Three cups of coffee a day could lessen the risk of ovarian cancer particularly for those women who do not take hormone supplements.

This new revelations contradicts report issued Monday that coffee doubles the risk of miscarriage.

In the study performed by Dr. Shelley Tworoger, of Harvard Medical School, he compared the diets of 80,000 women with the evidence of ovarian cancer from 1976 to 2004.

Results show that 737 of these women developed ovarian cancer.

Researchers observed an inverse trend of risk with total caffeine and caffeinated coffee intake, but no association with decaffeinated coffee. The potential reduction in risk with higher caffeine intake appeared to be strongest for women who had never used oral contraceptives or postmenopausal hormones.

Women who had at least three cups of coffee a day were 20 per cent less likely to develop ovarian cancer than those who drank none.

Among women who had never taken the pill, coffee drinking cut the risk of ovarian cancer by 35 percent. And for those who had not had hormone replacement therapy, the risk was 43 per cent.

Some studies have also shown caffeine can reduce the risk of Alzheimer's disease, Parkinson's disease, gallstones, diabetes and gout.

Others have found that excessive amounts of coffee cause anxiety, sleeplessness and palpitations.