Selenium, Healthy Aging and Longevity
One of the recent studies by Akbaraly and C. Berr was based on the results obtained by the Arterial Aging Study of 1991. It examined the effects of nutrition on aging and looked at the correlation between mortality and the amount of selenium in blood. This was quite a comprehensive study that covered 1400 older adults aged between 59 and 71.
The study found that selenium concentrations in the blood may well be related to longevity. 101 people that died during the study had fewer amounts of selenium in their blood 1.01 μmol / L vs 1.10 μmol / L. And 45 of these people died because of different cancers and they concluded that the lack of selenium may well be related to cancer.
22 people died because of cardiovascular problems but the team could not find a link between low selenium levels and this type of death. The death risk was multiplied by 1.5 per each decrease of 0.2 μmol / L of selenium in blood. The team analyzed all the data on hand very thoroughly and they had a look at the relationship between oxidative stress indicators like the glutathione peroxidase and vitamin E.
There was no link between the oxidative stress parameters but selenium levels and mortality were definitely related. Selenium was first discovered by the Swedish chemists Gahn and Berzelius in 1817 and the toxicity of the element was pointed out at the time. Then in 1950s experts found out that selenium can be risky if found in too small or too large amounts in the body.
The trace element selenium is integrated into the form of an amino acid in selenoproteins that are involved in keeping the balance between the free radical production and your body’s defense system. So you will actually find that selenium is involved in a variety of physiological processes in the body like the carcinogens, heart disease, viral infections, immune system, reproduction and viral infections.
Oxidative stress is the main connection between selenium and mortality. The glutathione peroxidase enzyme for which selenium is necessary for its proper functioning is important for defending your body. However, the link found between selenium and mortality is just a hypothesis at this stage. Further studies are needed, to apply the same to other populations and verify the dosage of the enzymes.
Selenium is found in high amounts in chicken, turkey, beef, pork, fish, shellfish, eggs, and also in adequate amounts in legumes- peas and beans. But taking it as a supplement can be a little risky as high amounts of selenium can be toxic for your body. And we do not know the exact amount needed for the elderly and/or how much of selenium is left in the body after you take the supplement. WHO recommends 400 mcg per day rather than the 800 mpg that was recommended earlier, for a larger safety margin.
The German scientist Klaus Schwarz discovered that his lab rats were developing the liver disease because of their source of protein- torula yeast lacking selenium. And this stopped when he switched them from torula yeast to baker’s yeast. There is no doubt that selenium plays very important roles in your body by integrating into 25 or so selenoproteins throughout your body: Removal of dangerous toxins, a powerful defense mechanism against cancer, maintaining the immune system, supporting optimal thyroid function and more.
Another Chinese study that had a look at 446 people’s plasma selenium levels, 238 of which were between 90 and 100 years of age and 208 people were over 100 years old. They found that the oldest had the highest concentrations of selenium, zinc and other minerals that are essential for body’s defenses. In a few studies carried out in the 90s and later, selenium supplementation was shown to protect against and reduce cancer rates by about 24%, especially the prostate, colorectal and lung cancers.
And selenium deficiency was linked to increased cancer risk (liver, stomach, lung, esophagus, and bladder) in many other large-scale epidemiological studies. The three forms of selenium that are most useful for fighting cancer are sodium selenite (boost’s immune response to abnormal cells), L-selenomethionine (stops cancer at the earliest stages), and selenium-methyl L-selenocysteine (induces apoptosis in cancer cells, kills the mature cancer cells that have been missed earlier). And it is not just about cancer, but also about preventing DNA damage and a variety of age-related chronic diseases like cognitive decline, and cardiovascular diseases.
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