A healthy diet is about more than keeping yourself fit and free of heart disease, wrinkles and impotence (yes, all are related to food!). It’s about preserving your memory, too.For instance, eating high amounts of saturated fat—more than four grams in an hour—can raise the levels of bad cholesterol in your blood, which can stick to your arteries, and, even worse, turns on inflammatory genes that result in those wrinkles, poor orgasm quality, and you got it, that gunk in your brain that makes  your memory be less than it is now.The same arterial plaque buildup from this saturated fat—we call it a food felon—that leads to heart disease is a major culprit for vascular dementia—when the brain neurons become inflamed or  don’t get enough oxygen and blood flow. Inflammation and lack of oxygen (resulting from that donut or sugary soda) result in accelerated memory loss.This gives serious meaning to the phrase “eating to forget.”Poor food choices cause poor cognitive functioning: the eight southern states in America that make up the “Stroke Belt” also have higher incidences of obesity and and greater chance of dementia. Of course, many factors are at play when it comes to developing dementia, but lifestyle factors like a high saturated fat diet (from four-legged animal fat, two legged animal skin, palm and coconut oil), coupled with little physical activity, are certainly big contributors to memory problems as well as wrinkles, orgasm decay and heart attacks.MORE: How Your Diet Affects Your Brain A recent study of healthy adults and adults with mild cognitive impairment tested out the effects of two diets. One was the “high diet,” which was high in saturated fat (at least 25 percent of the diet) and simple carbohydrates (glycemic index greater than 70). The other was a “low diet,” which was low in saturated fat (less than 7 percent of the diet) with a fewer simple carbs (glycemic index less than 55).Not surprisingly, the low (low in the food felons) diet improved or made the levels of three important markers of health better for you.Firstly, this diet was associated with decreased plasma lipids (read: less lousy or bad cholesterol). Secondly, the low diet was linked with lower insulin levels. Current research is looking at an optimal insulin dose to help cognitive functioning in people with mild cognitive impairment and Alzheimer’s disease.Lastly, the low in food felons diet lowered CSF F2-isoprostane concentrations, which is a fancy way of saying it lessened the biomarkers of free radical injury, a signal of oxidative damage to, or damaging inflammation in, your central nervous system (the brain and spinal cord).What does this all mean for the bigger picture? After just one month of the low saturated fat/low carbs diet, “visual memory” improved for healthy adults and adults with cognitive impairment. This was a small study of 49 subjects, but the implications have big promise for your enjoyment of life and brain functioning!Starting today, what can you do? Look out for the five food felons, which are guaranteed to age your brain and body. We like to kick the felons totally out, but truth be told,  the felons don’t have to be exiled from your diet—they just have to be put under very close watch.MORE: All About the Five Food Felons Here’s a quick review of how they can age you, so you can steer clear:1) Trans fat: Look out for “partially hydrogenated vegetable oils.” Trans fat alters metabolic processes and hardens your arteries. How much to have? Zilch!2) Saturated fat: Leads to the buildup of fatty tissue on the inner linings of your arteries and turns on inflammatory genes. How much to have? No more than 4 grams per hour.3) Added sugar: Excess sugar causes the proteins in your body to function improperly, aging your arterial system. How much to have? Main dishes and desserts should contain no more than 4 grams of added sugar per serving. Side dishes should contain no more than 2 grams of added sugars per serving. Total should be less than 4 grams added sugar per hour.4) Syrups: All syrups. Not just that high-fructose corn syrup (HFCS)—the man-made sugar that does the same things as sugar—all syrups, like all added sugars  increase the  risk of dysfunctional proteins, obesity and metabolic syndrome. Be wary of maple and malt syrups, as well. How much to have? Stay away! In total, you want to keep you added sugar count to less than 24 grams, or 6 teaspoons per day , and less than (when combined with added sugars) 4 grams of added sugar an hour.5) Any grain but 100-percent whole grain: Whole grains contain a lot of fiber, which helps preventing arterial aging. How much to have? Nada, Never have any—why age unnecessarily? Why forget what your ideal hunk looked like? Anytime you can swap simple carbohydrates for complex carbs with 100-percent whole grain, go ahead!MORE: Avoid Sneaky Sources of Sugar