Although several factors influence cancer risk and development, nutrition and physical activity are among the only modifiable lifestyle factors, apart from tobacco, that can contribute to disease prevention.

Several health organizations have proposed nutritional and lifestyle recommendations in an effort to promote overall healthier behaviors. In a new analysis, researchers sought to evaluate 4 nutritional scores to determine which recommendations most profoundly affected cancer risk. They found that better adherence to a healthy diet that includes physical activity and discourages alcohol intake can significantly reduce overall cancer risk, as well as lower the risk of breast, prostate, and colorectal cancers.

The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) estimated that in developed countries, approximately 35% of breast cancers and 45% of colorectal cancers could be avoided by better adherence to nutritional recommendations, the researchers wrote.

The study involved 3 previously validated nutritional recommendations: The cancer-specific WCRF/AICR score, the Alternate Healthy Eating Index, and the French Nutrition and Health Program-Guidelines Score. The MEDI-LITE score, a relatively new index that measures adherence to a Mediterranean diet, was also evaluated.

The researchers collected data from the NutriNet-Santé study, which launched in 2009, to investigate the association between nutrition and health in a French cohort. The study included 41,543 healthy participants aged 40 years or older, who had never been diagnosed with cancer prior to the study.

Each of the participants completed web-based dietary records every 6 months in which they detailed all foods and beverages consumed during a 24-hour period. The researchers calculated their adherence to each of the 4 nutritional scores. Between May 2009 and January 1, 2017, the researchers found that 1489 participants received cancer diagnoses, including 488 breast cancers, 222 prostate cancers, and 118 colorectal cancers.

Although adherence to all diets was associated with a reduced cancer risk, the WCRF/AICR index demonstrated greater statistical strength and a better predictive performance compared with the other recommendations. The researchers determined that the “synergistic contribution” of a healthy diet was more effective than any single dietary recommendation, allowing for a greater chance of cancer prevention.

Furthermore, the strict recommendation by the WCRF/AICR to avoid alcohol consumption likely played a significant role in the diet’s cancer risk-reducing effects, the researchers noted. Prior studies have linked alcohol consumption to increased risk for many cancers.

Because the study was volunteer-based, the researchers noted that it may have overrepresented women, individuals with health-conscious behaviors, and those with higher socioeconomic and educational levels.

The results could have a more dramatic impact in an American population because previous research has shown that the French consume more fruits and vegetables and fewer sugary beverages than Americans, the study concluded.

References

Lavelette C, Adjibade M, Srour B, et al. Cancer-specific and general nutritional scores and cancer risk: results from the prospective NutriNet-Santé cohort. Cancer Research. 2018. Doi: 10.1158/0008-5472.CAN-18-0155

Adherence to Healthy Diets Associated with Lower Cancer Risk [news release]. American Association for Cancer Research’s website. https://www.aacr.org/Newsroom/Pages/News-Release-Detail.aspx?ItemID=1209#.W2HF4MbMxPW. Accessed August 1, 2018.