Obesity along with its associated metabolic abnormalities like insulin resistance, changes in the insulin-like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) axis, and the state of chronic inflammation, elevates the risk of colorectal cancer (CRC) and hepatocellular carcinoma (HCC). 

But it can be interpreted in other ways as these metabolic disorders caused by obesity can serve as an effective target to prevent the development of CRC and HCC in obese individuals. Green tea catechins (GTCs) have shown anticancer and chemopreventive properties towards numerous cancer, including the colorectum and liver. Further, they also have anti-obesity, antidiabetic, and anti-inflammatory effects, suggesting their usefulness in preventing obesity-associated colorectal and liver carcinogenesis. 

Further, branched-chain amino acids (BCAA), which enhance protein malnutrition and control progressive hepatic failure in patients with chronic liver diseases, might also serve as an arrestor of obesity-related carcinogenesis since oral supplementation with BCAA ameliorates the risk of HCC in obese cirrhotic patients, by improving insulin resistance. 

Thus these nutraceutical approaches for targeting and restoring metabolic homeostasis may serve as a promising strategy to prevent the development of obesity-related CRC and HCC. Tea catechins, especially GTCs, are the most practical agents as their safety and efficacy as chemopreventive agents have already been demonstrated in recent interventional trials. BCAA preparations are also often used in clinical practice for patients with chronic liver diseases.

Source: Shimizu M, Kubota M, Tanaka T, Moriwaki H. Nutraceutical Approach for Preventing Obesity-Related Colorectal and Liver Carcinogenesis. International Journal of Molecular Sciences. 2012; 13(1):579-595. https://doi.org/10.3390/ijms13010579