Research & Development In Brief

Higher vitamin D could improve breast cancer survival; nicotine patches do not help pregnant women quit smoking; omega-3s lower blood pressure; and omega-3s not linked to lower CVD risk.

Vitamin D could boost breast cancer survival

Physicians should add vitamin D to breast cancer patients’ standard care to help increase survival rates, according to researchers at the University of California, San Diego School of Medicine. Cedric Garland, a professor in the Department of Family and Preventive Medicine, and colleagues found women with higher vitamin D levels were more likely to survive breast cancer than women with low levels, based on a meta-analysis of five studies with 4,443 breast cancer patients. Their study appears in the March issue of Anticancer Research. Specifically, they found women with an average of 30 ng/ml of 25-hydroxyvitamin D in their blood were twice as likely to survive breast cancer than women with 17 ng/ml in their blood. The researchers say vitamin D could improve survival by maintaining cell differentiation, promoting apoptosis and inhibiting angiogenesis. They acknowledge the findings could have resulted from reverse causation and they recommend randomized control trials to test the relationship. But there is no reason to wait for the results to take the supplements since the vitamin is safe at doses necessary to raise serum levels to more than 30 ng/ml, they added.

NRT patches do not help pregnant women quit

“Disappointing” results in a British Medical Journal study showed nicotine patches did not reduce smoking rates among pregnant French women and may increase diastolic blood pressure in the mothers, researchers say. The randomized, placebo-controlled, double-blind study found 5.5% of the 203 women who used nicotine patches for 12 to 20 weeks during their pregnancy abstained from smoking compared to 5.1% of the 199 in the placebo group. The mean birth weight of the babies was not significantly different between the groups with 3,065 g in the nicotine patch group and 3,015 g in the placebo group. These quit success results are significantly lower than similar previous studies with lower doses of 15 mg nicotine daily that resulted in 19% to 21% abstinence compared to this study which had doses ranging from 10 to 30 mg daily.

This study, led by Ivan Berlin, a practitioner at the Hopital Pitie-Salpetriere, also was the first to reveal increased blood pressure rates among women in the nicotine patch group. The increase was 0.02 mm Hg per day in the nicotine group compared with no increase in the placebo group. This is a preliminary finding that needs confirmation, but which could lead to potentially unfavorable pregnancy outcomes, the researchers note.

Omega-3s lower blood pressure

A meta-analysis of 70 randomized controlled trials shows use of eicosapentaenoic and docosahexaenoic acids from supplements or food lowers systolic and diastolic blood pressure. The study in the American Journal of Hypertension found a mean dose of EPA and DHA of 3.8 g daily lowered systolic blood pressure -0.99 mm Hg compared to placebo, which typically was olive oil, safflower oil or another vegetable oil. The most noticeable drop in systolic blood pressure was -4.51 mm Hg in the untreated hypertensive subjects, compared to -1.25 mm Hg among normotensive subjects who took omega-3s. The researchers, led by Paige Miller of the Center for Epidemiology, Biostatistics and Computational Biology, Exponent Inc., noted their study differs from previous meta-analysis on the subject because it includes shorter studies down to three weeks of treatment compared to a minimum of eight weeks in other meta-analysis. The current study also includes EPA and DHA consumption from food, which tend to have a lower compliance rate than supplements because subjects object to the taste of fish, availability restrictions and bones, according to the study.

Omega-3s, lower CVD risk link questioned

Evidence continues to mount against omega-3 supplementation combined with lutein and zeaxanthin helping reduce the risk of cardiovascular disease. The Cardiovascular Outcome Study, an ancillary study of the Age-Related Eye Disease Study 2, found omega-3 fatty acid supplementation of 350 mg DHA and 650 mg EPA with or without 10 mg lutein and 2 mg zeaxanthin did not reduce the risk of CVD over a median period of 4.8 years. The analysis in the March 17 JAMA Internal Medicine noted within the DHA+EPA analysis, there was 1.94 CVD incidence per 100 person-years compared to 2.04 in the no DHA+EPA group. Similarly, in the lutein+zeaxanthin group, there was 1.92 incidence of CVD per 100 person years compared to 2.05 for the no lutein+zeaxanthin group. The differences were not statistically significant, note the researchers led by Denise Bonds at the National Heart, Lung and Blood Institute.

The authors also note support for omega-3 and lutein+zeaxanthin reducing CVD is mixed. The Chicago Western Electric Study and the Nurses’ Health Study show omega-3s lowering heart disease events, but those results are not confirmed by the Health Professionals’ Follow-up Study or the Physicians’ Health Study. Likewise, the Atherosclerosis Risk in Communities Study showed lutein+zeaxanthin concentrations were lower in CVD cases, but no association was observed in the Physicians’ Health Study.