Mammograms do the most good later in life, a government task force declared in recommending that women get one every other year starting at age 50 until age 74.

But the latest guidelines from the U.S. Preventive Services Task Force also make clear that it’s an option for younger women even though they’re less likely to benefit.

Some groups urge mammograms every year starting at 40, although last year the American Cancer Society upped its starting age to 45.


Gut microbes can be pushed to brink

It may take more than a tub of yogurt to reverse the effects that a high-fat, low-fiber diet have wrought in the bellies of men and women in the industrialized world, said researchers from Stanford, Harvard and Princeton universities.

Indeed, the depletion of gut microbes that comes with diets deficient in fiber extend well beyond the lives of those whose dietary choices made it happen, said the study published in the journal Nature. Over generations of exposure to diets low in fiber, the research shows that a microbiotic population die-off threatens to drive some of the trillions of species that live in healthy human guts to the brink of extinction.

And just as in the world of larger plants and animals, when the population of a given gut bacterium falls below a certain level, it’s as good as gone, the research suggested. The reintroduction of more dietary fiber, and the frantic hawking of probiotic powders, may not be enough to bring all the endangered microbiotic taxa back and restore gut health to successive generations.


‘The Pill’ not tied to birth defects

Some small studies have suggested that oral contraceptive use may be associated with an increased risk of birth defects, possibly by altering vitamin levels in the blood. But a large new study has found that taking oral contraceptives around the time of pregnancy did not increase the risk.

The study, in BMJ, used records of 880,694 infants born in Denmark over 14 years, through March 2011. Birth defects per 1,000 births was consistent: 25.1 for those who never used the pill, 25.0 for use more than three months before pregnancy, 24.9 for use zero to three months before pregnancy, and 24.8 for those who became pregnant while using the pill.

Lead author Brittany M. Charlton, an instructor at Harvard Medical School, said, “Most previous studies have relied on women recalling contraceptive use, but we had the registries. This eliminates any recall bias.”

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