Functional foods have become big business. Sales reached $41 billion in 2011, according to Nutrition Business Journal, although I was interested to learn that as an industry category, "functional foods" includes energy drinks and nutrition bars, which pull in the biggest bucks. No legal or regulatory definition exists for these products, but the term is widely understood to mean a food that has been modified by adding something to provide specific health benefits – to lower cholesterol, for example, or to improve digestion, or give you extra calcium, omega-3 fatty acids, or vitamin D.
To avoid running into trouble with the FDA, manufacturers of functional foods can't be too specific about those claimed benefits. For example, they can't say that a product can cure – or prevent – cancer or heart disease, or, in the case of one widely advertised yogurt brand, tout "if eaten daily is clinically proven to help regulate your digestive system in two weeks." (Here, the Federal Trade Commission intervened, ruling that the claim exaggerated the yogurt's effect on "intestinal transit time.")
If you're tempted by all the hyped-up advertising to buy functional foods, I urge you to read the fine print on the packages about the promised benefits of a particular serving size. In some cases, manufacturers have omitted important information that would probably make consumers think twice about a product – for example, as the New York Times reported, the fact that to get the promised heart health benefits of a certain cereal you would have to eat three bowls of it daily.
Before going the functional food route, I suggest looking at the benefits provided by natural, unprocessed foods. Fruits and vegetables are full of healthy substances that can neutralize free radicals and thereby protect against heart disease and cancer. Omega-3 fatty acids and conjugated linoleic acid in fish, cheese, and meats do the same. Furthermore, you can get all the fiber you need to reduce your risks of heart disease and colon cancer by eating the recommended five to nine servings of fruits and vegetables daily. And remember that regular physical activity is an important part of the health equation – one you won't find on supermarket shelves.
My friend Marion Nestle, Ph.D., an author and professor of nutrition, food studies and public health at New York University, summed up the subject succinctly when asked about functional foods by the New York Times: "… they are not about health. They are about marketing." I agree.
Andrew Weil, M.D.