Q. After doing some research, I have been trying to reduce my intake of grains. But the big thing in the news this week is a new study finding that fiber from grains reduces the risk of colon cancer and that fiber from fruits and veggies doesn’t have the same effect. Have you looked at this new research? Do you still recommend reducing grains?
A. Just to be clear, I’m not anti-grain. Although I suspect that most Americans consume an excessive amount of grain products (especially refined grains), and I believe that grains are not essential to a healthy diet, I still think that a healthy diet can include grains (especially whole grains).
I have, however, questioned the dogma on the “benefits of whole grains” on the basis that the research doesn’t really distinguish between the benefits of adding whole grains and the benefits of reducing refined grains. (The two virtually always go hand in hand.)
Does this new study change my position? Not really.
The researchers still don’t address whether the “significant but modest” reduction in colon cancer risk is due to the increased fiber from grains or to the fact that people who eat more whole grains almost invariably eat fewer refined carbohydrates. A diet that’s lower in refined carbohydrates will have a considerably lower glycemic load, a factor that’s been linked to reduced risk of colon cancer in other studies.
Perhaps the reason that fiber from fruits and vegetables was not similarly correlated to a change in colon cancer risk is that when people increase their intake of fruits and vegetables they don’t necessarily decrease their intake of refined grains the way they do when they increase their intake of whole grains.
If you wanted to hedge your bets, you could incorporate 3 servings of whole grains into your diet. That’s the level found to offer that “modest” reduction in risk. At three servings a day, you’d still be eating a fraction of the 6 to 11 servings of grains that the 2010 Dietary Guidelines for Americans recommend.