Selenium: The mineral of youth
and why men may age faster than women!
Selenium is a mineral that was discovered in 1817 by John Jacob Berzelius. He named it after the Greek goddess of the moon – Selene.
Unfortunately, there seems to be no interesting reason for this apart from tellurium was named after the Roman goddess of the earth- Tellus.
Yet Selene the moon goddess was associated with love and selenium is critical for reproduction so maybe now the name fits!
Selenium is a superstar mineral offering protection against many health issues including cancer, infertility, cardiovascular disease and even viral infections.
But it is a recent addition to our therapeutic medicine cabinet. Initially, it was thought it was toxic but then researchers saw the impact of selenium deficiency in lab animals around the 1950s. From then on, scientists have been looking at the role it plays in human nutrition.
In the 70s and 80s, they discovered how critical selenium was for making certain enzymes and finally was recognised as essential by the U.S National Research Council in 1987.
Have you heard of selenium?
Maybe not? This is a major mineral but often gets overlooked so I am hoping to remedy this!
I will be covering how and why selenium works, its benefits, food sources and supplement forms.
Where to start…
One of the special powers of selenium lies in its ability to make a very special enzyme called glutathione peroxidase.
It has a long name, but it deserves one as it does a lot!
Glutathione peroxidase protects cells from oxidative damage and maintains glutathione levels within the body.
It doesn’t sound like much but this is HUGE because glutathione is one of the most important substances in the body.
Oxidative damage is linked to pretty much every disease especially when it comes to ageing!
Glutathione is the master anti-oxidant and is key to longevity.
People with higher levels of glutathione are healthier and live longer.
If you want to learn more specifically about glutathione then head here:
Ultimately, if glutathione production depends on selenium then selenium becomes a very important mineral!
So let’s look at the benefits of selenium.
Benefits of Selenium:
Ok so selenium is associated with:
Clearing up with the free radicals associate with ageing and protect against those pesky age spots
Enhancing the formation of antibodies (the things we need to protect against unwanted things in the body)
Binding to mercury and cadmium- toxic heavy metals making them less damaging to the body (if mercury is bound to selenium then it won’t bind to something else like your brain!)
Working with Vitamin E to prevent heart disease, improve alertness, emotional wellbeing, decreasing depression, poor appetite and fatigue.
Supporting thyroid hormone metabolism- also reduces post-partum thyroiditis
Activating p53 – the tumour suppressing protein! Without selenium, we cannot regulate p53 and therefore, no tumours get suppressed.
Health Conditions and Selenium:
So there are some conditions that are associated with low selenium such as:
Keshan disease- this is probably the most extreme selenium deficiency pathology. It was discovered in China where people lived in low selenium areas and is a potentially lethal form of heart failure.
Cataracts- selenium acts as an antioxidant and prevents damaged cells from building up causing cataracts.
Anaemia and iron deficiency is linked to selenium due to reduced glutathione peroxidase activity.
Lung, skin and gastrointestinal cancers
Rheumatoid arthritis see low levels of selenium in the blood
Cystic fibrosis- often see low levels of selenium, Vitamin E and zinc.
Thyroid – the enzyme 1 iodothyronine deiodinase (IDI) is a selenoenzyme (based on selenium) and responsible for converting T4 into T3 in liver and kidneys.
Those with lower selenium when compared to those with the higher selenium levels had a higher likelihood of experiencing cognitive and neurological problems.
Plus cirrhosis, Crohn’s Disease, high blood pressure, arthritis, atherosclerosis, muscular dystrophy, infertility, macular degeneration, diabetic neuropathy, jaundice and premature babies.
Cancer patients with low selenium levels tend to have a wider spread of the disease, more recurrences and die sooner. Dr. Harold Foster
Cancer is a big one for selenium. We have lots of studies, one found that those who took the selenium had an overall decrease in all cancers of 35% compared to those on the placebo. Prostate cancer decreased by 63 %, lung cancer by 46 %, and colorectal cancer by 58 %, another study showed a decrease risk of 70% for bladder cancer!
An interesting study with animals with selenium deficiency when contaminated with flu virus, then the virus would mutate into a far more virulent strain when passed on. For example, mild pneumonia would turn into life threatening pneumonia. (I was listening to Thomas Cowan earlier who would probably rinse this study!)
There is also a connection with AIDS. The disease progression is coupled with a decline in selenium blood levels. Not only this, but HIV infection rates are highest in geographic areas of the world where soil selenium levels are the lowest and vice versa.
Overall, though studies have found that selenium blood levels fall as we age and those with the lowest levels experience shorter life spans.
Selenium sources:
Grains and cereals- soil quality
Seafood, kidney, liver, meat poultry
Garlic and asparagus
Brazil nuts, sunflower seeds, turnips, brown rice, blackstrap molasses, clams, scallops, salmon
For animal sources then kidneys are the best.
For plants then Brazil nuts win hands down. Scientists at the University of Otago in New Zealand found that eating just two Brazil nuts a day is effective in increasing selenium status and enhancing glutathione peroxidase activity. However, Brazil nuts will vary depending on soil that they are grown in etc..
Quick note: Unlike other minerals, cooking and boiling foods reduces selenium so that’s a win for the raw food crew.
Selenium deficiency:
Selenium in the soil varies across the world so some people have abundant selenium in their food from the soil being high in it.
A great example is Senegal. Senegal has one of the highest concentrations of selenium in the soil and guess what…Senegalese people have the world's lowest rates for cancer of the trachea, lung, stomach, and colon!
Overall, our soils are trending towards low selenium levels though. This is because of soil depletion from farming and also pollution causing high levels of sulphur and nitrogen makes it harder for selenium to bind to plant roots.
A few notes:
We need B6 to convert selenium to glutathione peroxidase.
Vitamin C could decrease absorption of selenium
Vitamin E also causes deficiency in selenium
Copper is also involved in making glutathione peroxidase.
The testicles are the storage point in the body for selenium. I love where this goes actually….so apparently the reason that females out live males is because “Men freely give as much selenium to the female as possible,” writes Dr. Richard Olree.
Selenium Toxicity:
Anything in the wrong quantities and form can be toxic and there is actually a therapeutic window for using selenium as selenium toxicity can also be a problem. Usually this is from exposure in industry.
The first symptom of selenium toxicity is a garlicy smelling breath and metallic taste in the mouth then hair and nail loss or brittleness.
Severe signs: irritation of eyes, nose, throat, congestion, nausea, hair loss, changes in nails fatigue, irritability, nausea, vomiting, or, garlic breath odour, metallic taste and mottled teeth.
However, it takes a huge, huge amount to be fatal. There are no deaths associated even with consuming 20 times the recommended amount.
Testing:
Hair mineral is a useful way of evaluating selenium levels which is great as I use this for many of my clients. You can do blood too. Maybe do both.
Supplementing with selenium:
There are many forms of selenium such as: selenocysteine, selenomethionine and methylselenic acid.
However, sodium selenite is commonly used in cheaper supplements and this one is inorganic and not typically found in food. Some studies have shown it increased risk of ALS and exacerbated breast cancer. So for this one, seems to be more downside to upside
High-dose selenised yeast (HSY) does well under research and has a good safety profile. It’s produced when selenium is naturally incorporated into the protein of growing yeast and has a high concentration of the selenium-containing proteins, selenomethionine and selenocysteine.
So whether its Brazil nuts, kidneys or yeast, get some selenium to protect from ageing, cancer and cataracts! And if you are a man definitely do this!