The Mediterranean diet reduces the risk of obesity-related cancers

The Mediterranean diet reduces the risk of obesity-related cancers

New research finds that following a Mediterranean diet may reduce the risk of obesity-related cancers, including liver and kidney cancer. The study suggests that even moderate adherence provides some protection and highlights the role of diet in cancer prevention.

A current oneJama Network Open The study will determine whether adherence to the Mediterranean diet (Meddiet) affects the risk of developing cancer-related obesity.

How does obesity affect cancer risk?

The prevalence of both obesity and overweight increased significantly between 1975 and 2016 among male and female adults, with a recent study estimating that 39% of the world's population is now considered obese or overweight. The International Agency for Research on Cancer has reported that excess body weight is associated with a higher risk of developing cancer in thirteen anatomical sites, including the kidney, liver, breast, endometrium and esophagus.

Several epidemiological studies and clinical trials have reported the beneficial effects of Meddiet in promoting weight loss and reducing abdominal obesity. For example, the prospective investigation of the European Cohort Study of Cancer and Nutrition (EPIC)-Spain cohorts identified an inverse association between high adherence to diet and obesity risk in individuals with excess body weight. Likewise, another study showed that moderate survival rates improved after a breast cancer diagnosis.

The Epic study also found a 4% reduction in overall cancer risk for every two-point increase in mean score, with higher scores reflecting greater adherence to this diet. Similar observations were recently published in a meta-analysis reporting that higher median adherence reduced cancer mortality risk and specific cancer incidence.

Multiple factors, including genetic susceptibility, hypoxia, insulin resistance, adipokines, stromal cells, inflammation, and growth factors, are involved in the relationship between obesity and cancer. To date, it remains unclear whether adiposity mediates the beneficial role of Meddiet in obesity-related obesity-related disorders (ORCs).

About the study

The current study examined the association between Meddiet adherence and risk of ORC in the Epic cohort, which includes 521,324 people between 35 and 70 from 23 centers in 10 countries. The researchers also determined whether this association was mediated by body mass index (BMI) and waist-to-hip ratio (WHR).

Individuals diagnosed with cancer at baseline, without diagnosis or follow-up information, and without dietary or lifestyle data were excluded from analysis.

Fourteen food groups and nutrients were considered in the analysis. It estimated each participant's daily intake in grams of different dietary components and total energy intake.

The mean pattern was measured using the Meddiet score (MDS) and the relative Meddiet score (RMeddiet). The cases of cancer in the EPIC study were identified during the follow-up period of 14.9 years.

Study results

A total of 450,111 study participants, of which 29.2% were men and 70.8% women from the epic cohort, met the eligibility criteria for the current study. The average age of the study participants was 51.1 years. At baseline, the mean BMI was 25.3, while the median was 0.8.

Approximately 4.9% of study participants who were not diagnosed with cancer at baseline during the study follow-up period were undiagnosed. This includes 0.053, 0.049 and 0.043 per person-years in low, medium and high Meddiet adherence groups.

Individuals with the highest MDS scores reported higher levels of education, were more likely to be younger, non-smokers, less physically active, and have high energy intake. In the fully fitted model, higher moderate adherence was associated with lower risk of ORC.

A similar association was observed between mean Meddiet adherence and ORC; However, no association was identified when the MDS was modeled continuously. These results were consistent with sensitivity analyzes using the RMedDiet score and multivariable adjusted model.

A site-specific ORC assessment showed an inverse association between higher adherence to CME and the risk of hepatocellular, colorectal, and kidney cancers. Mean adherence to the medication diet was also inversely associated with esophageal cancer; However, this association was not observed in postmenopausal breast, endometrial, and ovarian cancers.

Stratified analyzes showed an inverse association between adherence to the MDS and the risk of ORC among former smokers. Taken together, a lower risk of incident ORC was associated with moderate alcohol consumption and lower meat consumption. Mediation analysis did not identify a significant association between high and low moderate adherence and ORC risk mediated by BMI or WHR.

Conclusions

The study results confirm that higher adherence to the Meddiet may moderately reduce the risk of ORCs, with moderate adherence being associated with a smaller reduction in the risk of certain cancers. Additional research is needed in the future to elucidate the mechanisms by which higher mean jet adherence may reduce the risk of cancer risk.

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