobody [in eugenics] can explain the survival value of red hair in Ireland, when Britain has pretty much the same climate”).

And there’s a fascinating discussion at the end in which he mentions that, thanks to advances in transportation over the past few thousand years, we’ve already been doing a lot more “intergeographical dating” than we realize. Large statistical studies of married couples around the world have revealed that, even when the pair appear to belong to different ethnic categories, they’ll commonly have matched features like proportional fingers, eyes, or earlobes, suggesting that their ancestors have already swapped some genes….

A quick thought…

An “action” movie is a competition fantasy, in which selection doesn’t exist. (Selection might mean that Man is thanked profusely by Woman for the saving of her life, but, a little ashamed, she confesses that she has no desire to sleep with him.)

A “romance” movie is a selection fantasy, in which competition doesn’t exist. (Competition might mean that, despite her best efforts, Woman really does end up forced into the loveless marriage with the rich and boring Man twenty years her senior.)