‘Pie hole’, colloquial for one’s mouth, is believed to have evolved in the USA in the 1980s from the British expression ‘cake hole’ (coined in the mid 20th century). Pie hole refers to a mouth, as in: Shut your pie hole or, in this case: Put less in your pie hole.

Wednesday, August 14, 2013

Should You Ante Up in the Oxidant Game?

They're in the news, they're hailed on many food labels, and they're also stealthily hiding in uncelebrated, under-marketed and unpackaged fruits and vegetables. What am I on about? Antioxidants. Join us on this juicy journey as we unmask these mysterious molecules that many claim will keep you young, healthy and disease-free.

What are oxidants, and why is everyone so anti them?

Oxidative stress is caused by 'free radicals'. Free radicals contain an unpaired electron which, for those of us who remember some rudimentary chemistry, means they are unstable and want to either accept or donate an electron. They can cause cellular damage (oxidative stress) by 'bumping' into other molecules, proteins and DNA. Think of them as hyperactive kids running around at a birthday party - they unpredictably knock into things and usually damage something.

Production of free radicals is a perfectly normal bodily process. Metabolism and exercise produce them internally, as well as external sources like pollutants and cigarette smoke.

At moderate concentrations, free radicals are actually really important in regulatory processes like cell signalling. It's at sustained, high concentrations that they are problematic and play a role in disease development. This is where antioxidants come in: Antioxidants are compounds that safely react with free radicals before they cause cellular damage. Think of them as your spam filter.

'Antioxidant' is a broad term. Based on my observations, and eavesdropping on the occasional Costco conversation, most antioxidant spruikers couldn't actually define the term 'antioxidant' to save their life. Most don't realise that both vitamins and minerals are antioxidants, as well as 'non-nutrient' compounds like phytochemicals (found in plants). When most people drop the keyword 'antioxidant', it's like a child dropping the f-bomb... They have no idea what it really means.

Oxidative stress, or excessive concentrations of free radicals, is associated with the development of  several diseases including atherosclerosis (hardening of the arteries), heart disease, Alzheimer's disease, joint inflammation, cancer and type II diabetes. So why not turn to antioxidants?

Several meta analyses (combination and analysis of independent studies) show large supplemental antioxidant doses do not prevent the incidence or progression of these diseases. In some cases, one example is beta carotene in smokers, it actually increases the risk of smoking related cancers and cancer death. Another analysis of 56 studies showed supplementation with antioxidants significantly increased risk of death. One meta analysis reported a potential benefit of low dose vitamin B6 and vitamin E... But, and there's always a but, those studies had the vitamins provided by pharmaceutical companies (which calls into question the legitimacy and accuracy of testing protocols/results, given this conflict of interest). Additionally, when only looking at high quality studies, the benefits of B6 and vitamin E were not supported.

So now I'll put my dietitian hat back on... Research shows people who eat large amounts of fruits and vegetables (Australian guidelines recommend 2 serves of fruit and 5 of vegetables, the US guidelines recommend 2 serves of fruit and 2-3 serves of vegetables) have lower rates of oxidative stress and associated diseases. It's unclear whether antioxidants, or something else is responsible (ie: the health benefits of eating a high fiber diet). But results are results: Plain old foods like cheap, humble fruits and vegetables prevent diseases better than artificial, man-made pills... Shocker.

The paradox here is that antioxidants are important for health, but too much of a good thing appears disadvantageous. If we go back to the spam filter analogy, we want a spam filter to keep out emails that contain viruses, obnoxious sale items, porn, etc, whilst still letting through emails from friends, family, work, etc. Having a mega spam filter tends to keep out the important emails we still want.

Take home points and tips:
  • Antioxidants come from many different kinds of foods that also contain fiber and other health supporting characteristics
    • Fruits, vegetables, whole grains, nuts, herbs, dairy, lean meat and seafood
  • Eating a varied and balanced diet provides us with a the necessary array of antioxidants that keep our bodies healthy with the right balance of free radicals
My apologies again to the pill popping, just-want-a-quick-fix crowd... There is just no supplement for real food.

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