This you probably know: Overeating usually leads to weight gain, and excess weight increases your risk of dementia. But intriguing new research suggests that overeating — regardless of how much you weigh — is linked to later memory loss. Umm….what was I talking about, again?

Seriously, too much food may lead to forgetfulness. According to research just presented at the American Academy of Neurology, the Mayo Clinic compared dietary data from 1,233 seniors, ages 70 to 89, with prevalence of mild cognitive impairment. About a third of all participants ate between 600 and 1,525 calories a day, another third between 1,526 and 2,142 calories a day, and the rest ate between 2,143 and 6,000 calories a day. Those in the last, highest calorie intake group had double the odds of suffering memory problems — even among those at a normal weight!

Why might this be? Well, one possibility is a high-fat diet: Not only are fatty foods the most calorie dense, they also clog arteries, and by extension, capillaries, which the brain relies on for oxygen. Additionally, simply metabolizing food increases levels of oxidation (think rust) — so metabolizing as many as 6,000 calories daily would mean a lot more free radicals in your system, poised to wreak havoc on brain cells. So what to do? Limit intake of fat — especially saturated and trans-fats — and fill up on fruit and vegetables, which contain the fewest calories and the most brain-saving nutrients and phytochemicals.

Published April 1, 2012