We hear so much about antioxidants these days. New ‘superfoods’ appear constantly and these are usually promoted for their high antioxidant values. But what does this actually mean?
Until I started studying nutritional medicine I had no idea what an antioxidant did or why free radicals are actually harmful. Recently I was studying more about this and I realised how important antioxidants must also be for our mental health. I thought I would share a basic understanding of what they are, why we need them and how I make the mental health connection. I hope you find it useful.
Lets start with Free Radicals: when our body uses oxygen in metabolic reactions the oxygen reacts with compounds in the body and produces highly unstable molecules which are called free radicals. This means that they have 1 or more unpaired electrons (think back to high school chemistry!). An electron without a partner is unstable and highly reactive and so to regain its stability it finds a stable but vulnerable compound to steal an electron from. This compound that has had its electron stolen then becomes a free radical itself and a chain reaction occurs where free radicals produce more free radicals.
So why is this bad?
Occasionally free radicals are useful for example when cells if the immune system use free radicals as ammunition to demolish disease causing viruses and bacteria but more often free radicals cause widespread damage. They damage polyunsaturated fatty acids in cell membranes and in lipoproteins which disrupts the transport of substances in and out of cells. They alter DNA, RNA and proteins which creates excesses and deficiencies of proteins, impairs cell functioning and elicits an inflammatory response in the body as well as contributing to cell damage, disease progression and aging.
This inflammatory response is where my mental health ears prick up. Inflammation has been linked to depression and schizophrenia as well as a host of problems such as diabetes, inflammatory bowel disorders, autoimmune disorders and heart disease. If free radicals are leading to inflammation in our bodies then that is something worth paying attention to.
Antioxidants are compounds that do not become free radicals because they are stable in any form. So they neutralise free radicals by donating one of their own electrons and ending the chain reaction. Our body’s natural defence system becomes less effective with age and the unrepaired damage accumulates. Environmental factors such as UV radiation, tobacco smoke and air pollution also contribute to free radicals so we need to make sure that we have antioxidants in our diets to defend our body against free radical damage (oxidative stress). Oxidative stress has been identified as a causative factor and antioxidants as a protective factor in cognitive function and ageing as well in the development of diseases such as cancer, arthritis, diabetes and heart disease.
So how does our body defend against free radicals? What can we do to look after our own health?
- A system of enzymes disarm the most harmful oxidants. For these enzymes to work properly they depend on the minerals selenium, copper, manganese and zinc.
- The body uses antioxidant vitamins E, C and beta-carotene. Vitamin E protects the body’s lipids (fats) by stopping the free radical chain reaction. Beta-carotene also acts as an antioxidant in lipid membranes. Vitamin C protects other tissues such as the skin and fluid of the blood against free radical attacks. Vitamins C also helps to neutralise free radicals from polluted air and cigarette smoke and restores oxidised Vitamin E to its active state.
- Dietary antioxidants also include some of the phytochemicals which are found in plant foods.
While studies have shown the benefits of these vitamins and minerals when consumed in foods, the role of supplements in these protective factors is questionable. Additionally, there are significant risk factors from vitamin supplements such as toxicity and, that in pharmacological doses they may act as prooxidants and actually stimulate the production of free radicals.
Take home message?
Eating a diet that includes a wide variety of vegetables and fruits to provide us with the vitamins and minerals that protect against this damage is essential. Whatever style of eating works for your body, making vegetables the main part of every meal is important. In order to be able to properly absorb these vitamins and minerals we need our gut to function properly so we need to ensure that we look after our gut health by including bone broths and fermented foods in our diets as well as removing inflammatory food that damage the gut (and again gut health and inflammation come into play!), Vitamin E and beta-carotene are fat soluble so we need an adequate intake of dietary fats (of the natural kind) to ensure that we can absorb these vitamins from the delicious variety of fruits and vegetable that we are eating. Turmeric is a potent antioxidant and anti inflammatory so include this in your diet in as many ways as you can.
Plus – raw cacao happens to be an excellent source of antioxidants! For recipe ideas that are both delicious and full of nutrients and good fats as well as excluding foods that cause inflammation check out my recipes page here.