As of Sunday, April 21, 2013
DEAR DOCTOR K: These days everything in the supermarket claims to contain whole grains, from sugary cereals to my favorite chips. How do I know which foods are healthy whole grains?
DEAR READER: “Whole grain” has become a healthy-eating buzz-phrase, and food companies aren’t shy about using it. But some of the products we buy may not deliver the healthful whole-grain goodness we’re expecting. And if sugary cereals can tout themselves as a whole-grain food, there’s something amiss.
Wheat, rice, barley and oats are all grains used to create bread, cereals and pasta. If those grains are processed heavily before the bread, cereals or pasta are made (such as in white bread or white rice) they’re called “refined” grains. The processing that leads to refined grains removes fiber — and iron and B vitamins — from the grain. If you see the term “enriched grains” on a package, it means the fiber is still gone, but some iron and B vitamins have been added back.
So what’s the best way to identify a healthful whole-grain food? Use the 10:1 rule: For every 10 grams of carbohydrate, there should be at least one gram of fiber. Why a ratio of 10-to-1? That’s about the ratio of carbohydrate to fiber in a genuine whole grain — unprocessed wheat.
Let’s say the Nutrition Facts label on a package shows that one serving of a whole-grain roll has 23 grams of carbohydrate. Divide that by 10 to get 2.3. It also has 5 grams of dietary fiber, which is bigger than 2.3. That signals a healthful whole-grain food. (I’ve put a sample Nutrition Facts label, along with an explanation of how to calculate the carbohydrate-to-fiber ratio, on my website, AskDoctorK.com.)
Intact grains — wheat berries, oat berries, brown rice and quinoa, for example — are the best source of whole grains. Ground whole grains come next, as long as they still deliver a good dose of fiber. To find those, use the 10:1 carbohydrate-to-fiber rule.
What’s the good of eating whole grains? Because they have more vitamins, minerals and antioxidants. Even more important, they are digested more slowly. When you eat a refined grain, there is a sudden surge of sugar in your blood. That stresses your pancreas, which has a hard time making enough insulin to drive all of the sugar into your cells for energy. The excess sugar gets turned into fat.
In fact, people who eat lots of refined grains and few whole grains are more likely to become obese and to develop diabetes and heart disease. People who eat mainly whole grains and keep their total calories in check are more likely to lose weight. I’m not preaching; I’m giving you advice proven to improve your health.
(Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.)
Dr. Anthony L. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.