Apr 04, 2013
Is There Something Fishy About Fish? + What is IGF-1?
I admit that while my diet is 99% plant-based, I do eat wild-caught salmon or trout once in a while. That once in a while was last night when we went out to dinner for my man’s birthday. I woke today not feeling so great! Fish can be an important source of Omega 3 fatty acids (EPA and DHA) in an otherwise plant-based diet. But make sure of the source. Wild-caught is the only fish that is safe to eat. And then you need to ensure that the fish is from waters that are safe. Many fish contain dangerous levels of mercury and other toxins.
Animal Protein, IGF-1 and Colon Cancer
Since the primary dietary factor that determines IGF-1 levels is animal protein, the excessive meat, fowl, seafood, and dairy intake common in our society elevates circulating IGF-1. Refined carbohydrates, like white flour, white rice, and sugars can also raise IGF-1 levels, because they cause rapid increases in insulin levels, leading to increases in IGF-1 signaling. In fact, IGF-1 signaling is thought to be a major factor in the connection between diabetes and cancer.11,12
Reducing IGF-1 levels by dietary methods is now considered by many scientists to be an effective cancer prevention measure. Minimizing or avoiding animal protein, isolated soy protein and refined carbohydrates can help to keep our IGF-1 levels in a safe range. Green vegetables, beans and other legumes, and seeds are rich in plant protein and they have cancer-preventive, not cancer-promoting properties. For optimal cancer protection, vegetables, beans, fruits, intact grains, nuts and seeds should comprise the vast majority of our calories.
1. Continuous Update Project Interim Report Summary. Food, Nutrition, Physical Activity, and the Prevention of Colorectal Cancer. World Cancer Research Fund / American Institute for Cancer Research.; 2011.
2. Thomson B: Heterocyclic amine levels in cooked meat and the implication for New Zealanders. Eur J Cancer Prev 1999;8:201-206.
3. Zheng W, Lee S-A: Well-Done Meat Intake, Heterocyclic Amine Exposure, and Cancer Risk. Nutr Cancer 2009;61:437-446.
4. Bartke A: Minireview: role of the growth hormone/insulin-like growth factor system in mammalian aging. Endocrinology 2005;146:3718-3723.
5. Chitnis MM, Yuen JS, Protheroe AS, et al: The type 1 insulin-like growth factor receptor pathway. Clin Cancer Res 2008;14:6364-6370.
6. Werner H, Bruchim I: The insulin-like growth factor-I receptor as an oncogene. Arch Physiol Biochem 2009;115:58-71.
7. Davies M, Gupta S, Goldspink G, et al: The insulin-like growth factor system and colorectal cancer: clinical and experimental evidence. Int J Colorectal Dis 2006;21:201-208.
8. Sandhu MS, Dunger DB, Giovannucci EL: Insulin, insulin-like growth factor-I (IGF-I), IGF binding proteins, their biologic interactions, and colorectal cancer. J Natl Cancer Inst 2002;94:972-980.
9. Ma J, Pollak MN, Giovannucci E, et al: Prospective study of colorectal cancer risk in men and plasma levels of insulin-like growth factor (IGF)-I and IGF-binding protein-3.J Natl Cancer Inst 1999;91:620-625.
10. Giovannucci E, Pollak MN, Platz EA, et al: A prospective study of plasma insulin-like growth factor-1 and binding protein-3 and risk of colorectal neoplasia in women.Cancer Epidemiol Biomarkers Prev 2000;9:345-349.
11. Cannata D, Fierz Y, Vijayakumar A, et al: Type 2 diabetes and cancer: what is the connection? Mt Sinai J Med 2010;77:197-213.
12. Venkateswaran V, Haddad AQ, Fleshner NE, et al: Association of diet-induced hyperinsulinemia with accelerated growth of prostate cancer (LNCaP) xenografts. J Natl Cancer Inst 2007;99:1793-1800.
13. Thissen JP, Ketelslegers JM, Underwood LE: Nutritional regulation of the insulin-like growth factors. Endocr Rev 1994;15:80-101.