What vitamins are antioxidants?
There are thousands of chemical reactions that occur in your body everyday during processes such as digestion. These reactions are known as oxidation reactions and are vital for survival. However, they may result in the creation of unstable chemicals known as free radicals, which can potentially cause damage to cell membranes, DNA and proteins. Free radicals are also introduced into your body from external sources such as the food you eat and cigarette smoke.
There are many different types of free radicals and they affect different parts of the body, however what they all have in common is that they are missing an electron and so try to steal one from other nearby substances that do have electrons. When they do this, they can change the structure or function of the substance they have stolen an electron from.
They may even start a chain reaction, causing the substances that have lost an electron to go out seeking an electron, stealing it from another substance, and on and on.
This is where antioxidants come in. Antioxidants are willingly able to donate electrons without causing them to seek out electrons after doing so. They therefore stabilise the free radicals, bringing the electron scavenging chain to an end.
There are lots and lots of different substances that can behave as antioxidants, vitamins being one of them. In particular, vitamin C, vitamin E and beta-carotene are the most commonly known ones.
Vitamin C – ascorbic acid is one form of vitamin C that dissolves well in water. Vitamin C plays an important role in the body, it helps boost immune system function, improves vision, heals burns & wounds and maintains healthy gums. The amount of vitamin C you need to consume daily depends on gender and age and varies between 40 mg and 120 mg. If you smoke, you need even more.
It is known that vitamin C is an antioxidant because it is an electron donor, however how effective it is in the body is not known. Diets that are rich in fruits and vegetables are associated with a reduced risk of stroke, cancer and heart disease, but it is not known whether vitamin C and its antioxidant property is responsible for these benefits.
There are many different foods that are rich in vitamin C and these include guavas, parsley, kale, kiwifruit, broccoli, papaya, strawberries and oranges.
Vitamin E – unlike vitamin C, vitamin E is fat soluble and also plays an important role in the body. It provides support to the immune system, widens blood vessels and assists with cellular functions. Again, the amount of vitamin E that you require varies by age and gender, ranging from 4mg to 19mg.
Vitamin E also behaves as an antioxidant, both in its natural and synthetic (α-tocopherol) forms. Despite its antioxidant properties, studies have found little evidence to support the claims that vitamin E consumption provides any substantial protection against cancer and heart disease.
Because vitamin E is fat soluble, it is abundant in many nuts and seeds such as sunflower seeds, almonds, hazelnuts, pine nuts and Brazil nuts. It can also be found in dark leafy greens such as spinach, avocados and certain types of fish.
Beta-carotene – carotenoids are natural pigments created by plants and are responsible for the bright colours of certain fruits and vegetables such as sweet potato and carrots. Beta-carotene is a carotenoid and is a converted into vitamin A in the body. Beta-carotene has been shown to help protect the skin from sun damage, slow down age related eye disorders and could potentially support immune function.
Unfortunately however, similar to studies carried out on other antioxidants, there isn’t sufficient evidence to show that beta-carotene can protect against cancer or cardiovascular disease. In fact, studies showed that high doses of carotenoids increased the risk of cancer and heart disease in smokers and asbestos workers.
Orange coloured foods such as carrots, butternut squash, cantaloupes and apricots are high in beta-carotene. Spinach, mustard greens, romaine lettuce and peas are great sources as well.
Vitamin C & E and beta-carotene are known to have antioxidant properties and could play a role in your health. However at the moment there is no evidence to suggest that these antioxidants are able to prevent or fight off diseases such as cancer.
That being said, it is important to consume foods that are rich in these vitamins as they bring many other benefits to the body. Your diet should include plenty of vegetables and fruits, together with nuts and seeds. You can find a comprehensive list of the best foods you can eat here.