April 2021. About this episode: Nuts are high in healthy fats and are energy (kilojoule) dense. But does this mean…
The body of evidence about nuts and cancer continues to grow, with new local and international research papers regularly published.
Key studies: systematic reviews and meta-analyses
Association of total nut, tree nut, peanut, and peanut butter consumption with cancer incidence and mortality: A comprehensive systematic review and dose-response meta-analysis of observational studies. (2020).
This newly-published review collated the findings from 52 published papers. It found a protective association between total nut and tree nut intake and the risk of cancer and its mortality. A 5g/day increase in total nut intake was linked with a 3%, 6% and 25% lower risk of overall, pancreatic, and colon cancers, respectively. For cancer mortality, the researchers found an 18% risk reduction with higher intakes of tree nuts. In addition, a 5g/day increase in total nut intake was linked with a 4% lower risk of dying from cancer.
Nut consumption and risk of cancer and type 2 diabetes: a systematic review and meta-analysis. (2015)
Nut consumption was inversely associated with the risk of total cancer, and with the risk of colorectal cancer, endometrial cancer and pancreatic cancer specifically, but not for other cancer types.
Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies. (2016)
Higher nut intake is associated with reduced risk of cardiovascular disease, total cancer and all-cause mortality, and mortality from respiratory disease, diabetes, and infections.
Nut consumption on all-cause, cardiovascular, and cancer mortality risk: a systematic review and meta-analysis of epidemiologic studies. (2015)
Nut consumption is associated with lower risk of all-cause, CVD, and cancer mortality, but the presence of confounding factors should be taken into account when considering such findings.
Adolescent alcohol, nuts, and fibre: Combined effects on benign breast disease risk in young women. (2020).
This prospective cohort study followed 9,031 females, aged 9-15 years at baseline (1996-2001), until 2014. The researchers hypothesised that consuming nuts/nut butter may lessen the elevated risk of benign breast disease (BBD) – a risk factor for breast cancer – among adolescents who drink alcohol. They found that that those who consumed both alcohol and nuts had a lower risk (RR = 0.47, 95% CI: 0.24–0.89; p = 0.02), compared to drinkers who didn’t eat nuts. The researchers concluded that for high school females who drink, their BBD risk may be offset by consuming nuts. Future studies are needed in this area.
Meta-analysis of the Association Between Nut Consumption and the Risks of Cancer Incidence and Cancer-Specific Mortality (2020).
Zhang D. et al.
Nut consumption is inversely associated with the risks of cancer incidence and mortality; a higher intake is significantly associated with a lower cancer risk.
Legume and Nuts Consumption in Relation to Glioma: A Case- Control Study. (2020)
Malmir H. et al
The study aimed to investigate the relation between legume and nuts consumption and glioma in a case-control study in Iranian adults. Individuals in the top category of legume and nuts consumption were 66% less likely to have glioma compared with those in the bottom category. There was an inverse association between legume and nuts consumption and odds of glioma, even after controlling for a wide range of confounders, including age, sex, energy intake, BMI and dietary intakes.
Nut Consumption and Risk of Cancer: A Meta-analysis of Prospective Studies. (2020)
Jieyi Long et al.
This meta-analysis evaluated the relationship between nut consumption and risk of cancer. Thirty-three studies, that included more than 50,000 cancer cases were analysed. When comparing the highest with the lowest category of nut intake, high consumption of nuts was significantly associated with decreased risk of overall cancer (RR = 0.90; 95% CI, 0.85–0.95). The protective effect of nut consumption was especially apparent against cancers from the digestive system (RR = 0.83; 95% CI, 0.77–0.89). The authors also observed a linear dose–response relationship between nut consumption and cancer. In conclusion, the results offer compelling evidence about the association between nut intake and the risk of cancer; with significant protective effects found at 9g/day and the risk of cancer decreasing by 10% for every 20g/day increase.
Nut and peanut butter consumption and the risk of lung cancer and its subtypes: A prospective cohort study (2019).
Significant associations found with total nut intake and small cell carcinoma in men, and non-significant inverse trends found for other lung cancer subtypes in men, but not in women.
Food groups and risk of colorectal cancer. (2018).
For intake of nuts, a decreased risk was observed for colon cancer only.
Dietary Patterns and Colorectal Cancer Risk: A Review of 17 Years of Evidence 2000-2016. (2017).
A “healthy” pattern, generally characterized by high intake of fruits and vegetables, wholegrains, nuts and legumes, fish and other seafood, milk and other dairy products, was associated with lower CRC risk.
Dietary Protein Sources and Incidence of Breast Cancer: A Dose-Response Meta-Analysis of Prospective Studies. (2016).
There was a null association between poultry, fish, egg, nuts, total milk, and whole milk intake and breast cancer risk. Higher total red meat, fresh red meat, and processed meat intake may be risk factors for breast cancer, whereas higher soy food and skim milk intake may reduce the risk of breast cancer.
Published January 28, 2020