Antioxidants are good. The free radical molecules they neutralize are bad. Or so we’ve all been led to think. Now a study of exercise and insulin sensitivity turns that conventional notion on its head.

After cancelling his wildly popular comedy tour “Weapons of Self-Destruction” because of serious heart problems, Robin Williams is soon to be back on the circuit. And by all accounts, his over-the-top sense of humor is undiminished. The tour was postponed after the comedian underwent major surgery at the Cleveland Clinic in March to replace his aortic valve, repair his mitral valve and treat an irregular heartbeat.

If the local 24-hour Fitness is any measure, sports drinks seem to be the favored breakfast of champions these days. But a new study by researchers at the University of Texas at Austin suggests that the best pre-workout meal is a whole grain cereal with milk.

Researchers have long known that women who get adequate amounts of folic acid are much less likely to give birth to infants with spina bifida, a devastating birth defect. New research shows that folic acid supplements dramatically reduce the risk of preterm births, as well.

Even when results from early clinical trials are overwhelmingly positive, medications once approved often prove less effective than first hoped. Indeed, there’s a joke among doctors about newly-approved drugs that goes like this: “Prescribe it now…while it still works.”

Why do drugs lose their lustre when they begin to be widely used? For many reasons. Initial enthusiasm on the part of investigators may bias the results to make them seem more favorable, even in controlled studies. Drug makers, who fund the clinical trials that are conducted to win approval, may intentionally make the results appear rosier by fiddling with statistics or leaving out less-encouraging results.

Now a new study offers another surprising reason. Volunteers chosen for clinical trials may not represent the patients who ultimately end up taking the drugs.