Isoleucine – Health Benefits & Side Effects

Isoleucine – Health Benefits & Side Effects:

It is an isomer of leucine and is part of the branched-chain amino acids group (BCAA). Branched-chain amino acids are involved in your body composition, the body’s regulation of protein metabolism, and healthy weight loss.

Moreover, the combination of these 3 essential amino acids is commonly used in high-quality protein powders, because they are known to increase physical resistance and promote muscle recovery after intense physical exercise sessions.

The three amino acids of the group (isoleucine, leucine, and valine) represent about 70% of the mass protein and therefore are extremely valuable to the body. Contrary to most other amino acids, branched-chain amino acids are usually broken down in the muscle, rather than in the liver.

Its chemical formula is HO2CCH(NH2)CH(CH3)CH2CH3.

The inability to break down this amino acid, along with other amino acids, is linked with the disease named – MSUD – Maple Syrup Urine Disease, a rare genetic disorder characterized by a deficiency of certain enzymes. Some of its symptoms are – vomiting, lethargy, poor feeding, and a maple syrup odor in the cerumen noted soon after birth.

This leads to a buildup of these amino acids in the blood. If left untreated, maple syrup urine disease can cause considerable neurological and physical problems.


It helps prevent muscle protein breakdown during physical exercise, preventing muscle loss at high altitudes and prolonging endurance and performance in the heat.

This amino acid participates in hemoglobin synthesis, adjusts blood sugar levels, speeds up the body’s recovery after surgery or injury, and has an anabolic effect (useful to bodybuilders).

It also improves mental alertness and contributes to the formation of components for essential biochemical elements, which are used in the production of energy and stimulation of the central nervous system.

Health Benefits

Improved physical performancemuscle man

Athletes use this amino acid to reduce muscle and protein breakdown during intense physical exercise and to improve exercise performance.

Furthermore, it is utilized as fuel by muscle cells, sparing other essential amino acids from being burned up. This is one of the important reasons why it is recommended to eat some foods before your workout.

Promotes A Healthy Growth

This amino acid is good for teens and children who are in their growing years because it is essential for healthy growth. More importantly, supplemental doses of this amino acid may be very helpful in promoting tissue repair after trauma or surgery.

Lowers Blood Sugar Levelhigh blood sugar levels diabetes

Type two diabetes Mellitus is characterized by resistance to insulin with subsequent high glycemia that leads to serious health problems.

According to the WHO – World Health Organization, the incidence of type 2 diabetes has grown dramatically from 108 million cases in 1980 to more than 400 million presently. This amino acid is important for regulating and stabilizing glycemia.

Brain Functionbrain

Regular use of branched-chain amino acids may improve mood and mental functioning.


A deficiency in this amino acid produces symptoms similar to those of hypoglycemia (occurs when the level of blood sugar in your blood drops below normal) and may include dizziness, headaches, depression, fatigue, irritability, and confusion.

Food Sources

Chickpeas, red kidney beans, adzuki beans, navy beans, soybeans, seaweed, rice bran, corn, dairy, eggs, meat, beer yeast, cabbage, peas, lentils, hemp seeds, flaxseeds, chia seeds, Brazil nuts, pecans, almond, peanuts, hazelnuts, kale, spinach, pumpkin seeds, amaranth, millet, oatmeal, oat bran.

Side Effects of Isoleucinedepression

It is considered safe by the FDA and granted GRAS (Generally Recognized As Safe) status. However, over-consumption of this amino acid (especially from supplements) may lead to excessive urination, liver disease, and depression.

In addition, BCAA could upset the balance of neurotransmitters by lowering the amount of tyrosine and tryptophan transported into your brain.

More importantly, replacing carbohydrates with protein may lead to a severe nutritional imbalance due to the fact that complex carbohydrates, such as whole grains, beans, and potatoes, are packed with vitamins, dietary fiber, minerals, and other phytonutrients.

Women who are pregnant and have children should not take supplements containing this branched-chain amino acid unless directed by a healthcare specialist.


Threonine – Side Effects

Tryptophan – Side Effects

Essential & Nonessential Amino Acids

Histidine – Side Effects


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