Skip Acai Juice: Antioxidants Are Not a Miracle Cure
Antioxidants are the masters of the health halo: add them to yoghurt and this yoghurt is now a healthy food. Marketers took this idea and scattered, but science was not enough – and the more they studied, the more scientists figured out that antioxidants are not the magic shield against disease that we were taught.
It’s a shame because the theory behind antioxidants is simple and beautiful: free radicals promote aging, cancer and other undesirable phenomena, and antioxidants neutralize those free radicals. Therefore, antioxidants should slow aging, prevent cancer, and generally promote health, right? Increase your diet – or cut back with pills – and you will be the best person for it. But that’s not all.
How our body uses antioxidants
To understand antioxidants, we have to get close to the atoms that make up our cells. All molecules in our body – such as DNA and proteins – are made up of atomsheld together bypairs of electrons . In general, electrons are happiest and most stable when they are in pairs.
So it’s too bad that free radicals – molecules with an odd number of electrons – sometimes end up in our cells. They can steal an electron (to form a pair) from anything they come across, turning their victim into a free radical that can damage something else.
This is a problem: too much free radical damage can kill the cell . Damage to the cell membrane can lead to malfunctioning of cells. DNA damage can lead to cancer.
This is where antioxidants come to the rescue : like bodyguards ready to take a bullet, antioxidants can react with free radicals to neutralize them and thus protect other molecules in the cell.
Where do antioxidants come from?
Our cells have complex, well-regulated systems to deal with stress, which is sometimes overwhelmed by free radicals. Some of the components of these systems are grown at home, while others we get in our diet in the form of vitamins and minerals. For example, vitamin E, vitamin C, and glutathione reductase work together as an antioxidant team . Glutathione contains selenium, a mineral that we get in our diet. This is why these vitamins and minerals are considered essential for human consumption.
Plants also have antioxidant systems, which are the source of many antioxidants in supplements and superfoods: green tea, red wine, cocoa and berries, to name a few. In general, fruits and vegetables contain tons of antioxidants.
Chemicals can have antioxidant properties in addition to any other function they perform, so there isn’t just one type of antioxidant; there are thousands of them. It’s probably not fair to mix them all up. Some of them may be useless without other members of their team; some may work better for certain purposes or in certain contexts than others.
Antioxidants work in the laboratory …
So far, antioxidants sound good. We have a solid scientific theory that free radicals are bad, antioxidants neutralize free radicals, so antioxidants are good.
We can do some simple experiments to show that antioxidants “work”, at least in the laboratory. They can also be made at home.
Oxygen is a common source of free radicals; it breaks down easily, sometimes with sunlight, into free radicals called reactive oxygen species. The act of stealing electrons is called oxidation (regardless of whether free radicals are involved). When metal rusts, it is a form of oxidation. When apples or avocados turn brown from exposure to air, that is also oxidation.
So you can cut an apple in the kitchen, but to prevent it from turning brown, submerge it in a solution of vitamin C, one of our classic antioxidants. The idea is so win-win that you can buy vitamin C in jars if you cut up a lot of apples.
This explains why antioxidants like vitamin C are found in many processed foods and cosmetics: they are preservatives . They prevent damage to the cells of applesauce, the pigments that give the juice, or the fatty acids in the lotion. In addition, manufacturers can add: “Contains vitamin C!” on the label, which makes you think it’s healthier .
… But they often don’t work in people
However, maintaining human health for years is more difficult than experimenting in the kitchen. In the 1990s, antioxidants were promising, and health conscious people began to take them to become healthier. For a while, this reinforced a good image of antioxidants: if you look at people who take antioxidants (or eat a lot of fruits and vegetables), you will find that they are generally quite healthy.
But this is a classic flaw in observational research : it cannot be proven that one factor (antioxidants) causes another (good health). To do this, you need to give some people the antioxidant, but not give to others, and see if the supplement affected their health. Here’s how the National Cancer Institute summarizes these years of research :
Overall … nine randomized controlled clinical trials provide no evidence that dietary antioxidant supplements are beneficial for primary cancer prevention. In addition, a systematic review of available data on the use of vitamins and mineral supplements for the prevention of chronic diseases, including cancer, conducted for the United States Preventive Services Task Force (USPSTF), also found no clear evidence of a benefit in cancer prevention. …
So, while antioxidants do help fight free radicals in your body, they are not magic cancer prevention. (This study also looked at heart disease prevention, butfound no benefit either.)
In one famous study, smokers took beta-carotene to reduce their risk of cancer. Instead, those who took the supplement got more lung cancer . And heart disease. And they were more likely to die for whatever reason.
Meanwhile, research on reactive oxygen species – those disgusting free radicals – has revealed evidence that they’re not even all bad. For example, they seem to aid wound healing . And while antioxidants are supposedly an ingredient in anti-aging skin care products , reactive oxygen species can be beneficial for the skin, at least for young people , which means that these antioxidant creams can do exactly the opposite of what the label says. … (The Telegraph has a report on this research here .)
Exercise increases the amount of free radicals in your cells, which has prompted athletes and trainers to praise antioxidants as a post-exercise recovery aid. But antioxidant trials in athletes have shown the opposite: large doses can impair your ability to build muscle, as reported in the journal Physiology . The New York Times reveals it here .
We don’t know much about what antioxidants actually do.
Don’t mistake these promising results: you don’t need to avoid antioxidants in your diet. Blueberries and green tea are still healthy, even if they’re not cancer-preventing superfoods.
There is a lot of confusion about health and nutrition , but everyone agrees : fruits and vegetables are good for you, they contain vitamins that we know we need, and most of us don’t have enough. Before worrying about additional antioxidants, correct this likely deficiency in your diet. As Time magazine reports :
For most healthy adults, the antioxidants found in a healthy diet rich in fruits and vegetables will be sufficient to combat most of the free radical damage that occurs in their bodies. But according to Jeffrey Bloomberg, director of the Antioxidant Research Lab and Professor of Nutrition at Tufts University, most people don’t meet the RDA for vitamins like C and E.
If you’re not doing well, multivitamins can help – or you can just do what everyone tells you since childhood and eat your vegetables. If you love chocolate, eat it because it tastes good, not because it is healthy . Don’t eat gallons of acai juice or waste money on antioxidant supplements; they probably do more for the merchant’s bank account than for your health.
Frustrated by uncertainty? Reversing scientific opinion is good , although sometimes it upsets us. This means the scientists didn’t just soak the apple in vitamin C and crown antioxidants – the miracle cure for everything for life. Biochemistry is complex, and with every laboratory experiment, observational study, and clinical trial, we come closer to understanding how these fairly simple chemicals affect something as big and complex as our health.
How can the observed contradictions be explained? Perhaps a little reactive oxygen is normal and a lot is bad (or vice versa), or that some of the thousands of antioxidants are good for us and others are not. Antioxidants may help against some diseases, but they exacerbate others, and we will have to make some difficult decisions.
In other words, we may have to balance risks and benefits, as we do with medications or other medical decisions. And we will be glad that unexpected scientists have shown enough persistence that we can understand what these risks and benefits are.
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