In Defense of Food Page 17
For most of our food animals, a diet of grass means much healthier fats (more omega-3s and conjugated linoleic acid, or CLA; fewer omega-6s and saturated fat) in their meat, milk, and eggs, as well as appreciably higher levels of vitamins and antioxidants. Sometimes you can actually see the difference, as when butter is yellow or egg yolks bright orange: What you’re seeing is the beta-carotene from fresh green grass. It’s worth looking for pastured animal foods in the market and paying the premium they typically command. For though from the outside an industrial egg looks exactly like a pastured egg selling for several times as much, they are for all intents and purposes two completely different foods.* So the rule about eating more leaves and fewer seeds applies not only to us but also to the animals in our food chain.
IF YOU HAVE THE SPACE, BUY A FREEZER. When you find a good source of pastured meat, you’ll want to buy it in quantity. Buying meat in bulk-a quarter of a steer, say, or a whole hog-is one way to eat well on a budget. Dedicated freezers are surprisingly inexpensive to buy and to operate, because they don’t get opened nearly as often as the one attached to your refrigerator. A freezer will also encourage you to put up food from the farmers’ market, allowing you to buy produce in bulk when it is at the height of its season, which is when it will be most abundant and therefore cheapest. And freezing (unlike canning) does not significantly diminish the nutritional value of produce.
EAT LIKE AN OMNIVOR E. Whether or not you eat any animal foods, it’s a good idea to try to add some new species, and not just new foods, to your diet. The dazzling diversity of food products on offer in the supermarket is deceptive because so many of them are made from the same small handful of plants, and most of those-like the corn and soy and wheat-are seeds. The greater the diversity of species you eat, the more likely you are to cover all your nutritional bases.
But that is an argument from nutritionism, and there is a better one, one that takes a broader view of health. Biodiversity in the diet means more biodiversity in the fields. To shrink the monocultures that now feed us would mean farmers won’t need to spray as much pesticide or chemical fertilizer, which would mean healthier soils, healthier plants and animals, and in turn healthier people. Your health isn’t bordered by your body, and what’s good for the soil is probably good for you too. Which brings us to a related rule:
EAT WELL-GROWN FOOD FROM HEALTHY SOILS. It would have been much simpler to say “eat organic” because it is true that food certified organic is usually well grown in relatively healthy soils-soils that have been nourished by organic matter rather than synthetic fertilizers. Yet there are exceptional farmers and ranchers in America who for one reason or another are not certified organic and the food they grow should not be overlooked. Organic is important, but it’s not the last word on how to grow food well.
Also, the supermarket today is brimming with processed organic food products that are little better, at least from the standpoint of health, than their conventional counterparts. Organic Oreos are not a health food. When Coca-Cola begins selling organic Coke, as it surely will, the company will have struck a blow for the environment perhaps, but not for our health. Most consumers automatically assume that the word “organic” is synonymous with health, but it makes no difference to your insulin metabolism if the high-fructose corn syrup in your soda is organic.
Yet the superiority of real food grown in healthy soils seems clear. There is now a small but growing body of empirical research to support the hypothesis, first advanced by Sir Albert Howard and J. I. Rodale, that soils rich in organic matter produce more nutritious food. Recently a handful of well-controlled comparisons of crops grown organically and conventionally have found appreciably higher levels of antioxidants, flavonoids, vitamins, and other nutrients in several of the organic crops. Of course after a few days riding cross-country in a truck the nutritional quality of any kind of produce will deteriorate, so ideally you want to look for food that is both organic and local.
EAT WILD FOODS WHEN YOU CAN. Two of the most nutritious plants in the world are weeds-lamb’s quarters and purslane-and some of the healthiest traditional diets, such as the Mediterranean, make frequent use of wild greens. The fields and forests are crowded with plants containing higher levels of various phytochemicals than their domesticated cousins. Why? Because these plants have to defend themselves against pests and disease without any help from us, and because historically we’ve tended to select and breed crop plants for sweetness; many of the defensive compounds plants produce are bitter. Wild greens also tend to have higher levels of omega-3 fatty acids than their domesticated cousins, which have been selected to hold up longer after picking.
Wild animals too are worth adding to your diet when you have the opportunity. Wild game generally has less saturated fat and more omega-3 fatty acids than domesticated animals, because most of the wild animals we eat themselves eat a diverse diet of plants rather than grain. (The nutritional profile of grass-fed beef closely resembles that of wild game.) Wild fish generally have higher levels of omega-3s than farmed fish, which are often fed grain. To judge by the experience of fish-eating cultures like the Japanese, adding a few servings of wild fish to the diet each week may lower our risk of heart disease, prolong our lives, and even make us happier.*
Yet I hesitate to recommend eating wild foods because so many of them are endangered; many wild fish stocks are on the verge of collapse because of overfishing. Up to now, all the recommendations I’ve offered here pose no conflict between what’s best for your health and what’s best for the environment. Indeed, most of them support farming and ranching practices that improve the health of the land and the water. But not this one, sorry to say. There are not enough wild animals left for us all to be eating more of them (except perhaps deer and feral pigs), and certainly not enough wild fish. Fortunately, however, a few of the most nutritious fish species, including salmon, mackerel, sardines, and anchovies, are well managed and in some cases even abundant. Don’t overlook those oily little fish.
BE THE KIND OF PERSON WHO TAKES SUPPLEMENTS. We know that people who take supplements are generally healthier than the rest of us, and we also know that, in controlled studies, most of the supplements they take don’t appear to work. Probably the supplement takers are healthier for reasons having nothing to do with the pills: They’re typically more health conscious, better educated, and more affluent. So to the extent you can, be the kind of person who would take supplements, and then save your money.
That said, many of the nutrition experts I
consulted recommend taking a multivitamin, especially as you get older. In theory at least, your diet should provide all the micronutrients you need to be healthy, especially if you’re eating real food and lots of plants. After all, we evolved to obtain whatever our bodies need from nature and wouldn’t be here if we couldn’t. But natural selection takes little interest in our health or survival after the childbearing years are past, and as we age our need for antioxidants increases while our bodies’ ability to absorb them from food declines. So it’s probably a good idea, and certainly can’t hurt, to take a multivitamin-and-mineral pill after age fifty. And if you don’t eat much fish, it might be wise to take a fish oil supplement too.
EAT MORE LIKE THE FRENCH. OR THE ITALIANS. OR THE JAPANESE. OR THE INDIANS. OR THE GREEKS. Confounding factors aside, people who eat according to the rules of a traditional food culture are generally much healthier than people eating a contemporary Western diet. This goes for the Japanese and other Asian diets as well as the traditional diets of Mexico, India, and the Mediterranean region, including France, Italy, and Greece. There may be exceptions to this rule-you do have to wonder about the Eastern European Jewish diet of my ancestors. Though who knows? Chicken and duck fat may turn out to be much healthier than scientists presently believe. (Weston Price certainly wouldn’t be surprised.) I’m inclined to think any traditional diet will do; if it wasn’t a healthy regimen, the diet and the people who followed it wouldn’t still be around.
There are of course two dimensions to a traditional diet-the foods a culture eats and how they eat them-and both may be equally important to our health. Let’s deal first with the content of traditional diets and save the form of it, or eating habits, for the next section.
In some respects, traditional diets resemble other vernacular creations of culture such as architecture. Through a long, incremental process of trial and error, cultures discover what works-how best to reconcile human needs with whatever nature has to offer us in a particular place. So the pitch of a roof reflects the amount of rain or snowfall in a particular region, growing steeper the greater the precipitation, and something like the spiciness of a cuisine reflects the local climate in another way. Eating spicy foods help people keep cool; many spices also have antimicrobial properties, which is important in warm climates where food is apt to spoil rapidly. And indeed researchers have found that the hotter a climate is, the more spices will be found in the local cuisine.
Of course cuisines are not only concerned with health or even biology; many culinary practices are arbitrary and possibly even maladaptive, like the polishing of rice. Cuisines can have purely cultural functions; they’re one of the ways a society expresses its identity and underscores its differences with other societies. (Religious food rules like kashruth or halal perform this function for, respectively, Jews and Muslims.) These cultural purposes might explain why cuisines tend to resist change; it is often said that the last place to look for signs of assimilation in an immigrant’s home is the pantry. Though as food psychologist Paul Rozin points out, the abiding “flavor principles” of a cuisine-whether lemon and olive oil in the Mediterranean, soy sauce and ginger in Asia, or even ketchup in America-make it easier for a culture to incorporate useful new foods that might otherwise taste unacceptably foreign.
Yet more than many other cultural practices, eating is deeply rooted in nature-in human biology on one side and in the natural world on the other. The specific combinations of foods in a cuisine and the ways they are prepared constitute a deep reservoir of accumulated wisdom about diet and health and place. Many traditional culinary practices are the products of a kind of biocultural evolution, the ingenuity of which modern science occasionally figures out long after the fact. In Latin America, corn is traditionally eaten with beans; each plant is deficient in an essential amino acid that happens to be abundant in the other, so together corn and beans form a balanced diet in the absence of meat. Similarly, corn in these countries is traditionally ground or soaked with limestone, which makes available a B vitamin in the corn, the absence of which would otherwise lead to the deficiency disease called pellagra. Very often when a society adopts a new food without the food culture surrounding it, as happened when corn first came to Europe, Africa, and Asia, people get sick. The context in which a food is eaten can be nearly as important as the food itself.
The ancient Asian practice of fermenting soybeans and eating soy in the form of curds called tofu makes a healthy diet from a plant that eaten almost any other way would make people ill. The soybean itself is a notably inauspicious staple food; it contains a whole assortment of “antinutrients”-compounds that actually block the body’s absorption of vitamins and minerals, interfere with the hormonal system, and prevent the body from breaking down the proteins in the soy itself. It took the food cultures of Asia to figure out how to turn this unpromising plant into a highly nutritious food. By boiling crushed soybeans in water to form a kind of milk and then precipitating the liquid by adding gypsum (calcium sulfate), cooks were able to form the soy into curds of highly digestible protein: tofu.
So how are these traditional methods of “food processing” different from newer kinds of food science? Only in that the traditional methods have stood the test of time, keeping people well nourished and healthy generation after generation. One of the hallmarks of a traditional diet is its essential conservatism. Traditions in food ways reflect long experience and often embody a nutritional logic that we shouldn’t heedlessly overturn. So consider this subclause to the rule about eating a traditional diet:
REGARD NONTRADITIONAL FOODS WITH SKEPTICISM. Innovation is interesting, but when it comes to something like food, it pays to approach novelties with caution. If diets are the product of an evolutionary process, then a novel food or culinary innovation resembles a mutation: It might represent a revolutionary improvement, but it probably doesn’t. It was really interesting when modernist architecture dispensed with the pitched roof; on the other hand, the flat roofs that replaced them tended to leak.
Soy again offers an interesting case in point. Americans are eating more soy products than ever before, thanks largely to the ingenuity of an industry eager to process and sell the vast amounts of subsidized soy coming off American and South American farms. But today we’re eating soy in ways Asian cultures with much longer experience of the plant would no
t recognize: “Soy protein isolate,” “soy isoflavones,” “textured vegetable protein” from soy and soy oils (which now account for a fifth of the calories in the American diet) are finding their way into thousands of processed foods, with the result that Americans now eat more soy than the Japanese or the Chinese do.
Yet there are questions about the implications of these novel food products for our health. Soy isoflavones, found in most soy products, are compounds that resemble estrogen, and in fact bind to human estrogen receptors. But it is unclear whether these so-called phytoestrogens actually behave like estrogen in the body or only fool it into thinking they’re estrogen. Either way the phytoestrogens might have an effect (good or bad) on the growth of certain cancers, the symptoms of menopause, and the function of the endocrine system. Because of these uncertainties, the FDA has declined to grant GRAS (“generally regarded as safe”) status to soy isoflavones used as a food additive. As a senior scientist at the FDA’s National Center for Toxicological Research wrote, “Confidence that soy products are safe is clearly based more on belief than hard data.” Until those data come in, I feel more comfortable eating soy prepared in the traditional Asian style than according to novel recipes developed by processors like Archer Daniels Midland.