The problem of premenstrual syndrome (PMS) is a worldwide one. Although no one cause can be singled out, numerous factors have all been implicated. These include hormonal imbalance, a diet high in refined sugar and alcohol, lack of certain nutrients, lack of exercise, oral contraceptives, cigarette smoking and caffeine consumption.

A study in China, published by the American Journal of Public Health (January 1989, Vol. 79, No. l) shows that the consumption of tea, high in caffeine, is directly related to premenstrual syndrome. The subjects, nursing students and factory workers, consumed between 1 and 4 cups per day. These women were quite active (bike riding), did not smoke cigarettes or consume any other caffeine products, did not use oral contraceptives, alcohol or tobacco, and had diets with few refined sugars.

The prevalence of premenstrual syndrome in the low tea consuming group (less than 4 cups per day) was 39% as compared to 77% in the high tea consuming group (more the 4 cups per day). Other studies have shown similar relationship between PMS and caffeine.