Go nuts for zinc, selenium and magnesium - Food for the Brain

Go nuts for zinc, selenium and magnesium

Antioxidants aren’t only vitamins. The essential minerals magnesium, zinc and selenium are vital antioxidant team players too.

Magnesium is one of the most commonly deficient minerals which, in modern day diets, falls along way short of what our ancestors ate. It’s found in greens, nuts, seeds and beans. Pumpkin seeds are a really good source. We are meant to get 375mg a day. The average woman in the UK gets 217mg. Men achieve 272mg. That means that four in ten women don’t achieve the recommended intake for magnesium. Our Palaeolithic ancestors, by comparison, consumed close to 500mg a day (about double what most of us achieve from our diet today). Their calcium intake was also less than ours today resulting in a big increase in the calcium: magnesium ratio, further inhibiting magnesium utilisation. Calcium, as a result of high dairy product consumption, is one of the few minerals that the average person eats more of than needed.


Of the body’s 25g of magnesium, 95 per cent is found within mitochondria, the energy factories within cells. It helps to mop up oxidants and reduce inflammation.

Magnesium deficiency is known to promote inflammation,

A reasonable quality multivitamin and mineral might give you 100mg of magnesium but you still need to eat greens, nuts, seeds and beans almost every day.

Zinc is vital for all growth, hence is found in the ‘seeds’ of plants – be it a nut, seed, bean or pea. These are the same foods rich in magnesium. But it’s also contained in eggs, fish, milk and meat. Zinc is vital for over 200 of the body’s known enzymes, especially in relation to healthy immune function, growth, repair and protein utilisation. Zinc is used up at a faster rate when there is an ongoing active inflammatory disease such as arthritis. Theoretically, then, it is necessary to have adequate zinc for cartilage repair, proper immune and inflammatory responses and warding off viruses and other  infections. Aim for a total of 20mg a day.

Most people achieve less than 10mg a day from food, so supplementing 10mg in a multivitamin makes a lot of sense.

Selenium is a tiny mineral with a big kick. It works together with glutathione as a dynamic duo in the critical antioxidant enzyme called glutathione peroxidase, sometimes abbreviated to GPX. It is a trace element, which means you need very little. The amount that you need on a daily basis is probably 50μg, up to 200 μg when under viral attack. It’s also one of the most toxic minerals. You certainly don’t want more than 500μg. Taking in 100μgin total would ensure you’re at an optimum level.

Selenium is rich in seafood, which includes both fish and seaweed, and also seeds and nuts. However, it is hard to know, or even guarantee, how much you’re getting. I generally assume you’ll eat at least 50μg from a wholefood and seafood diet, so supplement an additional 30μg to 50μg. You’ll find it included in both multivitamins and antioxidant supplements antioxidant supplement, so do check to avoid overdose. It may be that 200μg for short term use, only during an acute infection, has additional benefit but, without further studies, it is hard to know. Selenium is one mineral you don’t want to take too much of. It becomes toxic certainly above 500μg causing nausea, vomiting and nail discoloration.