Selenium - bad mood food

The study published in Biological Psychiatry in 1991 by doctors David Benton and Richard Cook at the University of Wales, was designed with the aim of examining the impact of selenium on moods.

While previous studies have looked at selenium deficiency in relation to the concentration of the mineral in red blood cells, kidney, liver and testes, its presence in the brain has always been ignored.

The Benton and Cook study was ground-breaking because it was the first time researchers considered the possibility that low selenium levels may have psychological consequences.

The 50 subjects who took part were either given a daily placebo or a 100mcg selenium supplement over a five-week period. They were then asked to monitor their feelings and moods, and which foods they had eaten – in order for the researchers to estimate their overall daily intake of selenium.

The results showed that the lower the level of selenium in the diet, the more the subjects reported feelings of anxiety, depression and fatigue. The results also showed that these feelings subsided following the addition of selenium supplements to the diet.

However, before you rush off to the nearest chemist to buy selenium supplements, be aware that overdoing it can be bad for your health. In 1991, the Department of Health reviewed the daily amounts of minerals necessary for an average person. It found that excessive doses of selenium – over 3.2 milligrams (3200 mcg) per day – were toxic and could lead to neurological abnormalities, dry, brittle hair or hair loss, and, in severe cases, paralysis.

So, in fact, supplementing a diet that already provides adequate amounts of selenium may not be beneficial. However, if you aim to eat a balanced diet of carbohydrates, a couple of portions of protein from meat or fish, the usual 5 portions of fruit and veg and a couple of portions of milk and dairy products every day, you should be getting sufficient amounts of selenium to put you in a positive frame of mind.