The B Vitamins
Dr Kilmer McCully pointed out that homocysteine in the blood
rises when folic acid is low.
Interestingly, folic acid is powerfully protective
against Alzheimer’s disease. At or
above the RDA (meaning supplements are necessary for most people), the risk of Alzheimer’s disease is more than halved.
Homocysteine is directly toxic to the endothelial cells which
line the arteries, so homocysteine is emerging as a risk factor for heart
disease. Since the level of enrichment
of folate in refined cereal grains was increased in 1998, the rate of fall in
the incidence of heart disease has increased from 1% to 4.5% per year. It’s clear that B6 and B12 are also
involved.
Vitamin B6 is involved in the metabolism of homocysteine, and
studies show that B6
deficiencies are an independent contributor to the heart problem. Dr John Ellis of
One reason may be that low B6 interferes with collagen
formation because B6 is the co-enzyme of lysyl oxidase so the cross-linking
step in the process of collagen formation cannot be completed. Researchers Rinehart and Moon found the
initial lesion of atherosclerosis of B6-deficient monkeys was the deposit of
mucin in the blood vessel walls. Only
then was cholesterol deposited in this mucoid formation. This is entirely consistent with, and adds
to, Linus Pauling’s idea of heart disease. (Rinehart JF and Moon HD, Circulation,
1952)
When Dr Walter Willett of Harvard studied the Nurses Health
Study data, he found the risk of heart attack for those who had the highest folate
and B6 levels to be less than half of those who had the lowest. He
concluded in a masterly piece of understatement that “intake of folate and
vitamin B6 above the current recommended dietary allowance may be important in
the primary prevention of CHD among women.”
Vitamin B6 must be converted in the body into the active
form, P5P, before we can make use of it.
The conversion is performed by a magnesium-dependent enzyme, so a
magnesium deficiency affects vitamin B6 utilization. Since some 85% of the population fails to
achieve the RDA for magnesium in their diet, this must contribute a functional B6 deficiency.
A 2004 case-control study found low P5P to almost doubled CHD risk, and
that the low-P5P state was associated with high C-Reactive
Protein, the inflammatory risk factor for heart disease.
When vitamin B6 was given to mature men who were deficient in
it, their cholesterol
levels and their LDL cholesterol levels fell.