Over the years, people have viewed the health benefits of vitamins and nutrients found in food individually. Most nutrition studies have isolated beta carotene, calcium, vitamin E, lycopene, omega-3, among other nutrients, to study its individual health benefits in the body. However, the disappointing results of various research studies only strengthened the growing belief that there is more to food and diet than just the sum of its nutrient parts.
David R. Jacobs, a professor of epidemiology at the University of Minnesota, argues in a recent commentary for the Nutrition Reviews journal that nutrition researchers should focus on whole foods rather than only on single nutrients. “We argue for a need to return to food as the source of nutrition knowledge.” Dr. Jacobs co-authored the article with Linda C. Tapsell, a nutrition researcher at the University of Wollongong in Australia.
According to Dr. Jacobs, nutrition science needs to consider the effects of “food synergy” — the notion that the health benefits of certain foods aren’t likely to come from a single nutrient but rather combinations of compounds that work better together than apart. “Every food is much more complicated than any drug,’’ said Dr. Jacobs. “It makes sense to want to break it down. But you get a lot of people talking in the popular press about carbohydrates and fats in particular as if they were unified entities. They’re not. They’re extremely complicated.’’
When two scientists won a Nobel Prize in 1937 for identifying vitamin C as the essential component in citrus fruit that prevents scurvy, it somehow set the trend for the scientific community to focus on the health effects of biologically active single nutrients in foods. Nutrition researchers are breaking down the nutrients in food to identify its most potent benefits, such as beta carotene from carrots, lycopene from tomatoes, omega-3 from salmon, potassium from the banana, among others. Foods rich in vitamin E have been widely considered as being good for the heart.
However, studies revealed that attributing the broad health benefits of a diet to a single compound is considered misguided. The idea that a diet rich in beta carotene and vitamin A can lower many types of cancer had been inaccurate based on the well-known 1994 Finnish study where smokers who took beta carotene were found to have an 18 percent higher incidence of lung cancer.
In a similar study done in 1996, researchers gave beta carotene and vitamin A to smokers and workers exposed to asbestos. But the trial had to be stopped because the people taking the combined therapy showed markedly higher risks for lung cancer and heart attacks.
Since then, studies of other vitamins, notably vitamins E and B, have also failed to show a benefit. According to some quarters, vitamins are too often examined in sick people while the real benefit may be in preventing disease. On the other hand, Jacobs notes that the better explanation may simply be that food synergy, rather than the biological activity of a few key nutrients, is the real reason that certain diets appear to lower the risks of heart disease and other health problems.
So, when you are not sure what vitamins to take, just remember to have a nutrient-rich diet.