A person’s diet can impact cancer in a variety of ways. Studies have identified dietary habits as a key factor in decreasing cancer risk, as well as slowing the progression of the disease.
The body of evidence supporting the idea that the food and drink we consume can directly impact cancer prevention and treatment is growing. A quick Google search will yield a seemingly endless list of dietary “dos” and “don’ts” related to the disease.
According to researchers from the UCLA Health Jonsson Comprehensive Cancer Center, a diet low in omega-6 and high in omega-3, in addition to fish oil supplements, deserves a place in the dos list, due to its ability to significantly lower levels of cancer cell growth.
Their findings, published in the Journal of Clinical Oncology, show that this diet regimen significantly reduced the growth rate of prostate cancer cells in men with early-stage disease.
According to the American Cancer Society, prostate cancer is the second-leading cause of cancer death in American men, second only to lung cancer. Roughly 1 in 44 men will die from the disease.
“This is an important step toward understanding how diet can potentially influence prostate cancer outcomes,” said Dr. William Aronson, Professor of Urology at the David Geffen School of Medicine at UCLA and first author of the study. “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.”
According to the researchers, many men with low-risk prostate cancer choose active surveillance – a treatment approach that involves “regular monitoring of the cancer without immediate intervention” – over immediate treatment.
But within five years, roughly 50% of these men must eventually undergo either surgery or radiation. As a result, the researchers say that many patients are looking for ways to delay the need for treatment, such as dietary changes or supplements.
The UCLA team’s prospective clinical trial aimed to determine whether “diet or supplements can play a role in managing prostate cancer.”
The trial, called CAPFISH-3, included 100 men with low risk or favorable intermediate risk prostate cancer who chose active surveillance. The participants 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 in the latter, “intervention arm” received personalized counseling by a registered dietician nutritionist and were guided on healthy habits and alternatives designed to reduce their consumption of foods with higher omega-6 content and ensure adequate intake of omega-3 fats.
To evaluate the success of the intervention, the team tracked changes in a biomarker called the Ki-67 index, a key indicator of how fast cancer cells are multiplying – a key predictor of “cancer progression, metastasis and survival.”
In order to accurately perform comparisons pre- and post-inervnetion, researchers obtained same site biopsies at the beginning of the study and again after the one-year mark.
The team’s results showed that the low omega-6, omega-3 rich diet and fish oil group had a 15% decrease in the Ki-67 index, as opposed to the control group, which saw a 24% 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.
While encouraged by the results, the team notes that further research is needed in order to confirm the long-term benefits of omega-3 fatty acids and lowering omega-6 in managing prostate cancer.
They conclude, “The findings support further, larger trials to explore the long-term impact of dietary changes on cancer progression, treatment outcomes and survival rates in men on active surveillance.”
