Selenium is an essential mineral for human health, although it is required in small amounts. It plays a crucial role in numerous body functions, offering important benefits for immunity, thyroid health, and cellular protection against oxidative stress.
In this article, we will explore the benefits of selenium, natural sources, and potential risks associated with excessive consumption.
What is selenium?
Selenium is a trace element found in soil, water, and certain foods. The body cannot produce it, so it must be obtained from diet or supplements. It is an important component of enzymes and proteins known as selenoproteins, which contribute to antioxidant processes and thyroid function.
Health benefits of selenium
- Antioxidant protection
Selenium is a powerful antioxidant that helps fight free radicals and reduce oxidative stress. It contributes to the protection of cells from damage caused by free radicals, thus reducing the risk of chronic diseases such as cardiovascular disease and cancer. - Supports thyroid function
The thyroid gland contains the highest concentration of selenium in the body. The mineral helps regulate thyroid hormones and protect the gland from oxidative stress. Selenium deficiency can affect thyroid function, contributing to conditions like hypothyroidism. - Boosts immunity
Selenium stimulates the immune system, improving defense against infections and diseases. Selenoproteins help maintain the normal functioning of immune cells and reduce inflammation in the body. - Reduces cardiovascular disease risk
Adequate selenium intake can help lower the risk of heart disease by reducing inflammation and improving blood flow. It also contributes to reducing oxidative stress, which can damage blood vessels. - May have anticancer effects
Research suggests that selenium may play a role in reducing the risk of certain types of cancer, such as prostate, lung, and colon cancer. The anticancer effects of selenium are attributed to its ability to protect DNA and reduce the proliferation of cancer cells. - Supports brain health
Selenium may help prevent neurodegenerative diseases like Alzheimer’s and Parkinson’s due to its antioxidant and anti-inflammatory effects.
Natural sources of selenium
Selenium is found in a variety of foods, depending on the selenium content in the soil in which they are grown. Some of the best sources include:
- Brazil nuts (the richest natural source)
- Fish and seafood (tuna, sardines, salmon, oysters)
- Meat (liver, beef, chicken, turkey)
- Eggs
- Whole grains
- Vegetables (broccoli, spinach, mushrooms)
Recommended daily intake (RDI)
- Adults: 55 micrograms/day
- Pregnant women: 60 micrograms/day
- Breastfeeding women: 70 micrograms/day
Brazil nuts contain an extremely high amount of selenium, so just one nut can cover the daily requirement. However, they should be consumed in moderation to avoid excessive intake.
Selenium deficiency
Selenium deficiency is rare but can occur in areas with selenium-deficient soils. Symptoms include:
- Weakened immune system
- Excessive fatigue
- Thyroid disorders
- Hair loss and brittle nails
Risks of excessive selenium consumption
Excessive selenium intake can lead to toxicity (selenosis), with symptoms such as:
- Hair loss
- Garlic-like breath odor
- Nausea and vomiting
- Neurological problems
- Liver and kidney damage
The safe upper limit is 400 micrograms/day for adults.
Selenium is an essential mineral for overall health, offering significant benefits for immunity, thyroid function, and protection against oxidative stress. However, it is crucial to maintain a balance, as both deficiency and excess selenium can have negative effects on health. By following a balanced diet that includes natural sources of selenium, we can enjoy the benefits of this essential mineral.
Pay attention to your body’s signals, and if in doubt, consult a doctor or nutritionist for personalized recommendations!