Picador, February 2016
Reviewed by Randy Rosenthal
I grew up on margarine, skim milk, and diet soda. My grandfather was a bus driver in Brooklyn, and after a lifetime of overeating and smoking a pack a day, he died in his sixties. My dad wanted to avoid this fate, and became somewhat of a health nut when I was a kid. My sisters and I were still allowed a weekly Happy Meal at McDonalds, or a greasy breakfast at Denny’s once a month. But otherwise we were taught to stay away from fat, which we were told would accumulate in our arteries as cholesterol, and eventually cause a heart attack. And so I was raised on a diet of highly processed foods that at the time were considered healthy.
Now we know we had it all backward. If food has been processed and contains complicated ingredients, it’s probably not wise to eat it, since our bodies won’t know what to do with it. Rather than pay attention to theories about health or special diets, I’ve learned to simply eat real food and not worry too much. This is similar to the message I got from Stephen Le’s book 100 Million Years of Food, which is a history of human evolution through the story of our changing diet. Or maybe it’s a panorama of our dietary options through the perspective of human evolution, I’m not quite sure. Either way, if you eat food, it’s a book you’ll want to read.
Instead of promoting a certain diet regimen and telling us what we should and shouldn’t eat, Le uses scientific evidence to explore what our ancestors ate and how these foods affect our bodies. He’s a biological anthropologist, but 100 Million Years of Food isn’t the dry and boring work of an academic. Much of the book is travel memoir, as Le journeys around the world to talk with all sorts of food enthusiasts and have adventures in eating, including fish sauce-covered palm worms and boiled fruit bat.
Le’s writing style is casual and humorous, but what he writes is often frustrating. Because again and again, the evidence doesn’t support common wisdom about health. One of Le’s main points is that we only run into health problems when we obsess over nutrition and lose sight of cuisine. And by cuisine he means traditional diets that are well-balanced and time-tested over hundreds—if not thousands or millions—of years. He starts with what our pre-human ancestors ate around 100 million years ago, which was mostly insects. Then he continues down the evolutionary trail, introducing fruits around 40 million years ago, meat and fish around 16 million years ago, and agricultural foods only 12,000 years ago. He finally comes to the “elixirs” milk and alcohol, which humans started consuming 8,000 and 7,000 years ago, respectively, and he also talks a lot about the influence sunlight, exercise, and parasites have on our health.
Le approaches everything through the lens of evolutionary biology. For instance, here’s his description of why our tongue has four basic tastes: “Bitterness helps us avoid being poisoned; sourness helps us avoid foods that are too acidic, such as spoiled food or unripe fruits; sweetness makes us favor high-energy snacks; and saltiness directs us towards sodium, essential in the ancestral environment.” After reading such passages, my usual thought was: Yeah, that makes sense. There’s no agenda. As long as you’re someone who still believes in science, you can’t argue with any of it, since it’s based on evidence, not theory. And so Le’s approach not makes us look at food differently, it also causes us to question how we define healthy.
For instance, evidence shows that a meat-heavy diet will increase our strength, sense of well-being, and ability to reproduce. But it will also shorten life spans, due to a rise in rates of cancer and other fatal diseases. On the other hand, eating a plant-based diet will allow us to live longer. But since grains, beans, and vegetables weren’t our original food source, they are tricky to digest and cause gastrointestinal problems and autoimmune disorders. So which one is healthier? Le simply presents the facts and leaves the choice to you. Similarly, there is solid evidence that a daily glass or two of an alcoholic beverage lowers our chance of heart disease and mortality. But it also increases our chances of having more than a daily glass or two, and this will likely lead to an earlier death, due to liver damage and other problems caused by the overconsumption of alcohol.
Like this, Le presents both benefit and harm throughout the book. And while it’s great to know what evolutionary biology teaches us about how food and drink affects our bodies, it’s also very frustrating, because it contradicts much of what we think we know. For instance, Le is skeptical of all vitamins and supplements, saying there’s simply no evidence that proves their health benefits. This goes for superfoods too. And he finds all diet fads “dubious,” whether it’s veganism or the low-carb “Paleo” diet.
The thing to remember, Le reminds us, is that evolution doesn’t care about longevity. Once we reproduce and then ensure our offspring has reached reproductive age, we’re basically useless, as far as evolutionary biology is concerned. Many people, however, might want to be around to spend time with our grandchildren. And some of us have even higher aspirations. Evolution wouldn’t look too favorably on vegetarian teetotalers like Gandhi and Henry David Thoreau, not to mention celibates, but motivations for such a lifestyle are spiritual, not material, and so there is no scientific evidence to support the benefits. (After all, Buddhists and yogis are trying to transcend the confines imposed by evolution, not work within them.)
All in all, according to Le, the evidence of evolutionary biology teaches us two indisputable facts about how we should approach our diet and lifestyle. The first is that so long as we’re “well-nourished,” it doesn’t really matter what we eat, because moderate exercise is the most important thing. Our ancestors walked an average of six to nine miles a day, so as long as we’re moving around a lot, we’ll basically be fine, no matter if our diet is high-fat or low-fat, meat-based or plant-based. (This is a bummer, since I spend most of the time sitting on my ass reading, writing, meditating, and watching HBO GO.)
Second, we should focus on traditional cuisine rather than nutrition; that is, we should eat what our genetic ancestors ate. For instance, Northern Europeans developed a gene that allows digestion of milk products, while the Japanese developed one that more easily digests seaweed. A Japanese person will have a hard time digesting cheese, and a Swede will have trouble with too much Nori; both situations will cause health problems. So as Le writes, “maintaining good health consists primarily of finding foods and lifestyles that reflect the conditions of our ancestors and then letting our bodies—exquisite products of millions of years of evolutionary refinement—do the rest.”
This makes sense. But for many Americans it can be troubling, since most of us are mutts. I mean, should I eat the traditional peasant slop my Ashkenazi ancestors ate in Russia, or should I eat the traditional peasant slop my Celtic ancestors ate in Scotland? Either way, I guess it’s peasant slop for me.