Study validates cancer risk reduction through lifestyle adherence

By Tarun Sai LomteReviewed by Danielle Ellis, B.Sc.Nov 28 2023

In a recent study published in BMC Medicine, researchers examined associations between adherence to cancer prevention recommendations by the World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) and cancer risk.

Background

Lifestyle factors are associated with the risk of common cancers. In the United Kingdom (UK), around 40% of cancers are attributed to modifiable risk factors like overweight/obesity, alcohol intake, smoking, and insufficient fiber intake. WCRF/AICR published updated cancer prevention recommendations in 2018, promoting a healthy lifestyle. Studies have examined associations between adherence to the recommendations and cancer risk, survival, and other outcomes.

Nevertheless, most studies examined adherence to the 2007 version of the recommendations. A systematic review and meta-analysis concluded that greater adherence to the 2007 version of recommendations was associated with lower risk of lung, breast, and colorectal cancers and mortality but also noted significant heterogeneity between studies.

As such, the 2018 WCRF/AICR Score, a standardized scoring system, was introduced to address this issue and improve comparability and consistency. However, limited studies have implemented this scoring system, many of which have considered overall cancer incidence with little consideration for common cancers. Further, most of these studies were conducted in the United States (US), Sweden, and Spain, and their generalizability to other countries is uncertain.

About the study

In the present study, researchers examined associations between the WCRF/AICR score and the incidence of several cancers in the UK. They used data from the UK Biobank prospective cohort, with over 500,000 participants recruited during 2006–10. Data on general health, diet, and sociodemographic factors were obtained, and anthropometric measurements were made at the baseline visit. The team implemented the seven-component 2018 WCRF/AICR Score.

Adherence to the body weight recommendation was examined using data on waist circumference and body mass index (BMI) and to the physical activity recommendation using self-reported physical activity data. Adherence to the remaining five recommendations (alcohol intake; whole grains, fruits, vegetables, and beans; sugar-sweetened drinks; processed and red meat; and fast foods) was assessed using data from the food frequency questionnaire and 24-hour dietary assessment.

The team assigned one point for complete adherence, 0.5 for partial adherence, and zero for non-adherence. The total adherence score (range : 0–7) was obtained from the sum of scores for seven components. The study’s outcomes were the incidence of all cancers (overall incident cancer) and 14 lifestyle-related cancers (bladder, kidney, breast, prostate, ovarian, lung, pancreatic, colorectal, gallbladder, esophageal, uterine, liver, stomach, and head and neck cancers).

The team used Cox proportional hazards models to explore the association of adherence score with the risk of all cancers and lifestyle-related cancers. The first model was adjusted for age, ethnicity, sex, and the Townsend deprivation index, whereas the second model was additionally adjusted for smoking status.

Findings

The study included 97,778 participants, who were followed up for a median of 7.9 years. Of these, 7,296 individuals developed cancer. Prostate, breast, and colorectal cancers were the most common cancers, with 1818, 1438, and 863 cases, respectively. A non-linear relationship was observed between adherence score and colorectal cancer risk.

The researchers observed significant associations between adherence score and the risk of overall cancer and breast, colorectal, kidney, esophageal, liver, gallbladder, and ovarian cancers. In the first model, adherence score was significantly associated with the risk of pancreatic and lung cancers, but it was not significant in the second model.

Participants with the highest tertile adherence score (4.5 to 7 points) had a lower risk of overall cancer and ovarian, esophageal, kidney, colorectal, and breast cancers than those in the lowest tertile (≤ 3.5 points). Participants in the mid-tertile (3.75 to 4.25 points) had a lower risk of overall cancer and colorectal and breast cancers than those in the lowest tertile.

Conclusions

Taken together, the study explored associations between cancer risk and adherence to the 2018 version of WCRF/AICR recommendations for cancer prevention. Higher adherence to recommendations was associated with a significantly lower risk of overall cancer as well as ovarian, esophageal, liver, breast, colorectal, gallbladder, and kidney cancers. These results support increasing compliance with the 2018 WCRF/AICR recommendations in the UK.