Combination of Physical Exercise and Computer Use Protective Against MCI in Late Life

Caroline Cassels

April 19, 2010

April 19, 2010 (Toronto, Ontario) — Combining moderate physical exercise with computer use, even in late life, may help reduce the risk of mild cognitive impairment (MCI), new research suggests.

Presented here at the American Academy of Neurology 62nd Annual Meeting, the latest findings from the Mayo Clinic Study of Aging show the combination of these 2 activities had a benefit that was over and above the beneficial effect of either activity alone.

Dr. Yonas E. Geda.

"Moderate physical exercise, such as brisk walking, biking, and swimming, may be beneficial in terms of reducing the risk of MCI, and we also know that mentally stimulating activities also reduce the risk of dementia or cognitive impairment. What our study showed is that when you combine moderate physical exercise and computer use there is an additive beneficial effect," principal investigator Yonas E. Geda, MD, MSc, a neuropsychiatrist and an associate professor of psychiatry and neurology at the Mayo Clinic in Rochester, Minnesota, told Medscape Psychiatry.

A number of studies have shown that exercise reduces the risk for Alzheimer's disease, and a recent study by Dr. Geda and colleagues published in the January 2010 issue of Archives of Neurology (2010;67:80-86) also demonstrated that any frequency of moderate exercise — which includes activities such as brisk walking, swimming, and cycling — performed in middle or late life also reduces the odds of developing MCI.

Another study also conducted by Dr. Geda and colleagues from the Mayo Clinic Study of Aging (MCSA) suggests mentally stimulating activities, such as craft activities (eg, quilting, knitting), reading books, playing games, and participating in computer activities, are associated with up to 50% decreased risk of developing MCI. These data were presented at the 61st annual conference of the American Academy of Neurology in Seattle, Washington, in April 2009.

In addition, the same team in the same study sample observed that increased caloric intake may increase the odds of developing MCI.

However, said Dr. Geda, it is not clear whether there is an added benefit when physical activity and mentally stimulating activities are combined after controlling for caloric intake and other relevant covariates.

Additive Interaction

To examine the joint effects of physical exercise and mental activity on the odds of developing MCI after adjusting for caloric intake, medical comorbidity, and other traditional confounders, the researchers conducted a case-control study derived from the population-based Mayo Clinic Study of Aging.

The study population included a sample of 926 elderly participants aged 70 to 90 years. Of these individuals, 817 were cognitively normal and 109 had MCI. Surveys gathering data on physical exercise cognitive activities and caloric intake for the previous year were administered.

Multivariable-adjusted analysis revealed that any frequency of moderate physical exercise in late life vs none and any computer use in late life vs none was associated with an odds ratio (OR) of 0.64 (95% confidence interval [CI], 0.42 – 0.98; P = .04) and 0.56 (95% CI, 0.36 – 0.89; P = .01), respectively.

In addition, the investigators found that compared with subjects who consumed 600 to 1526 calories per day, those who consumed 1526 to 2143 calories per day had a 7% increased risk of developing MCI (OR, 1.07; 95% CI, 0.61 – 1.88; P = .80), whereas those who consumed between 2143 and 6000 calories per day more than doubled their MCI risk (OR, 2.03; 95% CI, 1.21 – 3.41; P = .007).

The investigators also observed an additive interaction between moderate physical exercise and computer use (P = .01).

"This combined benefit of physical exercise and computer use is over and above the expected arithmetic sum of the two. This means you get a benefit from physical exercise and a benefit from mentally stimulating activities. Each of these is independently beneficial, but when you do them in combination the effect is even better," said Dr. Geda.

Although researchers did not examine the type and duration of computer use, Dr. Geda said that unfortunately we did not collect the type and duration of the computer use.

Potential Mechanism

At this point the mechanism is unclear, he added. However, some researchers have suggested that mentally stimulating activities may enhance synaptic activity, whereas physical exercise may increase blood flow to the brain and the 2 in combination may have a synergistic effect. However, added Dr. Geda, at this point the mechanism remains speculative.

A major limitation of the study is its cross-sectional design, and therefore, said Dr. Geda, the findings need to be replicated in a prospective cohort study.

Although no clinical recommendations can be derived from this study alone, these results, in combination with the results of a growing body of literature, support the premise that there is value in "advising patients — even elderly adults — to be more physically and mentally active and to be mindful of their caloric intake," he said.

Dr. Geda has disclosed no relevant financial relationships. The study was funded by the National Institutes of Health.

American Academy of Neurology (AAN) 62nd Annual Meeting: Abstract S44.004.


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