Medical Notes: Week of May 28, 2017

A lot of people take low-dose aspirin for heart health but a new study shows it may also protect women against breast cancer. The study in the journal Breast Cancer Research shows that a regular dose of baby aspirin cuts breast cancer overall by 16% and reduces “hormone-receptor positive, HER2 negative” breast cancers by 20%. Those are the most common form of breast cancer. Higher aspirin doses taken less often were not protective, nor were other non-steroidal anti-inflammatory drugs such as ibuprofen.

Vitamin D is known as “the sunshine vitamin” because the skin produces it when exposed to the sun. But a new study shows that sunscreen is getting in the way of vitamin D. The study in the Journal of the American Osteopathic Association shows that sunscreen has contributed to nearly a million cases of vitamin D deficiency around the world. Scientists suggest that people should spend between five and thirty minutes twice a week out in the midday sun before they put on sunscreen.

And finally… extra testosterone makes men go with their gut, and they’re often wrong. A study in the journal Psychological Science shows that men who’d been given a dose of testosterone gel performed 20% worse than a control group on brain teasers where a person’s initial guess is usually wrong. Researchers believe the testosterone produced overconfidence so they never thought twice about their answers.