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’.
