After heart attack, added arginine may pose a danger

THE QUESTION Blood vessels often become less pliable as people age, but the amino acid arginine — generally obtained in sufficient amounts through the diet — may help relieve this stiffness. Might over-the-counter arginine supplements benefit people with cardiovascular problems?

THIS STUDY randomly assigned 153 people older than 30 who recently had a heart attack for the first time to take arginine supplements or a placebo three times a day, along with their regular medications. After six months, standard measurements of heart functioning — including vascular stiffness and the amount of blood pumped out with each contraction of the left ventricle — revealed little difference between the groups. However, 17 percent of those taking arginine, compared with 10 percent of the placebo group, had another heart attack, were hospitalized for heart failure or died during this time. Six people (9 percent) taking the supplement had died; no one taking the placebo had died.

WHO MAY BE AFFECTED BY THESE FINDINGS? People with heart problems. Most people get sufficient amounts of arginine through their diet.

CAVEATS The researchers intended to enroll roughly 300 participants, but the study was stopped early because of the number of people who died.

FIND THIS STUDY Jan. 4 issue of the Journal of the American Medical Association; abstract available online at www.jama.com.

LEARN MORE ABOUT arginine at www.nlm.nih.gov (search for “arginine”; then click “Health Information”) and http://en.wikipedia.org.

When used first, letrozole may work better than tamoxifen for treating breast cancer

THE QUESTION A class of drugs called aromatase inhibitors has been shown to help women whose breast cancer does not respond to tamoxifen, the standard hormone treatment for cancers that require estrogen to grow. Might such a drug, which prevents estrogen from being produced, also prove beneficial if taken initially?

THIS STUDY randomly assigned 8,010 post-menopausal women with the type of early-stage breast cancer known as hormone-receptor-positive to take tamoxifen or letrozole (Femara) daily. After a little more than two years, cancer had recurred 19 percent less often among women taking letrozole than among those taking tamoxifen; the chance of its spreading to distant sites in the body was 27 percent less for the letrozole group. The study estimated that 84 percent of the letrozole group and 81 percent of the tamoxifen group would remain cancer-free for at least five years. Fractures, high cholesterol and serious heart problems were more common among women taking letrozole; blood clots, vaginal bleeding and endometrial cancer occurred more often in the tamoxifen group.

WHO MAY BE AFFECTED BY THESE FINDINGS? Women with hormone-receptor-positive breast cancer; 50 to 70 percent of all breast cancers are this type.

CAVEATS A longer study would be needed to determine whether letrozole would continue to affect the relapse rate after treatment had stopped, as tamoxifen has been shown to do. The study was funded by Novartis, which makes Femara; company employees were members of a committee that reviewed the article, and seven of 14 primary authors had received consulting fees from Novartis.

FIND THIS STUDY Dec. 29 issue of the New England Journal of Medicine; abstract available online at www.nejm.org.

LEARN MORE ABOUT breast cancer treatment at http://patients.uptodate.com and www.cancer.gov/cancerinfo.

Antioxidant-rich foods seem to lessen the risk of vision loss

THE QUESTION As people age, tissue in the macula — the part of the eye responsible for seeing fine detail — sometimes deteriorates, a condition known as age-related macular degeneration (ARMD). High doses of antioxidant supplements are believed to help slow the progression of this disease. Might eating foods high in antioxidants prevent it?

THIS STUDY analyzed medical and dietary data on 4,170 people 55 and older. During an eight-year period, 560 people (13 percent) were diagnosed with ARMD. Based on information from food diaries, medical tests and eye examinations, people who took in the most vitamin E and zinc from their diets were the least likely to develop the eye disease. Above-average consumption of foods high in vitamins C and E, beta carotene and zinc was associated with a 35 percent lower risk of the disease, compared with below-average consumption of at least one of these antioxidants.

WHO MAY BE AFFECTED BY THESE FINDINGS? Older people, who are most likely to have ARMD, the leading cause of vision loss in people over 65. It affects women more often than men, whites more than blacks.

CAVEATS The study, which was not randomized, did not account for all differences between participants.

FIND THIS STUDY Dec. 28 issue of the Journal of the American Medical Association; abstract available online at www.jama.com.

LEARN MORE ABOUT age-related macular degeneration at www.nei.nih.gov/health and www.medem.com.