Dr. Fuhrman, [Joel Fuhrman M.D.] is a board-certified family physician, NY Times best-selling author and nutritional researcher who specializes in preventing and reversing disease through nutritional and natural methods. Dr. Fuhrman is an internationally recognized expert on nutrition and natural healing, and has appeared on hundreds of radio and television shows including The Dr. Oz Show, the Today Show, Good Morning America, and Live with Kelly. Dr. Fuhrman’s own hugely successful PBS television shows, 3 Steps to Incredible Health! and Dr. Fuhrman’s Immunity Solution! bring nutritional science to homes all across America.
Food is the fuel for muscle growth
For years, protein powders have been a common dietary supplement used by bodybuilders and other athletes in training. The prevailing theory among these groups has been that the additional muscle-building properties of protein powder would provide them with a competitive advantage.
Knowing that protein is the key raw material involved in the repair, preservation and growth of muscle tissue, bodybuilders, in particular, believe that the protein supplied in powder is an economical way to get large amounts of protein, more easily absorbed — and that more is better to achieve their lean muscle mass goals.
These fallacies have made their way into the mainstream of late, and now protein powder is being packaged “to-go” and marketed to the non-athlete as a meal replacement, a quick pick-me-up, or even as a health food.
Let’s examine the role protein plays in muscle-growth and the relative effectiveness and safety of protein powder:
- Exercise is the primary factor that determines muscle mass, and the right foods are the fuel.
The first important thing to note is that it is exercise – not food – that stimulates muscle growth! Dietary protein does, however, provide the raw materials that muscles need in order to grow. Many whole plant foods, such as green vegetables, beans and seeds, are protein-rich and provide adequate protein for muscle growth.
- But what’s wrong with protein powders?
When we consume animal protein, the body increases its production of a hormone called IGF-1, (insulin-like growth factor 1). IGF-1 is one of the body’s important growth promoters early in life, but later in life IGF-1 promotes the aging process. Igf-1 has been shown to promote the growth, proliferation and spread of cancer cells, and elevated IGF-1 levels are linked to increased risk of several cancers, including breast, colon and prostate cancer.1-5
Unnaturally concentrated, “isolated” soy protein, such as that found in protein powders and meat substitutes, are particularly problematic. The essential amino acid profile of soy is the most “complete,” plant protein, meaning the closest to animal protein, as it is the amino acid profile of animal protein that sparks IGF-1 production.6 It is when soy is processed and concentrated as “isolated” soy protein, that it can have similar negative hormonal effects to animal proteins, which does not occur with more natural forms of soy such as tofu, tempeh and soybeans. Obviously, whey and casein based protein powders are strongly IGF-1 promoting.
Learn more in Dr. Fuhrman’s Healthy Times Newsletter #43: Insulin-like Growth Factor 1 and Cancer
- Can you build muscle while keeping IGF-1 levels in a safe range?
Muscle growth is not dependent on only the amount of IGF-1 circulating in the blood – muscle tissue produces its own IGF-1 in response to strength training to fuel muscle growth.7 A combination of strength training and a Nutritarian diet will result in lower, cancer-preventive levels of IGF-1 levels circulating in the blood, while still allowing for local production of IGF-1 needed for muscle-building.
- What are the best muscle-building foods?
Whole food sources of protein are the best choice. High-protein plant foods such as sunflower seeds, hemp seeds and Mediterranean pine nuts, blended into shakes and smoothies, is a high-nutrient substitute for nutrient-poor protein powders. Intact whole grains (such as oats, quinoa and wild rice) are rich in micronutrients, as well as protein.
For those that insist on using isolated protein powders, hemp, rice and pea proteins are better choices than soy protein, since their amino acid profiles are not as close to that of animal protein.
- Chitnis MM, Yuen JS, Protheroe AS, et al: The type 1 insulin-like growth factor receptor pathway. Clin Cancer Res 2008;14:6364-6370.
- Werner H, Bruchim I: The insulin-like growth factor-I receptor as an oncogene. Arch Physiol Biochem 2009;115:58-71.
- 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.
- 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.
- Kaaks R: Nutrition, insulin, IGF-1 metabolism and cancer risk: a summary of epidemiological evidence. Novartis Found Symp 2004;262:247-260; discussion 260-268.
- Thissen JP, Ketelslegers JM, Underwood LE: Nutritional regulation of the insulin-like growth factors. Endocr Rev 1994;15:80-101.
- Kraemer WJ, Ratamess NA: Hormonal responses and adaptations to resistance exercise and training. Sports Med 2005;35:339-361.