The beneficial heart health effects of Coenzyme Q10 and other micronutrients have been reported in a leading cardiology journal, the Journal of the American College of Cardiology. Researchers examined the data in 884 randomized controlled intervention trials enrolling 883,627 participants. They evaluated the clinical efficacy of 27 different micronutrients including Coenzyme Q10 [An 2022].

Hospital costs for heart disease

The US Centers for Disease Control estimates that heart disease costs the United States about $229 billion per year. The total includes the cost of health care services, medicines, and lost work productivity. CoQ10 treatment can help to lower the risk and the cost of heart disease.

The data showed that Coenzyme Q10, omega-3 fatty acid, and folic acid supplements were the top ranking micronutrients for cardiovascular disease prevention [An 2022].

Coenzyme Q10 and Heart Health

Specifically, the researchers examined 28 randomized controlled trials of CoQ10 supplementation. The RCTs enrolled a total of 2950 persons and comprised 6387 person-years. The researchers identified the following significant associations with CoQ10 supplementation [An 2022]:

  • reduced all-cause mortality significantly in seven clinical trials performed in heart failure patients
  • lowered systolic blood pressure significantly in 19 studies
  • lowered diastolic blood pressure in 18 studies but not quite at the statistically significant level
  • improved hemoglobin A1C significantly in eight studies
  • showed a trend toward reduction of fasting blood glucose levels in nine studies but not at the statistically significant level
  • showed a trend toward reduction of fasting blood insulin levels in six studies but not at the statistically significant level

Coenzyme Q10 and Chronic Heart Failure Patients

In the international multi-center Q-Symbio Study, researchers randomly assigned 420 chronic heart failure patients in nine countries to take either three x 100 mg of Coenzyme Q10 or matching placebos daily for two years. The patients enrolled in the study suffered from severe heart failure corresponding to NYHA functional classes III and IV [Mortensen 2014].

Note: Heart failure is the medical term for the failure of the heart to pump sufficient quantities of blood out to the rest of the body [Mayo Clinic 2023]. NYHA class III patients may be comfortable at rest, but even less than ordinary activity will cause them breathlessness, fatigue, and/or palpitation. NYHA class IV patients exhibit symptoms of heart failure at rest and cannot exert themselves without discomfort.

Analysis of the Q-Symbio study study data showed that patients in the CoQ10 adjuvant treatment group had significantly improved symptoms and survival compared to the placebo group:

  • 43% decrease in cardiovascular deaths
  • 42% decrease in death from all causes
  • 43% relative reduction in the incidence of major adverse cardiovascular events (MACE)

Note: MACE includes fatal heart attacks or a need for hospitalization, a heart transplantation, or a mechanical heart pump.

In 2019, researchers reported a sub-analysis of the Q-Symbio study data from the 231 European patients (108 patients in the CoQ10 treatment group and 123 in the placebo group). In the European sub-study, there were greater reductions in cardiovascular deaths, all-cause deaths, and major adverse cardiovascular deaths than in the total international group that included Asian and Australian patients. Moreover, in the European sub-study, the CoQ10 treatment significantly improved the patients’ left ventricular ejection fraction [Mortensen 2019].

Note: Ejection fraction is a measure of the percentage of blood that leaves the heart with each contraction.

One plausible explanation for the better performance of the CoQ10 treatment in the European segment of the Q-Symbio study is that the European patients had higher serum Coenzyme Q10 throughout the study period, implying better compliance on their part.

Coenzyme Q10 and Heart Function in Healthy Elderly Individuals

In the KiSel-10 study, researchers administered Coenzyme Q10 (2 x 100 mg) and organic selenium yeast (200 mcg) or matching placebos daily for four years 443 elderly community living individuals. The combined Coenzyme Q10 and selenium supplementation was significantly associated with the following outcomes [Alehagen 2013; Johansson 2015]:

  • reduced cardiovascular mortality
  • improved heart function seen on echocardiograms
  • improved health-related quality of life
Cardiologist Urban Alehagen

Cardiologist Urban Alehagen and his co-researchers have shown the beneficial heart health effects of combined supplementation with Coenzyme Q10 and selenium in elderly citizens who have low concentrations of both substances.

Using various tests, the researchers identified improvements in the following blood biomarkers as probable mechanisms explaining the beneficial clinical effects [Alehagen 2022]:

  • reduced inflammation
  • reduced oxidative stress
  • reduced fibrosis
  • improved endothelial function

Interestingly, the significant reduction in deaths from heart disease persisted another eight years after the cessation of the four-year supplementation period [Alehagen 2018].

Conclusion: CoQ10 Supplementation Benefits Heart Function

CoQ10 supplementation is useful as an adjuvant treatment for heart failure, atrial fibrillation, and myocardial infarction. It is useful for associated conditions like hypertension and insulin resistance [Martelli 2020].

Coenzyme Q10 has a key role in mitochondrial bio-energetics – it is essential to the generation of cellular ATP energy [Garrido-Maraver 2014].

Several RCTs show that CoQ10 supplementation is associated with substantial reduction of oxidative stress and inflammatory biomarkers [Martelli 2020].


Alehagen U, Johansson P, Björnstedt M, Rosén A, Dahlström U. Cardiovascular mortality and N-terminal-proBNP reduced after combined selenium and coenzyme Q10 supplementation: a 5-year prospective randomized double-blind placebo-controlled trial among elderly Swedish citizens. Int J Cardiol. 2013 Sep 1;167(5):1860-6.

Alehagen U, Aaseth J, Alexander J, Johansson P. Still reduced cardiovascular mortality 12 years after supplementation with selenium and coenzyme Q10 for four years: A validation of previous 10-year follow-up results of a prospective randomized double-blind placebo-controlled trial in elderly. PLoS One. 2018 Apr 11;13(4):e0193120.

Alehagen U, Johansson P, Svensson E, Aaseth J, Alexander J. Improved cardiovascular health by supplementation with selenium and coenzyme Q10: applying structural equation modelling (SEM) to clinical outcomes and biomarkers to explore underlying mechanisms in a prospective randomized double-blind placebo-controlled intervention project in Sweden. Eur J Nutr. 2022 Sep;61(6):3135-3148.

An P, Wan S, Luo Y, Luo J, Zhang X, Zhou S, Xu T, He J, Mechanick JI, Wu WC, Ren F, Liu S. Micronutrient supplementation to reduce cardiovascular risk. J Am Coll Cardiol. 2022 Dec 13;80(24):2269-2285.

Garrido-Maraver J, Cordero MD, Oropesa-Ávila M, Fernández Vega A, de la Mata M, Delgado Pavón A, de Miguel M, Pérez Calero C, Villanueva Paz M, Cotán D, Sánchez-Alcázar JA. Coenzyme Q10 therapy. Mol Syndromol. 2014 Jul;5(3-4):187-97.

Johansson P, Dahlström Ö, Dahlström U, Alehagen U. Improved health-related quality of life, and more days out of hospital with supplementation with selenium and Coenzyme Q10 combined. Results from a Double Blind, Placebo-Controlled Prospective Study. J Nutr Health Aging. 2015 Nov;19(9):870-7.

Martelli A, Testai L, Colletti A, Cicero AFG. Coenzyme Q10: clinical applications in cardiovascular diseases. Antioxidants (Basel). 2020 Apr 22;9(4):341.

Mayo Clinic Staff. Heart Failure. Mayo Clinic. 2023. Retrieved from

Mortensen SA, Rosenfeldt F, Kumar A, Dolliner P, Filipiak KJ, Pella D, Alehagen U, Steurer G, Littarru GP; Q-SYMBIO Study Investigators. The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO: a randomized double-blind trial. JACC Heart Fail. 2014 Dec;2(6):641-9.

Mortensen AL, Rosenfeldt F, Filipiak KJ. Effect of coenzyme Q10 in Europeans with chronic heart failure: A sub-group analysis of the Q-SYMBIO randomized double-blind trial. Cardiol J. 2019;26(2):147-156.

The information presented in this review article is not intended as medical advice and should not be used as such.