Memory loss may be one reason to cut back on meat and dairy products that are high in saturated fat and cholesterol. Researchers at the Medical University of South Carolina and Arizona State University, who collaborated on animal studies that were published in the Journal of Alzheimer's Disease, found that a high-saturated fat, high-cholesterol diet led to impaired working memory in laboratory rats. Knowing that, in humans, working memory loss is associated with inflammation of the brain, which in turn is associated with poor diet, the researchers suggest that a diet high in animal fats may also contribute to memory loss in humans.
Meat and Poultry
Some cuts of meat are higher in saturated fat than others, so to protect against memory loss, choose meat that is lower in saturated fat. For example, beef flank steak contains 3.7 g saturated fat, compared to an equal amount of top round or eye of round, which contains only 1.4 g. A 3-oz. serving of boneless center cut pork chops contains 2.9 g saturated fat compared to the same size serving of pork tenderloin, which contains 1.4 g saturated fat. Dark meat chicken is also higher in saturated fat than light meat. A 3-oz. serving of skinless thigh contains 2.5 g saturated fat, while a 3-oz. serving of skinless breast contains 0.9 g. All animal foods contain cholesterol, especially organ meats such as liver and kidney.
Dairy Products
Butter, cream, whole-milk and 2% milk are high in both saturated fat and cholesterol, so these foods may also contribute to memory loss. Although fat and cholesterol are separate substances, when the fat is removed from a dairy product much of the cholesterol goes with it. One cup of whole milk contains 5 g saturated fat and 24 mg cholesterol, compared to one cup skim milk, which contains no saturated fat and only 5 mg cholesterol. One cup of plain, whole milk yogurt also contains 5 g saturated fat and 32 mg cholesterol, while a cup of low-fat yogurt contains 2 g saturated fat and 15 mg cholesterol. Yogurt made with skim or fat-free milk contains no saturated fat and just 5 mg cholesterol.
Other Foods
While only animal foods like meat and dairy products contain cholesterol, other foods contain both saturated fat and trans fats (partially hydrogenated fats) from hardened vegetable oils. which are also associated with a decline in cognitive functions, such as memory. The typical American eats about 6 g of trans fat daily, while the maximum should be less than 2 g, and the ideal is none, according to Harvard School of Public Health. Foods that contain trans fats include shortenings, margarine and other bread spreads that contain hydrogenated oils, commercial baked goods such as cakes, cookies and other snacks and some fried fast foods. To determine if a food contains trans fats, check the nutrition facts label on the package.
References
- Medical University of South Carolina: MUSC Researchers Link Memory Loss to Poor Diet
- Harvard School of Public Health: Fats and Cholesterol: Out with the Bad, in With the Good
- Pub Med: Annals of the NY Academy of Sciences: Dietary Influences on Cognitive Function with Aging: From High Fat Diets to Healthful Eating
- Boise State University: Skinny Cuts of Meat
