Falafel and hummus are not just delicious, they also could save your life, according to data presented at United European Gastroenterology (UEG) Week 2022.  Results of the study (abstract 2064) from the Netherlands and United Kingdom suggest that a Mediterranean diet can improve response to immunotherapy in people with advanced melanoma, the deadliest form of skin cancer. 

Researchers observed a significantly higher overall response rate to immune checkpoint blockade in patients who consumed foods high in monounsaturated fatty acids (MUFA), polyphenols and fiber. The Mediterranean diet was also associated with improved progression-free survival (PFS), the study authors reported. 

“These nutrients have recently gained interest related to their immunomodulatory and anti-tumor activities,” said lead study author Laura Bolte, BSc, a dietitian currently pursuing MD and PhD degrees at the University Medical Center Groningen, in the Netherlands. “Our study underlines the importance of dietary assessment in patients starting immune checkpoint blockade and supports a role for dietary strategies to improve treatment outcomes.”

As Ms. Bolte explained, immunotherapy has revolutionized the treatment of several advanced cancers, leading to unprecedented clinical benefits in melanoma and becoming increasingly established in cancers of the gastrointestinal tract. Unfortunately, not all patients respond to these treatments, and immune checkpoint blockade can induce a range of immune-related adverse events, including colitis.

“The influence of the gut microbiome on response to immune checkpoint blockade has been demonstrated in numerous human cohort studies and preclinical models,” Ms. Bolte reported. “Interestingly, many of the identified gut microbes have well-described associations with the diet, which has led to the hypothesis that a high-fiber intake could enhance the efficacy of checkpoint inhibitors.”

Habitual Diet Examined

For this multiple-cohort study, Ms. Bolte and her colleagues investigated the link between habitual diet and checkpoint blockade outcomes in 91 patients with advanced melanoma . Patients were treated with anti-PD-1 and anti-CTLA-4 monotherapy or combination therapy at cancer centers in the United Kingdom and the Netherlands, and underwent routine radiographic response evaluation.

The study’s primary end points were overall response rate, PFS at 12 months, and occurrence of grade 2 or higher immune-related adverse events. Dietary intake was assessed by food frequency questionnaires prior to treatment.

Improvements in Response and Survival

As Ms. Bolte reported, the Mediterranean diet—which emphasizes vegetables, fruits, whole grains, beans and legumes, and a higher intake of MUFA (e.g., olive oil and nuts)—was significantly associated with improved overall response rate and PFS at 12 months. 

The researchers also observed an inverse correlation between treatment-related toxicity and consumption of whole grains and legumes. According to Ms. Bolte, patients who ate a diet rich in the latter were less likely to develop immune-related side effects such as colitis. Conversely, red and processed meats were associated with a higher probability of immune-related side effects, she added.

The investigators concluded that given the expansion of clinical trials of immunotherapy to various malignancies, including gastrointestinal cancers, these findings will be relevant for a large group of cancer patients.

—Chase Doyle

Ms. Bolte reported no relevant financial disclosures.