Federal health officials on Tuesday added new safety alerts to the prescribing information for statins, the cholesterol-reducing medications that are among the most widely prescribed drugs in the world, citing rare risks of memory loss, diabetes and muscle pain.

It is the first time that the Food and Drug Administration has officially linked statin use with cognitive problems like forgetfulness and confusion, although some patients have reported such problems for years. Among the drugs affected are huge sellers like Lipitor, Zocor, Crestor and Vytorin.

But federal officials and some medical experts said the new alerts should not scare people away from statins. “The value of statins in preventing heart disease has been clearly established,” said Dr. Amy G. Egan, deputy director for safety in the F.D.A.’s division of metabolism and endocrinology products. “Their benefit is indisputable, but they need to be taken with care and knowledge of their side effects.”

Diabetes patients and even those who develop diabetes while taking statins should continue taking the medicines, said Dr. Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic, who has studied the medicines extensively.