High vegetable and fruit intake improves QoL among Chinese breast cancer patients
High consumption of vegetables and fruits is found to be positively associated with quality of life (QoL), cognitive, physical and emotional functioning, as well as less severe symptoms of nausea, vomiting, dyspnoea, diarrhoea, loss of appetite, insomnia and constipation in Chinese women with early-stage breast cancer, researchers at the Chinese University of Hong Kong (CUHK) and Princess Margaret Hospital (PMH) have reported.
In the prospective cohort Hong Kong NTECKWC Brest Cancer Survival Study (HKNKBCSS), 1,462 Chinese women with early-stage breast cancer (American Joint Committee on Cancer [AJCC] stage 0–III) were longitudinally interviewed at months 0 (baseline), 18, 36 and 60 after diagnosis. Two main dietary patterns were identified: vegetable and fruit pattern, and grain and animal food pattern. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) was used to measure cancer-specific QoL in follow-ups. [Qual Life Res 2021;10.1007/s11136-021-02985-0]
Results showed that patients with the vegetable and fruit dietary pattern, which was characterized by high factor loading for leafy vegetables, other vegetables, potato, fruits and legumes, tended to have better global health status or QoL (unstandardized coefficient of linear regression model [B]=1.282; 95 percent confidence interval [CI], 0.545 to 2.019; p=0.001), physical functioning (B=0.545; 95 percent CI, 0.037 to 1.053; p=0.035), emotional functioning (B=1.428; 95 percent CI, 0.653 to 2.200; p<0.001), and cognitive functioning (B=0.822; 95 percent CI, 0.007 to 1.637; p=0.048).
Higher intake of vegetables and fruits was also inversely associated with symptoms, including nausea and vomiting (B=-0.382; 95 percent CI, -0.694 to -0.071; p=0.016), dyspnoea (B=-0.570; 95 percent CI, -0.570 to -0.570; p<0.001), insomnia (B=-1.412; 95 percent CI, -2.647 to -0.177; p=0.025), loss of appetite (B=-0.722; 95 percent CI, -1.311 to -0.132; p=0.016), constipation (B=-2.028; 95 percent CI, -2.775 to -1.281; p<0.001), and diarrhoea (B=-0.929, 95 percent CI, -1.481 to -0.377; p=0.001).
On the contrary, higher intake of grain and animal food, which was characterized by high factor loadings for refined grain, red meat, fish and seafood, oil, cake and snacks, processed meat and eggs, was inversely associated with role functioning (B=-0.744; 95 percent CI, -0.147 to -0.017; p=0.045) as well as symptoms of dyspnoea (B=-0.092; 95 percent CI, -0.092 to -0.092; p<0.001) and constipation (B=-1.322; 95 percent CI, -2.174 to -0.536; p=0.001).
Patients were also further categorized into three subgroups (tertile 1, tertile 2 and tertile 3) based on the tertiles of factor score which reflected adherence to a specific dietary pattern.
Interestingly, patients in the highest tertile (ie, the highest adherence) of vegetable and fruit dietary pattern had higher education level, were more likely to have normal body mass index (BMI), and were more physically active. “More highly educated individuals are more likely to follow healthier diets and lifestyles,” explained the researchers.HKNKBCSS is the first prospective cohort study with a large sample size to investigate the association between dietary pattern and QoL in Chinese breast cancer patients. The study results highlight the importance of educating breast cancer survivors to maintain a healthier diet, namely, to limit the consumption of meat and increase the intake of vegetables and fruits.