If we were to keep a list of all the nutrients our bodies need to survive, and check the composition of all foods to make sure we’re getting them, we’d have to spend all day shopping. Fortunately, the foods we eat, if we are a little careful, provide us with sufficient quantities of all of them. This includes micronutrients: vitamins and minerals.
Glutathione: what it is, why you need it, and how to get more
Many people know the importance of calcium, sodium, magnesium or iron for health. But there are other lesser known minerals that are just as important, and really micro. A good example is selenium. We need it in tiny amounts, about 70 micrograms a day (a microgram is one millionth of a gram). However, if it is not in our diet, the problems begin.
Selenium plays an important role in disease prevention, as well as helping to maintain a healthy immune system and metabolism. The main sources of selenium are Brazil nuts, fish and liver. People with very restrictive diets can easily forget about selenium.
Selenium not to rust
The main function of selenium is to act as an antioxidant, that is, to help protect cells from damage caused by free radicals that are generated in the normal functioning of the body. Selenium is an essential component of the enzyme glutathione peroxidase, on which glutathione, the antioxidant that our own cells produce for protection, depends.
If oxidation is controlled, there is less oxidative stress on cells. This means that inflammation is reduced and, with it, the risk of certain types of cancer, and also a better cardiovascular health, preventing the accumulation of plaque in the arteries. Additionally, selenium contributes to a healthy immune system by producing antibodies that fight viruses and bacteria.
Selenium is also involved in DNA synthesis and repair, which is important for keeping cells healthy and preventing mutations that could lead to cancer or other diseases. Additionally, selenium helps regulate thyroid hormones They control metabolism and growth. As such, selenium deficiency can make it more difficult to lose weight, even with controlled diet and exercise.
Finally, it has been shown that selenium has beneficial effects on fertility, Both men and women. Studies have found that higher selenium levels are associated with better sperm motility (movement), thus increasing the chances of conception. For women, higher levels of selenium can improve the quality of the eggs, which also increases the chances of becoming pregnant.
A lack of selenium can have serious health consequences, such as impaired immune system, leading to autoimmune diseases, and an increased risk of certain types of cancer. It can also cause infertility problems in both men and women, due to decreased sperm motility or egg quality, respectively. Additionally, low selenium levels may increase the risk of cognitive decline later in life, as we age, due to its role in DNA synthesis and repair, which keep our neurons healthy. Unfortunately, although deficiency is associated with a higher incidence of cognitive decline, selenium supplementation has not been shown to be enough to stop the progression of Alzheimer’s.
Why do we lose selenium
One of the problems of the current food system is the depletion of soils. 50% of the world’s agricultural production uses artificial fertilizers, which usually contain nitrogen, phosphorus and potassium, and with luck sulfur, magnesium and calcium, but very rarely other elements, and even less selenium, with which they disappear of the soil and, therefore, of the plants. At the same time, if it is missing from the grasses and grain used to feed animals, it will be missing from meat as well. The result is a high prevalence of selenium deficiency worldwide, which may affect more than 1 billion peopleand that will worsen with climate change.
Due to a selenium intake among the population, in the 1970s in Finland the Government decided to supplement fertilizers with this element in the form of sodium selenate. In a analysis of the results it was possible to see how the crops had improved, the health of the animals and, most importantly, the deficiency of the population had practically disappeared.
Soil selenium deficiency depends on geography, with the poorest selenium soils found in Germany, Denmark, Scotland, Finland, and some Balkan countries. However, climate change, which acidifies soils, is depleting selenium across Europe and other parts of the world.
How to get the selenium you need from the diet
A balanced diet containing fish, shellfish, meat and nuts need not be deficient in selenium. Even so, it is easy to ensure the necessary dose with foods that contain this mineral in sufficient quantity.
This is the content of the foods richest in selenium per 100 grams:
- Brazil nuts: 1917 μg
- Kidneys: 312 μg
- Oysters: 154 μg
- Liver: 111 μg
- Tuna: 108 μg
- Octopus or cuttlefish: 90 μg
- Mussels: 89 μg
- Sunflower seeds: 79 μg
- Anchovies: 68 μg
- Chia seeds: 55 μg
- Wild salmon: 35 μg
With a single Brazil nut a day we will already get all the selenium we need. In fact, you have to be careful not to eat too many, since the toxic dose of selenium is around 400 μg. With other foods it can be difficult to achieve, as it would require eating a large amount. For example, eating more than 100 grams of chia seeds by the spoonful does not seem like a very pleasant experience, while 100 grams of fresh mussels or tuna may be more swallowable.
What is all this based on?