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Exercise may help stave off Alzheimer’s

July 30, 2013
Courtesy of the University of Maryland
and World Science staff

Mod­er­ate ex­er­cise seems to im­prove mem­o­ry func­tion in peo­ple at risk for Alzheimer’s dis­ease, pos­sibly help­ing to ward off symp­toms of the mem­o­ry-robbing ill­ness, sci­en­tists have found.

“No study has shown that a drug can do what we showed is pos­sible with ex­er­cise,” said study lead­er J. Car­son Smith of the Uni­vers­ity of Mar­y­land. The re­search­ers stud­ied peo­ple with a con­di­tion con­sid­ered a risk fac­tor for Alzheimer’s: mild cog­ni­tive im­pair­ment, or MCI, which sig­nals an age-associated mem­o­ry loss that’s great­er than nor­mal.

“After 12 weeks of be­ing on a mod­er­ate ex­er­cise pro­gram, study par­ti­ci­pants im­proved their neu­ral ef­fi­cien­cy – bas­ic­ally they were us­ing few­er neu­ral [brain] re­sources to per­form the same mem­o­ry task,” said Smith. The find­ings are pub­lished in the Jour­nal of Alzheimer’s Dis­ease

Two groups of phys­ic­ally in­ac­tive old­er adults rang­ing from 60-88 years old were put on a 12-week ex­er­cise pro­gram that fo­cused on reg­u­lar tread­mill walk­ing, guid­ed by a per­son­al train­er. Both groups – one with MCI and the oth­er with healthy brain func­tion – im­proved their car­di­o­vas­cu­lar fit­ness by about 10 per­cent, the study found. Both al­so im­proved mem­o­ry per­formance and showed en­hanced “neu­ral ef­fi­cien­cy” dur­ing mem­o­ry tasks.

The re­sults were achieved with ex­er­cise con­sist­ent with the phys­ical ac­ti­vity rec­om­menda­t­ions for old­er adults, the sci­en­tists said. These call for mod­er­ate in­tens­ity ex­er­cise (ac­ti­vity that in­creases your heart rate and makes you sweat, but is­n’t so stren­u­ous that you can’t hold a con­versa­t­ion while do­ing it) on most days for a weekly to­tal of 150 min­utes.

The ex­er­cise in­ter­ven­tion was al­so found to improve word re­call via a “list learn­ing task.” In this, peo­ple were read a list of 15 words and asked to re­mem­ber and re­peat as many words as pos­sible on five con­sec­u­tive at­tempts, and again af­ter a dis­trac­tion of be­ing giv­en anoth­er list of words.

“Peo­ple with MCI are on a very sharp de­cline in their mem­o­ry func­tion, so be­ing able to im­prove their re­call is a very big step in the right di­rec­tion,” Smith said. The re­sults sug­gest that ex­er­cise may re­duce the need for over-ac­tiva­t­ion of the brain to cor­rectly re­mem­ber some­thing, he added.


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Moderate exercise seems to improve memory function in people at risk for Alzheimer’s disease, possibly helping to ward off symptoms of the memory-robbing illness, scientists have found. “No study has shown that a drug can do what we showed is possible with exercise,” said study leader J. Carson Smith of the University of Maryland. The researchers studied people with a condition considered a risk factor for Alzheimer’s: mild cognitive impairment, or MCI, which signals an age-associated memory loss that’s greater than normal. “After 12 weeks of being on a moderate exercise program, study participants improved their neural efficiency – basically they were using fewer neural [brain] resources to perform the same memory task,” said Smith. The findings are published in the Journal of Alzheimer’s Disease. Two groups of physically inactive older adults ranging from 60-88 years old were put on a 12-week exercise program that focused on regular treadmill walking, guided by a personal trainer. Both groups – one with MCI and the other with healthy brain function – improved their cardiovascular fitness by about 10 percent, the study found. Both also improved memory performance and showed enhanced “neural efficiency” during memory tasks. The results were achieved with exercise consistent with the physical activity recommendations for older adults, the scientists said. These call for moderate intensity exercise (activity that increases your heart rate and makes you sweat, but isn’t so strenuous that you can’t hold a conversation while doing it) on most days for a weekly total of 150 minutes. One of the first observable symptoms of Alzheimer’s is inability to remember familiar names. Smith and colleagues had study participants identify famous names and measured their brain activation while engaged in correctly recognizing a name – e.g., Frank Sinatra, or other celebrities well known to adults born in the 1930s and 40s. “The task gives us the ability to see what is going on in the brain when there is a correct memory performance,” Smith said. Tests and imaging were performed both before and after the 12-week exercise intervention. Brain scans taken after the exercise intervention showed a significant decrease in the intensity of brain activation in eleven brain regions while participants correctly identified famous names. The brain regions with improved efficiency corresponded to those involved in the pathology of Alzheimer’s disease, including the precuneus region, the temporal lobe, and the parahippocampal gyrus. The exercise intervention was also effective in improving word recall via a “list learning task,” i.e., when people were read a list of 15 words and asked to remember and repeat as many words as possible on five consecutive attempts, and again after a distraction of being given another list of words. “People with MCI are on a very sharp decline in their memory function, so being able to improve their recall is a very big step in the right direction,” Smith said. The results suggest that exercise may reduce the need for over-activation of the brain to correctly remember something, he added.