Sex and the Mind's Decline
All you have to do is visit a nursing home to see that Father Time is not as good to women as it might seem: Women may live longer than men, but they are more likely to face Alzheimer's disease. If the recent report in the journal Neurology from the French medical research institute INSERM bears out, Mother Nature may have stepped in by offering up the gift of coffee to protect her daughters' ability to think, remember, and communicate into old age. If its protective effect endures further study, coffee holds a promise of saving aging brains from the onslaught of dementia.
To be precise, over a four-year period, coffee use in excess of three cups a day in patients age 65 and older slowed down cognitive decline. People with mild cognitive impairment—a medical state halfway between normal brain functioning and Alzheimer's disease—have memory difficulties but show none of the deterioration in reasoning, mood, movement, and consciousness that defines life-destroying dementia. Once mild cognitive impairment emerges, however, the odds of Alzheimer's following within four years are at least 40 percent. Notably, many beat those odds, suggesting there's a window of opportunity for stopping or slowing down the pace of mental deterioration.
Cognition can be measured with a variety of tests of verbal recall, fluency, and visual retention. Once performance scores begin to fall, decline moves fastest in older patients and in women. Coffee seems to benefit both groups. In the French study, women over 80 who drank lots of coffee showed 70 percent less cognitive decline than their peers who imbibed a cup or less daily. The reduction was a more modest 27 percent for the younger women, and absent in men.
A shield. It is not the first study to show that coffee is good for some brains. As any aficionado knows, one cup is often enough to bring on a burst of energy and mental focus. But to generate an age-defying benefit in memory or thinking, it takes regular use over many years. This may be explained in part by lab studies showing caffeine can shield certain memory-forming neurons from destruction caused by the toxic amyloid deposits, which are known to accumulate in older brains long before dementia is evident.
What has researchers scratching their heads is why at least some studies show the gender difference. In a 2002 report, performance on a battery of memory and reasoning tests among elderly residents of Rancho Bernardo, Calif., was better among women—but not men—who had the highest lifelong intake of caffeinated coffee. Some researchers surmised that men and women may metabolize coffee differently. Others, that biological sex differences in cognitive decline make women more sensitive to coffee's protection. In the French study, men tended to have more advanced education—but they also scored higher on baseline mental testing than did the women, a fact the researchers tried to take into account. Still, the men may have been less prone to cognitive deterioration from the outset, coffee or no coffee.
This should remind us that using one's brain is a health food in and of itself. It's been long known that dropping out of school early is a risk factor for Alzheimer's later in life. And there is new evidence that regardless of formal schooling, cognitive activity in older individuals exerts its own benefit on brain health, while mental sluggards are more than twice as susceptible to cognitive decline. To be sure, keeping your brain active takes more effort than sipping a Starbucks. But it has none of coffee's side effects, like palpitations or trouble sleeping. So for those who like coffee, why not do both? Enjoy a good book and a cup of joe, or a lively kaffeeklatsch brimming with brainteasing discussion.
As for men, don't give up. The French study continues and just may turn up positive for them, too. Not long ago, researchers from Finland, Italy, and the Netherlands reported that elderly coffee-drinking European men, when followed for a full 10 years, behaved just like women: They had less mental decline with greater coffee consumption. And three cups a day seemed to be the magic number.
So it's quite possible that la difference will vanish with further study. After all, most other health benefits gleaned from a coffee habit—such as a lower incidence of gout, type 2 diabetes, and Parkinson's disease—serve men and women equally. I'd suggest for now that it's only prudent and fair to invite men to the kaffeeklatsch as well.
This story appears in the August 27, 2007 print edition of U.S. News & World Report.