Simple dietary changes could stave off prostate cancer – as scientists warn three foods to cut down on

DIETARY changes such as taking fish oil supplements may help reduce cancer cell growth, according to a new study.

The researchers described it as “an important step toward understanding how diet can potentially influence prostate cancer outcomes”.

The research, published in the Journal of Clinical Oncology, showed a diet low in omega-6 and high in omega-3 fatty acids, combined with fish oil supplements, significantly reduced the growth rate of prostate cancer cells in men with early-stage disease.

Dr William Aronson, Professor of Urology at the David Geffen School of Medicine at UCLA and first author of the study, said: “Many men are interested in lifestyle changes, including diet, to help manage their cancer and prevent the progression of their disease.

“Our findings suggest that something as simple as adjusting your diet could potentially slow cancer growth and extend the time before more aggressive interventions are needed.”

For men with low risk of prostate cancer, active surveillance is a treatment option.

This involves regular monitoring of the cancer instead of immediate treatment.

But according to the researchers, within five years, about 50 percent of these men eventually need to undergo therapy with either surgery or radiation.

Because of this, patients are eager to find ways to delay the need for treatment, including through dietary changes or supplements.

But until now, specific dietary guidelines in this area have yet to be established.

Other clinical trials have looked at increasing vegetable intake and healthy diet patterns – but these haven’t shown to have a significant impact on slowing cancer progression.

How the study was carried out

The UCLA-led team conducted a prospective clinical trial, called CAPFISH-3, that included 100 men with low risk or favourable intermediate risk prostate cancer who chose active surveillance.

They were then randomly assigned to either continue their normal diet or follow a low omega-6, high omega-3 diet, supplemented with fish oil, for one year.

Participants on the low omega-6, high omega-3 diet were counselled by a registered dietitian.

They were guided on healthier, lower fat alternatives for high fat/high calorie foods (such as using olive oil or lemon and vinegar for salad dressing).

They were also told to reduce consumption of foods with higher omega-6 content (usually fried or processed foods).

Three examples of foods that are often high in omega-6 are:

• Chips
• Cookies
• Mayonnaise

The participants in this group were also given fish oil capsules for extra omega-3s.

The researchers then tracked changes in a biomarker called the Ki-67 index, which indicates how fast cancer cells are multiplyiny.

This is a key predictor of cancer progression, metastasis and survival.

After one year, results showed the low omega-6, omega-3 rich diet and fish oil group had a 15 per cent decrease in the Ki-67 index, while the control group saw a 24 per cent increase.

“This significant difference suggests that the dietary changes may help slow cancer growth, potentially delaying or even preventing the need for more aggressive treatments,” said Aronson, who is also the Chief of urologic oncology at the West Los Angeles Veterans Affairs Medical Centre and member of the UCLA Health Jonsson Comprehensive Cancer Centre.

The researchers cautioned further research is necessary to confirm the long-term benefits of omega-3 fatty acids and lowering omega-6 in managing prostate cancer.