Diet & Fitness

 

Coenzyme Q10 contributes to the energy-making mechanisms of the heart. Angina patients given 150 mg of coenzyme Q10 each day have experienced greater ability to exercise without experiencing chest pain.¹ This has been confirmed in independent investigations.²

Coenzyme Q10 (coQ10) is an intracellular antioxidant and anti-inflammatory compound, and tissue levels are decreased in people with chronic conditions such as heart disease. CoQ10 has multiple positive effects on blood vessel function that contribute to vasodilation and may reduce blood pressure.³ CoQ10 showed promising effects in individuals with high blood pressure in observational studies and preliminary clinical trials, but findings from randomized controlled trials have been mixed.⁴ A meta-analysis that included data from 17 randomized controlled trials with a combined total of 684 participants determined coQ10 lowers systolic, but not diastolic, blood pressure.⁵

 

As is true for several other heart conditions, coenzyme Q10 (CoQ10) has been reported to help people with congestive heart failure,^6,7 sometimes dramatically.⁸ Positive effects have been confirmed in double-blind research⁹ and in an overall analysis of eight controlled trials.¹⁰ However, some double-blind trials have reported modest¹¹ or no improvement^12,13,14 in exercise capacity or overall quality of life. Most CoQ10 research used 90–200 mg per day. The beneficial effects of CoQ10 may not be seen until after several months of treatment. In one preliminary trial, treatment with ubiquinol (the chemically reduced form of CoQ10) was beneficial for people with severe heart failure, after the standard form of CoQ10 had been ineffective.¹⁵ Discontinuation of CoQ10 supplementation in people with congestive heart failure has resulted in severe relapses and should only be attempted under the supervision of a doctor.⁶

 

People with dilated congestive cardiomyopathy (DCM) have been shown to be deficient in coenzyme Q10.¹⁶ Most studies using coenzyme Q10 in the treatment of cardiomyopathy have demonstrated positive results, including improved quality of life, heart function tests, and survival rates.^17,18,19 Coenzyme Q10 also has been shown to improve cardiac function in people with hypertrophic cardiomyopathy—a less common form of cardiomyopathy.²⁰ A few studies, however, have found no benefit from CoQ10 supplementation in treating people with cardiomyopathy.^21,22 Despite a lack of consistency in the outcomes of published research, many doctors recommend that 100 to 150 mg be taken each day, with meals.

Researchers have also given coenzyme Q10 (CoQ10) to people with COPD after discovering their blood levels of CoQ10 were lower than those found in healthy people.²³ In that trial, 90 mg of CoQ10 per day, given for eight weeks, led to no change in lung function, though oxygenation of blood improved, as did exercise performance and heart rate. Until more research is done, the importance of supplementing with CoQ10 for people with COPD remains unclear.

 

Coenzyme Q10 (CoQ10) is an antioxidant that plays an important role in cellular energy production. People with type 2 diabetes have been found to have significantly lower blood levels of CoQ10 compared with healthy people. In multiple clinical trials, CoQ10 supplementation has been shown to lower blood glucose levels and HgbA1c, improve insulin sensitivity, and raise antioxidant status.^{24,25,26,27,28} Meta-analyses of randomized controlled trials have concluded that CoQ10 supplementation can improve blood glucose levels, HgbA1c, and cardiovascular risk factors in people with type 2 diabetes.^29,30 Although it has been suggested that CoQ10 might help reduce diabetes complications through its antioxidant effects, one clinical trial found no benefit of CoQ10 in treatment of diabetes-related neuropathy.³¹ Doses of CoQ10 used in the research are 100–200 mg of CoQ10 per day.

Coenzyme Q10 (CoQ10) has well known cardiovascular benefits.³² In people with metabolic syndrome, 100 mg of CoQ10 per day for eight weeks improved markers of insulin resistance, but had no impact on glucose, lipid, and inflammatory marker levels compared to placebo.³³ A controlled trial that included 104 participants with metabolic syndrome compared the effects of a dietary intervention alone to diet plus 30 mg of CoQ10 and red yeast rice providing 10 mg of monacolin K (a cholesterol-lowering compound) per day. After two months, those taking the supplements had greater improvements in blood pressure, cholesterol levels, and glucose levels.³⁴ Although CoQ10 has been reported to lower blood pressure in clinical trials in uncomplicated hypertensive subjects, a placebo-controlled trial in 30 patients with high blood pressure and metabolic syndrome found 200 mg of CoQ10 twice daily did not lower blood pressure after 12 weeks of treatment.^32,36 CoQ10 may be helpful in treating metabolic syndrome associated with polycystic ovary syndrome: in one trial, 100 mg of CoQ10 per day for 12 weeks was more effective than placebo for improving glucose and lipid metabolism.³⁷

Coenzyme Q10 (CoQ10) is needed for normal blood sugar metabolism. One research team reported that, in study subjects with vascular complications related to type 1 diabetes, adding CoQ10 to standard insulin therapy increased antioxidant status, reduced free radical damage to lipids, and improved blood vessel function.³⁷ The same research group also reported that CoQ10 supplementation, at the unusually high dose of 1,000 mg per day, improved blood glucose control in those with type 1 diabetes-related kidney dysfunction.³⁸ However, in a placebo-controlled trial, supplementation with 100 mg of CoQ10 per day for three months neither improved glucose control nor reduced the need for insulin in participants with type 1 diabetes.³⁹ Although the potential benefits of CoQ10 supplements in treatment of type 1 diabetes remains uncertain, some doctors recommend taking 50–100 mg per day due to its likely ability to protect heart, blood vessel, and kidney health.⁴⁰

 

Blood levels of coenzyme Q10 have been found to be low in about one-third of migraine sufferers.⁴¹ In a preliminary trial, supplementation of migraine sufferers with 150 mg per day of coenzyme Q10 for three months reduced the average number of days with migraine headaches by 60%.⁴² The beneficial effect of coenzyme Q10 was confirmed in a four-month double-blind study. By the fourth month of treatment, a reduction in migraine frequency of 50% or greater occurred in 47.6% of people receiving 100 mg of coenzyme Q10 three times a day, but in only 14.4% of those receiving a placebo (a statistically significant difference).⁴³ However, another double-blind trial found that coenzyme Q10 was not more effective than a placebo in children with recurrent migraines, although children receiving coenzyme Q10 appeared to improve faster than those given the placebo.⁴⁴

In a preliminary trial, supplementing with coenzyme Q10 (100 mg three times per day for three months) resulted in significant improvements in headaches and overall symptoms in patients with fibromyalgia.⁴⁵ In another study, cellular levels of CoQ10 were significantly lower in women with fibromyalgia than in healthy women. In the same study, ten women with fibromyalgia received 300 mg of CoQ10 per day for three months. Significant improvements were seen in symptoms such as fatigue, pain, depression, and anxiety.⁴⁶ A placebo-controlled trial confirmed that CoQ10, in the amount of 100 mg 3 times per day, can improve depression in people with fibromyalgia.⁴⁷

Strenuous physical activity lowers blood levels of coenzyme Q10 (CoQ10).⁴⁸ However, while some studies have shown that CoQ10 improves the way the healthy body responds to exercise,⁴⁹ other studies have found no improvement.^50,51,52,53 A few studies, using at least four weeks of CoQ10 supplementation at 60 to 100 mg per day, have reported improvements in measures of work capacity ranging from 3 to 29% in sedentary people and from 4 to 32% in trained athletes.⁵⁴ However, recent double-blind and/or placebo-controlled trials in trained athletes, using performance measures such as time to exhaustion and total performance, have found either no significant improvement or significantly poorer results in those taking CoQ10.^55,56,57

One double-blind study found that supplementation with ubiquinol (the chemically reduced form of CoQ10) in the amount of 300 mg per day for 6 weeks improved maximum power output in a group of trained athletes.⁵⁸

 

In a double-blind study, supplementation with a proprietary blend of acetyl-L-carnitine, omega-3 fatty acids from fish oil, and coenzyme Q10 for 12 months resulted in an improvement in both visual function and in objective findings on eye examination (a decrease in the drusen-covered area on the retina).⁵⁹

 

In a preliminary report, two people with a hereditary form of Alzheimer’s disease received daily: coenzyme Q10 (60 mg), iron (150 mg of sodium ferrous citrate), and vitamin B6 (180 mg). Mental status improved in both patients, and one became almost normal after six months.⁶⁰

Preliminary evidence has linked gingivitis to a coenzyme Q10 (CoQ10) deficiency.⁶¹ Some researchers believe this deficiency could interfere with the body’s ability to repair damaged gum tissue. In a double-blind trial, 50 mg per day of CoQ10 given for three weeks was significantly more effective than a placebo at reducing symptoms of gingivitis.⁶² Compared with conventional approaches alone, topical CoQ10 combined with conventional treatments resulted in better outcomes in a group of people with periodontal disease.^63,64

 

Nutritional supplements recommended by some doctors for prevention and treatment of periodontitis include vitamin C (people with periodontitis are often found to be deficient),⁶⁵vitamin E, selenium, zinc, coenzyme Q10, and folic acid.⁶⁶ Folic acid has also been shown to reduce the severity of gingivitis when taken as a mouthwash.⁶⁷

 

In a double-blind study, supplementation with a proprietary blend of acetyl-L-carnitine, omega-3 fatty acids from fish oil, and coenzyme Q10 for 12 months resulted in an improvement in both visual function and in objective findings on eye examination (a decrease in the drusen-covered area on the retina).⁶⁸

Pregnant women with preeclampsia have significantly lower plasma coenzyme Q10 levels, when compared with women with healthy pregnancies. In a double-blind study at women who were at high risk of developing preeclampsia, supplementing with coenzyme Q10 reduced the incidence of preeclampsia by 44%. The amount used was 200 mg per day; treatment was begun during the twentieth week of pregnancy and continued until delivery.⁶⁹

 

Coenzyme Q10 (CoQ10) is a nutrient used by the body in the production of energy. While its exact role in the formation of sperm is unknown, there is evidence that as little as 10 mg per day (over a two-week period) will increase sperm count and motility.⁷⁰ In one study, men with low sperm counts were given CoQ10 (60 mg per day for about three months). No significant change was noted in most sperm parameters, but a significant improvement was noted in in-vitro fertilization rates.⁷¹

 

In a preliminary trial, supplementation with coenzyme Q10 (CoQ10) in the amount of 100 mg three times per day for 16 weeks significantly improved tinnitus in people who had initially low blood levels of CoQ10. However, CoQ10 was not beneficial for people whose initial blood levels were not low.⁷²

 

Blood levels of coenzyme Q10 (CoQ10) were also found to be low in people with HIV infection or AIDS. In a small preliminary trial, people with HIV infection took 200 mg per day of CoQ10. Eighty-three percent of these people experienced no further infections for up to seven months, and the counts of infection-fighting white blood cells improved in three cases.⁷³