In a previous article I wrote about the effect of epicatechin on reducing myostatin, which may increase muscle mass (https://michaellustgarten.wordpress.com/2015/02/02/inhibit-myostatin-with-chocolate-increase-muscle-mass/). Are there any other ways to inhibit myostatin with the goal of increasing muscle mass?
10 grams of essential amino acids have been shown to reduce myostatin levels in skeletal muscle (Drummond et al. 2009). Because essential amino acids are found in high amounts in animal protein-containing foods, the answer to decrease myostatin would be to eat more protein, right?
Not so fast, because high protein diets (~20% of total calories), especially from animal sources are associated with an increased all-cause mortality risk in people younger than 65 years when compared with those eating a low protein diet (~10% of total calories; Levine et al. 2014). Fortunately, it isn’t just a bolus of essential amino acids that inhibits myostatin. Addition of the essential amino acid leucine to muscle cells inhibits myostatin expression, causing them to grow (Chen et al. 2013). If your goal is to maximize muscle mass but also, optimal health, what daily intake of leucine should you aim for while keeping your total protein intake low?
It has been reported that a leucine intake of 45 mg/kg/day (or more) may be required by athletes to maximize muscle protein synthesis (Mero 1999). For a 70 kg person, this translates into 3.15g of leucine per day (45 mg*70kg=3150mg, = 3.15g). Shown below is my 7-day average (5/21/2015-5/28/2015) protein intake. From the chart, my average daily leucine intake is 3.2 g. However, the nutrient tracking software that I use for some reason includes the total protein amount from my daily can of sardines but not its constituent amino acids. I used ndb.nal.usda.gov to get that info: 1 can of sardines has 1.6 g of leucine. In total, my daily leucine intake is 4.8 g/day. My body weight is currently at 69.1 kgs. These values put me at 70 mg leucine/kg body weight/day (70 * 69.1kg = 4837 mg, = 4.8 g), which is well above the 45 mg/kg/day value above.
So which foods are rich in leucine? Below I’ve ranked foods based on their leucine content (in grams) divided by total calories. Egg whites and cod fish are the all-stars for leucine content per calorie. Chicken and beef are relatively good sources of leucine. Although spinach is better than skim milk when comparing its leucine/calorie content, none of the vegetables or beans come close to the leucine/calorie content found in egg whites or cod fish.
Chen X, Huang Z, Chen D, Yang T, Liu G.MicroRNA-27a is induced by leucine and contributes to leucine-induced proliferation promotion in C2C12 cells. Int J Mol Sci. 2013 Jul 8;14(7):14076-84.
Drummond MJ, Glynn EL, Fry CS, Dhanani S, Volpi E, Rasmussen BB. Essential amino acids increase microRNA-499, -208b, and -23a and downregulate myostatin and myocyte enhancer factor 2C mRNA expression in human skeletal muscle. J Nutr. 2009 Dec;139(12):2279-84.
Levine ME, Suarez JA, Brandhorst S, Balasubramanian P, Cheng CW, Madia F, Fontana L, Mirisola MG, Guevara-Aguirre J, Wan J, Passarino G, Kennedy BK, Wei M, Cohen P, Crimmins EM, Longo VD. Low protein intake is associated with a major reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not older population. Cell Metab. 2014 Mar 4;19(3):407-17.
Mero A. Leucine supplementation and intensive training. Sports Med. 1999 Jun;27(6):347-58