Results from an Italian study have added to the evidence that adequate selenium status is necessary to prevent heart disease, especially in elderly individuals.
The Italian study data showed that study participants with plasma selenium concentrations below 60 micrograms per liter were 1.9 times more likely to suffer from cardiovascular disease compared to study participants with higher selenium status [Giacconi 2021].
Reduced plasma selenium status was associated with elevated levels of biomarkers of inflammation, increased expression of cytokines, and down-regulation of sirtuins in peripheral blood mononuclear cells [Giacconi 2021].
Selenium Status and Risk of Cardiovascular Disease
In a clinical trial with combined selenium and Coenzyme Q supplementation of elderly citizens, average age: 78 years, with low selenium status (mean: 67.1 micrograms per liter), for 48 months, researchers found reduced cardiovascular mortality after 10 and 12 years of follow-up [Alehagen 2018, 2015).
In elderly study participants diagnosed with chronic heart failure, researchers found that individuals with serum selenium concentrations below 70 micrograms per liter had worse New York Heart Association class, more severe signs and symptoms of heart failure, poorer exercise capacity (6-min walking test), and poorer quality of life. Individuals with serum selenium levels between 70 and 100 micrograms per liter were nearly as badly off as the individuals with serum selenium levels below 70 micrograms per liter [Bomer 2019].
Observational Study Results
Giacconi et al. cite evidence from three observations studies that have shown an inverse association between plasma/serum selenium levels and the risk of cardiovascular disease within a range of 55-145 micrograms per liter [Giacconi 2021].
The Italian Study Design: Reduced Plasma Selenium and Heart Disease
The Italian researchers investigated the association between reduced plasma selenium status – defined as less than 60 micrograms per liter – in 858 healthy control persons (average age: 73.4 ± 9.3) and 606 heart disease patients (mean age: 72.5± 8.7).
In both healthy controls and heart disease patients, the researchers found a significant association of reduced plasma selenium status with increased values of the C-reactive protein bio-marker for inflammation, enhanced gene expression of cytokines and chemokines, increased copper/zinc ratios, and down-regulation of several sirtuins [Giacconi 2021].
Sirtuins = proteins that are necessary for the stability and functioning of the cells.
The conclusion from the data: Selenium deficiency is independently associated with cardiovascular disease and with elevated inflammatory bio-markers. Reduced selenium status affects the expression of cytokines, chemokines, and sirtuins.
Adequate Selenium Status as Protection Against Heart Disease
How does selenium help protect against heart disease? The Italian researchers explain [Giacconi 2021]:
- Many European and Middle Eastern countries have low dietary intake of selenium. Furthermore, selenium concentrations are known to decline with increasing age, thus putting the elderly at greater risk of selenium deficiency.
- Selenium as a component of the amino acid selenocysteine is important for the formation of selenoproteins with antioxidant and anti-inflammatory properties.
- Adequate selenium concentrations may reduce the risk of cardiovascular disease by increasing the expression of antioxidants such as glutathione peroxidase and thioredoxin reductase.
- Selenium deficiency or inadequate selenium status represent a risk factor for cardiovascular disease and atherosclerosis development.
- Glutathione peroxidase reaches maximum activity when plasma selenium concentrations are between 70 and 90 micrograms per liter.
Conclusions: Selenium Status and Risk of Heart Disease
Giacconi et al.  showed evidence for the following relationships:
- The risk of heart disease was significantly higher — 1.9 times higher — in subjects with selenium deficiency.
- The Italian study showed no difference between cholesterol and glucose values in relation to selenium status quartiles.
- The main mechanism by which selenium deficiency seems to promote heart diseases is the inflammatory pathway. Selenium deficiency induces
the expression of different cytokines while selenoproteins are involved in the modulation of pro-inflammatory genes.
- Among the relationships evaluated, only smoking ranked higher than selenium deficiency as a risk factor for heart disease
Alehagen, U., Lindahl, T.L., Aaseth, J., Svensson, E., Johansson, P. Levels of sPselectin and hs-CRP decrease with dietary intervention with selenium and coenzyme Q10 combined: a secondary analysis of a randomized clinical trial. PLoS One. 2015;10:e0137680.
Alehagen, U., Aaseth, J., Alexander, J., Johansson, P., 2018. 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;13,e0193120.
Bomer N, Grote Beverborg N, Hoes MF, Streng KW, Vermeer M, Dokter MM, IJmker J, Anker SD, Cleland JGF, Hillege HL, Lang CC, Ng LL, Samani NJ, Tromp J, van Veldhuisen DJ, Touw DJ, Voors AA, van der Meer P. Selenium and outcome in heart failure. Eur J Heart Fail. 2020 Aug;22(8):1415-1423.
Giacconi R, Chiodi L, Boccoli G, Costarelli L, Piacenza F, Provinciali M, Malavolta M. Reduced levels of plasma selenium are associated with increased inflammation and cardiovascular disease in an Italian elderly population. Exp Gerontol. 2021 Mar;145:111219.
The information presented in this review article is not intended as medical advice and should not be construed as such.
1 March 2021