Nutritional Advice El Mondo

Coenzyme Q10

Scientific studies (review articles) on the relationship between coenzyme Q10 and disease prevention:
One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of randomized, placebo-controlled double blind clinical trials (RCTs) will answer the following question:
"Do taking dietary supplements make sense?" Yes for a positive conclusion and no for a negative conclusion.

One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of cohort studies or case-control studies will answer the following question:
"Should I change my diet?".

  1. Coenzyme Q10 supplements improve endothelial function 
  2. Coenzyme Q10 supplementation does not decrease body weight and BMI
  3. Coenzyme Q10 supplements reduce inflammation in patients with coronary artery disease
  4. Coenzyme Q10 supplementation reduces serum triglycerides levels of patients with metabolic disorders
  5. Coenzyme Q10 supplements result in lower mortality and improved exercise capacity of patients with heart failure
  6. CoQ10 supplementation reduces markers of inflammation and MMPs in patients with breast cancer
  7. Coenzyme Q10 supplementation reduces oxidative stress
  8. 60-500 mg/day coenzyme Q10 supplements reduce inflammation
  9. Coenzyme Q10 supplementation may decrease inflammation

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  • Coenzyme Q10 (CoQ10) is a fat-soluble compound found naturally in virtually every cell in the human body.
  • There are two forms of coenzyme Q10: ubiquinone and ubiquinol.
  • Coenzyme Q10 occurs in diet as ubiquinone and in humans mainly as ubiquinol.
  • The estimated daily intake of CoQ10 is 3-6 mg per day derived primarily from meat. Cooking by frying reduces CoQ10 content by 14-32%.
  • Rich sources of dietary coenzyme Q10 (ubiquinone) include mainly meat, poultry and fish.
  • Other relatively rich sources include soybean, canola oils and nuts.
  • CoQ10 as ubiquinone plays a key role in producing energy in mitochondria in the form of ATP.
  • Adequate amounts of CoQ10 are necessary for cellular respiration and ATP production.
  • CoQ10 as ubiquinol also functions as an intercellular antioxidant.
  • Alpha-tocopherol (vitamin E) and coenzyme Q10 (as ubiquinol) are the principal fat-soluble antioxidants in membranes and lipoproteins.
  • Symptoms of coenzyme Q10 deficiency have not been reported in the general population, so it is generally assumed that normal biosynthesis and a varied diet provide sufficient coenzyme Q10 for healthy individuals.
  • Dosages of 30-60 mg/day are recommended to prevent CoQ10 deficiency.
  • CoQ10 deficiency may occur among statin-users because coenzyme Q10 shares a common biosynthetic pathway with cholesterol.
  • Statins can reduce serum levels of CoQ10 by up to 40%. However, it may be emphasized that till date there are no conclusive reports that support the role of CoQ10 deficiency in the pathogenesis of statin-related myopathy.
  • The biosynthesis of coenzyme Q10 involves three major steps:
  1. Synthesis of the benzoquinone structure from either tyrosine or phenylalanine, two amino acids;
  2. Synthesis of the isoprene side chain from acetyl-coenzyme A (CoA) via the mevalonate pathway and;
  3. The joining or condensation of these two structures.
  • The enzyme hydroxymethylglutaryl (HMG)-CoA reductase plays a critical role in the regulation of coenzyme Q10 synthesis, as well as the regulation of cholesterol synthesis.
  • Biosynthesis is the major source of CoQ10. Biosynthesis requires at least 12 genes and mutations in many of them cause CoQ10 deficiency.
  • Adult human body pool has been found to be approximately 2 g and requires replacement of about 0.5 g/day based on its average turnover rate of about 4 days in various tissues.
  • Ubiquinol is the most common form of coenzyme Q10 in vivo and accounts for more than 80% of the total ubiquinol+ubiquinone pool in human plasma, intestine and liver.
  • Coenzyme Q10 levels are highest during the first 20 years of life and decline with age.
  • At age 80, coenzyme Q10 levels may be lower than at birth.
  • Coenzyme Q10 is absorbed from the small intestine, passes into the lymphatics and finally to the blood and tissues.
  • Coenzyme Q10 is absorbed slowly from the gastrointestinal tract, possibly because it has a high molecular weight and is not very water-soluble.
  • Coenzyme Q10 is best absorbed if it is taken with a meal. Peak plasma levels are achieved in 2-6 hours after oral administration.
  • In healthy adults, normal values for CoQ10 are 0.8 to 1.5 micrograms per milliliter.
  • CoQ10 may lower blood sugar levels.
  • Taken orally, coenzyme Q10 has a low clearance rate, with an elimination half-life of about 34 hours.
  • Administration of 100 mg CoQ10 3 times/day achieved a mean steady-state level that was estimated at 5.4 µg/mL.
  • The tolerable upper limit intake is up to 1.2 grams per day. However, the usual dose is 100-200 mg/day in deficiency states and other disease states.