The study, published in the Jan. 29 issue of the Canadian Medical Association Journal, found the larger a woman's bra cup size is at age 20, the greater her risk of developing Type 2 diabetes later in life.
Working with the U.S.-based Nurses' Health Study II, which started in 1989 and tracks 116,609 women from 14 states with biennial questionnaires on their health and lifestyles, the Canadian researchers assessed the onset of Type 2 diabetes between 1993 and 2003 in 92,106 participants. They excluded participants who did not include information about breast size or body mass index as well as those already diagnosed with diabetes.
They found the age-adjusted risk of developing Type 2 diabetes was two times higher for a B cup, four times higher for a C cup and five times higher for a D cup or larger than for women with the smallest cup size.
After adjusting for conventional risk factors such as family history, diet and exercise, they found the risk to be 1.3 times higher for women with a B cup at 20 compared to women who wore an A cup. For women with C and D cups, the risk was found to be 1.7 and 1.6 times higher respectively.
The study also suggests that women with the largest cup sizes develop diabetes on average about two years earlier, at age 44, than those with the smallest cup size, at 46 years.

