Some say big things come in small packages, well the same could be said for selenium. Selenium is what is known as a 'trace mineral' - a nutrient which is needed in only very small amounts by the body.
It is well known that good levels of selenium are important for male fertility, as it is essential for sperm formation and testosterone production. A lack of selenium in men is associated with sperm that cannot move properly, because selenium is essential for making sperm’s strong whiplash tails. Research also suggests that the antioxidant activity of selenium may even make sperm more fertile.
Scientists have more recently discovered that selenium can also boost a woman's fertility. The research, conducted from the University of Adelaide, found the mineral plays a crucial role in the early stages of conception - specifically, in the development of healthy ovarian follicles which are responsible for the production of eggs in women.
The study found that levels of selenium and protein containing selenium (GPX1) were higher in large, healthy ovarian follicles where the eggs are produced. In fact in some cases eggs that yielded a pregnancy had twice the levels of GPX1.
Lead researcher Melanie Ceko said: 'We suspect they play a critical role as an antioxidant during the late stages of follicle development, helping to lead to a healthy environment for the egg.'
While further research needs to carried out in order to understand how selenium levels can be optimised to increase the change of a woman getting pregnant, the researchers hope that their findings will help treat women with fertility problems.
Where can I get Selenium from in my diet?
Of all foods Brazil nuts contain the highest levels of this mineral. As well as Brazil nuts, the following foods also contain Selenium:
- Brazil nuts
- Seafood - especially tuna, swordfish, halibut, mackerel, oysters, mussels, squid, lobster and clams
- Wholewheat bread
- Red meat
- Whole grains like rye
How much should I take?
There is uncertainty over what constitutes 'optimal selenium status' however the recommended daily allowance (RDA) for men and women in the UK is 75 micrograms per day and 60 micrograms per day respectively. This differs from the US RDA of 55 micrograms per day for adults. The World Health Organization RDA for selenium is between 70 micrograms and 350 micrograms per day.
Since Brazil nuts are known to include as much as 95 mcg of selenium per nut you only need a couple to reach your daily quota.
It's important to note that too much selenium can negatively impact your health, toxicity (aka selenosis) is said to occur at around 400 micrograms. Signs of selenosis include hair loss, skin rashes, nausea, diarrhea, fatigue and mood changes.
Further health benefits of Selenium
- It has potent antioxidant properties, meaning it can help to combat the damaging effect of free radicals in the body.
- It stimulates the body's immune system.
- Plays an important role in the functioning of the thyroid gland, assisting with the metabolism of iodine and the production of critical thyroid hormones.