Comprehensive Assessment of Diet Quality and Risk of Precursors of Early-Onset Colorectal Cancer

Xiaobin Zheng, MD, PhD; Jinhee Hur, PhD; Long H. Nguyen, MD, MS; Jie Liu, MD; Mingyang Song, MD, ScD; Kana Wu, MD, PhD; Stephanie A. Smith-Warner, PhD; Shuji Ogino, MD, MS, PhD; Walter C. Willett, MD, DrPH; Andrew T. Chan, MD, MPH; Edward Giovannucci, MD, ScD; Yin Cao, MPH, ScD


J Natl Cancer Inst. 2021;113(5):543-552. 

In This Article


Among 29 474 women who reported a lower endoscopy between 1991 and 2011 when they were younger than age 50 years, those with a higher Western dietary pattern score were more likely to have higher pack-years of smoking and less likely to exercise or use multivitamins (Table 1). In contrast, participants with greater adherence to the prudent dietary pattern and DASH, AMED, and AHEI-2010 indexes tended to engage in healthier behaviors.

We documented 1157 cases of early-onset adenomas from 1991 to 2011. Compared with those in the lowest quintile of Western dietary pattern, individuals in the highest quintile had an increased risk of early-onset adenoma, after adjusting for a list of putative CRC risk factors (multivariable ORQ5 vs Q1 = 1.38, 95% CI = 1.13 to 1.68, P trend = .003; Table 2). In contrast, a higher prudent pattern score was associated with a lower risk of early-onset adenoma (ORQ5 vs Q1 = 0.81, 95% CI = 0.66 to 0.99, P trend = .03). For the same comparison, there were also suggestions of inverse associations between adherence to the DASH (ORQ5 vs Q1 = 0.84, 95% CI = 0.69 to 1.04, P trend = .04), AMED (ORQ5 vs Q1 = 0.80, 95% CI = 0.65 to 0.99, P trend = .07), and AHEI-2010 (ORQ5 vs Q1 = 0.85, 95% CI = 0.69 to 1.04, P trend = .11) and risk of early-onset adenoma. In a sensitivity analysis among only those who had a colonoscopy, effect estimates were slightly attenuated, but the overall direction of association was consistent (Supplementary Table 2, available online).

Notably, these associations appeared to be stronger for adenomas with higher malignant potential. We found a statistically significant positive association of the Western dietary pattern (multivariable ORQ5 vs Q1 = 1.67, 95% CI = 1.18 to 2.37, P trend = .01) and inverse associations of the prudent pattern (ORQ5 vs Q1 = 0.69, 95% CI = 0.48 to 0.98, P trend = .03), DASH (ORQ5 vs Q1 = 0.65, 95% CI = 0.45 to 0.93, P trend = .009), AMED (ORQ5 vs Q1 = 0.55, 95% CI = 0.38 to 0.79, P trend = .007), and AHEI-2010 scores (ORQ5 vs Q1 = 0.71, 95% CI = 0.51 to 1.01, P trend = .01; Table 3) with early-onset high-risk adenoma (n = 375 cases) but not with low-risk adenoma (n = 733 cases, all P trend ≥ .08). For early-onset adenoma overall and of high risk, we observed highly comparable results when stratified by age of endoscopy (younger than 45 years vs 45 years and older; data not shown). The stronger associations for high-risk adenoma were driven by large size (≥1 cm) and villous histology (Figure 1). Interestingly, the magnitude of these inverse associations was comparable between participants with or without symptoms (visible blood in stool specimen, positive result for fecal occult blood test, abdominal pain, and diarrhea or constipation) at the time of lower endoscopy (Supplementary Table 3, available online). In joint analyses, among women having the healthiest dietary pattern based on principal component analysis (ie, in the highest quintile of the prudent and the lowest quintile of the Western pattern), a statistically significantly lower risk was observed for early-onset high-risk adenomas, compared with those having the lowest score of the prudent and the highest score of the Western pattern (OR = 0.58, 95% CI = 0.36 to 0.92; Supplementary Table 4, available online).

Figure 1.

Diet quality and risk of early-onset (aged younger than 50 years) adenoma according to size (A) and histology (B), Nurses' Health Study II, 1991–2011. AHEI = Alternative Healthy Eating Index; AMED = Alternative Mediterranean Diet; CI = confidence interval; DASH = Dietary Approaches to Stop Hypertension; OR = odds ratio; Q1 = lowest quintile; Q5 = highest quintile. Odds ratio was adjusted for the covariates denoted in Table 2. P trend was calculated using the median of each quintile as a continuous variable.

By anatomical site, we observed stronger associations for the Western dietary pattern (multivariable ORQ4 vs Q1 = 1.65, 95% CI = 1.14 to 2.38, P trend = .01), prudent pattern (ORQ4 vs Q1 = 0.68, 95% CI = 0.47 to 0.99, P trend = .04), DASH (ORQ4 vs Q1 = 0.63, 95% CI = 0.42 to 0.94, P trend = .01), and AHEI-2010 scores (ORQ4 vs Q1 = 0.71, 95% CI = 0.49 to 1.03, P trend = .02), and risk of advanced adenomas in the distal colon and rectum (n = 271 cases; Table 4). However, we did not find any statistically significant associations for diet quality and risk of advanced adenoma in the proximal colon (n = 93 cases).