Value of Brain Exercises Questioned

Crossword puzzles, crafts and other mentally stimulating pastimes — with the notable exception of watching TV — have been associated with less cognitive impairment in old age.

But are these activities offering the brain direct protection or are they simply markers of a healthy lifestyle? It might be the latter, some researchers think.

Dr. Yonas Geda of the Mayo Clinic and his colleagues asked 1,321 randomly-selected people between the ages of 70 and 89 to complete a survey about their mid- and late-life cognitive activities, such as reading, playing games and quilting. About 15 percent of the participants had been diagnosed with mild cognitive impairment. The long-term cognitive habits of this subgroup were found to be more limited, and include more television, than those of healthy participants.

The results are set to be presented in April at the annual meeting of the American Academy of Neurology in Seattle.

Use it or lose it?

There are several explanations for this correlation. One is the popular "use it or lose it" theory. Just as physical exercise keeps our bodies strong and limber, mental activity may keep our brains flexible and adept at memory formation.

But cognitive impairment begins decades before it is diagnosed. One study in Scotland even linked future dementia risk with IQ at age 11. Therefore, when analyzing this sort of correlation, "you don’t know which one is the egg, which one is the chicken," Geda said.

In other words, watching TV for more than seven hours a day may take a toll on the brain. Or a dulled brain could simply be more attracted to the tube. Or both.

Margaret Gatz of the University of Southern California cautioned against believing that crossword puzzles will save you from dementia. Gatz, who was not involved with Geda’s research, has studied dementia in twins for 20 years.

She points out that if you regularly, say, play solitaire, you will remain relatively good at solitaire as you age. However, your solitaire skills may not protect other brain functions, such as remembering what is on your calendar next week.

Move it or lose it

Also, as with most correlations, "it is really hard to control all the variables," Gatz said. For example, people who like mental activity may be more likely to eat nutritiously and exercise regularly.

Indeed, the effect of physical health on cognition is much better established than the protective benefits of brainteasers and intellectual pursuits, Gatz said. Vascular risk factors — such as hypertension, being overweight and mid-life diabetes — can slowly damage the brain and result in memory impairments.

Physical exercise, on the other hand, has clear brain benefits. When people tell Gatz they feel guilty about neglecting their crossword puzzles, she encourages them to go for a walk instead.

Geda also emphasized the value of getting out of your chair. He even takes it a step further, expecting "a synergistic interaction between intellectual activity and physical exercise," which could result in a multitude of benefits.

Don’t stress about it

Of course, if you enjoy doing puzzles, there is no harm in them — especially if you find them relaxing. But Gatz, who is often called "the crossword curmudgeon," worries "there could be harm in turning this into a prescription." Putting undue emphasis on preliminary correlations may result in feelings of guilt or blame among patients and their families, she said.

Alzheimer's disease, in particular, may involve different biological pathways than normal age-related cognitive decline. At least half of a person’s susceptibility to Alzheimer's is due to genes such as the E4 variant of the gene APOE (apolipoprotein E), Gatz said. "And the people who get the greatest benefit from lifestyle changes do not have E4," she said.

As for the possible benefits of activities such as reading, gaming and pursuing hobbies, Gatz hypothesized one under-explored pathway: stress reduction.

"Stress bathes the hippocampus in bad chemicals," she said, referring to the seahorse-shaped brain structure that is heavily involved in memory. Leisure activities therefore may delay memory impairment simply by reducing overall stress. So, if the Saturday crossword gives you a headache, your mind might get a better workout in the park.

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