Branched-chain amino acids (BCAAs)

The branched-chain amino acids (BCAAs) comprise the three essential amino acids l-leucine, l-isoleucine and l-valine. 'Branched chain' refers to their chemical structure, which sets them apart from other amino acids. In humans, about 15-25% of total protein intake is BCAA's, and dairy products are particularly high in them. BCAA's make up 35-40% of the essential amino acids in body protein and 14% of the total amino acids in skeletal muscle. Branched-chain amino acids are considered essential amino acids because human beings cannot survive unless these amino acids are present in the diet. Leucine is obtained by the hydrolysis of protein by pancreatic enzymes during digestion and necessary for optimal growth in infants and children and for the maintenance of nitrogen balance in adults.

Valine contributes to the structure of proteins into which it has been incorporated by the tendency of its side chain to participate in hydrophobic interactions. Isoleucine is used in the body to produce biochemical compounds that help in energy production. BCAA's are metabolised directly in the muscle. This unique quality means that they are very anabolic (they build muscle) and very anti-catabolic (they stop muscle breakdown). BCAA supplementation is used most frequently by body builders and athletes undergoing intense exercise.

Functions, uses, and health benefits of branched-chain amino acids (BCAAs)

Branched-chain amino acids may be helpful in a minority of patients with hepatic encephalopathy. Branched-chain amino acids may improve encephalopathy symptoms in some by decreasing the accumulation of these false neurotransmitters and perhaps other substances involved in the encephalopathy. BCAAs serve as important fuel sources for skeletal muscle during periods of metabolic stress. BCAAs are needed for the maintenance of muscle tissue and appear to preserve muscle stores of glycogen. BCAAs also help prevent muscle protein breakdown during exercise.

BCAAs have an effect on all protein metabolism and during periods of stress are required by the body in larger amounts than any other amino acid. BCAAs may help build muscle during and following exercise by decreasing protein breakdown and increasing protein synthesis. BCAA supplementation may also improve mood and the performance of difficult tasks following exercise. BCAAs have been used in medicine as part of the treatment for some forms of liver disease and following surgery and chronic illness to improve healing and recovery.

Isoleucine is necessary for the optimal growth of infants and for nitrogen balance in adults. Isoleucine is needed for hemoglobin formation and also helps to maintain regular energy levels. It is turned into muscle tissue after entering the body and being metabolized. Isoleucine is important for stabilizing and regulating blood sugar and energy levels and is required through the diet as it cannot be produced by our bodies. Leucine is necessary for the optimal growth of infants and for the nitrogen balance in adults.

Leucine lowers elevated blood sugar levels and is necessary in promoting the healing of bones, skin, and muscle tissue. Leucine is a direct-acting nutrient signal that regulates protein synthesis in adipose tissue. In skeletal muscle, leucine stimulates protein synthesis through multiple independent mechanisms. Valine is helpful in synthesis of glucose in liver especially during anaerobic activities (activities without proper amount of oxygen intake).

Dietary sources of branched-chain amino acids (BCAAs)

Dairy products and red meat contain the greatest amounts of BCAAs. Whey protein and egg protein supplements are other sources of BCAAs. Isoleucine is found in most food sources and is particularly high in many meats, fish, and cheeses. Leucine is found primarily in high quality protein foods such as beans, brewer's yeast, brown rice bran, caseinate, and corn. Food sources of valine include soy flour, cottage cheese, fish, grains, mushrooms and peanuts, meats, and vegetables.

Dosage and intake of branched-chain amino acids (BCAAs)

Most diets provide an adequate amount of BCAAs for most people, which is about 25-65 mg per 2.2 pounds of body weight. Approximately 3-5 grams of BCAAs can be taken during exercise to delay fatigue and improve exercise performance.

Leucine is one of the 20 most common amino acids on earth, and coded for by DNA. Its chemical composition is identical to that of isoleucine, but its atoms are arranged differently resulting in different properties. Leucine is obtained by the hydrolysis of protein by pancreatic enzymes during digestion and necessary for optimal growth in infants and children and for the maintenance of nitrogen balance in adults.

Leucine is a member of the branched-chain amino acid family, along with valine and isoleucine. The branched-chain amino acids (BCAAs) are found in proteins of all life forms. The three branched-chain amino acids constitute approximately 70 percent of the amino acids in the body proteins. Leucine is an essential amino acid, meaning it cannot be synthesised by the body and must be obtained through food.

Leucine functions, uses, and health benefits

Leucine is necessary for the optimal growth of infants and for the nitrogen balance in adults. It appears to have no particular therapeutic role, but it is vital in supporting functions. Leucine lowers elevated blood sugar levels and is necessary in promoting the healing of bones, skin, and muscle tissue. Leucine is used as a source for the synthesis of blood sugar in the liver during starvation, stress, and infection to aid in healing. Leucine is a direct-acting nutrient signal that regulates protein synthesis in adipose tissue. Leucine works with valine and isoleucine to protect and fuel the muscles. Leucine is believed to help a person maintain muscle mass, which is essential for long-term weight management because muscle helps the body burn more calories.

Supplements and protein powders that contain leucine are used extensively by bodybuilders and other athletes to promote muscle recovery. It also works to increase endurance and enhance energy. Leucine is an important amino acid for the production of hemoglobin. It maintains blood sugar levels and increases growth hormone production. Leucine is found in both animal and vegetable products. The branched chain amino acids (BCAA), valine and Leucine, play an important role in stress, energy and muscle metabolism. BCAAs may be helpful in a minority of patients with hepatic encephalopathy.

Dietary sources of leucine

Leucine is found primarily in high quality protein foods such as beans, brewer's yeast, brown rice bran, caseinate, corn, dairy products, eggs, fish, hemp seed, lactalbumin, legumes, meat, nuts, pumpkin seeds, seafood, seeds, soy, squash seeds, whey, whole grains.

Leucine dosage, intake

Young adults need about 31 mg of this amino acid per day per kilogram (14 mg per lb) of body weight. Therapeutic use of leucine occurs at doses between 500 and 1,000 mg per day. Follow with your doctor's avices for how much leucine you should take.

Leucine deficiency

Deficiency of leucine is rare. Insulin deficiency is known to result in poor utilization of leucine. A deficiency of leucine can cause a biochemical malfunction producing hypoglycemia in infants. Hypoglycemia symptoms may include dizziness, fatigue, headaches, irritability etc.

Isoleucine functions, uses, and health benefits

Isoleucine, used in conjunction with l-leucine and l-methionine, is necessary for muscle building as well as muscle recovery after exercise. Isoleucine also helps prevent muscle proteins from breaking down during exercise. L-Isoleucine is a branched chain amino acid found in high concentrations in muscle tissues. It's used in the body to produce biochemical compounds that help in energy production. Isoleucine, together with the other two branched-chain-amino-acids promote muscle recovery after physical exercise and on its own it is needed for the formation of hemoglobin as well as assisting with regulation of blood sugar levels as well as energy levels. It is also involved in blood-clot formation.

Dietary sources of isoleucine

Isoleucine deficiency

A deficiency of isoleucine can produce symptoms similar to those for hypoglycemia. Isoleucine has been found to be deficient in people suffering from many different mental and physical disorders.

L-valine is a branched-chain amino acid (BCAA). Other branched chain amino acids are isoleucine and leucine. Valine is an aliphatic amino acid that is closely related to leucine and isoleucine both in structure and function. Valine differs from threonine by replacement of the hydroxyl group with a methyl substituent. Valine is often referred to as one of the amino acids with hydrocarbon side chains, or as a branched chain amino acid. A German scientist, Emil Fischer discovered Valine in 1901.

It is an essential amino acid and can not be prepared by the body. Valine is a constituent of fibrous protein in the body. Valine contributes to the structure of proteins into which it has been incorporated by the tendency of its side chain to participate in hydrophobic interactions. Valine is incorporated into proteins and enzymes at the molar rate of 6.9 percent when compared to the other amino acids.

Valine functions, uses, and health benefits

As a branched-chain amino acid (BCAA), valine has been found useful in treatments involving muscle, mental, and emotional upsets, and for insomnia and nervousness. The branched-chain amino acids (BCAAs) are needed for the maintenance of muscle tissue and appear to preserve muscle stores of glycogen (a storage form of carbohydrate that can be converted into energy). BCAAs serve as important fuel sources for skeletal muscle during periods of metabolic stress. BCAAs may promote protein synthesis, suppress protein catabolism and serve as substrates for gluconeogenesis.

The BCAAs valine and leucine play an important role in stress, energy and muscle metabolism. These two amino acids are used directly by skeletal muscle as energy sources and are thought to have anabolic properties. This means they help promote protein production, storage and muscle growth. Valine may help treat malnutrition associated with drug addiction. Valine is also helpful in synthesis of glucose in liver especially during anaerobic activities (activities without proper amount of oxygen intake).

Dietary sources of valine

Valine dosage, intake

Valine supplements should be taken together with leucine and isoleucine, the other two branched-chain amino acids (BCAAs). Young adults need about 23 mg of this amino acid per day per kilogram (10 mg per lb) of body weight.

Valine deficiency

Valine deficiency results in negative hydrogen balance in the body, deterioration of muscle function and mental health, insomnia, and skin hypersensitivity. Low level of valine and other branched chain amino acids it can result in maple syrup urine disease. Some symptoms of valine deficiency include loss of balance during locomotion, changes in the ventral horn and susceptibility to irritation allergens.