Can Vitamin-like PQQ Help Reduce the Risk of Alzheimer's Dementia?

Many things remain to be determined before PQQ can conclusively be said to be a vitamin in human biology and nutrition.
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There is a growing epidemic of Alzheimer's dementia in our country. There are two major types of Alzheimer's dementia. One is an early onset variety. It usually begins well before the age of 65, runs in families and is strongly related to the genes inherited from parents. The other major variety is late-onset Alzheimer's dementia. This form of Alzheimer's appears after 65 years of age, is less dependent on genetics, and is more likely to be preventable by changes in diet and lifestyle. Almost every month, scientists discover new genes that appear to predispose people to the late onset form of Alzheimer's. But in most cases, these gene variations simply seem to exacerbate the adverse effects of ill-chosen diet and lifestyle factors. That is, they do not seem to be either necessary or sufficient to develop full-blown cases of Alzheimer's dementia.

Correcting dietary insufficiencies is one way to reduce the risk of developing Alzheimer's and other forms of dementia. Deficiencies of certain vitamins and nutrients, for example, anti-oxidants and vitamin B12, can increase the risk of dementia. There is now growing evidence that supplementation with a substance that many nutritional scientists believe is a newly discovered vitamin, pyrroloquinoline quinone, or PQQ, may also help reduce the risk of various forms of dementia, including Alzheimer's dementia.

A vitamin is a substance that is necessary for normal function of the body, but is not produced in adequate amounts by the body itself. Thus, it is necessary for this substance to be supplied by the diet. PQQ is a substance that was discovered in 1979 as a cofactor in bacterial enzyme activity. It was first suspected that PQQ might be a vitamin when in 1989 it was found that mice deprived of the substance in their diets suffered retardation of growth, arthritic changes and failure to reproduce.

Here it should be noted that while PQQ is generally recognized as an important nutrient, there remains some controversy as to whether or not it is indeed a vitamin, that is, if it is essential to have a dietary supply of the substance. Nonetheless, there are many substances that are not strictly defined as vitamins that individuals greatly benefit from as supplements to diet. For example, while the body can produce the omega-3 fatty acids EPA and DHA from the alpha-linolenic acid found in flax seed and other oils, the body is so inefficient in doing so that it behooves all of us to obtain EPA and DHA ready-made in fish oil.

There is growing interest in the possibility that PQQ might be one more substance that can help us maintain cognitive function as we age, and may possibility help us avoid dementia. The possibility that PQQ might enhance cognitive was first suggested in a study on the effects of learning in mice. It was found that PQQ enhanced the ability of mice to learn how to negotiate a maze. It was also found that PQQ helped mice subjected to oxidative stress maintain their cognitive function.

There are a number of ways by which PQQ might improve cognitive function and protect the brain from pathological processes that increase the risk of Alzheimer's dementia. The hallmark of Alzheimer's dementia is accumulation of the abnormal protein called amyloid in brain tissue. PQQ has been found to reduce amyloid formation in the brain, and to protect the brain from the neurotoxic effects of existing amyloid deposits. It also helps protect the brain from the damaging effects of another type of reactive substance called peroxynitrite. In yet another study, PQQ was found to stimulate the growth of neurons. This effect would also tend protect the brain the pathological processes of dementia.

Another fascinating and potentially important effect of PQQ, with bearing on Alzheimer's dementia, is its affect on mitochondria. Mitochondria are the energy factories of every cell in the body. The mitochondria is where the oxidation of fuel takes place, and where energy rich molecules are generated for distribution in the cell to drive necessary biochemical reactions. Without mitochondria, cells cannot live, and with insufficient mitochondrial activity, cells cannot function properly. There has long been evidence of abnormalities in mitochondria in the brains of sufferers of Alzheimer's dementia. PQQ not only protects mitochondria from oxidation and toxic effects of amyloid, it also appears to stimulate the production of new mitochondria in human tissue.

At this point, studies of possible benefits of PQQ for humans are few, particularly in regard to cognitive function. However, the naturopathic physician, Michael T. Murray, described a study, published in Japanese, in which the effects of PQQ on human cognition were tested. In that study, 20mg of PQQ alone improved cognitive function in non-demented people aged 40 to 70. PQQ improved it even more when combined with the natural substance Co-enzyme Q10. I would be very reluctant to advise the use of PQQ based on that evidence alone. However, when seen in the light of numerous studies showing a plausible physiological basis for such improvement, as well as the fact that it is a natural substance in food, such recommendation is not unreasonable.

Many things remain to be determined before PQQ can conclusively be said to be a vitamin in human biology and nutrition. PQQ is found in a variety of foods in the human diet, but there is currently no knowledge of how much PQQ humans might need each day. It is also unclear if deficiencies of PQQ actually occur in normal human beings eating normal diets. Finally, it is not yet certain that deficiencies of PQQ actually cause problems in humans or that such deficiencies have any specific relationship to Alzheimer's dementia. Hopefully, more research into the potential of PQQ to keep the brain healthy, and to help avoid Alzheimer's and other forms of dementia will be forthcoming.