Aerobic Exercise Preserves Cognition in Nondemented Elderly

Pauline Anderson

May 01, 2014

PHILADELPHIA — Continuous long-term aerobic activity has a protective effect on cognitive status and psychomotor speed in nondemented elderly, a new study has found.

"We recommend daily low-impact aerobic physical activity in older people who are able to do this type of exercise," said lead researcher Manuel Seijo-Martinez, MD, Neurology Hospital do Salnes Pontevedra, Spain.

Dr. Seijo-Martinez presented the findings here at the American Academy of Neurology (AAN) 66th Annual Meeting.

Continuous Cycling

The analysis included 39 older individuals who were in geriatric institutions. Of these, 22 patients (8 women and 14 men; mean age, 77.94 years) had been randomly assigned to the exercise group and 17 patients (7 women and 10 men; mean age, 83.59 years) to a control group.

Researchers had originally recruited close to 500 participants, but most did not complete the study because of death or unwillingness or physical inability to carry out the continued aerobic activity, said Dr. Seijo-Martinez.

Patients in the experimental group completed at least 15 minutes of aerobic activity in the form of continuous stationary cycling every day for 15 months. The mean weekly exercise duration in this group was 134.21 minutes, or roughly 18 minutes a day.

Those in the control group carried out nonphysical activities, such as reading and playing cards.

Researchers assessed cognition using 3 tests:

  • The MEC, which is the Spanish version of the Mini-Mental State Examination but includes 3 items that analyze executive function; thus, it is "a little bit more complete," according to Dr. Seijo-Martinez. (The cutoff score for dementia on this test is 24.)

  • The Fuld Object Memory Evaluation (FOME)

  • The Symbol Digit Modality Test (SDMT), which measures psychomotor speed and attention

The study showed that compared with the control group, the exercise group had improved cognitive status according to the MEC score (P = .037).

"There was a statistically significant worsening in the control group in terms of global cognition; however, the experimental group improved," said Dr. Seijo-Martinez.

The exercise group, which initially did worse than the control group on the SDMT, improved significantly in the assessment of psychomotor speed (P = .011).

There was no significant difference between the groups on the FOME test of memory and learning, said Dr. Seijo-Martinez.

"We conclude that the practice of continuous long-term aerobic physical exercise seems to have a neuroprotective effect on cognitive status and psychomotor speed in elderly nondemented individuals," said Dr. Seijo-Martinez.

The research group is planning a large study using genetic markers and MRI to measure hippocampal volume in the same nondemented population of older patients who exercise, said Dr. Seijo-Martinez.

He and his research colleagues have collected data on the effect of daily aerobic activity on older persons with mild cognitive impairment (MCI) and dementia. Although the results are yet to be presented, Dr. Seijo-Martinez said that it looks like an exercise intervention has a positive cognitive benefit in these patients.

"Maybe it won't reverse MCI, but it might help maintain cognition or delay the start of dementia."

Greatest Impact

Invited to comment on this new research, Maria Carrillo, PhD, vice president, medical and scientific relations, Alzheimer's Association, said that regular physical activity, including exercise, may prove to be a beneficial strategy to lower the risk for Alzheimer's disease and vascular dementia.

"Physical activity may have its greatest impact on brain health through its positive effects on heart health," she told Medscape Medical News. "Some evidence suggests physical activity may directly benefit brain cells by increasing blood and oxygen flow. Because of the known cardiovascular benefits, a medically approved exercise program is a valuable part of any overall wellness plan."

Growing evidence shows that physical activity doesn't have to be strenuous or even require a major time commitment, added Dr. Carrillo. "It's most effective when done regularly, and in combination with a brain-healthy diet, mental activity and social interaction."

At this point, more research is needed, especially in large, diverse populations, to find out exactly what types of physical activity, and in what amounts, may be specifically beneficial against Alzheimer's disease and other dementias, she added.

American Academy of Neurology (AAN) 66th Annual Meeting. Abstract P1.004. Presented April 28, 2014.


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