"The Effects of Obesity on Dementia, Brain Function, and Fertility"
In the ABCs of health consequences of obesity, if A is for Arthritis,
and B is for Back Pain and Blood Pressure, C is for Cancer,
and D is Diabetes, then E is for Encephalopathy.
Encephalopathy means brain disease.
There’s consistent data linking obesity in middle age
to higher risk of dementia later in life.
Overweight individuals have about a third higher risk,
and those who are obese in mid-life seem to have about
90% greater risk of becoming demented.
The risk isn’t just limited to future dysfunction, though.
People with excess body weight don’t appear to think
as clearly at any age.
Obese individuals show broad impairments in what are called
executive functions of the brain, such as working memory,
decision-making, planning, cognitive flexibility, and verbal fluency.
These “play a critical role in everyday life.”
People may think about their obesity and the resulting stigma
they experience as much as five times an hour,
but the cognitive deficits do not appear to rise
just from distraction; there are structural brain differences
between normal weight and overweight individuals.
A review entitled “Does the brain shrink as the waist expands?”
noted gray matter atrophy across all ages
among those carrying excess body fat.
This reduced brain volume has then been correlated
with the lower executive function.
Compromised integrity of the rest of the brain—the white matter—
suggests accelerated brain aging,
even in young adults and children with obesity.
Cognitive deficits in young populations suggest it’s something
about the obesity itself that’s affecting brain function,
rather than a later clinical consequence such as high blood pressure.
Purported mechanisms for this executive dysfunction
include obesity-related inflammation and oxidative stress.
So, does weight loss improve cognitive function?
Based on a meta-analysis of 20 studies, mental performance
across a variety of domains can be significantly improved
with even modest weight loss; though, no studies have yet to be done
to determine if this then translates into
a normalization of Alzheimer's disease risk.
F is for Fertility, or rather failed fertility.
Overweight couples struggling to have children
“should be educated on the detrimental effects of fatness,”
one meta-analysis concluded, as weight loss is associated with
an improvement in pregnancy rates among infertile women.
Men also may suffer impaired fertility.
The heavier a man is, the greater the risk of having
a low sperm count or being completely sterile.
This may in part be due to the effects
of excess body fat on testosterone levels.
Fat isn’t just the primary site of estrogen production
in postmenopausal women, but in men as well.
There’s an enzyme in body fat that actually converts
testosterone into estrogen.
Men even going from obese to just overweight could potentially
raise testosterone levels in their blood 13%.
A more dramatic cause of infertility in obese men is called
“hidden penis.” Also referred to in the medical literature
as buried penis, concealed penis or inconspicuous penis.
It occurs when excess fat in the pubic area subsumes the male member
(since the base of the penis is attached internally to the pubic bone).
It’s also called trapped penis, because the moist enfolding skin
surfaces can result in a chronic inflammatory dermatitis
leading to scarring, requiring a surgical intervention.
So, “F” may also stand for Free Willy.