I recently read an article that downplayed the value of liver supplements for athletes, bodybuilders and exercisers. I could say some unsavory words regarding my reac-tion to the article’s misinformation, but I’ll spare you! Liver supplements-specifically desiccated liver-are an absolute must in your nutrition program, whether you’re a competitive bodybuilder, endurance athlete or exerciser who desires supreme fitness. The reason is, liver provides heme iron, high quality protein and B vitamins, thereby meeting several of the increased nutritional needs of athletes. To understand the importance of desiccated liver supplementation, let’s review how iron works in the body-and why it is so vital to your performance. Heme iron is intimately involved in key energy-producing reactions in your body.
Energy comes from the breakdown of food and its consequent transport to body cells. Inside the cells, the foods are burned in a chemical reaction called “oxidation,” which simply means reaction with oxygen. For foods to be converted to energy, the cells have to get plenty of oxygen. This constant need for energy is so critical that if tissues are deprived of oxygen for more than a few minutes, they will perish. Oxygen is carried to cells by red blood cells. They perform this shuttle service by binding to hemoglobin, the red pigment in the blood. Hemoglobin is a protein that in-cludes a special chemical structure known as heme-a complex of porphyrin and iron. It’s the iron that binds oxygen in the lungs and subsequently releases it in the muscles and other peripheral tissues . Muscles contain myoglobin, an oxygen-carrying protein that works inside cells. Like hemoglobin, myoglobin also requires iron to bind oxygen. Without the iron, the whole oxygen transport system won’t work. Not only that, iron is also required by the enzymes in the electron transport chain-the series of reactions in which oxy-gen is consumed in the cells. Iron, then, is required not only for transporting oxygen to the tissues but also for its use inside cells. Because of its critical role in oxygen utilization, iron has earned its reputation for occupying a central position in energy metabolism.
Iron deficiencies sap strength, yet, iron deficiency remains a major health problem. In fact, it is widely recognized as the most common nutritional deficiency in the world (1,2,3). In the U.S. alone, 22 percent of American women are iron deficient, (1,2). The daily iron requirement for women is 18 mg a day, while on average they obtain only 10 to 12 mg a day (1). Among athletes, about 10 percent of males are iron deficient, compared to 22 to 25 percent of females (1). Many times a feeling of fatigue or low energy is the result of an unrecognized iron deficiency (2,3). A condition called sports anemia often afflicts athletes, particularly endurance athletes (1,3,6). Sports anemia, however, is not always associated with a true iron deficiency. During hard train-ing, you actually damage skeletal muscle fibers-damage that must be repaired during recovery. Interestingly, if you haven’t been eating enough protein, your body will draw on red blood cells, hemoglobin and plasma proteins as a source of protein to repair your muscles (3).
This reparation process may soak up all of the incoming protein and not leave enough left to rebuild new red blood cells at the normal rate . Thus, increased protein intake may be effective in treating sports-induced anemia (1). If you have low hemoglobin levels, you won’t perform as well at endurance events. Interestingly, endurance athletes have the highest inci-dence of sports anemia and also have the highest protein requirements. There seems to be an iron cost associated with exercise (3). Female athletes and endurance athletes are especially at risk of iron deficiency (1,2,3,6). Iron deficiency anemia reduces maximal oxygen uptake, reduces work output and increases the time required to recover between workouts (1). The good news is that iron supplements have been shown to be effective in several critical areas (1,2,3). Iron supplements: • Reverse the effects of iron deficiency; • Re-store hemoglobin levels; • Improve athletic performance in those who are deficient; and • May prevent an iron deficiency caused by training. Iron supplementation alone will not cor-rect true sports anemia, which is reason-able considering it is a protein deficiency. However, since liver provides both high quality protein and heme iron it should be beneficial to athletes suffering sports anemia . Iron is also available in foods, as the chart shows. However, heme iron can be damaged by cooking.
Heat reduces the ability of iron to be absorbed in half (5). Additionally, many iron-rich foods are high in saturated fat and cholesterol. Thus, desiccated liver supplements represent a highly bioavailable iron source. Our Par-rillo Liver-Amino(tm) Formula is made from defatted liver, which means you don’t get all the fat and cholesterol that comes along with liver and red meat. Plus, we add predigested casein to further increase the protein content to 1.5 grams per tablet. This is why our Liver Amino is one of the best supplements available for bodybuilders and endurance athletes: it provides heme iron, quality protein and B vitamins all in one. Now, what does all this mean to you?
Actually, our Liver-Amino Formula is one of our “universal’ supplements; in other words, it is vitally useful for every ac-tive person. What follows are the specific categories of people who should take this supplement daily: • Endurance athletes (whose iron needs are often elevated); • All female athletes and exercisers (deficiencies are common in this group); • Beginning bodybuilders who desire mass (the Liver-Amino Formula is one of the supplements in our Growth Program for Beginners); • Bodybuilders dieting and training for definition or competition (the supplement provides additional protein needed during dieting to guard against dieting-induced muscle loss); and • Experienced bodybuilders and ex-ercisers striving to gain additional lean mass . Our suggested usage is five to eight tablets with each meal. If you have information on how to use our Liver-Amino Formula(tm) success-fully, please call our Info-Line at 513-531-1311 or access our web site at www.parrillo.com. What is the effect of diet compo-sition on the hormones that act to control body composition? This topic is quite involved and we will deal with some basic concepts. The major players in this drama are insulin, glucagon, cortisol, growth hormone, thyroid, and to some extent tes-tosterone . The most important relationship is the insulin-glucagon axis. These two hormones are made by the pancreas and act to control nutrient storage and nutrient utilization. Insulin is essentially a storage hormone and is released in response to eat-ing.
The most potent stimulus for insulin release is carbohydrate ingestion, followed by protein ingestion. Insulin shuttles carbo-hydrate molecules (glucose) inside cells for storage. It promotes the use of carbohydrate as fuel and stores carbohydrate as glyco-gen. After a meal, insulin is released and acts to help store nutrients and use glucose as fuel. Insulin promotes fat storage and converts excess carbohydrate into fat. Al-though, under normal conditions, not much carbohydrate is converted into fat – insulin does promote this. Insulin also prevents the release of fatty acids from adipose tissue and decreases the use of fat as fuel. Insulin behaves like a switch that turns off fat burn-ing and turns on carbohydrate burning. Glucagon is a counter-regulatory hor-mone. It has the opposite actions of insulin. Several hours after a meal, when most of the ingested nutrients have been burned or stored, glucagon levels increase.
This promotes fat utilization and decreases carbohydrate oxidation. Immediately after a meal, insulin acts to promote fat storage, but after several hours of fasting, glucagon acts to promote fat oxidation. After the calories from your last meal have been used you begin to switch over to a fat burning mode. Of course, by this time most people get hungry and eat again, so they spend relatively few hours a day burning any significant amount of fat. The complete picture is much more complicated . The pri-mary site of glucagon action is in the liver, with relatively little impact on peripheral fat stores. The main stimulus for release of fat from adipose tissue is the sympathetic nervous system. The nerve endings release norepinephrine at the adipose cell, which in turn stimulates breakdown of stored tri-glyceride and fatty acid release. The major reason for considering the use of fat in a bodybuilding diet is that fat causes very little insulin release. By eating a low car-bohydrate diet higher in fat, insulin levels should remain lower. Also, if carbohydrates are not available the body shifts into a fat burning metabolism during the day. Other studies (in rats) have demonstrated that the protein-to-carbohydrate ratio in the diet determines to a large extent the ratio of insulin-to-glycogen in the blood (11-13).
These hormones seem to be almost entirely controlled by diet. Furthermore, studies suggest that the insulin-glycogen ratio influences bodyfat levels (11-13). For the same number of calories, more will be stored as fat if insulin levels are higher, simply because insulin promotes fat storage and prevents fat utilization. On a different diet, providing the same number of calories, we would expect bodyfat levels to be lower if insulin levels are lower. This is logical. For these rea-sons we have seen the emergence of diets higher in fat and lower in carbohydrate. The disadvantages are problems inherent to fat metabolism, discussed above. One desirable alternative would be to use another energy source besides carbo-hydrate – which had favorable effects on the insulin profile – but which avoided the other problems faced by conventional fats. Medium chain triglycerides, such as CapTri(r), offer such an alternative.
Conventional fats are comprised of long chain fatty acids, usu-ally 16 to 20 carbon atoms long. Medium chain triglycerides (MCT) are a specially engineered, semi-synthetic fat that is built from fatty acid molecules that are only eight to 12 carbon atoms long. This small difference in chemical structure results in very different biological effects. MCT has a much higher thermogenic effect than conventional fat – probably higher than car-bohydrate (14-19). MCT does not require the carnitine shuttle for transport inside the mitochondria and its oxidation is essen-tially unregulated. MCTs are oxidized very rapidly, more rapidly than glucose (14-19). The liver converts the excess energy to ketones, or beta-hydroxy butyr ate and acetoacetic acid. These ketones are used as an immediate fuel source by the muscles. While conventional fats are preferentially stored, MCT are immediately oxidized as fuel. This results in almost no storage of MCT as adipose (14-19). MCT thus represents a dietary energy source, which has the advantages of fat but does not elicit much insulin response .
MCT does not contribute to adipose depots. Another problem with the convention In our experience the 30 percent protein, 40 percent carbohydrate, 30 percent conven-tional fat diet works adequately – but not optimally – as long as an energy deficient diet is consumed. If fewer calories are consumed than expended, weight loss will result no matter what the diet composition. This diet (or practically any diet) will promote weight loss as long as an energy deficit is maintained. The high-fat diet can actually promote fairly rapid weight loss because of its favorable effects on insulin. However, you will run into problems on this diet when you approach maintenance level, calorically. Disaster occurs during calorie-excess when using the high-fat diet. Fat intake does not promote fat oxidation. If you consume excess calories supplied in the form of fat, they will be stored as fat. Period. You cannot use this diet to gain weight, unless you want to gain fat. By using MCT as the fat source – instead of long chain triglyceride – you can avoid the inherent problems. This results in a favorable insulin profile and eliminates the metabolic complications of consum-ing conventional fat. And since MCT is not retained as adipose, this makes it an ideal energy substitute during a weight gain phase .
MCT use seems to minimize fat deposition during weight gain.al 30:40:30 high-fat diet is the inclusion of sugars, particularly in the form of fruit. Fruit can blow a diet. Fruit provides most of its calories in the form of simple sug-ars: glucose and fructose. Fructose is an especially bad choice for bodybuilders be-cause it bypasses the phosphofructokinase enzyme step during glycolysis (20). This enzyme acts as a switch and determines whether sugars are stored as glycogen or burned as fuel. Fructose enters the glyco-lytic pathway and bypasses this enzyme. The fructose molecules are automatically shunted toward oxidation. During carbo-hydrate oxidation the carbon skeleton is converted to acetyl-CoA in the process of ATP generation. Fructose is rapidly con-verted into acetyl-CoA, which overwhelms the pathway that converts it into ATP. The acetyl-CoA piles up in the liver. Acetyl-CoA, it turns out, is the building block for fatty acid synthesis. Most of the fructose-derived energy is converted into fat by the liver and is subsequently released into the blood to be stored in fat cells (20). This is bad news! The argument used by fruit lovers is that eating it has almost no effect on increasing insulin release. True, but this has not been totally thought through.
The reason fruit doesn’t increase insulin levels is that it is released from the liver as fat instead of carbohydrate, and fat doesn’t stimulate insulin release . If you want to try the high-fat diet ap-proach we would suggest you use MCT in place of conventional fat and avoid simple sugars, particularly fructose. This is very similar to some of the competition diets we have been devising for bodybuilders over the years. In the Parrillo version, start by eating one gram of protein per pound of bodyweight per day. Limit conventional fat as much as possible and provide 30 percent of total calories from CapTri(r). Derive the remainder of your calories from complex carbohydrate. Avoid simple sugars, includ-ing those found in milk and fruit. Avoid refined carbohydrates such as bread and pasta as well. Divide your daily total num-ber of calories into five or six small meals, with roughly equal amounts of protein and carbohydrate at each meal. If your goal is to gain muscle mass, increase overall calories by increasing carbohydrates. If your goal is to lose bodyfat, decrease calories by de-creasing carbohydrates. For exact instruc-tions on how to construct meals, consult the Parrillo Nutrition Manual.
1. Haymes, Proteins, Vitamins and Iron; in Ergogenic Aids in Sport: ed. Williams; Hu-man Kinetics Publishers: 1983: p. 27-55.
2. Scrimshaw, Iron Deficiency, Scientific The Impact of Dietary Energy of Body CompositionAmerican, October 1991, p. 46-52.
3. Sherman and Kramer, Iron Nutrition and Exercise, in: Nutrition in Exercise and Sport, eds. Hickson and Wolinsky, CRC Press, 1989, p. 291-308.
4. Steen, Nutrition Considerations for the Low Body Weight Athlete, in Sports Nu-trition for the 90s, eds Berning and Steen, Aspen Publishers, 1991, p. 153-174.
5. Wapnir, Protein Nutrition and Mineral Absorption, CRC Press, 1990, p. 99-129.
6. Whitmire, Vitamins and Minerals: A Perspective in Physical Performance, in Sports Nutrition for the 90s, eds. Bern-ing and Steen, Aspen Publishers, 1991, p. 129-151 .