Which fat is best?

Researchers questioned 6,183 senior women about their eating habits to study the relationship between dietary fat and brain (cognitive) function. The women were 65 years of age or older, and participated in tests of brain function beginning five years after providing dietary data. They were retested after an additional four years, which allowed the study authors to look for connections between dietary fat and changes in thinking ability over time.

The results indicated that cognitive functioning and verbal memory were significantly better in women who ate the most monounsaturated fat (approximately 14% of total calories) compared with women eating an average of 8% of calories from monounsaturated fat. Women eating the most monounsaturated fat were also 48% less likely to have the poorest cognitive function and 44% less likely to have the poorest verbal memory compared with women eating the least monounsaturated fat.

On the other hand, cognitive functioning and verbal memory in women eating the most saturated fat (approximately 13% of total calories) were significantly worse compared with women eating an average of 7% of calories from saturated fat. Women eating the most saturated fat were also 64% more likely to have the poorest cognitive function and 65% more likely to have the poorest verbal memory compared with women eating the least saturated fat.

High marks for monos

This study is observational, so it does not prove that saturated fat harms brain health or that monounsaturated fat protects the brain. Still, these results make sense, for, as the study authors point out, “the results regarding saturated fatty acids are similar to those from prior large-scale studies.” We know that too much saturated fat can harm health in a variety of ways, and many health experts believe monounsaturated fat is a better choice. Try these tips to trim the saturated fat and get healthy monounsaturated fat into your diet:

• Know the numbers. This study suggests that eating 7% or fewer calories from saturated fat is a good goal. For a 2,000 calorie diet, this means eating no more than 16 grams of saturated fat per day. If you eat 1,500 calories, this translates to 12 or fewer saturated fat grams daily.
• Munch on monos. This study found that eating 14% of total calories from monounsaturated fat may protect brain health. For a 2,000 calorie diet, this translates to about 31 grams of monounsaturated fat per day, and for a 1,500 diet, this translates to 23 grams daily.
• Snack smart. Nuts and seeds are loaded with healthy monounsaturated fat. Try a handful of almonds, walnuts, or pumpkin seeds, and skip the processed snack foods such as chips, crackers, and cookies.
• Dial in on dinner. Limit the amount of red meat and high fat dairy you eat to a few times per week. Instead, try fish, chicken, or beans for a protein source. When you cook, use olive oil instead of other vegetable fats.

(Ann Neurol 2012; doi 10.1002/ana.23593)