The association between the risk of heart disease and dietary intakes of selenium remains unclear. Here we report the results of some of the recent observational studies on this topic.
Risk of Cardiovascular Disease
Selenium and Good Health
Selenium is an essential trace element for good health. If we are to survive and reproduce, we need some selenium in our diets. Not much but some. The reason is that our bodies cannot synthesize the selenium we need. Many of us live in a region of the world with low selenium content in the soil and in the regionally grown food products. Accordingly, it is difficult for us to get enough selenium in our diet.
For example, Alexander et al point out that mainland Europe and Scandinavia are regions with a low intake of selenium. North America, by contrast, is a region with much higher selenium intake. There is considerable variation in the selenium content of locally cultivated food products around the world. Consequently, daily selenium intake varies considerably. Depending upon the region we live in, we may be at risk of sub-optimal selenium intakes or selenium deficiency [Alexander 2024].
Selenium and Heart Failure and Immune Function
Selenium has beneficial effects on the prevention and treatment of heart failure. Higher serum selenium levels are associated with a lower risk of new-onset heart failure and with a lower risk of mortality. Now, data from a 2024 cohort study suggest that strengthened immune system function may be a mechanism that explains the positive effect of selenium [Al Mubarak 2024].
In the study, Al Mubarak et al analyzed the data from a cohort of 2,328 patients diagnosed with heart failure. Heart failure is the medical term to describe patients with a heart muscle that cannot pump as much blood out to the tissues and organs as it should. The heart is too weak or too stiff to fill up with blood and pump out blood optimally. Heart failure is frequently associated with a build-up of fluid in the lungs – causing shortness of breath – and in the lower extremities. The bottom line is that heart failure can be life-threatening [Mayo Clinic Staff 2025].
Selenium and Heart Failure
Heart failure is a condition in which the heart no longer performs as well as it should. It affects millions of people in the United States and Europe. Heart failure is characterized by the following symptoms:
• shortness of breath
• build-up of congestion in the lungs
• accumulation of fluid in the lower extremities
What do we know about selenium status and the risk of heart failure?
Low serum selenium levels are associated with increased risk of heart failure [Al-Mubarak 2021; Bomer 2020].
What do we know about selenium supplementation and heart failure?
- Selenium supplementation of individuals with low selenium status may improve heart function and may reduce the need for hospitalization [Alehagen 2022].
- Selenium supplementation of individuals with low selenium status may reduce the oxidative stress and systemic inflammation that increase the risk of heart failure [Alehagen 2022].
Selenium and the Risk of Cardiomyopathy
Myocardium is the medical term for the heart muscle. Cardiomyopathy is a disease or disorder of the heart muscle, often of unknown cause. Keshan disease is a form of cardiomyopathy that develops as a result of selenium deficiency and exposure to a strain of the coxsackievirus. The disease takes its name from Keshan County in northeastern China Its symptoms were first observed there. Keshan disease can result in heart failure [Zhou 2018].
Selenium and Heart Disease
Heart disease. The evidence from clinical studies is increasing. Selenium deficiency is associated with an increased risk of heart trouble [Bomer 2020]. Selenium supplementation of elderly individuals who have low selenium status is associated with improved survival, improved heart function, and improved quality of life [Alehagen 2013].
Especially in northern Europe, clinical studies show the relationship between the need for selenium and the risk of heart disease. This makes sense because the dietary selenium intake in northern Europe is considerably lower than the dietary selenium intake in much of the United States. Consequently, the mean plasma selenium concentrations in Europe tend to be well below 80–90 mcg/L. In the USA, on the other hand, the mean plasma selenium concentrations are generally above 120 mcg/L [Alehagen 2022].
Heart Failure Risk and Selenium Deficiency
Low plasma selenoprotein P levels are associated with a higher risk of heart failure in a Swedish population [Jujic 2023].
Plasma and serum selenoprotein P concentrations are useful biomarkers of selenium status in individuals with relatively low selenium intakes because selenoprotein P responds to different intake forms of selenium [Hurst 2010].
Selenium deficiency – defined as serum selenium concentrations below 70 mcg/L – has been associated with more severe symptoms of heart failure, poorer exercise capacity, and poorer quality of life. Sub-optimal serum selenium concentrations of 70–100 mcg/L have similar adverse associations, suggesting that values less than 100 mcg/L, might be considered abnormal [Bomer 2020].
Selenium and Coenzyme Q10 Supplementation for Senior Citizens
In senior citizens, and delayed aging and longevity are associated with the antioxidant and anti-inflammatory protection derived from daily supplementation with selenium and Coenzyme Q10 [Alehagen 2023].
The KiSel-10 Study was a randomized, double-blind, placebo-controlled clinical trial of the effect of combined selenium and CoQ10 supplementation of senior citizens on cardiovascular mortality.
Researchers administered 200 micrograms of selenium in a selenium-rich yeast preparation and 200 milligrams of Coenzyme Q10 in the ubiquinone form or matching placebos to community living senior citizens daily for 48 months [Alehagen 2013].
Summary of Statistically Significant KiSel-10 Study Outcomes
- reduction of cardiovascular mortality in the active treatment group vs. the placebo group (5.9% vs. 12.6%) and better cardiac function observed on echocardiograms in the active supplementation group compared to the placebo group [Alehagen 2013]
- reduction of plasma levels of the N-terminal natriuretic peptide (NT-proBNP), a bio-marker for increased risk of heart failure [Johansson 2013]
- improvement of health-related quality of life and fewer days in hospital [Johansson 2015]
- reduction of cardiovascular mortality in senior citizens with low serum selenium status [Alehagen 2016a; Alehagen 2016b]
- reduction of cardiovascular mortality that persisted after 10 and 12 years in the supplemented group and in subgroups with diabetes, hypertension, ischemic heart disease, and reduced functional capacity due to impaired cardiac function [Alehagen 2015a; Alehagen 2018]
- reduction of plasma levels of two bio-markers for oxidative damage [Alehagen 2015c]
- reduction of plasma levels of six bio-markers for systemic inflammation [Alehagen 2015b; Alehagen 2019b]
- reduction of serum levels of seven bio-markers for fibrosis [Alehagen 2017b]
- reduction of plasma levels of bio-markers for endothelial dysfunction [Alehagen 2020c]
- increase in plasma levels of insulin-like growth factor-1, attenuating an age-related decline in IGF-1 concentrations [Alehagen 2017a]
- reduction of fructosamine concentration compared with the concentration in the placebo group, which tended to increase, important because fructosamine concentration is positively associated with incidence of diabetes and increased blood glucose level [Alehagen 2020b]
- improvement of renal function in elderly citizens deficient in selenium [Alehagen 2020a]
- prevention of an increase in D-dimer levels, which are associated with increased risk of thrombotic disorders [Alehagen 2021]
- association with significant changes in metabolic profiles and with significant changes in the pentose phosphate, the mevalonate, the beta-oxidation, and the xanthine oxidase pathways [Alehagen 2019a]
- association with significant changes in circulating microRNA [Alehagen 2017c]
- structural equation modelling that shows that antioxidant and anti-inflammatory effects are the primary underlying biological mechanisms to explain the success of the KiSel-10 study [Alehagen 2022b]
- decrease in concentrations of fibroblast growth factor 23 (FGF-23) [Alehagen 2022a]
- less shortening of leukocyte telomere length [Opstad 2022]
- increase in serum SIRT1 concentrations [Opstad 2023]
- improvement in serum free thiol levels, supporting a reduction in systemic oxidative stress [Dunning 2023]
- positive effects on five age-related blood biomarkers – ICAM-1, adiponectin, leptin, stem cell factor, and osteoprotegerin – indicating an anti-aging direction compared to placebo [Alehagen 2023].
Conclusion: Delayed aging and longevity associated with Selenium and Coenzyme Q10 for senior citizens
Professor Urban Alehagen and Professor Jan Aaseth have explained an important biological interrelationship between selenium and Coenzyme Q10 and pointed to a theoretical advantage in using both substances in an intervention if there are deficiencies within the population [Alehagen 2015d].
Selenium Protects Against Cadmium Poisoning and Atherosclerosis
Cadmium leaking from iron water pipes into drinking water may be a primary cause of increased risk of atherosclerosis – the increased risk of a buildup of plaque on the inside of the artery walls with inflammation as a consequence. This is the thesis of the Danish cardiologist Anton Dorph-Petersen.
Dr. Dorph-Petersen asserts that the danger of cadmium toxicity is greatest in regions of the world in which the selenium content of the soil and plants is low and in regions of the world in which there is low dietary intake of selenium containing fish [Dorph-Petersen 2017].
Let me lay out Dr. Dorph-Petersen’s reasoning step by step. His hypothesis has not yet been verified by clinical trials.
However, we do know from a survey of 15,689 study participants in the US that low blood selenium and high blood cadmium are independent risk factors for heart failure.
Selenium and Systemic Oxidative Stress
Oxidative stress. A new study shows that selenium supplementation together with Coenzyme Q10 supplementation reduces the levels of systemic oxidative stress in the body. In the study, the reduction of systemic oxidative stress is significantly associated with a reduction in the risk of death from cardiovascular diseases [Dunning & Alehagen 2023].
Oxidative stress: An imbalance of harmful free radicals vis-à-vis protective antioxidants leads to oxidative damage to DNA, lipids, and proteins in the body and to a disruption of redox signaling processes in the cells [Dunning & Alehagen 2023].
In a 2023 KiSel-10 sub-analysis, Prof. Urban Alehagen and his research colleagues investigated the level of free thiols in the serum of elderly study participants taking 200 mcg of selenium and 200 mg of Coenzyme Q10 daily for 48 months [Dunning & Alehagen 2023].
Selenium Supplementation Increases Serum Sirtuin1 Concentrations
Daily supplementation with 200 mcg of selenium and 200 mg of Coenzyme Q10 for four years has resulted in significant increases in serum SIRT1 concentrations. In the parallel placebo group, the serum SIRT1 concentrations decreased significantly [Opstad, Alehagen 2023].
This is the latest evidence from the KiSel-10 Study in which researchers randomly assigned elderly community-living Swedish men and women, average age: 76 years, 49% female, to a combined selenium and Coenzyme Q10 treatment group or to a placebo group [Alehagen 2013].
In earlier papers, the KiSel-10 Study researchers have reported beneficial effects of the combined supplementation of the elderly Swedish citizens with low baseline selenium levels [Alehagen 2022; Opstad 2022]: