Dr. James Anderson, professor of medicine and clinical nutrition at the University of Kentucky in Lexington, spoke with TIME.com Wednesday about the feminization of diabetes.
TIME.com: Why is the incidence of diabetes increasing so dramatically among American women?
James Anderson: There are a number of reasons. First, and perhaps most important, obesity is increasing at a frightening rate. In fact, 55 percent of women in the US are considered overweight, and 35 percent are considered obese. So basically, weíre talking about 60 million women who are overweight and therefore at a heightened risk for diabetes.
Whatís the connection between obesity and diabetes?
Basically what weíre seeing is a sort of evolutionary backlash. Humans today are programmed to resist famine, because over time, the only people who survived and propagated are those who are well-equipped to survive famine. But today most of the planet doesnít face famine; it only exists in certain pockets of the world. For those of us not living in famine-prone areas, an overabundance of food has become more dangerous than a lack of it. We have no protection against excess food intake, and as food has become more available and less expensive all over the world, obesity and diabetes have followed.
Part of the bodyís protection against famine is insulin resistance. That means that our muscles are not as receptive to insulin, which is critical to moderating blood sugar. To make matters worse, more than half of women who are obese also have insulin resistance. That means their pancreas has to work even harder to produce more insulin so their muscles know itís there.
In an overfed state, the pancreas is forced into an overproduction of insulin because thereís so much food to process, and the pancreas quickly becomes exhausted and cuts down on insulin production. When the pancreas gives up, or slows down production, blood sugar starts to rise. Thatís when people get the symptoms of diabetes, including excessive thirst, excessive urination and blurred vision.
Why do women make up the majority of modern diabetes cases?
Thereís more obesity in women than in men, and women live longer and generally less active lives than men. Prototypic jobs for women are less active than those traditionally assigned to men. This inactivity puts women at a greater risk for obesity, which is often a direct precursor to diabetes.
What are the risk factors for Type 2 diabetes?
A family history of diabetes is a very strong risk factor. Obesity is also a very dramatic risk factor 80 percent of people with Type 2 diabetes are obese. A diet thatís low in carbohydrates and fiber, or high in fat can also increase risk. Finally, an inactive lifestyle is also a factor.
Why are minority women particularly susceptible to diabetes?
The risk of diabetes is lowest among Caucasians. In Great Britain, the risk for Type 2 diabetes is the lowest of anywhere in the world. In Hispanics, Asians and blacks, the risk is much higher. In Native Americans and Pacific Islanders, the risk is highest.
At this point, any answers as to why thereís such a disparity are based on pure speculation. It could be that Caucasians may have emerged in an area where food intake was more plentiful, and perhaps they didnít have to develop the same defenses against famine as some other groups did.
What can women do to guard against diabetes?
The good news is, these steps are all changes women can make fairly easily.
Women need to keep weight gain to a minimum. For every one percent of her body weight a woman gains after high school, her risk for heart disease increases about five percent. For every same one percent gained, that womanís risk of developing diabetes increases by 10 percent. In other words, if youíve gained weight since high school (and thatís probably pretty much everyone), your risk for heart disease and diabetes has increased.
Regular exercise is another critical defense against diabetes. Simply increasing your walking to 20 minutes each day can decrease your risk dramatically.
Finally, women need to make sure theyíre getting in five servings of fruit and vegetables a day. A healthy diet is key in preventing diabetes.