Alzheimer's and diabetes rates are both on the rise. And as the population ages, Alzheimer's disease rates will "escalate rapidly in coming years," the Alzheimer's Association reports. It's believed that Alzheimer's is brought on by a combination of genetics, environmental, and lifestyle factors — but the type 3 diabetes idea adds new credence to the suggestion that diet and exercise, more than any other factor, can prevent Alzheimer's.

The omega-3 fatty acids found in fish, walnuts, and flaxseed have been shown to decrease risk of cognitive decline, as have the antioxidants in fruits, vegetables, and tea — foods that have all been shown to help prevent type 2 diabetes. The answer, healthy eating advocates like Bittman say, is adopting a "sane" diet full of plants, and low in saturated fat and sugar to head off cognitive decline, diabetes, and the host of negative side effects that come with.

A drug called CaPre is made from krill oil, It recently got approval to do trials for Diabetes.