The relationship between nut intake and risk of colorectal cancer: a case control study.

Nutrition journal. 2018;17(1):37
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Nut consumption has been shown to be associated with reduced risk of obesity, Type 2 diabetes and cardiovascular disease. This retrospective, case-controlled study aimed to examine the association between nut consumption and the risk of colo-rectal cancer in a cohort of Korean adults. 923 colorectal cancer patients and 1846 controls were included in the study. Each completed a validated food frequency questionnaire, including peanuts, pine nuts and almonds. A nut serving was considered to be 15g and was categorised as none, less than 1 serving per week, 1-3 servings per week and greater than 3 servings per week. Nut consumption was found to have a strong association with reduced colo-rectal cancer in both men and women, after adjusting for age, education level, alcohol consumption, BMI, regular exercise, red meat intake, fruit and vegetable intake and total energy intake. This association was found in all sub-sites of the colon for men and for the distal and rectum subsites for women.

Abstract

BACKGROUND Nut consumption is known to reduce the risk of obesity, diabetes mellitus, and cardiovascular disease. However, in previous studies, portion sizes and categories of nut consumption have varied, and few studies have assessed the association between colorectal cancer risk and nut consumption. In this study, we investigated the relationship between nut consumption and colorectal cancer risk. METHODS A case-control study was conducted among 923 colorectal cancer patients and 1846 controls recruited from the National Cancer Center in Korea. Information on dietary intake was collected using a semi-quantitative food frequency questionnaire with 106 items, including peanuts, pine nuts, and almonds (as 1 food item). Nut consumption was categorized as none, < 1 serving per week, 1-3 servings per week, and ≥3 servings per week. A binary logistic regression model was used to estimate odds ratios (OR) and their 95% confidence intervals (CI) for the association between nut consumption and colorectal cancer risk, and a polytomous logistic regression model was used for sub-site analyses. RESULTS High nut consumption was strongly associated with reduced risk of colorectal cancer among women (adjusted ORs: 0.30, 95%CI: 0.15-0.60 for the ≥3 servings per week group vs. none). A similar inverse association was observed for men (adjusted ORs: 0.28, 95% CI: 0.17-0.47). In sub-site analyses, adjusted ORs (95% CIs) comparing the ≥3 servings per week group vs none were 0.25 (0.09-0.70) for proximal colon cancer, 0.39 (0.19-0.80) for distal colon cancer, and 0.23 (0.12-0.46) for rectal cancer among men. An inverse association was also found among women for distal colon cancer (OR: 0.13, 95% CI: 0.04-0.48) and rectal cancer (OR: 0.40, 95% CI: 0.17-0.95). CONCLUSIONS We found a statistically significant association between high frequency of nut consumption and reduced risk of colorectal cancer. This association was observed for all sub-sites of the colon and rectum among both men and women, with the exception of proximal colon cancer for women.

Lifestyle medicine

Fundamental Clinical Imbalances : Immune and inflammation
Patient Centred Factors : Mediators/Nut consumption
Environmental Inputs : Diet ; Nutrients
Personal Lifestyle Factors : Nutrition
Functional Laboratory Testing : Not applicable
Bioactive Substances : Vitamins ; Minerals ; Polyphenols ; Essentialfattyacids

Methodological quality

Allocation concealment : Not applicable

Metadata

Nutrition Evidence keywords : Nutconsumption ; Foodfrequencyquestionnaire ; Cancerrisk