Personal Health: News and Notes

Lots of studies have looked at whether the plant estrogens in soy foods affect breast cancer risk, but the results have been conflicting.

Now, a study of 5,042 breast cancer survivors in China has found that those with the highest soy food intake had the lowest risk of cancer recurrence and death. The only similar study - of breast cancer patients in California - also found a protective effect from soy "isoflavones."

These results may not be easily extrapolated to the United States, says an editorial accompanying the new study in the current Journal of the American Medical Association. Not only do the Chinese gobble up to 47 times more grams of soy per day than Americans, they eat more unprocessed forms, such as cooked soybeans, edamame and miso.

Even so, the editorial writers from the National Cancer Institute conclude: "Patients with breast cancer can be assured that enjoying a soy latte or pad thai with tofu causes no harm" - and may even be helpful.

- Marie McCullough

For those who suffer from cluster headaches, the answer may not be a breath of fresh air, a new study finds.

Much better is inhaling pure oxygen for 15 minutes, say the findings in the current Journal of the American Medical Association.

At the National Hospital for Neurology and Neurosurgery in London, both oxygen and fresh air were administered on different occasions to 76 patients with either episodic or chronic cluster headaches.

When given pure oxygen by face mask, patients reported adequate relief 78 percent of the time, whereas regular air was helpful just 20 percent of the time. The difference was statistically significant.

Cluster headaches typically involve severe pain in the eye or temple area, lasting 15 minutes to three hours, and they occur in clusters that can last for weeks. Some patients take a class of medicines called triptans, but these are not recommended for those with heart issues.

- Tom Avril

Losing weight, even a moderate amount, improves the heart health of obese people, indicates a study in the current Journal of the American College of Cardiology.

A group of researchers, including Gary D. Foster at the Center for Obesity Research and Education at Temple University, studied 60 moderately obese patients for two years, randomly assigning them to low-carbohydrate or low-fat diets.

The researchers examined the pumping ability of the participants' hearts and the thickness of their heart muscles, among other measures of cardiovascular health.

They concluded that moderate weight loss - 5 to 10 percent of body weight from either diet - led to improvements in heart function. They noted that when the participants regained weight, some of the benefit was lost.

"Losing 20 or so pounds might seem daunting to some people, but we showed that even a more modest weight loss can yield heart and vascular benefits," said the study's lead author, Lisa de las Fuentes, a heart specialist at Washington University.

- Josh Goldstein

Exercise protects against chronic diseases in midlife. It may help ward off dementia in old age. Want more? For high-school-age boys, a large new study finds that cardiovascular fitness helps predict both educational achievement and job status well into the future.

Swedish and American researchers examined multiple records for every man in Sweden who enlisted for compulsory military service between 1950 and 1976 - more than 1.2 million in all - and followed them for up to 36 years. Analysis of 260,000 sets of siblings and twins allowed them to separate genetics and shared environment (each of which played a large role) from variables that were not shared. The study focused on ages 15 to 18.

The key finding, reported online last week in Proceedings of the National Academy of Sciences, was this: Better physical fitness in the late teen years was associated with significantly better cognitive performance at age 18 and for years beyond. Greater muscle strength, on the other hand, made only a slight difference.

This type of study cannot prove cause-and-effect. But the researchers said their findings fit with what is known about brain development.

- Don Sapatkin