People who
drank moderately over the course of decades had a 66% lower rate of
beta-amyloid deposits in their brains compared to nondrinkers
Moderate
drinking was defined as one to 13 standard drinks a week, with a
standard drink defined as 12 ounces of beer, 5 ounces of wine or 1.5
ounces of hard liquor
Because the
study relied on participants’ recall for alcohol drinking history and
was observational in nature, it does not prove that alcohol consumption
caused the reduction in beta-amyloid
Separate research suggests consuming alcohol may accelerate brain aging and contribute to dementia and cognitive decline
There are many
other foods and beverages you can consume that are linked to positive
brain health without the risks associated with drinking alcohol
Excess alcohol consumption is known to
harm brain health. In the case of binge drinking or heavy alcohol
consumption, it may even make it more likely that your brain may
accumulate damaging beta-amyloid proteins, potentially contributing to
the development of Alzheimer's disease.1
However, controversy remains over whether all alcohol consumption is
harmful, with some research suggesting that moderate intake may instead
have a protective effect.
Preclinical studies from both animal and cell culture models have
shown that consuming moderate amounts of alcohol may be protective
against Alzheimer's by attenuating beta-amyloid production, but little
is known about how this affects beta-amyloid deposition in the human
brain — leading researchers to conduct a study to find out.2
Moderate Drinkers Had Less Beta-Amyloid in the Brain
Researchers from Seoul National University College of Medicine
conducted a study involving 414 middle- and old-aged individuals who
were free from dementia and did not have an alcohol-related disorder.
The participants were interviewed about their current and past alcohol
intake and had brain imaging to check for Alzheimer's disease pathologies.
Moderate drinking was defined as one to 13 standard drinks a week,
with a standard drink defined as 12 ounces of beer, 5 ounces of wine or
1.5 ounces of hard liquor. Those who drank moderately over the course of
decades indeed saw benefits, with a 66% lower rate of beta-amyloid
deposits in their brains compared to nondrinkers.3
Those who recently started drinking moderately did not have the same
results, however, nor did those who drank more than 13 standard drinks a
week. According to the study:4
"We observed that moderate lifetime alcohol intake (i.e., 1–13
standard drinks [SDs]/week) was significantly associated with lower
amyloid deposition compared to no drinking, whereas current alcohol
intake did not affect amyloid deposition.
The present findings from middle- and old-aged individuals with
neither dementia nor alcohol-related disorders suggest that moderate
lifetime alcohol intake may have a beneficial influence on AD by
reducing pathological amyloid deposition."
Because the study relied on participants' recall for alcohol drinking
history and was observational in nature, it does not prove that alcohol
consumption caused the reduction in beta-amyloid. However, the study's
senior author, Dong Young Lee, told The New York Times, "In people
without dementia and without alcohol abuse or dependency, moderate
drinking appears to be helpful as far as brain health is concerned."5
Other Brain Benefits of Moderate Drinking
Other studies have also found benefits to moderate amounts of alcohol
on the brain, including one published in the journal Scientific
Reports.6
While high alcohol exposure increased brain inflammation and impaired
function of the glymphatic system, which removes waste products from the
brain, acting as a "brainwide metabolite clearance system,"7 moderate drinking had the opposite effect.
Surprisingly, drinking the equivalent of about 2.5 alcoholic drinks a
day not only reduced brain inflammation in mice but also increased
function of the glymphatic system.8 By pumping cerebral spinal fluid through your brain's tissues, your glymphatic system flushes waste from your brain back into your circulatory system and liver for elimination.
The findings should be taken with a grain of salt, with researchers
noting, "Naturally, this study performed in mice should not be viewed as
a recommendation for alcohol consumption guidelines in humans."
What's more, there's still much to be learned, as while low-to-moderate alcohol intake has been associated with a lower risk of dementia,
heavy drinking may enhance cognitive decline. Further, the researchers
noted, "Daily intake of alcohol for 30 years at doses scalable to those
in the present study reduces human hippocampal volume by 3.4% to 5.8%
compared to abstainers."9
Adding to the controversy over whether or not modest amounts of
alcohol are a good thing, a study of 9,000 adults that took place over
23 years found a sweet spot of sorts in terms of alcohol consumption and
dementia.10
Both heavy drinkers and abstainers had a higher risk of dementia than
moderate drinkers, which was defined as no more than 14 units of
alcohol a day, or roughly one medium-sized glass of wine or pint of beer
daily. Separate research found that light-to-moderate alcohol intake,
especially wine, was associated with larger total brain volume,
suggesting it is potentially beneficial for brain aging.11
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Is Moderate Drinking Harmful?
Despite some of the positive findings, I do not recommend chronic
drinking, regardless of the amount. As demonstrated in the BBC
investigation above, drinking tends to do far more harm than good, even
if you're within guidelines for "moderate" alcohol consumption.
In the film, using identical twin brothers as guinea pigs, they each
drink 21 units of alcohol over differing time scales — one consumes them
all in one night while the other has three drinks per day over the
course of a week. Twenty-one units amounts to three-quarters of a bottle
of whiskey, two bottles of wine or 10.5 pints of beer.
The test continues for a month. Medical tests before and after
assesses the physical effects and potential damage. Overall, the tests
reveal that alcohol consumption is quite detrimental in general, no
matter how it's consumed. Even the doctor was surprised at how bad
moderate drinking was, considering it's within the U.K. guidelines for
alcohol consumption.
Whether or not a smaller amount of alcohol would have had a different
effect is unknown, but there exists a wealth of data showing that
alcohol can damage your body, including your brain.
Daily Drinking Accelerates Brain Aging
Drinking even 1 gram of alcohol daily is enough to accelerate aging
in your brain, according to one of the largest studies ever conducted on
brain aging and alcohol.12
Researchers from the University of Southern California examined
17,308 human brain scans from people between 45.2 years and 80.7 years
old, revealing that each additional gram of alcohol consumption per day
was associated with 0.02 years, or 7.5 days, of increased relative brain
age (RBA), which is a measure of a person's brain age relative to their
peers, based on whole-brain anatomical measurements.
One gram of alcohol is equal to 0.035 ounces, and most people who
drink alcohol are going to consume 1 ounce or more, which is equal to
approximately 29 grams — an amount that would increase RBA by 0.58
years, or 211.5 days.
It could be that daily, or almost daily, drinking is part of the
problem, as the study did not find a significant difference in RBA among
those who drank less frequently or abstained from drinking.
A 2019 review published in Frontiers in Neuroscience also addressed
the complex interplay between alcohol consumption and cognitive decline,
noting that chronic alcohol abuse leads to "changes in neuronal
structure caused by complex neuroadaptations in the brain."13
Does Alcohol Really Reduce Alzheimer's Risk?
As mentioned earlier, heavy drinking may contribute to the development of Alzheimer's,14
but the featured study suggested that moderate drinking may decrease
the condition. However, this was based on the finding that alcohol
consumption reduction beta-amyloid in the brain. Whether or not this
translates to a reduced risk of Alzheimer's is also controversial.
With no known cure, researchers are scrambling to find Alzheimer's
treatments, often with a misguided focus on drugs designed to remove
excess beta-amyloid in the brain. Drug development for Alzheimer's has so far been a dismal failure, with 300 failed trials to date.15
Now, with experimental drugs failing to lead to improvements,
researchers are asking if the focus on drugs to target and neutralize
beta-amyloid in the brain is all wrong, and other potential targets
should become the focus of future research.16
The reason why beta-amyloid drugs continue to fail to improve
Alzheimer's disease, however, is because beta-amyloid is a symptom of
Alzheimer's — not the cause. And when you consider this, then it's
possible that moderate drinking may not actually reduce Alzheimer's risk
just because it reduces beta-amyloid deposits.
Alzheimer's has many causes, as discussed by Dr. Dale Bredesen,
professor of molecular and medical pharmacology at the University of
California, Los Angeles School of Medicine, and author of "The End of
Alzheimer's: The First Program to Prevent and Reverse Cognitive
Decline."17
Bredesen's ReCODE protocol evaluates 150 factors, including
biochemistry, genetics and historical imaging, known to contribute to
Alzheimer's disease. This identifies your disease subtype or combination
of subtypes so an effective treatment protocol can be devised. An
algorithm is used to determine a percentage for each subtype based on
the variables evaluated, and an individualized treatment protocol is
created.
Exercise Is Important if You Drink Alcohol
Exercise is important for everyone, but if you consume alcohol
getting physical activity may help to buffer some of alcohol's ill
effects. According to a report published in the International Review of
Neurobiology:18
"There are vast literatures on the neural effects of alcohol and
the neural effects of exercise. Simply put, exercise is associated with
brain health, alcohol is not, and the mechanisms by which exercise
benefits the brain directly counteract the mechanisms by which alcohol
damages it."
Indeed, chronic drinkers who exercise regularly have less damaged
white matter in their brains compared to those who rarely or never
exercise.19
The white matter is considered the "wiring" of your brain's
communication system and is known to decline in quality with age and
heavy alcohol consumption.
Even among chronic drinkers, those who got at least 2.5 hours a week
of moderately intense exercise significantly reduced the biological
impact of their drinking,20 including reducing some of the cancer and all-cause mortality risks associated with alcohol drinking.21
Should Moderate Alcohol Be Advised for Brain Health?
Even though some research suggests moderate alcohol intake may have a
protective effect on some measures of health, I do not recommend
drinking alcohol, especially if your purpose is to obtain better health.
There are many other foods and beverages you can consume that are
linked to positive brain health but do not have the corresponding
downside that alcohol does.
Whole, healthy foods are best when it comes to protecting your brain, and this includes foods like animal-based omega-3 fats, cruciferous vegetables and leafy greens, pastured organic eggs and blueberries.
As for beverages, organic coffee and tea consumption has shown some
promise, and drinking one to two cups of coffee daily may lower your
risk of Alzheimer's disease and other forms of dementia, cognitive
decline and cognitive impairment compared to drinking less than one cup.22
If you choose to drink alcohol, keep your consumption to moderate
levels or less, and if you don't, do not feel compelled to start
drinking to stay healthy — there are plenty of other ways to do that.
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