When I was a kid, my Mom used to tell me to eat fish, it would make me smarter. "What does she know?" I'd grump to myself as I picked at my tuna salad.
A lot, as it turns out.
A new study by Alzheimer's experts at UCLA's Easton Center for Alzheimer's Disease Research confirms that motherly advice. The researchers found that people with low blood levels of the omega-3 fatty acids found in fish not only had smaller brains, they also didn't do as well on memory and cognitive skills tests.
The study, led by Zaldy Tan, M.D., an associate professor of geriatrics, looked at 1,575 older adults, average age 67, who were free of dementia and stroke. Tan and his colleagues compared the subjects' red blood cell levels of two nutrients in omega-3 fatty acids with MRI brain scans and tests designed to measure memory, abstract reasoning, problem-solving and other cognitive skills.
They found that people in the bottom 25 percent for omega-3 levels had slightly smaller brains and scored lower on the mental skills tests.
"People with lower levels of omega-3 fatty acids had lower brain volumes that were equivalent to about two years of brain aging," Tan told cnn.com.
What makes the UCLA study different from past diet-and-dementia research was that it used blood tests to more precisely measure fish oil intake, instead of relying on subjects to fill out food-frequency questionnaires about what they had eaten.
Tan said the MRI scans also showed those with lower omega-3 levels had small structural changes in the brain, including tiny lesions, that would put them at greater risk for death, stroke and dementia.
Previous studies have suggested that eating more fatty fish like salmon and tuna can reduce the risk of Alzheimer's, heart disease and stroke because of the anti-inflammatory properties of the fatty acids in fish oil.
The one thing the new study didn't answer was exactly how much fish or other foods with omega-3 fatty acids a person needs to consume. The most recent federal dietary guidelines recommends eating two servings of fish a week; other health experts have recommended eating it three times a week.
Oily fish, like salmon, mackerel, trout, tuna, sablefish (also called black cod), sardines and herring, offer the highest amount of omega-3 fatty acids, but flaxseed, walnuts, canola oil and some dark green vegetables (like spinach and kale) also contain a form of it.
In other health news:
New at the meat counter -- nutrition labeling. Nutrition labels on raw meat has been voluntary for nearly a decade, but starting today it's mandatory. The new rule from the U.S. Department of Agriculture affects all ground meat and poultry and 40 of the most popular cuts of meat in the U.S., such as chicken breasts, steaks, pork chops, roasts, lamb and veal. If the nutrition facts are not on the package, as in the case of some larger cuts of meat, you should find posters or signs at the meat counter with the information, according to cnn.com.
Old flu drug speeds brain injury recovery. Researchers are reporting the first treatment to speed recovery from severe brain injuries caused by falls and car crashes: a cheap flu medicine whose side benefits were discovered by accident decades ago. Severely injured patients who were given amantadine got better faster than those who received a dummy medicine, the Associated Press reports. After four weeks, more people in the flu drug group could give reliable yes-and-no answers, follow commands or use a spoon or hairbrush - things that few of them could do at the start. Far fewer patients who got amantadine remained in a vegetative state, 17 percent versus 32 percent.
Older adults with lung cancer often get unhelpful radiation. Americans age 65 and up who have surgery for a particular type of lung cancer often have radiation afterward. But a new study suggests that the radiation typically does nothing to extend their lives, reports Reuters.
5 so-called health foods you should avoid. Dietitian Katherine Tallmadge says words on food labels like "reduced-fat," "multigrain," and "natural" can be deceptive. She writes in the Washington Post about five such seemingly healthy foods that really aren't. A couple examples: reduced-fat peanut butter and baked or air-popped chips.
Photo credit: Andrea Pokrzywinski via flickr.com