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Dr Paul Batman takes a look at antioxidant veggies – and, ironically, the toxins they contain.

It seems that everywhere we look we see all types of antioxidant supplements or super foods available on the shelves. Antioxidant foods such as broccoli are reported to neutralise the free radicals and reduce oxidative stress caused by our diet and/or the intense exercise we undertake. They reportedly do this through the release of antioxidants.

Ironically, it turns out that eating these foods might be more beneficial not only because of their antioxidant capabilities but because of the toxins they contain.

How can this be?

Aren’t we eating these foods primarily to combat oxidative stress and not create more?

There are many fruits and vegetables that we eat that have evolved as toxins to prevent insects and animals from eating them. Mark Mattson from the National Institute of Ageing reports that plants induce a mild stress response in the form of the release of mild toxins. Mattson further suggests that broccoli, for example, releases a chemical called sulforaphane that activates stress response pathways in the cell that upregulate its antioxidant enzymes. This means that the broccoli by itself is not releasing enough antioxidants to provide protection.

It is the toxins within the plant that cause an increase in the release of antioxidants from elsewhere in the cell that helps guard against oxidative stress. It appears over time that the resilience gained by the release of these antioxidants from elsewhere to fight the new toxins is released by the plant causing the cells to build up a resistance to the accumulation of free radical damage to the cell membrane. It demonstrates that, while “out of control” stress is harmful to our health, mild stress is necessary to build up a resistance to fight additional toxins. To illustrate this point, the US Department of Energy commissioned a study in 1980 to evaluate exposure to sustained low radiation levels. They compared workers who were exposed to a mild dose of radiation to a group of other workers who had no exposure at all for over eight years. Common sense would tell us that the exposed workers would experience greater health issues.

The results were confusing as well as dramatic. The 28,000 workers exposed to mild radiation had a 24% lower mortality rate compared to the 32,000 workers who were not exposed to any dose of radiation. Apparently, the mild toxins from the low dose radiation helped the affected workers to build up immunity to the adverse affects of radiation. Just as with the low dose radiation workers, mild toxins from our food can generate an adaptive stress response that makes the cells more resilient and protects them from further damage. So it might not be so much about detoxing as building up a tolerance to existing toxins.

Where to next? Find out what Dr Batman has to say about ‘active couch potatoes’.

About the Author

Dr Paul Batman

Exercise physiologist, academic and writer

Dr. Paul Batman has worked in health, fitness and sport for over 40 years. Originally a Physical Education teacher and then an Academic lecturing in Exercise Science at Australian Universities for over 20 years and for the last 18 years as owner and operator of two successful Registered Training Organisations (Fitness Institute Australia and Australian College) specializing in developing and delivering vocational educational courses in health, fitness and sport to thousands of fitness professionals. Paul received his Diploma of Physical Education from Australian College of Physical Education, Diploma of Education from Hawthorn State College, BSc and MSc from the University of Oregon (USA) and a PhD from the University of New South Wales. For over 25 years Paul has presented at international conventions in Australia, Canada, United Kingdom, Singapore and Malaysia and conducted lectures, workshops and in house presentations in many countries throughout the world. In 2012 Paul was awarded a Lifetime Achievement Award for his services to the Australian Fitness Industry, inducted into the Australian College of Physical Education Hall of Fame and recognized as an Institute Scholar at the International Institute for Sport and Human Performance, University of Oregon. Paul has written over a hundred articles on all aspects health and fitness and authored or co-authored 10 books.

Key expertise:

  • Exercise Physiologist, University Academic, Vocational Educator, Researcher, Writer, Conference Presenter


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