Many elderly adults have low serum selenium concentrations. This is especially true in the United Kingdom and much of Europe and the Middle East [Stoffaneller & Morse 2015]. Now, a published report shows that over 80 % of the 85-year-old adults in a study in northeastern England had suboptimal serum selenium and selenoprotein P concentrations. Over 40 % had deficient selenium status, judged by reference values derived from studies of healthy adults in all age categories [Perri 2024].
Suboptimal serum selenium status was defined as 70 mcg/L or lower. Serum selenium deficiency was defined as 45 mcg/L or lower.
The researchers observed a linear association between serum selenium levels and serum selenoprotein P (SELENOP) levels. SELENOP is the primary transport protein carrying selenium from the blood to the peripheral tissues. The findings in this study indicate that most study participants had suboptimal selenium intakes and status. Their diets were not sufficient to saturate the level of circulating SELENOP [Perri 2024].
Low Selenium Status Associated with Health Outcomes
The analyses of the data from the English 85-year-olds revealed the following significant associations of lower selenium status [Perri 2024]:
- with higher medication counts
- with poorer self-rated health reports
- with lower cognitive performance scores
- with higher systemic inflammation values
- with higher free T4 hormone and lower free T3 hormone
- with higher BMI, fat-free mass, and waist:hip ratio
Note that the above listed correlations are from a cross-sectional study. They cannot be used to establish cause and effect.
Determinants of Serum Selenium Status
The Newcastle 85+ study results showed that higher concentrations of all three biomarkers of selenium status – serum selenium, serum SELENOP, and GPx3 activity – were associated with higher protein intake. Foods high in protein content tend to contain higher amounts of selenium.
Note: GPx3 is the selenoenzyme glutathione peroxidase-3. Its expression reaches a saturation point at serum selenium levels well below the serum selenium levels needed to saturate SELENOP. GPx3 expression seems to reach the saturation point when the plasma/serum selenium concentration is approximately 90 mcg/L [Hurst 2010]. To optimize the concentration of SELENOP, the serum selenium concentration needs to be in the range 120-130 mcg/L [Larsen 2024].
Additional predictors of serum selenium concentration were as follows:
- sex (females had higher concentrations)
- waist:hip ratio
- disease count
- self-rated health reports
The study results also indicated that concurrent illness is a notable risk factor for suboptimal selenium status, particularly among very old adults [Perri 2024].
Supplementation of Swedish Citizens Low in Selenium
In the KiSel-10 study of the effect of combined selenium and coenzyme Q10 supplementation of elderly Swedish citizens low in selenium, Prof. Urban Alehagen et al observed beneficial health effects of the daily supplementation. Compared to placebo, the active treatment of 200 mcg/day of selenium from selenium-enriched yeast together with 200 mg/day of coenzyme Q10 significantly improved [Alehagen 2018]:
- heart health
- inflammation biomarkers
- oxidative stress biomarkers
- survival
Conclusions: Selenium Status in elderly adults
The Newcastle 85+ study results show that there is a high prevalence of
suboptimal selenium status in very old adults in northeast England.
It seems likely that adults with selenium and SELENOP concentrations below 45 mcg/L and 2.6 mg/L, respectively, will have considerably elevated health risks.
There is a need for longitudinal studies of the relationship between selenium intake and status at baseline and subsequent health outcomes.
Sources
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.
Hurst R, Armah CN, Dainty JR, Hart DJ, Teucher B, Goldson AJ, Broadley MR, Motley AK, Fairweather-Tait SJ. Establishing optimal selenium status: results of a randomized, double-blind, placebo-controlled trial. Am J Clin Nutr. 2010 Apr;91(4):923-31.
Larsen C, Winther KH, & Bonnema SJ, et al. Selenium supplementation and placebo are equally effective in improving quality of life in patients with hypothyroidism. Eur Thyroid J. 2024 Jan 1;13(1):e230175.
Perri G, Mathers JC, Martin-Ruiz C, Parker C, Walsh JS, Eastell R, Demircan K, Chillon TS, Schomburg L, Robinson L, Hill TR. Selenium status and its determinants in very old adults: insights from the Newcastle 85+ Study. Br J Nutr. 2024 Mar 14;131(5):901-910.
Stoffaneller R, Morse NL. A review of dietary selenium intake and selenium status in Europe and the Middle East. Nutrients. 2015 Feb 27;7(3):1494-537.
The information presented in this review article is not intended as medical advice. It should not be used as such.