Mediterranean Diet Linked to Reduced Mortality in Long-Term Cancer Survivors: JACC

After nearly 13 years of follow-up, cancer survivors who adhered closely to the Mediterranean diet experienced a 32% lower risk of all-cause mortality compared to those with low adherence (hazard ratio 0.68), the researchers reported in JACC: CardioOncology.

The findings suggested the benefit of maintaining or adopting a traditional [Mediterranean diet] even after a cancer diagnosis and motivated the additional science concerning the development of dietary recommendations specifically targeted at cancer survivors.

The Mediterranean diet includes foods naturally rich in polyphenols and bioactive compounds known for their antioxidant, anti-inflammatory, and potential antitumor properties. These benefits are relevant to cancer prevention and progression and play a significant role in preventing cardiovascular mortality.

Research investigating the connections between the Mediterranean diet (MD) and mortality in cancer survivors has yielded inconclusive results. The majority of studies originate from the United States, with limited evidence available from Europe. Additionally, many studies focus on specific types of cancer survivors, which restricts the applicability of findings to the broader population of cancer survivors.

Against the above background, Marialaura Bonaccio, Department of Epidemiology and Prevention, IRCCS Neuromed, Pozzilli, Italy, and colleagues aimed to clarify the role of a traditional MD among Italian long-term cancer survivors concerning mortality, using postdiagnosis dietary data.

Using data from the Moli-sani cohort, established in Italy between 2005 and 2010, which included 24,325 adults aged 35 years or older, the study focused on 802 participants diagnosed with cancer at baseline. These individuals provided medical records and details on cancer treatment. Dietary habits were assessed using a semiquantitative food frequency questionnaire administered by interviewers.

The study group comprised 476 women (59%) and 326 men (41%), with an average age of 63 years. Diet assessment occurred approximately 8.8 years after their cancer diagnosis.

Participants' adherence to the Mediterranean diet was evaluated using a 9-point scale, categorized as poor (scores 0-3), average (scores 4-5), or high (scores 6-9). Those with higher adherence tended to have a higher socioeconomic status and were more likely to engage in regular physical activity compared to those with poor adherence.

The following were the key findings of the study:

• During 12.7 years of follow-up, a total of 248 deaths were recorded, including 59 attributed to cardiovascular causes and 140 from cancer. Analyses were adjusted for age, sex, energy intake, education, smoking status, physical activity, and hormone replacement therapy, among other factors.
• Each 2-point increment in the Mediterranean diet score was associated with a 16% lower risk of all-cause mortality (HR 0.84) and a 31% lower risk of cardiovascular death (HR 0.69).
• Survivors with high adherence to the diet had a 32% lower risk of all-cause mortality compared to those with poor adherence (HR 0.68).
• High adherence to the diet was not significantly associated with lower cancer mortality (HR 0.79).

"Our results indicate that continuing or adopting a traditional Mediterranean diet following a cancer diagnosis could offer benefits," the researchers concluded. "This underscores the need for further research to develop tailored dietary guidelines for cancer survivors."

Reference:

Bonaccio M, et al "Mediterranean diet is associated with lower all-cause and cardiovascular mortality among long-term cancer survivors" JACC CardioOncol 2024; DOI: 10.1016/j.jaccao.2024.05.012.