Microwaving ‘impairs’ anti-cancer foods benefits
Some methods of cooking vegetables can remove cancer-busting antioxidants, according to new research.
The finding has prompted a warning that the way food is prepared is as important as the content of a healthy balanced diet.
Naturally occurring antioxidant compounds protect the body by eradicating free radicals. These free radicals can trigger heart disease or cancer by attacking the DNA of cells.
When broccoli is microwaved, it loses 97% of one type of antioxidant, Dr Cristina Garcia-Viguera and her colleagues explain in the Journal of the Science of Food and Agriculture. In comparison the team found steamed broccoli only loses 11% of the same antioxidant.
Dr Garcia-Viguera explains that the water solubility of the antioxidants allows the active compounds to leach into the cooking water, reducing the nutritional benefits of the vegetable.
‘Because of this it is recommended to cook vegetables in the minimum amount of water (as in steaming), in order to retain their nutritional benefits’, she says.
The research is supported by another study published in the JSFA. Finnish researchers report blanching vegetables – briefly immersing them in boiling to set the colour and flavour before freezing – causes losses of as much as a third of antioxidant content.
Report co-author Dr Riitta Puupponen-Pimi points out that although minimal further losses occur while the vegetables are frozen, most antioxidants remained quite stable.
