How nuts inhibit growth of cancers

*Using enough water to cook rice reduces heart disease, tumour risk
Roasted and salted, ground as a baking ingredient or fresh from the shell — for all those who enjoy eating nuts, there is good news from nutritionists at Friedrich Schiller University Jena (Germany). Their latest research shows that nuts can inhibit the growth of cancer cells.

“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,” says Dr. Wiebke Schlörmann.

Some studies have also indicated a protective effect against colon cancer, she adds. “What we have not known in detail up to now is what this protective effect of nuts is based on.”

Schlörmann and her colleagues from the Department of Nutritional Toxicology at the University of Jena are now in a position to give specific answers to that question. In a publication in the specialist journal ‘Molecular Carcinogenesis’, they present results from a recent study, which throw light on the molecular mechanisms of this protective effect.

According to this 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 Deoxy ribonucleic Acid (DNA) damage that leads to cancer development.

“The body has a whole series of protective mechanisms that render reactive oxygen species harmless,” explains Schlörmann. The nutritionists in Jena have now shown that these mechanisms are stimulated by nuts and the substances they contain.

The researchers investigated the effect of five different types of nuts: macadamia nuts, hazelnuts and walnuts, as well as 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.

Also, scientists have found that using enough water to cook rice reduces the risk of heart disease and cancer. They said that cooking the grains in excess water helps to flush out arsenic, preventing any possible chemical poisoning.

A contamination expert claims that while soaking rice overnight slashes levels of the industrial toxin by around 80 per cent, cooking rice in excess water flushes out arsenic – which has been linked to a range of health problems. Arsenic gets into the rice as a result of industrial contaminants and pesticides that were used in the past. It can remain in the flooded paddy fields where the rice is grown for decades, research has suggested.

Professor Andy Meharg, a leading expert on rice contamination from Queens University Belfast, tested chemical levels after cooking rice three different ways. He first used a ratio of two parts water to one part rice, whereby the water was absorbed or evaporated during cooking. Increasing the ratio to five parts water halved arsenic levels and soaking it overnight cut the toxin levels the most.

Typically, rice has ten times more inorganic arsenic than other foods and the European Food Standards Authority has reported that people who eat a lot are exposed to worrying concentrations.

Chronic exposure can cause a range of health problems including developmental problems, heart disease, diabetes and nervous system damage. However, most worrying are lung and bladder cancers.

Professor Meharg has previously suggested that cooking rice in a coffee perculator would stop any arsenic from binding to the rice.

By allowing steaming hot water to drip through the rice, contaminants will be washed away. In previous experiments, there was a 57 per cent reduction in arsenic with a ratio of 12 parts of water to one of rice and in some cases as much as 85 per cent.