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South Beach and other Atkins derivatives make the diet more palatable by allowing more fruits and vegetables. The newest alterna-Atkins is the popular paleo diet, which postulates that since the human genome appeared in its current form during the Paleolithic Period about 2.6 million to 10,000 years ago we are genetically designed to eat what was available then. The paleo diet focuses on lean meats and fish, fresh fruits and nonstarchy vegetables. It eliminates dairy, grains and legumes because they didn't appear on our menus until about 12,000 years ago. According to some clinical trials, the diet has indeed been shown to lower the risk of cardiovascular disease, high blood pressure and inflammation as well as reduce acne, improve athletic performance and help with weight loss.
Many nutritionists, however, are concerned about eliminating whole grains and dairy products. A wealth of research shows that both can help decrease the risk of certain cancers and heart disease. What's more, it's worth remembering that cavemen tended to be much shorter than modern people and often died in their 40s in part because they weren't eating a diet that left them with much ability to fight off infection (or saber-toothed tigers). I would rather follow a diet that sees me lucid and active enough to play with my grandchildren than one under which I die young but look great.
It's no secret that a diet that's good for a boy in his prime growth-spurt years is not so good for a middle-aged man, or that what counts as adequate nutrients for a woman when she is breast-feeding in her 20s is different from when she is postmenopausal in her 70s. Yet as consumers, we accept blanket statements about how many servings of which food groups to eat and what constitutes optimum calorie counts and vitamin percentages. I have performed more than 5,000 heart surgeries, and I recommend a diet low in saturated and trans fats to prevent the buildup of arterial plaque. But I still can't tell you why I can see two patients in one afternoon who have both spent decades eating large amounts of bacon, butter and baked goods and yet have completely opposite angiogram reports.
The University of North Carolina Nutrition Research Institute is a leader in the growing field of individualized nutrition, studying what's known as nutrigenomics: the link between genes and diet. The science is a comparatively new one, but the early reports are tantalizing.
One study of mice, for example, has pinpointed a binding protein in some individuals that overactivates a suite of genes involved in the synthesis and uptake of cholesterol and other fats. That in turn can lead to insulin resistance, high triglycerides and a condition called fatty liver, in which fat builds up in the liver and inhibits its ability to filter toxins in the blood. People with a similar genetic glitch might be similarly sensitive to dietary fats and have to adjust what they eat accordingly. Another mouse study has found a gene variation that specifically affects the risk of developing high-LDL cholesterol. Yet another has found a gene variation that plays a role in how susceptible individuals are to the carcinogens that are produced when meat is cooked at high temperatures.
It's too early for these and other nutrigenomic studies to have clinical applications, but your doctor should already be looking at food as a tool for disease prevention at least when it comes to regulating the intake of salt, cholesterol and other substances in people who are sensitive to them. Food allergies come into play here too. You can hardly recommend wheat-based cereal to someone who can't process gluten, or milk to a person who's lactose intolerant.
But pulling those foods out of the diet and replacing them with nothing or worse, with junk is hardly the answer. Instead, try whole grains without gluten, like quinoa and chia; also try yogurt, kefir, cheese and other fermented dairy products that contain less lactose than fresh dairy foods because the bacteria used to make them digest some of the lactose, so you don't have to. The longer a cheese is aged, the less lactose it has. (A sharp cheddar aged for two years contains almost none at all.) The vast constellation of food that's available to us means that almost anyone's nutritional needs can be met even if it takes a little work.