Cognitive decline, supplements, breast cancer

COGNITIVE DECLINE

Frequently eating fish appears to slow memory loss in old age.

THE QUESTION: Does the amount of fish in the diet have an effect?

THIS STUDY analyzed dietary and medical data on 3,718 people ages 65 and older. Participants were given four standardized tests of cognition, and they were questioned periodically about the foods they ate. Over a six-year period, cognitive scores declined overall. Compared with those whose diets included no fish, scores dropped 10 percent more slowly for people who ate fish once a week and 13 percent more slowly for those who ate fish twice or more a week. The authors described this difference as equivalent to being three to four years younger.

WHO MAY BE AFFECTED BY THESE FINDINGS? Older people. About 15 percent of men and 11 percent of women over 65 have some degree of memory impairment.

CAVEATS: The study did not determine whether the benefit comes from the presence in fish of omega-3 fatty acids, which are key to brain development early in life.

FIND THIS STUDY: December issue of the Archives of Neurology; abstract available online at www.archneurol.com.

Information

Learn more about memory loss with aging: familydoctor.org and www.niapublications.org (search for "forgetfulness")

SUPPLEMENTS

Following a 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.

BREAST CANCER

When used first, letrozole may work better than tamoxifen.

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 .

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.