Antioxidants for Health
Antioxidants in Action
For quite a few years now, antioxidants have been in the news quite frequently; but many people don’t actually know what they are and what they do. This article will perhaps clear up that confusion.
Antioxidants are, to put it in the most basic terms, substances that prevent oxidation. Examples of oxidation in the sense usually meant in this context include the cut surfaces of fruit going brown, fats and oils going rancid and the drying of linseed oil when exposed to air. It’s notable that at least two of these examples are usually thought to indicate damage; what is not quite so obvious is that the same processes can occur inside the body as well as out. The third is a useful process if you’re using the oil to treat a cricket bat; perhaps not quite so useful if you were intending to eat the oil!
More generally, however, antioxidants in nutritional terms are substances that remove free radicals. This is another buzzword often used to blind people with science, so it might be useful to explain it. Free radicals are unstable molecules that tend to react uncontrollably with others. If these reactions occur inside the body, the result is very rarely useful and often causes damage to the body’s structure and workings. The eventual results of this sort of damage include heart disease, cancer, stroke and acceleration of all the infirmities associated with ageing.
Free radicals are formed in many ways. Probably the most important source of free radicals, and one that cannot be entirely stopped, is the release of energy from food using oxygen. This process is a complicated one involving quite a lot of different free radicals, and is under tight control; but the control is not perfect and inevitably some of the free radicals escape from the process to cause damage.
Another source of free radicals is the consumption of food that has been subjected to high temperatures as in frying and grilling, forming unstable and toxic substances that form free radicals inside the body. Yet another source is the inhalation of smoke, and another is ionising radiation. This type of radiation includes the ultraviolet component of sunlight and also nuclear radiation (radioactivity) and X-rays. Radioactivity is impossible to entirely avoid for at least two reasons; one is cosmic radiation from space, and another major source is the potassium in your own body. Perhaps unfortunately, although avoiding ultraviolet light altogether might well protect the skin from damage it may also cause a deficiency in vitamin D. This vitamin is formed in the skin from other chemicals naturally present, by the action of ultraviolet light. This is yet another one of those cases where a little is good but a lot is harmful.
Antioxidants, then, reduce the ongoing damage that is inevitable for anyone is still breathing, and thus slow down the effects of ageing and also make it less likely that you will suffer from various specific diseases, associated with this ongoing damage that get more likely as you get older – such as cancer, heart disease and possibly Alzheimer’s disease.
Antioxidants come in two general classes; water-soluble and fat-soluble. This is important because quite a lot of rather important processes in the body occur in places mainly composed of fats and oils; these places include the membranes that enclose every cell in the body. The water-soluble antioxidants protect everything else, which includes the DNA in your cells and also the collagen that forms most of the structure of all tissues – which includes the skin, the lining of the blood vessels and the lens of the eye, among others. Therefore, both water-soluble and fat-soluble antioxidants are necessary for optimum health.
Water-soluble antioxidants include vitamin C, various sulphur-containing amino acids, alpha lipoic acid and also various plant pigments collectively called proanthocyanidins, which are found in any plant with a deep red or purple colour. These plants include beetroot, blackberries, blackcurrants, blueberries and red grapes – and also red wine, which of course is made from red grapes.
Fat-soluble antioxidants include vitamin E, coenzyme Q10 (which also has many other uses), and carotenoids including beta-carotene and various others. The carotenoids are usually red to orange in colour, and are found in many places; common sources are carrots, sweet peppers, yams (also known as sweet potatoes), certain types of melon and tomatoes. Vitamin E is found in various plant oils, notably wheatgerm oil; coenzyme Q10 is also found in wheatgerm but also in most freshly-prepared foods.
Of course, commercial supplements exist of most of the antioxidants; but one way of getting plenty of all of them is to eat plenty of brightly-coloured plant foods of various colours from yellow to purple. Ideally, the fresher and less-processed these foods are the better; many of the antioxidants are fairly unstable if exposed to oxygen. A notable exception to this rule of thumb is tomatoes, in which the main active carotenoid (lycopene, which gives them their red colour) is actually better absorbed if the tomatoes have been cooked.