A friend takes vitamin B supplements, thinking they can help prevent heart problems. But I thought they found out that doesn't work. Can you clarify?
B vitamins do appear to help reduce levels of a substance called homocysteine. And high levels of homocysteine seem to be linked with cardiovascular problems. But you're right -- recent studies indicate that relationship between homocysteine and the heart isn't what scientists thought.
Despite the new findings, it's important to note that the B vitamins in question -- B6, B12 and folate -- are still good for you. You need vitamin B6 to synthesize neurotransmitters. You need vitamin B12 to maintain healthy nerve cells and red blood cells. You need folate (or folic acid, the synthetic form) to prevent a type of anemia, to make DNA, and, if you're pregnant or may become pregnant, to prevent -birth defects. A diet that's rich in leafy greens, beans, whole grains, bananas, potatoes, fortified cereal, and that includes meat, poultry and fish or dairy products, should get you the B vitamins you need.
But in 1969, a researcher discovered a link between high levels of homocysteine in the blood and premature hardening of the arteries. Normally, the body uses B vitamins to break down homocysteine into important amino acids, but that doesn't happen in people with a genetic disorder called homocysteinuria, who often have heart problems.
In the 1990s, studies did seem to indicate that high homocysteine levels in the blood could be a risk factor for heart disease independent of other factors such as high blood pressure, high blood cholesterol and diabetes. But recently, large-scale studies, including two published in the March 12, 2006, issue of the New England Journal of Medicine, showed no effect. The studies, conducted by Canadian and Norwegian researchers, both followed thousands of people for years, giving some participants B vitamin supplements and others a placebo. Both found that the B-vitamin group did, in fact, have lower homocysteine levels. But there were no differences in deaths due to heart disease.
Now, scientists wonder if heart disease causes high homocysteine levels rather than the other way around. It's hard to tell at this point.
But the bottom line is twofold: First, scientific research is complex, and it takes years to ferret out links between specific nutrition guidelines and health outcomes. Second, a well-balanced diet with plenty of fruits and vegetables, whole grains and healthy fats is the best health bet for the long run.
Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or firstname.lastname@example.org.
Editor: This column was reviewed by Anne Smith, associate professor of human nutrition in the Department of Human Nutrition, College of Education and Human Ecology.
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