Monday, May 5, 2014

Minding your PQQs by Jerry Brainum

Odds are good that you've never heard of a supplement called "PQQ," which stands for pyrroloquinoline quinone. It was first discovered as a growth factor for bacteria in 1979. Later animal studies showed that it also played a role in the growth of animals, too. It may even do this in humans, since human breast milk is known to contain 15 percent PQQ. The human body produces about 100 to 400 nanograms of PQQ a day, which is a very small amount. It's also found in various foods, particularly soy-based foods, such as natto and tofu, as well as in spinach. However, the amount found in foods is also infinitesimal. Still, the fact that it exists in the human body, albeit in very small quantity,indicates that it must do something.
   The fact that it seems to be required for animal growth and reproduction suggested that it could be a new vitamin compound. While PQQ does affect the activity of various body enzymes, which is one requirement of a vitamin, it does not seem to satisfy the other vitamin requirement, in that there is no established deficiency condition associated with PQQ.  Still, it is capable of doing some significant things in the body. Among these are activation of PGC-1A, a substance that promotes the development of new mitochondria. Mitochondria are cigar-shaped structures in the cell where such vital processes as electron transport and beta-oxidation occurs, resulting in the production of the energy factor, ATP, and fat oxidation. A loss of function of mitochondria is thought to be  major cause of aging, since when mitochondria die out, the cell loses its energy source, and cannot function, so it too dies. A loss of mitochondria is also suspected of being a major cause of sarcopenia, the loss of muscle with age.
    While the effects of PQQ in animals are clear-cut and beneficial, the effects on human health are preliminary to say the least. In animals, PQQ lowers triglycerides (blood fat) more efficiently than fish oil, but in the one human study that has tested the effects of PQQ, it had no effect on triglycerides. Animal studies show that PQQ may modify the activity of NMDA brain receptors. These receptors are involved in memory and learning, but when overstimulated, can lead to loss of neurons, or brain cells. PQQ seems able to block such overstimulation. Much of the benefits of PQQ may be ascribed to an antioxidant activity. While antioxidant vitamins, such as vitamins C and E are quickly oxidized and thus no longer capable of exerting anti-oxidant activity, PQQ can be quickly converted back to antioxidant status, and go through thoussands of such cycles, known as redox cycling.
    Articles about PQQ have suggested that it can improve cognitive ability, or brain activity related to memory and intelligence. This could be related to both the increased mitochondria fostered by PQQ or the effect on NMDA brain receptors. However, most of the animal studies that have shown this effect involved PQQ being injected directly into the brain, a method of administration not likely to be popular with humans. Whether the current oral supplement of PQQ does likewise for human brains is not known or proven yet, although some studies did show slight improvements in memory in older adults after PQQ supplementation.
   As noted, there is a dearth of human studies related to PQQ supplementation. In one recent human study, however, a number of beneficial effects did occur.  The study only had 10 subjects, 5 women and 5 men, ages 21 to 34. In the first part of the study, the subjects were provided 0.2 milligrams of PQQ per kilogram of bodyweight in a fruit-flavored drink. This part of the study measured antioxidant effects of PQQ, and found only a slight effect.In the second part of the study, the subjects increased the dose of PQQ to 0.3 milligrams per kilogram of bodyweight. The subjects who ingested this dose showed a lowering of C-reactive protein and interleukin-6, both indicative of decreased body inflammation. The subjects also showed lowered excretion  of TMAO, which was in the news recently because it was implicated as a promoter of atherosclerosis. TMAO is a byproduct of the metabolism of both choline and carnitine that have been acted upon by intestinal bacteria. PQQ also lowered the excretion of a few amino acids, suggesting that it may have a beneficial effect on nitrogen retention. Other indices did show definite beneficial effects on mitochondria.One other thing worth noting: the study was sponsored by the Mitsubishi Gas and Chemical Company--the major supplier of PQQ in supplement form.
   So, is PQQ worth taking as a supplement? Based on the current available human research, the answer would have to be no. On the other hand, for those seeking to maintain healthy mitochondria, PQQ might be useful, but you can get the same effect for free merely by engaging in high intensity aerobic exercise.The  suggested dose of PQQ is 10-20 milligrams a day.


Harris, CB, et al. Dietary pyrroquinoline quinone (PQQ) alters indicators of inflammation and mitochondrial-related metabolism in human subjects.J Nut Biochem 2013;24:2076-84.

 ©,2013 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited.

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