Lacking a special selenium protein in the blood increases your risk of heart failure

Having too little selenoprotein P in your blood increases the risk of heart failure, according to a Swedish population study, in which the authors look closer at selenoprotein P’s role as a marker of the body’s selenium status and as a precursor of other selenoproteins. We need more than 100 micrograms of selenium daily to properly saturate selenoprotein P, but because the European soil is low in selenium it is difficult to get enough from the diet.

Selenium deficiency has a long-established role in cardiovascular disease, impaired prognosis in heart failure, and early death. According to a recent population study, higher blood levels of selenium are also related to a lower risk of heart failure and early death, but only among non-smokers. The new Swedish study aimed to find if selenoprotein P (SELENOP) is related to the risk of heart failure.
The researchers measured plasma concentrations of selenoprotein P in blood samples from 4,803 participants from the “Malmö Preventive Project”. Seventy percent of the participants were men, the average age was 69.6 years, and 19.7 percent of the participants were smokers. Anyone with a history of heart failure was excluded from the study.
The researchers used ELISA (enzyme-linked immunoassay), a measuring method that reveals the concentration of specific proteins in a blood sample. Afterwards, they compared heart health in participants with the highest and lowest plasma levels of selenoprotein P
The follow-up period was 14.7 years, and the scientists observed an inverse relation between plasma levels of selenoprotein P and risk of heart failure. They concluded that having low levels of selenoprotein P in the blood increases the risk of heart failure in the general population, including smokers. The scientists referred to an earlier Swedish population study that found that low blood levels of selenoprotein P are linked to poor quality of life, increased risk of early death, and a worse prognosis in patients with acute heart failure.

Selenium deficiency causes cardiovascular disease

In the northeastern Chinese Keshan province, the agricultural soil contains very little selenium. It was in this region that a link between selenium deficiency and lethal heart disease was originally discovered in the 1930s. The disease was named Keshan disease and is caused by an otherwise harmless virus called Coxsackie B, which the immune system is unable to fight if a person lacks selenium. In the 1960s, the Chinese people in this region started eradicating the disease with help from selenium supplements.
Later, studies and meta-analyses have found a link between selenium deficiency and cardiovascular disease, including coronary artery disease (also called ischemic heart disease). Selenium deficiency can also increase the risk of cancer and other serious diseases.

How does selenium protect against cardiovascular disease?

Selenium is needed by the body to make between 25-30 different selenoproteins that help control energy turnover, immune defense, thyroid function, and different antioxidant mechanisms. The liver gets different selenium types from our diet, and they are all part of an intricate selenium metabolism. One of the selenoproteins, selenoprotein P, is the main carrier of selenium throughout the body. Once selenoprotein P is taken up by cells, it gets converted into the many other selenoproteins in accordance with body’s requirements.
The hard-working heart muscle uses selenium when producing energy. Selenium is also important for different antioxidant systems such as GPX that protects the heart and circulatory system against oxidative stress, where free radicals start chain reactions that can attack cells and tissues. Cholesterol, which is otherwise an essential compound, is only harmful if attacked by free radicals, which oxidizes it and causes oxidized cholesterol to accumulate in the blood vessel walls. It’s not cholesterol in itself that is the problem, it is when the cholesterol is damaged by oxidation that the problems occur and atherosclerosis develops. The risk of oxidative stress is increased by factors like age, stress, overweight, type 2 diabetes, smoking, poisoning, and the use of various types of medicine. Increased oxidative stress requires more antioxidant protection.

Optimal blood levels and the use of supplements

The optimal blood level of selenium is around 120 µg/L. In Europe, the average level is only around 70-85 µg/L, except for Finland. In the mid-1980s, the Finnish government introduced mandatory selenium enrichment of the soil. As a result of this measure, the average selenium intake in Finland has increased to 100-110 µg per day, which is sufficient to optimize selenium levels in the blood. However, there are still many Europeans who get far too little selenium, and that increases their risk of heart failure, cardiovascular disease, cancer, and many other diseases. It is therefore a good idea to consider taking a high-quality selenium supplement as a way of ensuring optimal blood levels of the nutrient.

Referencer:

Amra Jujic et al. Selenoprotein P deficiency is associated with higher risk of incident heart failure. Free Radical Biology and Medicine. 2023