Natural aging process is associated with some
inevitable changes such as skin wrinkles, crow's feet, and gradual loss of
memory in some people. Memory loss is a common symptom of dementia, which
incidentally is the second most feared disease after cancer. However,
researchers say that people who keep healthy and fit at midlife have the lowest
risk of developing dementia when they grow older.
"We already know exercise has cardiovascular
and many other benefits, but this may give people more incentive to get
moving," lead author, Laura F. DeFina, MD, from The Cooper Institute,
There is a lot of literature on physical activity
and dementia, a 2010 statement from the National Institutes of Health suggested
that evidence was insufficient to promote lifestyle change for brain health
because the studies conducted so far have been small, with short follow-up, and
the definition of patients and of dementia has been inadequate.
The study included 19,458 individuals
participating in the Cooper Clinic Longitudinal Study at the Cooper Institute,
a preventive medicine clinic. All underwent standardized fitness testing in
midlife (median age, 49.8 years) and were then followed for an average of 25
years. Cases of dementia were found from Medicare claims data.
There were 1659 cases of all-cause dementia
reported. After multivariable adjustment, participants with the highest fitness
level (quintile 5) at midlife had a 36% reduction in risk of developing
dementia from any cause during follow-up than those in the lowest fitness
category (quintile 1).
Dr. DeFina added "Another strength of the
study is that, it objectively measured cardio respiratory fitness in a uniform
way (on a treadmill) in all participants. Normally studies looking at physical
activity rely on self-reported exercise which is notoriously inaccurate."
Dr. DeFina also pointed out that the reduction in
dementia was consistent in patients who had had a stroke and in those who
hadn't, suggesting that the mechanism does not just involve vascular disease.
"Exercise is known to reduce cardiovascular disease, which we would expect
to be translated into benefit on stroke, but because there was a similar
reduction in dementia with improved fitness in patients who hadn't had a stroke,
this suggests that other mechanisms are also involved."
She added that animal studies have suggested that
increased fitness and activity correlates with a reduction in brain atrophy and
loss of cognition, and changes in amyloid have been seen with regular activity.
Never Too Late to Start
The researchers believe that although it is best
to achieve fitness earlier in life and keep it up throughout life, benefits
could still be seen in people starting later. Dr. DeFina noted: "It is
never too late to improve fitness. If you're not 49, there are still functional
benefits of being active in your later years."
For now, it seems that staying fit is your best chance
to ward off dementia and keep it at bay. Take care of your body; after all it's
the only place you have to live!