Good News in the Daily Grind

To judge by recent headlines, coffee could be the latest health-food craze, right up there with broccoli and whole-wheat bread.

But don't think you'll be healthier graduating from a tall to a venti just yet. While there has been a splash of positive news about coffee lately, there may still be grounds for concern.

The Latest Findings on Coffee

Hector Sanchez for The Wall Street Journal

• Diabetes: Many studies find that coffee—decaf or regular—lowers the risk of developing Type 2 diabetes, but caffeine raises blood sugar in people who already have it.
• Cancer: Earlier studies implicating coffee in causing cancer have been disproven; may instead lower the risk of colon, mouth, throat and other cancers.
• Heart disease: Long-term coffee drinking does not appear to raise the risk and may provide some protection.
• Hypertension: Caffeine raises blood pressure, so sufferers should be wary.
• Cholesterol: Some coffee—especially decaf—raises LDL, the bad kind of cholesterol.
• Alzheimer's: Moderate coffee drinking appears to be protective.
• Osteoporosis: Caffeine lowers bone density, but adding milk can balance out the risk.
• Pregnancy: Caffeine intake may increase the risk of miscarriage and low birth-weight babies.
• Sleep: Effects are highly variable, but avoiding coffee after 3 p.m. can avert insomnia.
• Mood: Moderate caffeine boosts energy and cuts depression, but excess amounts can cause anxiety.

Source: WSJ research

This month alone, an analysis in the Archives of Internal Medicine found that people who drink three to four cups of java a day are 25% less likely to develop Type 2 diabetes than those who drink fewer than two cups. And a study presented at an American Association for Cancer Research meeting found that men who drink at least six cups a day have a 60% lower risk of developing advanced prostate cancer than those who didn't drink any.