There’s so much hype these days about superfoods, antioxidants, detox diets, and cleanses it’s difficult to know whether to jump on the latest bandwagon, or stick to the affirmation that the body is adept at cleansing itself if you give it a break from the booze and fags.
I’ve always been pretty sceptical of detox diets. The kidney and liver are perfectly capable of removing toxic chemicals from our system and there is currently no scientific evidence that i’m aware of to show that detox “cleanses” work.
Antioxidants, however, are something slightly different. They have been scientifically proven to positively impact health, protecting us against a range of scary diseases. Read on to understand how antioxidants work and which foods contain them.
I’m about to completely over simplify what is actually some quite complicated science. If you want to read a more detailed account from a scientific source, this paper on PubMed Central is highly recommended.
Let’s take it back to the beginning and talk about oxidation.
Oxidation occurs when a molecule that has an unpaired electron steals an electron from another molecule. Another word for one of these unstable molecules with a missing electron is a “free radical”. I’m sure you’ve heard of those. Free radicals in balanced numbers are fine, and can even be useful to you in fighting infections.
Oxidation sounds like a reaction that involves oxygen right? Whilst that’s often true (think rusting and fruit browning, both of which are caused by oxidation of oxygen) oxygen doesn’t actually need to be involved. Oxidation occurs when one molecule takes an electron from another.
As oxygen is often involved in oxidation reactions, these reactions are a natural part of being alive and our bodies have a natural ability to deal with a certain level of oxidation and free radical production. Modern living however leaves us exposed to a fair few more free radicals than the body can deal with by itself. As these free radicals set of a chain of electron stealing reactions, this can set off a domino effect that can eventually cause damage to your cells and your DNA.
In fact, science understands oxidation to be at the root of many diseases such as diabetes, heart disease, cancer, rheumatoid arthritis, alzheimer’s and respiratory infections.
What are the biggest causes of these oxidation reactions in the human body?
- SMOKING. Guys, please just stop this. It’s one of the worst things you can be doing to your body
- Breathing in polluted city air
- Radiation from the sun, particularly when the UV level is higher than 3 (in Sydney the UV level averages around 11 in the summer)
- Any combustion process in fact so frying and BBQ food (BBQs are too much fun to compromise on)
- Detergents, pesticides, food additives, stress and infection also cause oxidative stress
If oxygen promotes free radical creation, does that mean exercise is bad?
As oxygen does promote free radical creation, and exercise does increase the amount of oxygen entering our cells, exercise can cause an increase in the free radicals present in our bodies. However, regular exercise also increases our natural ability to neutralise free radicals. So no, exercise is not bad!
Those who push their bodies to the limit through endurance training may be generating more free radicals than the body can neutralise and might want to talk to a dietician about making sure they’re getting the right amount of antioxidants. This post is a great review of the literature on endurance exercise and oxidative stress.
So what do antioxidants do?
Antioxidants, that buzz word that we so often hear bandied around the media and across skincare packages, are essentially molecules that can prevent or stop oxidation reactions by donating an electron.
Which foods contain these antioxidants?
There are many nutrients that can act as antioxidants, including the below four essential vitamins.
- Vitamin A. This can be found in dairy products, fish and liver. Vitamin A is fat soluble. Fat soluble vitamins are not substantially depleted through cooking.
- Vitamin C. This can be found in vegetables and fruit eaten raw. Vitamin C is water soluble. Water soluble vitamins are rapidly destroyed by heat. Broccoli and strawberries are great sources of vitamin C.
- Vitamin E. This can be found in seed foods, including peas, broad beans and whole grains. Vitamin E is fat soluble.
- Beta-Carotene. This can be found in red, orange and yellow vegetables and fruits. For example carrots and sweet potatoes. Our bodies makes vitamin A from beta-carotene
Each of these vitamins counteract oxidative stress in different ways, and are effective against different forms of oxidation. This is why it’s so beneficial to “eat the rainbow”.
It’s also wise to ensure that the majority of this rainbow is made up of vegetables. In the UK we are all advised to eat 5 a day. Over in Oz they recommend 5 + 2. That’s 5 servings of veg and two of fruit each day. That’s because vegetables have been shown to increase longevity to a greater extent than fruit.
Do I need antioxidant supplements?
Whilst I’m not qualified to advise on supplements, my personal opinion is that If you eat a healthy and varied diet, and reduce your exposure to toxins (cigarettes, booze, food additives) wherever possible, you shouldn’t need to take them. If you do want to supplement, speak to a professional first as high doses of some vitamins of their own can do more harm than good.The famous study of Beta Carotene supplementation in smokers is case in point.
What is the point of all of this?
There will always be a new health craze, and marketers will always come up with a new way of convincing us that we are in dire need of their products. Whether this be juicing, souping, supplementing or something entirely different. The truth is that you don’t need to buy anything special in order to support your body in maintaining health. The advice that has been around for years still stands: eat your greens. And your reds, purples, yellows and oranges.
I am not a qualified dietician. You should always consult with a professional before making any changes to your diet and especially before taking supplements.