Selenium is an essential trace element that is important for many functions in the body. Recent research shows that selenium slows down aging and may even protect against age-related diseases. This article reviews the latest research on selenium's role in aging, says medicalnewstoday.com.
Selenium is a trace element, which means that the body needs it only in very small amounts. It is found naturally in many foods and is also available as a dietary supplement. Most of the selenium we take in with food is stored in muscle tissue, although the thyroid gland is the organ with the highest concentration of this trace element. Selenium is an important component of enzymes and proteins - known as selenoproteins - that play key roles in reproduction, thyroid hormone metabolism and DNA synthesis.
Selenoproteins also act as powerful antioxidants that help protect against free radicals. They are unstable atoms that form naturally in the body as a byproduct of normal body functions. They cause damage to cell membranes and DNA. Over time, this can lead to inflammation, premature aging of the skin, and a host of age-related ailments.
Benefits of it
Biological aging is a complex process that involves molecular damage, metabolic imbalance, changes in the immune system, and increased susceptibility to environmental stressors and disease. According to a 2018 review, selenium may fight aging and prevent age-related he alth problems such as tumors, cardiovascular disease, and neuropsychiatric disorders. Some researchers also believe that selenium may reduce chronic inflammation, which is closely related to aging.
According to research, selenoproteins are primarily responsible for many of the he alth benefits of selenium. For example, a 2021 review found that selenoproteins play a key role in controlling and removing misfolded proteins that accumulate as we age. Experts note that the accumulation of misfolded proteins is a common feature of aging and age-related diseases, including type 2 diabetes and Alzheimer's disease.
Experts also believe that selenium protects the skin from ultraviolet (UV) oxidative stress by stimulating the selenium-dependent antioxidant enzymes glutathione peroxidase (GPx) and thioredoxin reductase (TDR). TDR is located in the plasma membrane of epidermal keratinocytes. This can potentially help fight skin aging caused by UV exposure.
A 2020 study found that increased dietary selenium intake is linked to the creation of longer telomeres in the body. This study found that each 20 microgram increase in dietary selenium intake was associated with 0.42% greater telomere length in participants over the age of 45. Telomeres are "protective caps" located at the ends of our chromosomes that affect how quickly our cells age.
Some experts consider telomere length to be an informative biomarker of aging. Researchers also believe that higher levels of selenium are associated with longevity. Mortality in elderly people with low selenium levels is significantly higher. However, it is important to note that the results remain controversial and more research is needed on the topic.
Should we take it as a supplement?
Overall, research remains conflicting regarding selenium supplements and their effects on aging. According to the 2018 review discussed above, most studies indicate that selenium supplements have antiaging properties and prevent age-related diseases. However, more studies are needed to clarify its role. There is currently no solid evidence that selenium supplementation is beneficial in a person who is not at risk of deficiency.
Selenium deficiency is rare in the US due to the trace element-rich soil found throughout North America. However, some groups of people are at risk of selenium deficiency. Such are those living with HIV, people with kidney failure requiring hemodialysis, residents of regions with low levels of selenium in the soil, including some European countries, Russia and China. The risk is further increased in people who follow a vegetarian or vegan diet. Selenium deficiency can impair the ability of cells to grow and divide, contributing to aging. It can also lead to delayed wound healing, cataract development.
Most adults need 55 micrograms (mcg) of selenium per day. However, pregnant women should consume 60 mcg. During breastfeeding, the need for selenium further increases to 70 mcg. Since the human body does not generate its own selenium, it is essential to obtain optimal amounts from food to benefit overall he alth. Fortunately, selenium is found in a wide variety of foods that can be easily incorporated into a person's diet. Brazil nuts, seafood, and meat are among the highest dietary sources of selenium. Other good food sources of selenium are tuna, halibut, sardines, beef, ham, shrimp, cottage cheese, brown rice, boiled eggs, whole grain bread, beans/lentils.
If a person consistently exceeds the recommended upper limit of 400 mcg of selenium through food or supplements, it can lead to adverse he alth effects. One of the first signs of excessive selenium intake is garlicky breath and a metallic taste in the mouth. Other signs of chronically high selenium intake are: hair loss and brittle hair and nails, skin lesions, mottled or decayed teeth, nausea, diarrhea, fatigue, irritability.