Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Sep 1;150(9):2442-2450.
doi: 10.1093/jn/nxaa194.

Soy Intake and Colorectal Cancer Risk: Results from a Pooled Analysis of Prospective Cohort Studies Conducted in China and Japan

Nikhil K Khankari  1 , Jae Jeong Yang  1 , Norie Sawada  2 , Wanqing Wen  1 , Taiki Yamaji  2 , Jing Gao  3 , Atsushi Goto  2 , Hong-Lan Li  3 , Motoki Iwasaki  2 , Gong Yang  1 , Taichi Shimazu  2 , Yong-Bing Xiang  3 , Manami Inoue  2 , Xiao-Ou Shu  1 , Shoichiro Tsugane  2 , Wei Zheng  1
Affiliations

Soy Intake and Colorectal Cancer Risk: Results from a Pooled Analysis of Prospective Cohort Studies Conducted in China and Japan

Nikhil K Khankari et al. J Nutr. .

Abstract

Background: Soy is commonly consumed in east Asian countries and is suggested to reduce colorectal cancer (CRC) risk. However, results from epidemiologic studies are inconsistent, despite the anti-inflammatory and antiproliferative properties of soy isoflavones and soy protein.

Objective: We evaluated the association between soy isoflavones and soy protein and CRC risk using 4 prospective cohort studies from China and Japan.

Methods: Data were pooled from the Shanghai Women's Health Study (SWHS), Shanghai Men's Health Study (SMHS), Japan Public Health Center-based Prospective Study Cohort 1 (JPHC1), and Cohort 2 (JPHC2). Cox proportional hazards models estimated HRs and corresponding 95% CIs for the association of soy protein and isoflavone intake with CRC risk. The study included 205,060 individuals, among whom 2971 were diagnosed with incident CRC over an average follow-up of 12.7 y.

Results: No statistically significant associations with CRC risk were observed for soy protein or isoflavone intake. No association was observed among ever smokers consuming higher isoflavones (HRisoflavones: 0.83; 95% CI: 0.68, 1.00) and soy protein (HRsoy protein: 0.81; 95% CI: 0.39, 1.10). However, risk reductions were observed among premenopausal women with a body mass index [BMI (kg/m2)] <23.0 at baseline for higher isoflavone (HRisoflavones: 0.58, 95% CI: 0.34, 0.98).

Conclusions: No evidence for an overall reduction in CRC risk by increasing soy food intake (i.e., protein or isoflavones) was observed. However, the association between soy and CRC risk may vary by BMI, smoking, and menopausal status among women. Future investigations are needed to further understand the biologic mechanisms observed.

Keywords: Asian; China; Japan; cohort; colorectal cancer; diet; isoflavones; soy.

PubMed Disclaimer

Figures

FIGURE 1
FIGURE 1
Association between dietary soy isoflavone (mg/d; A) and soy protein (g/d; B) intake and colorectal cancer risk by study cohorts and fixed-effects meta-analysis. P-heterogeneity for soy isoflavone intake was 0.60, 0.45, and 0.14, for Q2, Q3, and Q4, respectively. P-heterogeneity for soy protein intake was 0.22, 0.33, and 0.71, for Q2, Q3, and Q4, respectively. The cohort- and sex-specific quartiles were used (see Supplemental Table 2 for specific cutpoint values for each cohort). Complete case analyses (based on total sample size of n = 186,755 with 2589 colorectal cancer cases) were adjusted for age, total energy, sex, smoking status, alcohol consumption, physical activity, obesity status, family history of colorectal cancer, intake of red meat, vegetable intake, folate intake, and menopausal status in women. JPHC1, Japan Public Health Center–based Prospective Study Cohort 1; JPHC2, Japan Public Health Center–based Prospective Study Cohort 2; Q, quartile; SWHS, Shanghai Women's Health Study.
See this image and copyright information in PMC

References

    1. Messina M. Soy and health update: evaluation of the clinical and epidemiologic literature. Nutrients. 2016;8:754. - PMC - PubMed
    1. Yu J, Bi X, Yu B, Chen D. Isoflavones: anti-inflammatory benefit and possible caveats. Nutrients. 2016;8:361. - PMC - PubMed
    1. Chun OK, Lee SG, Wang Y, Vance T, Song WO. Estimated flavonoid intake of the elderly in the United States and around the world. J Nutr Gerontol Geriatr. 2012;31:190–205. - PubMed
    1. Messina M, Nagata C, Wu AH. Estimated Asian adult soy protein and isoflavone intakes. Nutr Cancer. 2006;55:1–12. - PubMed
    1. Hsieh C-C, Martínez-Villaluenga C, de Lumen BO, Hernández-Ledesma B. Updating the research on the chemopreventive and therapeutic role of the peptide lunasin: properties of the peptide lunasin. J Sci Food Agric. 2018;98:2070–79. - PubMed

Publication types