Berlin: Munching on nuts - such as almonds and pistachios - may not only protect you from heart diseases and diabetes, but also help prevent colon cancer, a new study has claimed.
According to the study, nuts have a positive effect on health because, among other things, they are involved in activating the body's own defences for detoxifying reactive oxygen species. Such substances, which are created by ultraviolet radiation, various chemicals or distinct food metabolites, for
example, can cause DNA damage that leads to cancer development.
"For a long time now we have known that nuts are full of substances that are good for the heart and the cardiovascular system, or that protect against becoming overweight or developing diabetes," said Wiebke Schlormann from Friedrich Schiller University Jena in Germany. Some studies have also indicated a protective effect against colon cancer, Schlormann said.
"What we have not known in detail up to now is what this protective effect of nuts is based on," she said. The new research throws light on the molecular mechanisms of this protective effect. "The body has a whole series of protective mechanisms that render reactive oxygen species harmless," said Schlormann.
Researchers have shown that these mechanisms are stimulated by nuts and the substances they contain. They studied the effect of five different types of nuts:
macadamia nuts, hazelnuts, walnuts, almonds and pistachios. The nuts were artificially 'digested' in test tubes and the effects of the resulting digestion products on cell lines were then analysed.
The researchers established that the activity of the protective enzymes catalase and superoxide dismutase increases in the cells that are treated. In addition, the digestion products induce what is called programmed cell death in the cancer cells thus treated. "We were able to show this effect is mediated by all the
types of nuts studied," said Michael Glei from from Friedrich Schiller University Jena. The study was published in the journal Molecular Carcinogenesis.