By Dr Kevin Currell, Triathlon Plus | Monday, Mar 21, 2011 4.00pm
Nutrition: The power of antioxidants (Sophia Winters – Fotolia.com)
Antioxidants seem to be everywhere these days. They’re the ‘in’ thing in nutrition and if you believe the hype they can cure every disease, help you go faster and even live forever. Let’s take a look at the science behind the hype and see if there’s any evidence that as a cyclist you should be including these in your diet.
Antioxidants act by counteracting something called oxidative stress, which causes damage to the body. During day-to-day living your body produces things called reactive oxygen species that attack the body. Think of it as oxygen on a rampage around your body. You naturally produce antioxidants to protect your body from this attack, so think of this as your body’s police force. However, you need to get extra antioxidants from your diet to support this police force – think of these as the riot police.
There’s a huge body of research looking into the effect of antioxidant intake on health. With the advent of processed food a lot of the antioxidant capacity of our foods has been removed. It’s quite clear from the research that antioxidants can help prevent diseases such as cardiovascular disease, diabetes and cancer and help you live a long life.
The health benefits of a diet high in antioxidants is clear, but the performance benefits are less so. We know that exercise, particularly hard training, increases oxidative stress, but we also know that the body responds to this by increasing the size of its police force. However, when you train hard, the body can’t increase its natural antioxidants enough, so you need to make sure the riot police are ready to go.
A recent study from the University of Newcastle in Australia looked at restricting fruit and vegetable intake on exercise performance and how the body responded to the training. Fruit and vegetables are probably the most important source of antioxidants in the body. The study showed decreasing your weekly fruit and veg intake from five a day to one a day caused performance to be impaired by two percent and the stress of the exercise was greatly increased. So there is a performance benefit to a diet high in antioxidants.
As we’ve seen, fruit and vegetables are the most common food source of antioxidants. They contain nutrients such as vitamin C and E as well as other antioxidant compounds. Nuts and seeds as well as wholegrains (as opposed to refined grains like white bread and pasta) also contain high amounts of antioxidants.
There are also many supplements on the market that may help improve your antioxidant capacity, although these aren’t proven by science. The antioxidant system is very complicated and food is always going to be more effective, as nutrients work in interaction. A good example is a recent study showing high doses of vitamin C actually inhibited the adaptation from training.
What to eat
So how can you increase your antioxidant capacity? Sources of antioxidants can be found in all kinds of common foods, so make sure you get enough:
You know these foods are good for you, so make sure you:
- Eat five portions of fruit per day
- Eat five portions of veg per day
- Steam your vegetables rather than boil them
You might try to avoid these, but in moderation they help provide powerful antioxidants:
- Red wine: a glass a day is plenty
- Dark chocolate: stick to two or three small squares a day
You might think these things wouldn’t make much difference, but they do:
- Add herbs to your food
- Add extra virgin olive oil and balsamic vinegar to meals
- Look for foods which are dark in colour such as berries