Antioxidants are phytochemicals, vitamins and other nutrients that protect our cells from damage caused by free radicals. In vitro en in vivo studies have shown that antioxidants help prevent the free radical damage that is associated with cancer and heart disease. Antioxidants can be found in most fruits and vegetables but also culinary herbs and medicinal herbs can contain high levels of antioxidants. Dragland S and colleagues showed in their study entitled "Several Culinary and Medicinal Herbs are Important Sources of Dietary Antioxidants", and published in the Journal of Nutrition (2003 May) that the antioxidant level of herbs
can be as high as 465 mmol per 100 g.
A study in 2006 by Thompson HJ showed that a botanical diversity
of fruits and vegetables plays a role in the biological effect of antioxidant phytochemicals. The consumption of smaller quantities of many phytochemicals may result in more health benefits than the consumption of larger quantities of fewer phytochemicals.
What are free radicals?
Free radicals are formed as part of our natural metabolism but also by environmental factors, including smoking, pesticides, pollution and radiation. Free radicals are unstable molecules which react easily with essential molecules of our body, including DNA, fat and proteins. All organic and inorganic materials consist of atoms, which can be bound together to form molecules. Each atom has a specific number of protons (positively charged) and electrons (negatively charged). Most single atoms are not stable because they have to few or to may electrons. Atoms try to reach a state of maximum stability by giving away or receiving electrons from other atoms, thereby forming molecules. Free radicals are molecules which have one electron too much or too less in order to be stable. Free radicals try to steal or give electrons to other molecules, thereby changing their chemical structure.
When a free radical attacks a molecule, it will then become a free radical itself, causing a chain reaction which can result in the destruction of a cell. Antioxidants have the property to neutralize free radicals without becoming a free radicals themselves. When antioxidants neutralize free radicals by receiving or donating an electron they do not become antioxidants themselves because they are stable in both forms. In other words, antioxidants are chemicals that offer up their own electrons to the free radicals, thus preventing cellular damage. However, when the antioxidant neutralizes a free radical it becomes inactive. Therefore we need to continuously supply our body with antioxidants.
The action of free radicals could increase the risk of diseases such as cancer and hearth problems and could accelerate ageing. Antioxidants have the property to neutralize the free radicals and prevent damage. Well known examples of antioxidants are the vitamin C, E and beta-carotene. These three vitamins are often added to the so called ACE drinks. But there are numerous other rather unknown antioxidants such as lycopene, lutein,
Benefits of antioxidants
Numerous studies with plant phytochemicals show that phytochemicals with antioxidant activity may reduce risk of cancer and improve heart health.
Antioxidants reduce the risk of cancer
Not all results are conclusive but many studies show that antioxidants may reduce the risk of cancer. A large randomized trial on antioxidants and cancer risk was the Chinese Cancer Prevention Study (1993). This study showed that a combination of the antioxidants beta-carotene, vitamin E and selenium significantly reduced incidence of cancer. However, the Alpha-Tocopherol / Beta-Carotene Cancer Prevention Study (1994) showed that intake of beta-carotene increased lung cancer rates of male smokers.
Antioxidants protect the heart
Everyone knows that cholesterol causes heart diseases and tries to limit cholesterol intake. But a more important cause of fatty buildups in the arteries is the oxidation of low-density lipoprotein cholesterol. The use of dietary supplements of antioxidants could reduce the risk of cardiovascular disease, but there is no hard evidence. At this stage, studies only show that the intake of foods, naturally rich in antioxidants reduces this risk.