When it comes to nutrition, the saying "The whole is greater than the sum of its parts" is a recognized truth.
That's what I thought when I read an article from the American Journal of Medicine that looked at dietary approaches to prevent coronary heart disease. The article found that a whole-diet approach — a pattern of eating that emphasizes vegetables, fruits, fish, whole grains and olive oil — reduces cardiovascular events, such as heart attack, to a greater extent than diets that focus only lowering fat.
The authors reviewed major nutrition studies since 1957 and their impact on medical practices and nutrition advice. Early on the focus was on restricting certain nutrients — fat and cholesterol. Does the following sound familiar?
- Reduce (total) dietary fat
- Reduce saturated fat — substitute polyunsaturated (vegetable) fat
- Reduce dietary cholesterol
According to this article, these early clinical trials showed that the "focus on fat" approach decreased cholesterol levels by 11 to 12 percent. However, it did not lower the number of deaths from heart attacks.
Later studies began to look at increasing consumption of specific foods or food groups, rather than restricting fat and cholesterol. Foods found to be heart healthy include:
- Whole grains
- Olive oil
- Alcohol (in moderation)
Subsequent studies compared combinations of these foods to fat- and cholesterol-restricted diets. They found that dietary patterns that included the above foods (such as Mediterranean-style diets) were more effective in preventing heart attacks and resulting deaths than the fat- and cholesterol-restricted diets were. Although whole-diet approaches reduced the number of heart attacks, they didn't reduce total and LDL ("bad") cholesterol levels.
As a dietitian, I've always tried to focus on the whole diet. Sure, you can get people to restrict certain things. However, if the rest of what they're eating isn't healthy — then they won't be healthy. Truly the whole of what you eat is greater than the sum of its parts. Increasingly nutrition research and practices are catching on.
March 14, 2014