Flashback Friday: Preventing Brain Loss with B Vitamins?


“Preventing Brain Loss with B Vitamins” By our 70s, one in five of us will
suffer from cognitive impairment, and within 5 years half
will progress to dementia, in a progression from cognitive
impairment without dementia, to dementia and death. The earlier we can slow or
stop this process, the better. Although an effective treatment
for Alzheimer’s disease is unavailable, even interventions just to control risk
factors could prevent millions of cases. So an immense effort has
been spent on identifying risk factors for Alzheimer’s and
developing treatments to reduce them. In 1990, a small study of 22
Alzheimer’s patients reported that they had high concentrations
of something called homocysteine in their blood. The homocysteine story
starts back to 1969 when a Harvard pathologist
reported two cases of children, one dating back to 1933, whose
brains had turned to mush. They both suffered from extremely
rare genetic mutations that led to abnormally high levels
of homocysteine in their bodies. So is it possible, he asked, that
homocysteine could cause brain damage even in people without
genetic defects? Well, now here we are in the 21st century
and homocysteine is considered a strong, independent risk
factor for the development of dementia and Alzheimer’s disease. Having a blood level over 14
may nearly double our risk. In the Framingham Study
they estimated that as many as 1 in 6 Alzheimer’s
cases may be attributable to this elevated homocysteine
in the blood, now thought to play a role in brain
damage, cognitive and memory decline. Our body can detoxify
homocysteine, though, using three vitamins: folate,
vitamin B12, and vitamin B6. So why don’t we put them to the test? No matter how many
studies find an association between high homocysteine, cognitive
decline, dementia or Alzheimer’s disease, a causal role, a cause and effect role can only be confirmed by
interventional studies. Now initially, the results
were disappointing; vitamin supplementation
did not seem to work. But the studies were tracking
neuropsychological assessments, which are more subjective,
compared to structural neuroimaging – actually seeing what’s
happening to the brain. And a double-blind randomized
controlled trial found that homocysteine-lowering by B vitamins can
slow the rate of accelerated brain atrophy in people with mild cognitive impairment. As we age, our brain slowly atrophies,
but the shrinking is much accelerated in patients suffering
from Alzheimer’s disease. Kind of an intermittent rate
of shrinkage is found in people with mild
cognitive impairment. So the thinking is maybe if we could
slow down the rate of brain loss, we could slow down this conversion
to Alzheimer’s disease. So they tried giving people
B vitamins for two years and they found it markedly slowed
the rate of brain shrinkage. The rate of atrophy in those with high
homocysteine levels was cut in half. A simple, safe treatment can slow
the accelerated rate of brain loss. A follow-up study went
further by demonstrating that B-vitamin treatment reduces, by as
much as seven fold, the brain atrophy in the regions specifically vulnerable
to the Alzheimer’s disease process. Here’s the amount of brain atrophy
over two years in the placebo group; here’s the amount of loss
in the B vitamin group. Less brain loss. Now the beneficial
effect of B vitamins was confined to those
with high homocysteine indicating a relative deficiency
in one of those three vitamins. So wouldn’t it be better to not
get deficient in the first place? Most people get
enough B12 and B6, but the reason these folks were
stuck up at a homocysteine of 11 is that they probably weren’t
getting enough folate, which is found predominantly
in beans and greens. 96% of Americans don’t even make the
minimum recommended amount of dark green leafy vegetables — the same pitiful number that don’t eat
the minimum recommendation for beans. In fact, if you put people on
a healthy diet, on a plant-based diet, you can drop their homocysteine
levels 20% in just one week, up from around 11 down to 9. The fact that they showed significant
homocysteine lowering without any pills, without supplements even at one week suggests that multiple mechanisms
may have been at work. They suggest it may be
because of the fiber. Every gram of daily fiber consumption
may increase folate levels in the blood nearly 2%, perhaps by
boosting vitamin production in our colon by our
friendly gut bacteria. It also could be from the
decreased methionine intake. That’s where homocysteine comes from. Homocysteine is a breakdown
product of methionine, which comes mostly
from animal protein. And so if you give someone
bacon and eggs for breakfast, then a steak for dinner,
you can get these spikes of homocysteine levels in the blood. Thus, decreased methionine
intake on a plant-based diet may be another factor contributing to
these lower, safer homocysteine levels. The irony, of course, is that those who
eat plant-based diets long-term, not just at a health spa for a week,
have terrible homocysteine levels. Meateaters up at 11, but vegetarians
at nearly 14, vegans at 16. Why? They’re getting more fiber and folate, but
they’re not getting enough vitamin B12. Most vegans can be classified
as being likely to suffer from hyperhomocysteinaemia,
too much homocysteine in the blood because most vegans
in this study were not supplementing with vitamin B12,
or eating vitamin B12 fortified foods, which is critical for anyone
eating a plant-based diet. But if you take vegans
and give them B12, their homocysteine
can drop down below 5. Why not down to just 11? The reason the meat eaters
were stuck up at 11 is probably because they
weren’t getting enough folate. But once vegans got enough B12 they could finally fully exploit the
benefits of their plant-based diets and come out with the
best levels of all.

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