An Italian study has revealed the potential benefits of adhering to the Mediterranean diet for cancer survivors, suggesting a notable reduction in all-cause mortality and cardiovascular-related deaths.
The Mediterranean Diet is rich in natural antioxidant sources like fruits, vegetables, and olive oil, which are believed to play a crucial role in reducing mortality. The diet emphasizes healthy fats from sources like olive oil, which have been linked to cardiovascular health benefits. Whole grains and legumes also contribute to overall health and longevity.
"The beneficial role of the Mediterranean diet in primary prevention of some tumors is well known. However, little is known about its benefits for those who have already received a cancer diagnosis," noted lead study author Marialaura Bonaccio, PhD, co-principal investigator in the Department of Epidemiology and Prevention at the I.R.C.C.S. Neuromed.
In the recent study, published in JACC: CardioOncology, investigators recruited 802 Italian adults patients—476 of whom were female and 326 of whom were male—with a mean age of 63 ± 12 years who had been diagnosed with various types of cancers prior to enrollment in the Moli-sani Study between 2005 and 2010. They assessed the participants' dietary intake an average of 8.8 ± 8.3 years following their cancer diagnosis using a food frequency questionnaire. The study was conducted as part of the UMBERTO Project by the Joint Research Platform Umberto Veronesi Foundation and I.R.C.C.S. Neuromed.
The patients' adherence to the Mediterranean diet was assessed using a standardized scoring system based on their consumption of key diet components such as fruits, vegetables, whole grains, nuts, legumes, and olive oil. The investigators found that the patients had a mean Mediterranean Diet Score (MDS) of 4.4 ± 1.6. After a follow-up of 12.7 years (9,279 person-years), there were 248 total deaths, including 59 from cardiovascular-related causes and 140 from cancer-related causes.
The cancer survivors who had high MDS adherence, with scores of 6 to 9, experienced a 32% reduction in all-cause mortality (hazard ratio [HR] = 0.68, 95% confidence interval [CI] = 0.46–0.99) compared with those who had low adherence, with scores of 0 to 3. Each 2-point increase in the MDS was associated with a 16% lower rate of all-cause mortality (HR = 0.84, 95% CI = 0.71–0.99).
Further, the investigators found a 58% reduction in cardiovascular-related mortality (HR = 0.42, 95% CI = 0.19–0.93) among the patients who showed high adherence to the Mediterranean diet compared with those who showed low adherence. For each 2-point MDS increase, there was a 31% reduction in the risk of cardiovascular-related mortality (HR = 0.69, 95% CI = 0.49–0.97).
The study's findings may align with the increasing number of cancer survivors—attributed to advances in targeted and effective therapies—highlighting the importance of exploring how a healthy diet can influence survival rates in this population.
Study author Maria Benedetta Donati, MD, PhD, principal investigator of the Joint Platform, emphasized that the results of the study may support the hypothesis that chronic diseases such as cancer and cardiovascular disease may share common molecular mechanisms, often referred to as "common soil."
"The Mediterranean diet is mostly composed of foods such as fruits, vegetables, and olive oil, which are natural sources of antioxidant compounds. This could explain the observed reduction in mortality from both cancer and cardiovascular disease," underscored Chiara Tonelli, President of the Scientific Committee of the Umberto Veronesi Foundation.
The investigators noted that the study's strengths included its prospective design, long follow-up, validated dietary questionnaire, adjustment for multiple confounders, and the mixed cancer cohort supporting generalizability. However, limitations such as the observational nature precluding causal inference, potential survival bias and residual confounding, lack of repeated dietary measures, and insufficient power for cancer type–specific analyses should be considered when interpreting the results.
The findings indicated that adopting a Mediterranean diet post–cancer diagnosis may reduce mortality risk, especially from cardiovascular causes, aligning with the "common soil" hypothesis of shared disease mechanisms. The results may encourage further research to develop targeted dietary guidelines for cancer survivors, with randomized controlled trials potentially helping to establish causal effects.
Conflict of interest disclosures were not made available at time of publishing.
