wedish scientists have found a substantially increased heart failure rate among people with low blood levels of the essential micronutrient selenium.
Now, you have yet another reason to make sure to get plenty of selenium from your diet. Scientists from the University of Lund in Sweden have found that people who are deficient in the nutrient have an increased risk of heart failure – even if they do not have a history of heart trouble.
The recent study1, which is published in the science journal Free Radical Biology and Medicine, includes 4,803 men and women, all of whom participated in the large Swedish population study, Malmö Förebyggande Medicin. The researchers looked at their blood levels of selenium and compared these with the prevalence of heart failure.
Double risk
”Our study shows that there is a link between low selenium levels and an increased risk of heart failure during a follow-up period of 15 years. In the 20 percent of participants with the lowest selenium status the risk was twice as high as in those with most selenium,” says postdoc, Amra Jujic, PhD, who headed the study.
The Swedish team of scientists already knew about selenium’s role in heart health from earlier research.
“Back in 2019, our research team showed that selenium deficiency is linked to a worse prognosis among patients who have already been diagnosed with heart failure,” says chief physician and cardiologist at Skånes Universitetssjukhus, Martin Magnusson, who is a co-author of the new study.
Supports earlier findings
The study supports earlier research headed by Professor Urban Alehagen, a Swedish cardiologist. In collaboration with a group of research colleagues, Alehagen demonstrated that healthy male and female seniors who were given a daily supplement of selenium for five years had a 54 percent lower risk of dying of cardiovascular disease compared with those who got a placebo. Besides the tablets with 200 micrograms of selenium yeast (SelenoPrecise), the participants in the active treatment group got two 100-mg capsules with the vitamin-related substance coenzyme Q10.
The study2, which was published in 2013 in the International Journal of Cardiology, also showed that the heart muscle performance of the participants who got selenium and coenzyme Q10 had improved substantially. This was demonstrated with help from cardiac ultrasound (or echocardiography) that is used to examine the heart. Also, the scientists measured levels of a specific protein called NT-proBNP, which is released by the cardiac muscle when working under stress. Higher levels of this compound indicate the heart is strained. In the Q10 and selenium groups, levels were reduced.
Anti-inflammatory properties
Over the five-year course of the study, blood samples were collected in the active treatment group and the placebo group. These blood samples were stored in freezers for further analysis. The researchers have looked at how selenium and coenzyme Q10 have affected other biomarkers and found a consistent pattern. For example, various inflammation markers that typically move in one direction as a natural part of the ageing process, have turned out to move in the opposite direction in the group that was supplemented. This is a clear sign that selenium and coenzyme Q10 have anti-inflammatory properties, which can have a positive effect on cardiovascular health and numerous other things. So far, around 23 individual studies have been conducted by analyzing these blood samples, each time looking for new markers. Every single study is published, and new research projects are in the pipeline.
Low blood selenium levels
The KiSel-10 study, as the original randomized, double-blind placebo-controlled study is named, was quite special in that it was carried out on seemingly healthy seniors and not people with specific diseases. Some of them may have had various age-related conditions such as moderate hypertension, type 2 diabetes, or similar undiagnosed health problems, but they were viewed as a representative selection of the normal ageing population. What the researchers did observe after studying the blood tests, however, was that this group of men and women had comparatively low selenium status (67.1 mcg/L). This is not uncommon for Europeans. One of the reasons is that the agricultural soil in vast parts of Europe contains very little selenium, which is reflected in the selenium content in crops and the food chain in general.
UK soil is selenium-depleted
Great Britain is no exception. A recent statistical analysis revealed that selenium intake in the UK is low, with around 50.3 percent of women and 25.8 percent of men getting less than the lower reference intake for this nutrient. This issue may be compounded by the fact that several agricultural surveys have pointed to low selenium levels in agricultural soil in the UK.
A soil survey from 2000 found that 74 percent of samples fell below the threshold that is viewed as adequate for ensuring sufficient selenium status in grazing animals. Also, a 2009 study of Scottish soils found that 90 percent of samples were classified as deficient.
As far back as in 1997, Professor Margaret Rayman mentioned in her article3 (“Dietary Selenium: Time to Act) in British Medical Journal that there was evidence of dwindling selenium intake in Europe. She wrote specifically that selenium intakes 22 years ago (which was in the mid-70s) was 60 micrograms per day, which was not high compared with American intakes but very much higher than the 34 micrograms per day found in a survey undertaken for Britain’s Ministry of Agriculture Fisheries, and Foods in 1994.
Last year, the so-called Nordic Nutrient Recommendations were updated, introducing substantial increases. The recommended selenium intake was increased by 50 percent in Denmark, Norway, Sweden, Finland, Island, and the Baltics. According to the new guidelines, men should get 90 micrograms of selenium daily, while women need 70. Even this intake falls short of studies suggesting that it takes around 100 micrograms of selenium daily to optimize health.
SOURCES
1 Free Radical Biology and Medicine, Volume 207, October 2023, Pages 11-16
2 International Journal of Cardiology, 2013 Sep 1;167(5):1860-6
3 BMJ, 1997 Feb 8;314(7078):387-8.
