Selenium is an essential mineral we all need – the trouble is, like with many other nutrients, we don’t always get enough of it. Luckily for me, my nutrition training means that I was able to tap into the many benefits of selenium years ago, and it’s now one of my favourite minerals to use therapeutically in the clinic, where I find it helpful for a range of different conditions. My patients also love their selenium once they start using it!
Selenium is found in the soil, which is where we ultimately source it from – depending on where our food has been grown. The amount of selenium in the soil can vary greatly from area to area – meaning that your intake also vary if you are eating foods that have been grown in selenium-poor soils. Here in Australia we are well-known to have poor-quality nutrient-depleted soils. In particular New Zealand soils are well-known to be extremely low in selenium.
If you don’t get enough of this crucial mineral, because of its widespread activity within the body, then there are many aspects of your health that may suffer. That’s because selenium plays a vital role in our enzymes – particularly those that are involved in our antioxidant network. Basically, it plays a role in protecting cells from damage.
Here are a few ways in which selenium works hard for you within your body:
Selenium & The Thyroid:
Selenium is one of the minerals needed for the thyroid gland and thyroid hormones to work properly. If you aren’t familiar with your thyroid, it happens to be a small gland in your neck that controls your metabolism, and if it is out of balance it can cause you to feel pretty ordinary. A sub-optimal thyroid may contribute to fatigue, hormonal imbalances, sleep disturbances, low moods, sluggish digestion and weight gain, just to name a few! So it is extremely important that your thyroid is kept happy.
If you are low in selenium, your body may have difficulty converting the storage form of thyroid hormone (T4) into the active form (T3) – the one that is responsible for doing most of the work within the body and keeps you feeling good. Selenium also helps iodine to work properly within the thyroid.
Selenium & Immunity:
This mineral is crucial for a healthy immune system – both for improving resistance to colds & flus, and in autoimmune conditions.
The mineral helps enhance the body’s own natural defences, which means that you can fight off infections far easier if you aren’t deficient. It also can have a potent anti-inflammatory effect, which helps your immune cells stay strong and healthy.
As part of its antioxidant duties, selenium helps men to produce healthy sperm. Sperm quality is known to be rapidly declining (by almost 50% over the past 40 years!), which is a huge concern for couples trying to conceive, as well as for future generations. Sperm are very susceptible to damage, and selenium assists with the formation of the male hormone testosterone, as well as normal development and activity of sperm. In other words – so that they develop properly and can swim well in order to fertilize the egg.
Selenium is even thought to play a role in cancer prevention (possibly by way of a few mechanisms such as its antioxidant activity and its immune-boosting properties), reducing inflammation and enhancing detoxification of heavy metals like lead and mercury.
Most of the selenium in foods is found in the form selenomethionine, which is very well absorbed by the body. The richest food sources of selenium include:
- Brazil nuts
- Wholegrain flours (wheat, rye)
- Sesame seeds
As with all minerals, just because there are benefits to eating more or supplementing, this doesn’t necessarily mean that ‘more must be better’. Selenium can be toxic if you take too much of it, and it can actually cause significant side effects such as fatigue, depression and digestive upsets.