One can hardly watch a morning news show or talk show without hearing some “doctor” (quotation marks because very often the person is no more a real doctor than I’m a nuclear physicist) going on about one or more “super foods” that are practically guaranteed to prevent your getting cancer or heart disease, usually both.
Blueberries, tomatoes, walnuts, cranberries, chocolate, wild salmon, pomegranates, garlic, spinach, soy, spices like cinnamon and turmeric, figs, and green tea are just some of the foods that have been touted as holding the key to your physical salvation, or at least, longevity. Regular old stand-by foods are considered neutral at best and at worst, harmful.
Particular foods are promoted as a cure-all or kill-all for the worried well. But many diseases including coronary heart disease, hypertension, osteoporosis, diabetes, cancer and obesity can occur in individuals without any specific contribution from any one food. Total diet, on the other hand, is a horse of a different colour.
This recent attention to super foods is basically the rebirth of an old idea deeply ingrained in nutrition lore that there are good and bad foods. For various reasons, some of them purely emotional, others based on a belief in the value of something “special” in the food, the foods I’ve mentioned have come to be seen as “good foods” or, “good for you”. For equally unscientific reasons foods such as red meat, whole milk, eggs, butter and animal foods in general, have been considered by some as “bad foods”. Throughout my professional life I’ve been troubled by the notion of something being “bad for you” or “good for you”. It always depends: how much, how often, what is the overall impact of one bite of something. You see how complicated it can get.
It seems obvious to me that no single food consumed in the usual portions can determine the quality of an individual’s diet over a 24-hour period. Simply stated, there are good and bad diets, but not good and bad foods. The single exception would be a food containing chemical or bacterial toxins. Not even “junk food” (often identified with fast food) is “bad” if eaten occasionally as part of an otherwise balanced diet. Your entire food intake, not just a part of it, is the critical factor in determining the healthfulness of your eating pattern. It’s the whole diet, not part of it, that satisfies (or not) the guidelines designed to prevent nutrition-related chronic diseases. Simply put, it’s habit that can make or break you.
But back to these “special” foods. I remember a while ago seeing an ad in an American publication. There was a small glass of orange juice under which was the caption “Fight cancer”. Next to it was a much larger glass of orange juice with the caption “Fight harder”. The clear message was that the more orange juice you drank, the less likely your chances of getting cancer. Is this true? I doubt that there’s an amount of orange juice that can deliver this guarantee. Do you suppose that orange grove owners and workers don’t get cancer? Adding to the irony was the small print that implied only Florida orange juice was beneficial.
Cranberry juice is another interesting example. Women have been told, with good justification, that there is something special in cranberry juice that helps ward off urinary tract infections. What hasn’t become as well known is that cranberry juice can put those susceptible to kidney stone formation at greater risk for this extremely painful condition. More irony, kidney stone sufferers are advised to avoid milk…the very opposite of what they should do. The calcium in milk actually helps prevent the formation of calcium oxalate—the essence of 95% of kidney stones.
Since the early part of the last century, nutrition education has been based on the concept that good diets are composed of a variety of foods taken in moderation. The concept of four basic food groups has aided consumers in identifying foods that are complementary in achieving the proper intake of essential nutrients. Prior to 1987, public health organizations around the world didn’t make any health claims about individual foods, although, quite appropriately, they promoted nutrition and ingredient labelling. Then the U.S. began permitting ads like the orange juice one I mentioned earlier. This would never have been permitted in Canada because regulations prevent food manufacturers from claiming a functional effect of a food on the body. There are now certain claims that can be made in conjunction with specific elements of a food, within the context of a balanced diet, but never is a cure or such able to be attributed solely to a food.
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