Sunday, June 9, 2013

Coenzyme Q-10

     After I mentioned the effect of statins on muscles and referred to coenzyme Q-10, I have received a number of questions about this ubiquitous molecule,  so I thought I would answer a few of them here.

     Coenzyme Q-10 is contained in animal foods that we eat, but over 90% of this molecule is synthesized in the body. Curiously enough, it shares a common molecule with the synthetic process for cholesterol. The subscript "10" refers to the number of side chains. This is important, because lab rats synthesize and use Co-Q-9, which is chemically different, so the results with lab rats should not be extrapolated to human use. Your tissue level of CoQ decreases with age, chronic heart failure, diabetes, some cancers, and HIV, but adding CoQ to the diet has not been shown to benefit any of these conditions. It will, however, help protect the heart from the side effects of doxorubicin, an anti-cancer drug, and does help the immune system of lab rats.

     As I mentioned in my earlier blog, CoQ is a vital molecule for the electron transport chain that lets the cell generate aerobic (requiring oxygen) energy, which accounts for over 90% of the body's requirement. No other molecule in the body can do this job.The molecule was discovered in 1957, and is found in the membranes of many cell organelles, especially in mitochondria, the energy factories of the body. The molecule is fat-soluble,  and also has anti-oxidant properties as well as the ability to regenerate other antioxidants such as Vitamin E.

     Because the molecule is fat soluble, absorption is best when taken with food. A typical dose is 150 to 300 mg/day. It was found that it may help some migraneurs, and when taken with magnesium citrate and Vitamin B2 (riboflavin) help prevent migraine attacks in some patients. Because it shares a common molecule with the synthesis of cholesterol, statins, which reduce the level of cholesterol, also reduce the level of CoQ. Oddly enough, some beta-blockers also reduce the tissue level of CoQ.

     There are few studies that show any unequivocal benefit from taking CoQ-10. It does improve the immune system of lab rats, but not of humans. It also seems to protect lab rats from the damages of external radiation.The two interventional studies, one on patients with heart failure  and one on patients with breast cancer failed to show a significant benefit. Studies to see if CoQ supplementation increased the lifetime of lab rats led to contradictory results.
However, a meta-analysis (and see my previous blog for my critique of such studies) did show that Co-Q-10 lowered the blood pressure in humans, by as much as 15mm systolic and 10 mm diastolic, which is a very powerful result. No study has shown that Co-Q supplementation reverses the decrease of CoQ caused by statins.

     In summary, coenzyme Q-10 is a vital molecule for energy generation, and we are busily looking for a clinical use for supplemental doses.  I am looking forward to a double-blind study to validate its benefit in patients with hypertension, as well as  to see if it can prevent the muscle aches  and muscle breakdown that can develop with the use of statins.



No comments:

Post a Comment