Incipient's article
Source: MedicalXpress
Older people who regularly walk, garden, swim or dance may have
bigger brains than their inactive peers, according to a preliminary
study to be presented at the American Academy of Neurology's 72nd Annual
Meeting in Toronto, Canada, April 25 to May 1, 2020. The effect of
exercise was equal to four fewer years of brain aging.
The study used magnetic resonance imaging (MRI) scans to measure the brains of people with a range of activity levels, including those who were inactive to those who were very active. The scans showed less active people had smaller brain volume.
"These results are exciting, as they suggest that people may potentially prevent brain shrinking and the effects of aging on the brain simply by becoming more active," said study author Yian Gu, Ph.D., of Columbia University in New York and a member of the American Academy of Neurology.
"Recent studies have shown that as people age, physical activity may reduce the risk of cognitive decline and dementia. Our study used brain scans to measure the brain volumes of a diverse group of people and found that those who engaged in the top third highest level of physical activity had a brain volume the equivalent of four years younger in brain aging than people who were at the bottom third activity level."
The study involved 1,557 people with an average age of 75. None had dementia, but 296 people had mild cognitive impairment and 28% had the APOE gene that is linked to a greater risk of Alzheimer's disease.
Participants were given physical exams, thinking and memory tests, and were asked about their daily tasks and other physical activities. Researchers then calculated how much time and energy each person spent on those tasks and activities.
Researchers divided people into three groups: those who were inactive; those who were somewhat active meaning each week they either had roughly two-and-a-half hours of low-intensity physical activity, one-and-a-half hours of moderate physical activity or one hour of high-intensity physical activity; and those who were most active meaning each week they either had seven hours of low-intensity physical activity, four hours of moderate physical activity or two hours of high-intensity physical activity.
Researchers then reviewed MRI brain scans of all participants and found that when compared to the people in the inactive group, those who were most active had larger total brain volume.
After adjusting for age, sex, education, race/ethnicity and APOE gene status, the average brain size for those who were inactive was 871 cubic centimeters compared to 883 cubic centimeters for those who were most active, a difference of 12 cubic centimeters, or 1.4%, or the equivalent of nearly four years of brain aging. The results remained similar even after excluding people who had mild cognitive impairment.
"Our results add to the evidence that more physical activity is linked to larger brain volume in older people," said Gu. "It also builds on evidence that moving your body more often throughout one's life may protect against loss of brain volume."
A limitation of the study was that information on physical activity
relied on a person's ability to remember how often and for how much time
they were active. Additionally, Gu noted that due to the particular
study design, this study does not prove that exercise prevents brain
shrinkage; it shows an association.
Source: British Medical Journal
And among women, a higher number of sexual partners is also linked to heightened odds of reporting a limiting long term condition, the findings indicate.
Few studies have looked at the potential impact of the number of sexual partners on wider health outcomes.
To try and plug this knowledge gap, the researchers drew on information gathered for the English Longitudinal Study of Ageing (ELSA), a nationally representative tracking study of older adults (50+) living in England.
In 2012-13, participants were asked how many sexual partners they had had. Complete data were provided by 5722 of the 7079 people who responded to this question: 2537 men and 3185 women. Responses were categorized as 0-1; 2-4; 5-9; and 10 or more sexual partners.
Participants were also asked to rate their own health and report any long standing condition or infirmity which impinged on routine activity in any way.
Other relevant information obtained included: age; ethnicity; marital status; household income other than a pension; lifestyle (smoking, drinking, physical activity); and presence of depressive symptoms.
The average age of participants was 64, and almost three out of four were married. Some 28.5% of men said they had had 0-1 sexual partners to date; 29% said they had had 2-4; one in five (20%) reported 5-9; while 22% reported 10 or more.
The equivalent figures for women were: just under 41%; 35.5%; just under 16%; and just under 8%.
In both sexes, a higher number of sexual partners was associated with younger age, single status, and being in the highest or lowest brackets of household wealth.
Those who reported a higher tally of sexual partners were also more likely to smoke, drink frequently, and do more vigorous physical activity on a weekly basis.
When all the data were analyzed, a statistically significant association emerged between the number of lifetime sexual partners and risk of a cancer diagnosis among both sexes.
Compared with women who reported 0-1 sexual partners, those who said they had had 10 or more, were 91% more likely to have been diagnosed with cancer.
Among the men, those who reported 2-4 lifetime sexual partners were 57% more likely to have been diagnosed with cancer than were those who reported 0-1. And those who reported 10 or more, were 69% more likely to have been diagnosed with the disease.
While the number of sexual partners was not associated with reported long standing conditions among the men, it was among the women.
Women who reported 5-9 or 10+ lifetime sexual partners were 64% more likely to have a limiting chronic condition than those who said they had had 0-1.
This is an observational study, and as such, can't establish cause. Nevertheless, the findings chime with those of previous studies, implicating sexually transmitted infections in the development of several types of cancer and hepatitis, suggest the researchers.
They didn't obtain information on the specific types of cancer participants reported, but speculate: "...the heightened risk of cancer might be driven by those types known to be associated with [sexually transmitted infections]."
And they suggest that inquiring about the number of sexual partners might complement existing cancer screening programmes by helping to identify those at risk, if further research can establish a causal association between the number of sexual partners and subsequent ill health.
But an explanation for the gender difference in long term condition risk remains "elusive," they write, especially given that men tend to have more lifetime sexual partners than women, while women are more likely than men to see a doctor when they feel ill, so potentially limiting the associated consequences for their long term health.
