In a study that tracked more than 6,000 women aged 65 and older for 10 years, the average participant consumed about 175 mg of caffeine a day. Those who got more than that were 26 percent less likely to show signs of cognitive impairment or dementia than those who got less caffeine.
But in a 2010 meta-analysis of seven studies that lasted an average of about 10 years, people who reported consuming more caffeine had no lower risk of dementia or cognitive impairment.
“The studies on caffeine and dementia are intriguing,” says Martha Clare Morris, a nutritional epidemiologist at Rush University in Chicago. “But the findings are all over the place and are not consistent enough for us to be confident that there’s really an association there.”
Coffee consumption typically declines in older age, notes Morris. “The people who choose to continue to drink coffee may be different from those who choose not to, and it’s this difference and not caffeine that may matter more.”
A new study of diet and the brain
Martha Clare Morris is spearheading a new study, called The MIND Trial, that will test the effect of a nutritious diet on the cognitive health of older adults with a family history of dementia. The diet emphasizes natural plant-based foods and limited amounts of animal foods or other foods high in saturated fat. It also includes green leafy vegetables and fruits that may be especially protective for the brain.
Participants must be 65 to 84 years old, overweight or obese, looking to improve their diets, and who are cognitively healthy but have dementia in their family.
The two study centers are at Rush University in Chicago and Harvard University in Boston. Participants must be able to travel to one of these sites at least six times during the three-year study for lab work and questionnaires. There will also be group sessions and cooking demonstrations that participants will be able to attend throughout the study.
For more information, visit mind-diet-trial.org or call 708-660-6463 in Chicago or 617-998-6333 in Boston.
Sources: J. Gerontol. A Biol. Sci. Med. Sci. 71: 1596, 2016; J. Alzheimers Dis. 20: S187, 2010.
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