The study involved over 700 women, 268 women of whom had breast cancer and 457 women who were cancer free. The women filled out detailed questionnaires asking which supplements they took during the past five years, how frequently they took them, and whether they still took them.
The women also gave blood samples so the researchers could measure the ability of their DNA to repair damage, a complex biological process that is critical to preventing cancer.
Taking multivitamin tablets in the past five years was associated with 31% lower odds of having breast cancer. The use of calcium supplements was linked to a 40% reduced risk.
Pretty darn impressive.
One of the things researchers looked at was the ability of the body to repair damage to DNA. "We've known that DNA repair capacity is linked to several other types of cancer," said lead researcher Jaime Matta, PhD, professor of pharmacology, physiology and toxicology at Ponce School of Medicine in Ponce, Puerto Rico. "DNA repair capacity is very, very linked to breast cancer risk," he added.
The study suggested that calcium supplements may specifically enhance DNA repair capacity whereas multivitamins may have other anticancer benefits in addition. Dr. Matta said in an interview that the findings suggest that vitamins may work better together than individually to lower cancer risk. "We found that taking multivitamins and calcium supplements were strongly protective against breast cancer," added Dr. Manuel Bayona, a professor in the public health program at the Ponce School of Medicine. "Which vitamins exactly? We don't know because they were multivitamins."
If you're only going to take a few basic supplements, a high-quality multivitamin should definitely be one of them.
