Healthy Mind

Our reward center in the midbrain gets activated for the prospect of food and available food of a kind we like, so until our sensory-specific satiety mechanism tells us the portion size is sufficient, addictive chemicals are released, such as dopamine, to keep us eating.

A decade or more before memory-related symptoms of Alzheimers disease (AD) appear, disordered processes are underway in the brain - including changes that may affect sense of smell. In a study published in Annals of Neurology, researchers gave 183 community-living older adults cognitive tests to assess brain function, followed by tests of their ability to recognize and remember familiar odors, such as leather, menthol and grape.

Increasingly needing to write yourself reminder notes or repeatedly bumping into furniture after rearranging your living room (spatial memory) is frustrating, to say the least. It also may signal future cognitive decline, including dementia, a catch-all term for memory loss and difficulty with thinking, problem-solving or language, the most common of which is Alzheimer's disease.

You've heard time and again that it's not wise to eat too much red meat, especially if processed, since higher intakes are linked with increased risks of obesity, cardiovascular disease, type 2 diabetes and several cancers. A growing number of studies suggest dietary patterns high in meat may promote cognitive decline, too.

Poor sleep quality and diet may contribute to the early accumulation of the plaques associated with Alzheimer's disease, according to a new review. Part of the reason may involve cortisol, a hormone manufactured by the body that plays a role in regulating many core functions, including sleep.

Two new studies provide important evidence of how physical activity might reduce the risk of Alzheimer's disease and other forms of cognitive decline. One study reported that participants who were most active showed the least decline - the equivalent of 10 years of mental aging. In a second study, the most active older adults were found to have the largest volume of gray matter in brain regions typically affected most by Alzheimer's.

If concerns about mercury in seafood have kept you from the possible brain benefits of consuming more fish, an unusual new study has good news. Researchers did find that older adults who ate more seafood had higher brain levels of mercury - but that toxin was not associated with any signs of dementia. On the other hand, people at greatest genetic risk for Alzheimer's who consumed the most seafood showed less evidence of the diseases damage in the brain.

Science continues to prove Hippocrates right when he said, "Walking is man's best medicine." If youre beginning to lag on your New Year's resolutions, or that Fitbit you got for Christmas is gathering dust, a trio of recent studies provide incentive to get up off the couch and lace up those walking shoes.

While observational studies have shown an association between physical activity and lower rates of mental decline, findings from randomized clinical trials have been mixed. And now the largest and longest such trial has reported surprisingly disappointing results.

Q. I keep seeing ads during the nightly news for a supplement containing a protein originally found in jellyfish thats supposed to protect your memory. Could this really work?