Effect of diet on mortality and cancer recurrence among cancer survivors: a systematic review and meta-analysis of cohort studies

Abstract

Context: Evidence of an association between dietary patterns and individual foods and the risk of overall mortality among cancer survivors has not been reviewed systematically. Objective: The aim of this meta-analysis of cohort studies was to investigate the association between food intake and dietary patterns and overall mortality among cancer survivors. Data Sources: The PubMed and Embase databases were searched. Study Selection: A total of 117 studies enrolling 209 597 cancer survivors were included. Data Extraction: The following data were extracted: study location, types of outcome, population characteristics, dietary assessment method, risk estimates, and adjustment factors. Results: Higher intakes of vegetables and fish were inversely associated with overall mortality, and higher alcohol consumption was positively associated with overall mortality (RR, 1.08; 95%CI, 1.02–1.16). Adherence to the highest category of diet quality was inversely associated with overall mortality (RR, 0.78; 95%CI, 0.72–0.85; postdiagnosis RR, 0.79; 95%CI, 0.71–0.89), as was adherence to the highest category of a prudent/healthy dietary pattern (RR, 0.81; 95%CI, 0.67–0.98; postdiagnosis RR, 0.77; 95%CI, 0.60–0.99). The Western dietary pattern was associated with increased risk of overall mortality (RR, 1.46; 95%CI, 1.27–1.68; postdiagnosis RR, 1.51; 95%CI, 1.24–1.85). Conclusion: Adherence to a high-quality diet and a prudent/healthy dietary pattern is inversely associated with overall mortality among cancer survivors, whereas a Western dietary pattern is positively associated with overall mortality in this population.

Can Nutrition Lower the Risk of Recurrence in Breast Cancer

“…In breast cancer survivors (41 cohort studies), a recently published systematic review and meta-analysis [26] showed an association of decreased overall mortality and adherence to high diet quality indices (high intake of fruit, vegetables, whole grains, legumes, and nuts as well as low intake of red and processed meat) (RR 0.74, 95% CI 0.60-0.90, 3 studies) and adherence to a prudent/healthy dietary pattern (high intake of fruit, vegetables, whole grains, poultry, and low-fat dairy products) (RR 0.76, 95% CI 0.60-0.95, 3 studies). High adherence to a Western/unhealthy dietary pattern (high intake of red and processed meat, refined grains, sweets and desserts, and high-fat dairy products) was associated with an increased risk of overall mortality (RR 1.44, 95% CI 1.17-1.77, 3 studies) [26].…”

“…High adherence to a Western/unhealthy dietary pattern (high intake of red and processed meat, refined grains, sweets and desserts, and high-fat dairy products) was associated with an increased risk of overall mortality (RR 1.44, 95% CI 1.17-1.77, 3 studies) [26]. No association was found with single food groups, and no significant results were presented for recurrence or breast cancer-specific mortality [26].…”

“…High adherence to a Western/unhealthy dietary pattern (high intake of red and processed meat, refined grains, sweets and desserts, and high-fat dairy products) was associated with an increased risk of overall mortality (RR 1.44, 95% CI 1.17-1.77, 3 studies) [26]. No association was found with single food groups, and no significant results were presented for recurrence or breast cancer-specific mortality [26]. Even though the studies presented as well as the meta-analysis did not find consistent significant effects of dietary patterns and diet quality scores on breast cancer recurrence and breast cancer-specific mortality, it is noteworthy that healthy dietary choices may be important, as women with diagnosed breast cancer are also at risk of death from non-breast cancer-related causes affected by diet.…”

“…A recently published systematic review and meta-analysis, including 7 studies for breast cancer, demonstrated that alcohol intake was associated with an increased risk of breast cancer recurrence (RR 1.21, 95% CI 1.06-1.39). However, an association with overall mortality (including 21 cohort studies with pre-and postdiagnosis alcohol exposure) was not found [26]. Altogether, due to the well-known adverse effects of alcohol on general health as well as its likely contribution to breast cancer development in both preand postmenopausal women [38], adherence to national dietary guidelines for alcohol intake seems to be appropriate also for breast cancer survivors [39].…”

Food groups and risk of colorectal cancer

“…A recent systematic review and meta‐analysis summarized evidence on dietary factors and risk of CRC and indicated that higher intake of red and processed meat was associated with increased risk of CRC, while higher intake of whole grains, dairy products, vegetable and fish showed inverse associations with risk . Previous meta‐analyses pointed out that dietary patterns were also related to risk of CRC, and mortality among CRC survivors . A “healthy” dietary pattern, characterized by high intake of vegetables, fruit, whole grains, olive oil, fish, soy, poultry and low‐fat dairy was associated with decreased risk of CRC, whereas a “western” diet, characterized by high consumption of red and/or processed meat, refined grains, sweets, high‐fat dairy products, butter, potatoes and high‐fat gravy and low intake of fruit and vegetables was related to increased risk of CRC .…”