Antioxidants and Oxidative Stress
Antioxidants – everybody has probably heard of this term. But what does it mean? You may have heard awhile ago about the health benefits of antioxidants, but do you know what an antioxidant is – and how they actually work? Can they help to slow down the ageing process, for example?
Throughout the ages, human beings have sought a magic formula to stay young. Legends relating how people have sacrificed everything and even sold their soul to the devil to maintain eternal youth, are found in many cultures. In this youth-orientated 21st century the pressure to stay young is greater than ever before.
Despite our space-age technology in this 21st century, we are still seeking the elusive “spring of eternal youth”. Luckily modern research techniques which are advancing our knowledge at an amazing rate, have come up with a host of encouraging information which we can use to slow down and sometimes reverse, the ravages of time.
Here are some quick links that will take you to different pages of interest:
- Health On A Budget
- Healthy Food Choices
- High Value Foods
- What Is An Antioxidant?
- Dietary Supplements
- Lifestyle Changes
Antioxidants Lead The Way
One of the most exciting fields of present-day research concerns antioxidants and the important role they play in combatting the aging effects of so- called “free radicals”. Not only has this research produced evidence that well-known nutrients such as vitamins A, C, E, and B complex, can prevent ageing, but new compounds found in foods which we were not aware of a few decades ago, are constantly being added to the anti-ageing arsenal. In the past few years many new antioxidant nutrients, such as bioflavonoids, catechins, and ubiquinones have been identified in common foods and beverages.
Antioxidants are dietary substances including some nutrients such as beta carotene, vitamins C and E and selenium, that can prevent damage to your body cells or repair damage that has been done. Antioxidants work by significantly slowing or preventing the oxidative – or damage from oxygen – process caused by substances called free radicals that can lead to cell dysfunction and the onset of problems like heart disease and diabetes. For example, antioxidants may also improve immune function and perhaps lower your risk for infection and cancer.
Antioxidants – to conteract oxidative stress
To counteract oxidative stress, the body produces an armoury of antioxidants to defend itself. It’s the job of antioxidants to neutralise or ‘mop up’ free radicals that can harm our cells. Your body’s ability to produce antioxidants (its metabolic process) is controlled by your genetic makeup and influenced by your exposure to environmental factors such as diet and smoking. Changes in our lifestyles, which include more environmental pollution and less quality in our diets, mean that we are exposed to more free radicals than ever before. Antioxidants can be rated, you may like to look at the ORAC Rating to see which fruits and vegetables have the highest antioxidant value.
How Much Do I Need?
Your body’s internal production of antioxidants is not enough to neutralise all the free radicals. You can help your body to defend itself by increasing your dietary intake of antioxidants. By eating three serves of vegetables daily and two servings of fruit, you are well on your way to getting plenty of antioxidants. By taking an antioxidant dietary supplement along with such a diet, you are ensuring you have no deficit in antioxidants.
Examples Of Food-Based Antioxidants
Many foods contain antioxidants, particularly the brightly coloured fruits and vegetables. Chocolate and tea contain considerable amounts, surprisingly.
- Vitamins: vitamin E, vitamin C and beta carotene.
- Trace elements that are components of antioxidant enzymes such as selenium, copper, zinc, and manganese.
- Non-nutrients such as ubiquinone (coenzyme Q) and phenolic compounds such as phytoestrogens, flavonoids, phenolic acids and butylated hydroxytoluene (BHT), which is used as a food preservative.
Tomatoes contain a pigment called lycopene that is responsible for their red colour but is also a powerful antioxidant. Tomatoes in all their forms are a major source of lycopene, including tomato products like canned tomatoes, tomato soup, tomato juice and even ketchup. Lycopene is also highly concentrated in watermelon.
Oranges, grapefruit, lemons and limes possess many natural substances that appear to be important in disease protection, such as carotenoids, flavonoids, terpenes, limonoids and coumarins.Together these phytochemicals act more powerfully than if they were given separately. It’s always better to eat the fruit whole in its natural form, because some of the potency is lost when the juice is extracted.
Black tea, green tea and oolong teas have antioxidant properties. All three varieties come from the plant Camellia sinenis. Common brands of black tea do contain antioxidants, but by far the most potent source is green tea (jasmine tea) which contains the antioxidant catechin.
- Black tea has only 10 per cent as many antioxidants as green tea.
- Oolong tea has 40 per cent as many antioxidants as green tea. This because some of the catechins are destroyed when green tea is processed (baked and fermented) to make black tea.
Beta-carotene is an orange pigment that was isolated from carrots 150 years ago. It is found concentrated in deep orange and green vegetables (the green chlorophyll covers up the orange pigment). Beta-carotene is an antioxidant that has been much discussed in connection with lung cancer rates. The evidence is conflicting, with one study showing an increase in risk, but further research is being done to see if it has a protective effect.
Will eating antioxidants really protect me from disease?
Studies have shown that people who eat a diet that is rich in fruit and vegetables are less likely to get diseases such as cancer, heart disease and stroke. It has not yet been proven that antioxidants alone are responsible for this drop in risk. For example, the research that has been done on the effect of diet on cancer has been difficult to conduct and interpret. Even so, there is now a good body of evidence to indicate the protective effect of fruit and vegetables on many common cancers, including those of colon, breast and bladder.