The Importance of B Vitamins for
Brain Health and Combating Dementia
March 17, 2016
Story at-a-glance
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Recent research found that giving a multivitamin
supplement to seniors suffering from mild cognitive
impairment and depression helped improve both
conditions
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Compared to placebo, seniors with high omega-3
levels who were given high doses of vitamins B6,
folic acid (B9) and B12 experienced a 40 percent
reduced brain atrophy rate over the 2-year treatment
course
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Not only do B vitamins slow brain shrinkage, but
they specifically slow shrinkage in brain regions
known to be most severely impacted by Alzheimer's
disease
By Dr. Mercola
A number of studies have investigated the impact of vitamin
supplementation to prevent and/or treat cognitive dysfunction and
decline.
It's well-established that healthy fats such as animal-based
omega-3 fats are really important for brain health, but other
nutrients such as vitamins are also necessary for optimal brain
function.
Most recently, a Korean study1
concluded that giving a multivitamin supplement to seniors suffering
from mild cognitive impairment and depression helped improve both
conditions.
B vitamins in particular, especially folate (B9, aka folic acid
in its synthetic form) and vitamins B6 and B12, have made headlines
for their powerful role in preventing cognitive decline and more
serious dementia such as
Alzheimer's disease.
Mental fogginess and problems with memory are actually two of the
top warning signs that you have vitamin B12 deficiency, indicating
its importance for brain health.
B Vitamins and Omega-3 — An Important Combo for Brain Health
Although Dr. Michael Greger's video is a good review on the
research about B vitamins, being a vegetarian he does not include
information about animal-based omega-3 fats, which are also
beneficial in reducing dementia.
Low plasma concentrations of omega-3 and high levels of the amino
acid homocysteine are associated with brain atrophy, dementia, and
Alzheimer's. Vitamins B6, B9, and B12 help convert homocysteine into
methionine — a building block for proteins.
If you don't get enough of these B vitamins, this conversion
process is impaired and as a result your homocysteine levels
increase. Conversely, when you increase intake of folic acid
(folate), vitamin B6, and vitamin B12, your homocysteine levels
decrease.
In one placebo-controlled trial2
published in 2015, 168 seniors diagnosed with mild cognitive
impairment were randomly assigned to receive either placebo, or
daily supplementation with 0.8 mg of folic acid, 20 mg of vitamin
B6, and 0.5 mg of B12.
It's worth noting that these are quite high doses — far above the
U.S. RDA. All participants underwent cranial magnetic resonance
imaging (MRI) scans at the outset of the study, and at the end, two
years later.
The effect of the vitamin B supplementation was analyzed and
compared to their omega-3 fatty acid concentrations at baseline.
Interestingly, only those who had high omega-3 levels reaped
beneficial effects from the B vitamins.
As noted by the authors:
"There was a significant interaction between B vitamin
treatment and plasma combined omega-3 fatty acids
(eicosapentaenoic acid and docosahexaenoic acid) on brain
atrophy rates.
In subjects with high baseline omega-3 fatty acids (>590
μmol/L), B vitamin treatment slowed the mean atrophy rate by 40
percent compared with placebo.
B vitamin treatment had no significant effect on the rate
of atrophy among subjects with low baseline omega-3 fatty acids
(<390 μmol/L). High baseline omega-3 fatty acids were associated
with a slower rate of brain atrophy in the B vitamin group but
not in the placebo group...
It is also suggested that the beneficial effect of
omega-3 fatty acids on brain atrophy may be confined to subjects
with good B vitamin status."
B Vitamins Significantly Slow Brain Shrinkage
As mentioned above, elevated homocysteine is linked to brain
degeneration, and B vitamins are known to suppress homocysteine.
A 2010 study,3
in which participants again received higher than normal doses of B
vitamins, also found that people receiving B vitamins experienced
far less brain shrinkage than the placebo group.
Here the participants received either a placebo or 800 micrograms
(mcg) folic acid, 500 mcg B12, and 20 mg B6. The study was based on
the presumption that by controlling homocysteine levels you might be
able to reduce brain shrinkage, thereby slowing the onset of
Alzheimer's.
Indeed, after two years those who received the vitamin B regimen
suffered significantly less brain shrinkage compared to those who
had received a placebo. Those who had the highest levels of
homocysteine at the start of the trial experienced brain shrinkage
at half the rate of those taking a placebo.
Research Shows B Vitamins Specifically Slow Alzheimer's Disease
A 2013 study4
takes this research a step further, showing that not only do B
vitamins slow brain shrinkage, but they specifically slow
shrinkage in brain regions known to be most severely impacted by
Alzheimer's disease. Moreover, in those specific areas the shrinkage
is decreased by as much as seven-fold!
The brain scans clearly show the difference between placebo and
vitamin supplementation on brain atrophy. As in the studies above,
participants taking high doses of folic acid and vitamins B6 and B12
lowered their blood levels of homocysteine, and brain shrinkage was
decreased by as much as 90 percent.
As noted by the authors:
" … B vitamins lower homocysteine, which directly leads
to a decrease in GM [gray matter] atrophy, thereby slowing
cognitive decline.
Our results show that B vitamin supplementation can slow
the atrophy of specific brain regions that are a key component
of the AD [Alzheimer's disease] process and that are associated
with cognitive decline."
B12-Rich Foods Reduce Risk of Alzheimer's in Later Years
Other supporting research includes a small Finnish study5
published in 2010. It found that people who consume vitamin B12-rich
foods may reduce their risk of Alzheimer's in their later years.
For each unit increase in the marker of vitamin B12
(holotranscobalamin), the risk of developing Alzheimer's was reduced
by 2 percent. This makes a strong case for ensuring your diet
includes plenty of B vitamin foods, such as meat, poultry, eggs,
dairy products and wild-caught fish.
Leafy green vegetables, beans, and peas also provide some of the
B vitamins, but if you eat an all vegetarian or vegan diet, you're
at a significantly increased risk of
vitamin B12 deficiency, as B12 is naturally present in foods
that come from animals, including meat, fish, eggs, milk and milk
products.
In such a case, supplementation is really important. Another
concern is whether your body can adequately absorb the B12. It's the
largest vitamin molecule we know of, and because of its hefty size,
it's not easily absorbed.
This is why many, if not most, oral B12 supplements fail to
deliver any benefits. Vitamin B12 requires a gastric protein called
intrinsic factor to bind to it, which allows it to be absorbed in
the end of your small intestine (terminal ileum). The intrinsic
factor is absorbed first, pulling the attached B12 molecule along
with it.
As you grow older, your ability to produce intrinsic factor
decreases, thereby increasing your risk for vitamin B12 deficiency.
Use of metformin (Glucophage, Glucophage XR, Fortamet, Riomet, and
Glumetza) may also inhibit your B12 absorption, especially at higher
doses. Drinking four or more cups of coffee a day can reduce your B
vitamin stores by as much as 15 percent, and use of antacids will
also hinder your body's ability to absorb B12.
Other Valuable Vitamins for Brain Health
Besides B vitamins, vitamins C and D are also important for
optimal brain health.6
Vitamin C plays a role in the production of neurotransmitters,
including serotonin, which has antidepressant activity. Vitamin C
has also been shown to improve IQ, memory, and offer protection
against age-related brain degeneration and strokes.
In one study,7
the combination of vitamin C and E (which work synergistically)
helped reduce the risk of dementia by 60 percent. Vitamin C also has
detoxifying effects, and due to its ability to cross your
blood-brain barrier, it can help remove heavy metals from your
brain.
Vitamin D, a steroid hormone produced in your skin in response to
sun exposure, also has profound effects on your brain. Pregnant
women need to be particularly cognizant of this, as
vitamin D deficiency during pregnancy can prevent proper brain
development in the fetus, plus a host of other problems. After
birth, children need vitamin D for continued brain development, and
in adulthood, optimal levels have been shown to help prevent
cognitive decline.8,9
Where to Find These Valuable Brain Nutrients
There's nothing "normal" about cognitive decline. More often than
not, it's due to poor lifestyle choices, starting with a
nutrient-deficient diet that is too high in sugars, non-vegetable
carbs, unhealthy fats like trans fats, and too many toxins
(pesticides and artificial additives, etc).
As a general rule, I recommend getting most if not all of your
nutrition from REAL FOOD, ideally organic to avoid toxic pesticides,
and locally grown. Depending on your situation and condition
however, you may need one or more supplements.
To start, review the following listing of foods that contain the
brain nutrients discussed in this article: animal-based omega-3s,
vitamins B6, B9, and B12, C, and D. If you find that you rarely or
never eat foods rich in one or more of these nutrients, you may want
to consider taking a high-quality, ideally food-based supplement.
I've made some suggestions to keep in mind when selecting a good
supplement.
Animal-based
omega-3 |
Fatty fish that is low in
mercury, such as wild-caught Alaskan salmon, sardines, and
anchovies, as well as organic grass-fed beef.10
Sardines, in particular, are one of the most concentrated
sources of omega-3 fats, with one serving containing more
than 50 percent of your recommended daily value. |
Antarctic krill
oil is a sustainable choice. It also has the added benefit
of containing natural astaxanthin, which helps prevent
oxidation.
Another good option is wild-caught Alaskan salmon oil. |
Vitamin B6 |
Turkey, beef, chicken,
wild-caught salmon, sweet potatoes, potatoes, sunflower
seeds, pistachios, avocado, spinach and banana.11,12 |
Nutritional
yeast is an excellent source of B vitamins, especially B6.13
One serving (2 tablespoons) contains nearly 10 mg of vitamin
B6.
Not to be confused with Brewer's yeast or other active
yeasts, nutritional yeast is made from an organism grown on
molasses, which is then harvested and dried to deactivate
the yeast.
It has a pleasant cheesy flavor and can be added to a number
of different dishes. For tips, see this vegan blog post.14 |
Folate (B9) |
Fresh, raw, and organic
leafy green vegetables, especially broccoli, asparagus,
spinach, and turnip greens, and a wide variety of beans,
especially lentils, but also pinto beans, garbanzo beans,
navy and black beans, and kidney beans.15
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Folic acid is a synthetic type of B vitamin used in
supplements; folate is the natural form found in foods.
Think: folate comes from foliage (edible
leafy plants).
For folic acid to be of use, it must first be activated into
its biologically active form — L-5-MTHF.
This is the form able to cross the blood-brain barrier to
give you the brain benefits noted.
Nearly half of the population has difficulty converting
folic acid into the bioactive form due to a genetic
reduction in enzyme activity.
For this reason, if you take a B vitamin supplement, make
sure it contains natural folate rather than synthetic folic
acid.
Nutritional yeast is an excellent source.16 |
Vitamin B12 |
Vitamin B12 is found almost
exclusively in animal tissues, including foods like beef and
beef liver, lamb, snapper, venison, salmon, shrimp,
scallops, poultry, eggs, and dairy products.
The few plant foods that are sources of B12 are actually
B12 analogs that block the uptake of true B12.
Also consider limiting sugar and eating fermented foods.
The entire B group vitamin series is produced within your
gut, assuming you have healthy gut flora.
Eating real food, ideally organic, along with fermented
foods will provide your microbiome with important fiber and
beneficial bacteria to help optimize your internal vitamin B
production. |
Nutritional
yeast is also high in B12, and is highly recommended for
vegetarians and vegans.
One serving (2 tbsp) provides nearly 8 micrograms (mcg) of
natural vitamin B12.17
Sublingual (under-the-tongue) fine mist spray or vitamin B12
injections are also effective, as they allow the large B12
molecule to be absorbed directly into your bloodstream. |
Vitamin C |
Sweet peppers, chili
peppers, Brussel sprouts, broccoli, artichoke, sweet potato,
tomato, cauliflower, kale, papaya, strawberries, oranges,
kiwi, grapefruit, cantaloupe, and lemon.
To boost your intake of fruits and vegetables, consider
juicing. As an alternative, you can also
make fermented vegetables at home.
The vitamin C in sauerkraut (fermented cabbage) is about six
times higher than in the same helping of
unfermented cabbage, so it's an excellent way to boost your
vitamin C intake. |
The most
effective form of oral vitamin C is liposomal vitamin C.
It's not associated with many of the complications of
traditional vitamin C or ascorbic acid (such as
gastrointestinal distress), which will allow you to achieve
higher intracellular concentrations.
You can expect a significant rise in plasma vitamin C
concentration at doses between 30 and 100 mg/day.
Taking
vitamin C frequently throughout the day is more
effective than taking one large dose once a day. |
Vitamin D |
Vitamin D is created
naturally when your skin is exposed to sunshine.
While you can get some
vitamin D from grass-fed meats and other whole foods and
fortified foods, sun exposure is an ideal primary source.
|
When taking
supplemental vitamin D, also be sure to increase your intake
of
vitamin K2 and
magnesium, either from food or a supplement. |
© Copyright 1997-2016 Dr. Joseph Mercola. All Rights Reserved.
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