How Diet Can Contribute to Better Cancer Treatment Outcomes: 2 RCCA Oncologists Share Insights and Approaches

Avishek Kumar, MD, says that while the role of diet in reducing the risk of developing cancer is well known, many people don’t realize that what you eat after being diagnosed with the disease can have a significant impact on outcomes.

“When we think of dietary choices for people undergoing cancer treatment, the focus often is on selecting foods that a person experiencing chemotherapy-related nausea can tolerate, or that can help with the fatigue that can result from cancer or certain therapies. Those considerations are very important, but a growing body of scientific evidence is showing that good nutrition also can reduce the risk of cancer recurrence and even help extend survival in certain patients and types of cancer,” explains Dr. Kumar, a board-certified medical oncologist who practices at the Edison, NJ offices of Regional Cancer Care Associates (RCCA), one of the nation’s largest networks of oncology specialists.   

Rachel Levenbach, MD, notes that a particularly encouraging study about diet and cancer outcomes was presented this June at the annual meeting of the American Society of Clinical Oncology. Dr. Levenbach, a board-certified medical oncologist and hematologist with a practice emphasis on breast cancer, explains, “The study involved almost 500 women recently diagnosed with breast cancer. At the start of the study, the women received advice to follow a Mediterranean diet and to engage in physical activity. Roughly three years later, women with hormone receptor-positive (HR+) breast cancer who closely followed that advice had a 76% reduction in their risk of cancer recurrence compared to other women with HR+ breast cancer who did not embrace the nutritional and exercise guidance.”

Dr. Levenbach, who practices at the RCCA offices in Moorestown, NJ, adds that the research illustrates both the promise of incorporating diet into the overall care of people with cancer and the many questions that still need to be addressed. “The study included both women with HR+ breast cancer – meaning cancer whose growth is driven by estrogen or progesterone – and women with hormone receptor-negative (HR-) breast cancer. The women with HR+ cancer obtained a significant benefit in adopting healthy lifestyle practices, while that benefit was not seen in their counterparts with HR- disease. Roughly 80% of cases of breast cancer are hormone receptor-positive, so these findings hopefully will be helpful to the great majority of women dealing with the disease, but the difference in outcomes underscores the importance of conducting further research in this area. The currently available evidence shows that diet can help ease fatigue, enhance quality of life, and have other positive benefits for people with cancer. However, as Dr. Kumar referenced, findings vary by cancer type and patient population, particularly in terms of progression to metastasis, risk of cancer recurrence, and survival. 

“This reinforces the fact that in treating cancer, there is no ‘one-size-fits-all’ approach. That is why at RCCA we individualize our care plans to each person’s specific situation. It also is why patients should consult their oncologist before adopting a new diet or exercise plan, starting a supplement or herbal preparation, or making similar changes. We encourage people to take a proactive approach to their health, but you want to confirm that any planned step is applicable to you, safe for you, and potentially beneficial.”  

The oncologist adds, “The other noteworthy aspect of this trial is that the reduced risk of breast cancer recurrence was seen in women who adopted an overall dietary plan while also engaging in physical activity and receiving Vitamin D supplementation. It is important to take a comprehensive approach to your well-being: not diet or exercise, but diet and exercise appropriate to your physical abilities – as well as obtaining adequate sleep, managing stress, and other healthy behaviors.”

‘So, What Should I Be Doing About My Diet?’

Dr. Kumar says that while there is not a “cancer survivors’ diet,” per se, the American Cancer Society and the National Comprehensive Cancer Network both encourage survivors to follow a predominantly plant-based eating plan. 

The oncologist explains that such diets entail:

• Eating plenty of vegetables, fruit, beans and legumes, whole grains, seed, and nuts;
• Limiting red meat;
• Avoiding processed meats, such as bacon, ham, sausages, and hot dogs;
• Limiting consumption of highly processed foods high in sugar, fat, or starches, such as cookies, chips, and candy bars;
• Limiting consumption of sugar-sweetened drinks and refined sugars; and,
• Avoiding or limiting alcohol.

“If possible, consultation with a registered dietitian or other healthcare professional trained in nutrition can be incredibly helpful, not only in terms of specific foods to eat or avoid but also for proven approaches to adopting good nutritional practices,” Dr. Kumar says. He adds that dietitians also can help ensure that in making changes, people continue to obtain adequate levels of key nutrients – such as assuring sufficient protein intake by replacing red meat with poultry, fish, low-fat dairy foods, and nuts.

“Beyond providing general guidance, dietitians who have experience working with patients with cancer also can help with specific challenges a person may be facing. For example, a patient receiving radiation therapy for head and neck cancer may have difficulty swallowing or experience a very dry mouth, which can make eating difficult. Dietitians can provide strategies for overcoming those issues,” he says.