Handful of walnuts a day could keep cancer away, study finds

Eating a handful of walnuts every day could help slow the growth of cancerous tumours, the Mirror reports, citing a new study

The research has found that omega 3 fatty acids in the nuts may reduce inflammation in bowel cancer cells.

In addition, the compounds reduce blood supply, slowing down tumour growth.

Experiments on mice by US scientists showed that animals fed a walnut diet had tumours containing 10 times the amount of protective omega 3s.

Colorectal, or bowel cancer, is the third most common type of cancer worldwide and is second only to lung cancer as the leading cause of death in Western countries.

In Britain, 41,581 people were diagnosed with bowel cancer in 2011 and in the following year 16,187 people died from the disease.

Previous research has shown that changing to a healthier diet can help prevent cancer, and it is estimated 30-50% of colorectal cancer in men and 20% in women can be prevented by diet and other lifestyle changes.

The latest study, carried out by Dr Christos Mantzoros, of Beth Israel Deaconess Medical Center, Harvard Medical School, is the first of its kind to analyse the impact of walnuts on micro-ribonucleic acids (miRNA), which control how genes adapt to environmental factors.

Dr Mantzoros said: "Our research demonstrates that a walnut diet causes significant changes in the expression profile of miRNAs in localised colorectal cancer tissue, and that a walnut diet incorporates protective fatty acids in the colonic tumor either through its direct effects or through additive or synergistic effects of multiple other compounds present in walnuts.

"While future studies are needed, we're optimistic of the role of miRNAs as biomarkers of disease and prognosis, and may demonstrate a potential therapeutic target for colorectal cancer treatment."

Researchers fed mice the equivalent of two servings (2ozs) per day of walnuts for humans, while a second group received a similar control diet without walnuts

After 25 days researchers found that in walnut-fed mice, key miRNA that may affect cancer cell inflammation, vascularization (blood supply) and proliferation were positively engaged.

In mice fed that were fed the walnut-containing diet, they were found to have 10 times the amount of total omega-3 fatty acids, including plant-based alpha-linolenic acid (ALA), a fatty acid critical to various body processes and known for its inflammation reducing properties, compared to the mice fed the control diet.

The study, published in the Journal of Nutritional Biochemistry, found that the greater the amount of Omega 3s the smaller the tumour, suggesting that ALA may offer some protection.

Tumor growth rate was also significantly slower in the walnut group compared to the control group, but the scientists say that because the study was conducted on animals the results won't necessarily be the same for people.

Walnuts are the only nut that contain a significant source of (ALA), 2.5 grams per ounce, as well as a variety of antioxidants, (3.7 mmol/ounce), and numerous vitamins and minerals.