You’ve probably heard that dietary fiber is good for your heart. But if you’ve been eating lots of whole wheat bread and high-fiber cereal in hopes that you’re doing your cardiovascular system a favor, then you may have been barking up the wrong tree.
Two recent studies reinforce previous research that revealed a clear relationship between dietary fiber and heart health. And the studies show that choosing your fiber sources carefully can make all the difference. Because there are two types of fiber, and while both are good for you, one has a more positive effect on your heart than the other.
There’s no need to stop the presses for the “news” that dietary fiber is good for you. Low fiber intake has been associated with an increased risk of a variety of cancers (including breast and colon cancers), and I think it would be a very rare HSI member who was not aware that dietary fiber helps maintain a healthy digestive system.
All dietary fibers are classified as either water-soluble or insoluble. And because water-soluble fibers have been shown to support cardiovascular health, a team of researchers at Tulane University studied the dietary and medical records of nearly 10,000 subjects enrolled in the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study (NHEFS) looking for correlations between water-soluble fiber intake and coronary heart disease (CHD).
All subjects were disease-free when the study began. During an average follow-up period of 19 years, 1843 cases of CHD were recorded. Examination of the dietary records showed that subjects with the highest intake of insoluble fiber (approximately 21 grams per day) had about 12 percent lower risk of developing CHD as those with the lowest intake (approximately 6 grams per day).
When the same records were compared for water-soluble fiber intake, subjects with the highest intake of this fiber (approximately 6 grams per day) had a 15 percent lower risk of developing CHD, compared to those with the lowest intake (less than one gram per day).
Another recent study among almost 1,000 heart patients in Milan, Italy, produced conclusions similar to the Tulane study.
Dietary factors were assessed in interviews that showed that higher fiber intake reduced the risk of heart attack by well over 25 percent. But among those who had the highest intake of fruit and water-soluble fiber, heart attack risk was reduced by an impressive 36 percent.
One surprising fact emerged from the collected data: Those with the highest intake of cereal fiber actually increased their heart attack risk by more than 10 percent. This was attributed to the fact that the sources of this type of fiber appeared to be refined grains. It’s no secret to most of us that many food products claim to be “whole grain” or “whole wheat,” but actually contain very little of either.
Go to the source
Most people don’t eat enough unrefined, water-soluble fiber to produce the positive results shown in the Milan and Tulane studies. But good quality water-soluble fiber is easy to come by when a little care is taken to find unrefined sources of these foods:
- Fruits, including oranges, peaches, apples, and grapes
- Vegetables, including carrots, squash, and corn
- Nuts and seeds (in particular, psyllium seeds)
- Legumes, including peanuts, lentils, peas, and kidney, black, and pinto beans
- Oats and barley
Some people add fiber supplements to their diets, but William Campbell Douglass, M.D., has warned against using these supplements and eating fiber-enriched food, stating that the total effect they may have on the human body is still unknown and potentially dangerous. Dr. Douglass compares fiber-enriched foods to trying to make a silk purse out of a sows ear, noting that, “adding fiber to foods with refined carbohydrates and artery clogging vegetable fats isn’t going to make these already unhealthy foods any less bad for you.”
Exactly so. Especially when it’s so easy to find plenty of water-soluble fiber foods in your neighborhood grocery store.
To Your Good Health,
Health Sciences Institute
“Dietary Fiber Intake and Reduced Risk of Coronary Heart Disease in US Men and Women” Archives of Internal Medicine, Vol. 163, No. 16, 9/8/03, archinte.ama-assn.org
“Fibre-Rich Diet Proves Good for Heart” NutraIngredients.com, 9/10/03, nutraingredients.com
“Which Fibre is Most Healthy?” NutraIngredients.com, 3/13/03, nutraingredients.com
“Fiber Fibs” William Campbell Douglass, M.D., Daily Dose, 2/18/03