Eating too much junk food does more than just wreak havoc with your weight and your waistline. A growing body of research suggests that diets loaded with cholesterol and saturated fat are bad for your brain.

In an article published in the June issue of the Journal of Alzheimer's Disease, scientists at the Medical University of South Carolina and Arizona State University offered evidence supporting a strong link between diet and brain function. The researchers reported that middle-age laboratory rats consuming a diet rich in cholesterol and saturated fat for just eight weeks showed significant declines in working memory.

Rats fed a high-fat diet were found to have detrimental inflammatory changes in their brains. The scientists concluded that this diet-induced inflammation might also contribute to the loss of hearing and eyesight that typically occurs with advancing age.

Earlier research demonstrated that mice fed high-cholesterol diets had high levels of beta amyloid protein, a finding consistent with Alzheimer's disease. Beta amyloid protein is a sticky substance that accumulates in the brain and interferes with critical cognitive tasks, including thinking, learning and remembering.

The results of the new study suggest that as we age, memory and other brain functions may be improved — or at least maintained — by lowering our intake of foods rich in cholesterol and saturated fats. As an added bonus, eating a low-fat diet can dramatically reduce the risk for other age-related afflictions, such as high blood pressure, type-2 diabetes and heart disease.

Cholesterol and saturated fat are found primarily in animal products, including eggs, beef, pork, poultry and dairy foods. Saturated fats are also found in snack foods and fried foods prepared with coconut oil and palm kernel oil.

According to the American Heart Association, intake of saturated fat should be limited to less than 7 percent of total daily calories. The organization recommends a daily intake of no more than 300 milligrams of cholesterol daily for good health.

While you're cutting back on your intake of saturated fat and cholesterol, it's a good idea to rid your diet of foods rich in trans fats. Found in many snack foods, pastries and fast foods, trans fats can trigger inflammatory changes in the brain and body.

Polyunsaturated and monounsaturated fats are considered to be beneficial fats. Both are rich in omega-3 fatty acids, substances known to help reduce inflammation.

Omega-3 fatty acids are found in nuts and seeds, avocados and olive oil. They're especially abundant in fatty fish, including tuna, mackerel and salmon.

When scientists at Tufts University evaluated the diets of nearly 900 men and women, they found that those whose diets were highest in fatty fish had a significantly lower risk of developing Alzheimer's disease. A study published in the medical journal Archives of Neurology demonstrated that individuals who consumed fish at least once weekly had a 60 percent lower risk of developing Alzheimer's disease compared with those who rarely or never ate fish.

Eating more curried foods can also be good for your brain. Turmeric, an Asian spice used to flavor curry powders, has been shown to help boost brainpower and combat Alzheimer's disease.

In a recent study of more than a thousand elderly adults, researchers evaluated performance on a standard test of cognitive function. Individuals who ate curry often, or even occasionally, scored significantly higher than those who rarely or never consumed the spice.

If you're not a fan of fish or curried foods, adding more fresh produce to your diet is an excellent brain-boosting strategy. While most fruits and vegetables are excellent sources of disease-fighting antioxidants, recent research suggests that the antioxidants in blueberries, known as anthocyanins, are especially potent.

In the brain and body, antioxidants neutralize free radicals — highly reactive molecules that can injure cellular components, particularly the genetic material. Free radical-induced damage, known as oxidative damage, is implicated in memory loss and in the development of Alzheimer's disease.

When researchers at the University of Reading in Pennsylvania and Peninsula Medical School in England fed blueberries to laboratory rats over a 12-week period, the rats exhibited an 83 percent improvement on tests of memory within just three weeks. Scientific evidence suggests that the anthocyanins in blueberries can help prevent or even reverse some age-related memory decline in humans, as well.

Memory loss isn't an inevitable part of aging. Making a few simple changes in your diet can go a long way toward boosting your brainpower and improving your overall health.

Rallie McAllister is a board-certified family physician, speaker and the author of several books, including "Healthy Lunchbox: The Working Mom's Guide to Keeping You and Your Kids Trim." Her website is www.rallieonhealth.com. To find out more about Rallie McAllister, M.D., and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.

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