Caffeine & hypertension.

Caffeine doesn't raise the risk of high blood pressure, or hypertension, but cola may play a role, say researchers who tracked more than 155,000 women for roughly 12 years.

Those who consumed the most caffeine (600 milligrams a day, on average) had no greater risk of being diagnosed with hypertension than those who consumed the least caffeine (20 mg a day). (A cup of coffee has about 135 mg of caffeine.)

However, the risk of hypertension was about 30 percent higher in women who drank at least 4 cups or cans of sugared cola a day and about 20 percent higher in women who drank at least 4 cups or cans of diet cola, possibly because of ingredients other than caffeine.

What to do: If you're a coffee drinker, don't give it up to lower your risk of high blood pressure. It's too early to say whether colas cause hypertension, but if you're drinking four or more cans a day, you're getting too much sugar or too much of the artificial sweeteners aspartame or acesulfame potassium anyway.

Journal of the American Medical Association 294: 2330, 2005.