Selenium protects against dangerous cholesterol
- atherosclerosis, and early death
Cholesterol is an essential compound with many different functions. However, it can also turn into a potentially dangerous substance if it oxidizes and is embedded in the blood vessel walls. This oxidative process is what eventually leads to atherosclerosis. The trace element selenium protects against atherosclerosis because of its antioxidant properties and because of other mechanisms, according to a review article published in Biomedicine. This is highly relevant in our part of the world where cardiovascular disease is the leading cause of death, and where selenium deficiency is so widespread.
For years, selenium deficiency has been associated with countless cardiovascular problems, including atherosclerosis, cardiac insufficiency (heart failure), ischemic heart disease, and coronary thrombosis. In their new review article, the authors look closer at different cardiovascular diseases and selenium’s role in regulating various pathological processes such as oxidative stress, chronic inflammation, embedding of oxidized cholesterol in the vessel walls, calcium depositions, and dysfunctional cells in the endothelial layer of the blood vessels. The authors also look at selenium supplementation and its potential to prevent and treat cardiovascular disease and atherosclerosis, which involves other factors than cholesterol alone.
- Cholesterol is important for cell membranes, the immune defense, and for making steroid hormones (sex hormones and cortisol), vitamin D, and Q10.
- Cholesterol is synthesized from carbohydrates in the liver
- There is dietary cholesterol in eggs and animal fat
- Most of the body’s cholesterol is made by the liver
Selenium counteracts oxidative stress and chronic inflammation that damages cholesterol
We humans generate free radicals as part of our cellular oxygen turnover and other metabolic processes. The free radical load is increased by tobacco smoke, poisoning, ageing processes, overweight, and chronic diseases like diabetes. Free radicals are highly reactive molecules that, by nature, should only operate withing very narrow boundaries.
Oxidative stress occurs when protective antioxidants such as selenium are outnumbered by free radicals. It is particularly harmful if the free radicals attack cholesterol in the blood. Here, cholesterol is carried by LDL (low-density lipoprotein) that serves as a transport unit. If LDL oxidizes it goes rancid and the cholesterol is no longer functionable. What happens next is that the oxidized cholesterol is consumed by monocytes, a type of white blood cells, and turned into so-called foam cells. These cholesterol-laden foam cells gravitate towards areas in the vessel wall that are already inflamed due to factors such as elevated blood pressure, lesions, bacteria, LPS (lipopolysaccharides on the cell walls of certain bacteria), spike proteins (from COVID-19 infections and COVID-19 vaccines), and other irritants. When the engorged foam cells have entered the blood vessel wall, they perish, leaving the oxidized cholesterol. This increases local inflammation and attracts even more foam cells. It’s a vicious cycle.
Therefore, it is oxidative stress, chronic inflammation, and accumulation of cholesterol-containing foam cells in the vessel wall that cause atherosclerosis, not the cholesterol as such. Whether a person has high or low cholesterol levels makes no difference. In the review article the authors describe how the powerful antioxidants called GPX (glutathione peroxidase) combat free radicals and many different markers of chronic inflammation. Selenium has also been seen to prevent foam cells from forming. Selenium supplementation generally has the ability to reduce oxidative damage to molecules, cells, organs, and tissues. The authors therefore conclude that selenium protects against atherosclerosis by counteracting oxidative stress and chronic inflammation, which are also related to one another.
Selenium, calcium deposits, and atherosclerosis
Atherosclerosis is a complicated process. In its final stages, it also includes a fibrin layer and a type of calcium lattice that surrounds the embedded foam cells in the vessel wall. Here, the muscle cells in the soft tissue of the vessel wall play a key role, as they express different genes that remind of ones involved in bone formation, and they may cause calcium to be deposited in the tissue.
More and more science points to oxidative stress as a factor that makes soft muscle cells initiate these unwanted calcium depositions in the vessel walls. Selenium is believed to counteract this process because of its role as an antioxidant and its anti-inflammatory properties.
Selenium, endothelial cells, and other functions
Endothelial cells form a dense layer that lines the blood vessels. They are especially important for capillaries where the metabolism from tissues and organs takes place. Selenium as an antioxidant protects the endothelial cells against free radicals and apoptosis (programmed self-destruction of cells). Also, selenium protects microRNA that regulates and adjusts the DNA expression of cells. Studies altogether suggest that selenoenzymes and selenoproteins have several vital roles in supporting normal endothelial cell function.
- Around one billion people worldwide are believed to lack selenium
- Selenium deficiency, atherosclerosis, and early death are often related
Human studies of selenium supplementation
The link between selenium deficiency and cardiovascular disease has been known since the 1960s. Here, scientists discovered a serious heart condition in the Keshan Province of China, where the soil is very low in selenium. Keshan disease, as this condition was named, affects the heart muscle and is caused by an otherwise harmless virus called Coxsackie that can be potentially life-threatening if contracted by a selenium deficient person.
However, the disease was effectively eradicated with help from selenium supplements.
Finland, a country with notoriously low selenium in the soil, used to have the highest rate of coronary thrombosis worldwide. In the mid-1980s, however, when mandatory selenium-enrichment of fertilizers was introduced by the government, the disease rate plunged.
Also, the Swedish KiSel-10 study showed that older people who got daily supplementation with 200 micrograms of selenium yeast and 200 mg of pharmaceutical-grade Q10 for five years had better heart muscle function and a 54 percent lower cardiovascular mortality rate compared with those who got matching placebo. The combination of these two supplements is highly relevant in Scandinavia where the soil is also low in selenium. Moreover, our endogenous Q10 synthesis decreases as we grow older, so there is also an increased need for this compound. Furthermore, Q10 and selenium work as a team and support each other. A 12-year follow-up of the KiSel-10 study revealed that supplementation with Q10 and selenium has a long-term protective effect on the heart, the epithelial cells, microRNA, telomeres (a measure of biological aging), and lifespan.
There are also other controlled, randomized studies where selenium has been shown to prevent atherosclerosis, cardiovascular disease, and early death in populations with low selenium status. Selenium and zinc also protect against poisoning from heavy metals like mercury and cadmium, which is a problem that is associated with cardiovascular disease.
Selenium supplements generally have the best effect on people who live in areas with low selenium content in the soil. Also, it is important for the overall result to take selenium for a prolonged period in order to have optimal selenium levels in the blood throughout life. It can even be a good idea to take selenium in combination with other antioxidants like Q10, vitamin D, and zinc.
- The agricultural soil in Europe is low in selenium. This is reflected in the crops
- The average diet provides less than 50 micrograms of selenium daily
- According to the new Nordic Nutrient Recommendations, women need 60 micrograms of selenium daily, while women need 90.
- Many selenium studies haver been conducted using 200 micrograms per day
- Make sure to choose pharmaceutical-grade selenium with documented absorption and good bioavailability
Siarhei A. Dabravolski et al. The Role of Selenium in Atherosclerosis Development, Progression, Prevention and Treatment. Biomedicines 2023
Juan Pablo Robles. The spike protein of SARS-CoV-2 induces endothelial inflammation through integrin α5β1 and NF-kB signaling. Journal of Biological Chemistry. 2022
Urban Alehagen et al. Improved cardiovascular health by supplementation with selenium and coenzyme Q10: applying structural equation modeling (SEM) to clinical outcomes and biomarkers to explore underlying mechanisms in a prospective randomized double-blind placebo-controlled intervention project in Sweden. European Journal of Nutrition. 2022
Uffe Ravnskov. Hvorfor et højt kolesterol er nyttigt. Hovedland. 2010
Hjerte / Kredsløb Arkiv - (vitalraadet.dk)
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