New research published in Tuesday’s Journal of the American Medical Association comes to contradict previous beliefs according to which vitamins taken on regular bases might prevent cancer.

All the persons involved in the study suffered from cardiovascular disease, high blood pressure or high cholesterol levels.

Dr. Shumin Zhang of Brigham and Women's Hospital and Harvard Medical School in Boston and his colleagues found that folic acid and B vitamins don’t prevent breast cancer or cancer in general. They followed 5,442 women, half of whom had been taking a supplement including vitamins B6, B12 and B9 (also known as folic acid) on daily basis over a period of about seven years. All of them suffered from cardiovascular disease, high blood pressure or high cholesterol levels.

At the end of the study in 2005, out of the 5,442 participants, 379 of them developed invasive cancer. Of them, 187 had received the supplement combination and 192 the placebo. Of the women who developed cancer, 154 developed breast cancer – 70 in the active treatment group and 84 in the placebo group.

“In women at risk of cardiovascular disease, we found that folic acid, vitamin B6 and vitamin B12 had no beneficial or harmful effects on the risk of invasive cancer of breast cancer,” said Dr. Zhang.

The researchers noted there was a more significant difference among women 65 and older: those who took the daily supplements were 25 percent less likely to develop any kind of cancer and 38 less likely to develop breast cancer.