The Homocysteine/Osteoporosis Connection

New Marker for Debilitating Disease

Much news has been made recently about homocysteine levels becoming a new critical marker for heart disease and stroke -- possibly being even more important than cholesterol levels. Now it seems that high levels of this amino acid also have been linked to osteoporosis. To find out more, I spoke with Kilmer McCully, MD, probably the most respected authority on homocysteine in America and author of The Homocysteine Revolution (Keats).

BACKGROUND ON HOMOCYSTEINE

Homocysteine is a naturally occurring metabolite of the amino acid L-methionine used by the body for many functions including detoxification. It normally shows up in the blood at levels of about 6 millimeters(mm) to 8 mm for women and 8 mm to 12 mm for men. As long as the body keeps levels in check, there's not much of a problem. However, homocysteine may be toxic and inflammatory when in excess, and this can lead to serious consequences, including heart disease.

Dr. McCully first became interested in homocysteine back in the 1960s when he came across a few unusual cases involving children with atherosclerosis, a heart disease that generally is associated with much older people. Dr. McCully also found atherosclerosis scattered through the arteries of a boy who had died of a stroke. After some rigorous detective work, he noted that all these children had high levels of homocysteine. In 1969, he wrote his first paper suggesting that homocysteine was causing arthero sclerotic plaque. Now, 35 years and a substantial amount of research later, it is well accepted that elevated homocysteine is a risk factor for vascular disease.

LINK TO OSTEOPOROSIS

So the connection to cardiovascular disease is well-known -- but what about the connection to osteoporosis? Could high homocysteine levels really have a correlation with osteoporosis? And if so, what can be done about it?

"Osteoporosis is a prominent feature of children with high levels of homocysteine. About two-thirds of the children with high levels of homocysteine also have severe osteoporosis," said Dr. McCully. "They also get scoliosis, a curvature of the spine, and have an increased risk for fractures. More recently, we've found that adult patients with elevated homocysteine also have an increased risk for osteoporosis."

Dr. McCully explained that the osteoporosis connection was revealed through a rather ingenious study in Japan, published in The Journal of the American Medical Association in the spring of this year. The study was done on stroke victims who, for reasons not completely understood, have a much greater risk for hip fractures. The Japanese researchers divided a number of stroke patients into two groups and followed them for two years. One group was given a combination of 5 milligrams (mg) of folic acid and 1,500 micrograms (mcg) of vitamin B-12 while the other group received a placebo. Researchers wanted to see if the B vitamins would reduce hip fractures in this high-risk population. The results were dramatic: In the placebo group, 43 people had hip fractures, but in the vitamin group, only 10 did. And, homocysteine levels dropped in the treatment group by 38%, while they increased in the placebo group.

Could homocysteine be the connection? It sure looks like it. "Two other studies, in Germany and the Netherlands, also demonstrated that patients with higher homocysteine have a higher risk for osteoporotic fracture," Dr. McCully said. "It's likely that homocysteine affects the matrix upon which calcium and other minerals are deposited in the bone. This matrix becomes calcified during bone formation. Homocysteine seems to affect the formation of this matrix in a negative way." Dr. McCully also pointed out that men are less susceptible to osteoporosis than women, probably because testosterone maintains the bone matrix better. In women, it's a double whammy since osteoporosis risk goes up after menopause, and -- for reasons not fully understood -- so do homocysteine levels.

GETTING CONTROL OF HOMOCYSTEINE LEVELS

How do we bring homocysteine down?

"Easily," Dr. McCully replied. "It can be done with dietary improvement and by increasing B vitamins. Eliminate processed foods, including flour and sugar, and eat more fresh vegetables, fresh meats, fresh fruits and whole grains." The three vitamins which have been shown to markedly reduce homocysteine are B-6, folic acid and B-12. "Only about 400 mcg of folic acid and 3.5 mg of B-6 are needed," said Dr. McCully.

Vitamin B-12 is another story, since older people have a harder time absorbing it. "About 15% of people over age 65 are deficient in B-12," Dr. McCully told me, "but not because they don't eat enough -- they don't absorb it well." He recommends taking B-12 (at least 1,000 mcg) sublingually -- under the tongue -- as directed on the bottle, since part of it is absorbed directly through the mucous membranes. Make sure that the B-12 is in either the hydroxycobalamine or methylcobalamine form. The conventional cyanocobalamine is poorly absorbed through the mucous membranes. The bottle will indicate which kind it is.

The take-home point: Get your homocysteine checked by a blood test. Improve your diet and talk to a trained professional about B-12, B-6 and folic acid supplements. Assuming proper dosing, taking these supplements is one of the easiest possible things you can do to improve your health and reduce your risk for both heart disease and osteoporosis.

Be well,

Carole Jackson
Bottom Line's Daily Health News