Those of us living in the Western societies have grown to accept our familiar diseases (e.g., heart disease, diabetes and obesity) as part of life. Yet for those humans who still live in their native habitat and eat the way their ancestors did, there is little or no heart disease, diabetes, cancer, obesity, hypertension, stroke and no tooth decay, varicose veins, ulcers or hemorrhoids. When individuals living in such remote places come to the West and adopt the Western diet they succumb to the same diseases that Westerners do. The remarkable thing is, when they return to their native environments and assume their native diets, their health dramatically improves.
The common diets we eat in the West, especially in the United States, consist of an overabundance of processed foods, with too much added fats and sugars, too much chemicals of all kinds (added to preserve shelf life), too much refined grains and not enough fresh vegetables, fruits and whole grains. The link between this diet and our modern diseases is undisputed but what do we do about it? The modern approach has been to try and correct the deficiencies in the Western diet by identifying specific compounds which can be linked to different conditions or diseases. This approach to date has not been too helpful and leads to confusion on the part of the public as ideas change (i.e., do we eat reduced amounts of fats or carbohydrates?).
While we can listen to scientists and perhaps find some useful ideas, we should take most of our nutritional advice from our ancestors who survived quite well on traditional diets of whole foods. In short, we should eat whole foods grown organically - the way they have been for centuries, seasoned with natural spices and herbs and reject all industrially prepared commercial foods, the so-called convenience or value-added foods. When you think about it, it takes a lot of audacity to assume we humans can, with knowledge achieved over just the last few decades, improve on millions of years of nature. After all, within a single leaf, there are probably thousands of chemical compounds and interactions which we do not yet understand. So until science really uncovers all the miracles of natural nutrition we should eat only whole foods and use some simple rules to select our foods, such as "if the food contains chemicals whose names an 8 year old cannot pronounce, don't eat it" or "if your grandmother would not know what you are attempting to eat, don't eat it". Read labels and if you don’t see a label ask what is in the food and if it is not a pure whole food, don’t eat it. This discussion has be abstracted from Michael Pollan’s “In Defense of Foods” and “Food Rules,” Penguin Books, 2009.