Patrick Holford talked about high homocysteine being associated with brain shrinkage in this YouTube …
complete with charts and MRI images of brains with normal (7.8) and high homocysteine. Higher the homocysteine, the greater the brain shrinkage. But this shrinkage can be slowed by B vitamins. He says …
“The level of homocysteine above which you get brain shrinkage (and probably bone shrinkage) is 9.5.”
And 75% of older people have this high level.
He also writes in his book Optimum Nutrition for the Mind …
“the higher the homocysteine, the greater the damage to the brain. They also confirmed that high homocysteine levels were strongly correlated with low folic acid levels. Other researchers have also found that older people with low levels of folic acid have an increased risk of developing Alzheimer’s disease”
As we age, our need for B vitamins (especially B12) goes up due to reduced methylation and poorer absorption of B vitamins.
Homocysteine levels can be easily tested by your doctor. Although he/she may know of that test as a test for risk of heart disease. This is true, because high homocysteine is damaging to the heart and arteries. But it is damaging to the brain as well.
In fact, Dr. Mark Hyman writes in Ultraprevention …
“More than any other single test, homocysteine correctly identifies the risks of such conditions as heart attack, stroke, and dementia years before the onset of any symptoms. More important, if found to be elevated, homocysteine can be easily lowered using the correct dose of B vitamins such as folate acid, B6, and B12.”
and that …
“whereas the proteins in vegetables, containing different amino acid structures, do not raise homocysteine. Thus an excess of animal protein in the diet may cause harm, whereas consuming many plant proteins won’t.” [page 157]
Eating more methionine that you need may produce excessive conversion of methionine into homocysteine. The body will use B vitamins (such as B6) to convert the homocysteine into cystathionine which the body can safely excrete. So a lack of B vitamins may reduce this conversion resulting in higher homocysteine.
A UK study showed that participants taking folate, B12, and B6 showed lower rates of brain shrinkage.
It is important to know which came first. Is it high homocysteine first and then Alzheimer’s? Or Alzheimer’s disease that caused high homocysteine levels? A study in the New England Journal of Medicine says that it is the former …
“The prospective nature of this study and the strong association between newly diagnosed dementia and Alzheimer’s disease and plasma homocysteine levels measured eight years before base line suggest that the elevation in the homocysteine level preceded the onset of dementia.”
But how would high homocysteine cause dementia? High homocysteine is associated with atherosclerosis which increase risk of stroke, which in turn increases risk of Alzheimer’s.
Other study says that high homocysteine levels are neuro-toxic and can kill brain cells. It says in more scientific terms …
“Human studies suggest that homocysteine (Hcy) plays a role in brain damage, cognitive and memory decline. … Hcy itself or folate and vitamin B12 deficiency can cause disturbed methylation and/or redox potentials, thus promoting calcium influx, amyloid and tau protein accumulation, apoptosis, and neuronal death.”
But the good news is that …
“Numerous neurotoxic effects of Hcy can be blocked by folate, glutamate receptor antagonists, or various antioxidants.”
That means that folate can help prevent the harmful effects of high homocysteine. Folate is the natural form of vitamin B9 that is found in foods.