Science has proved that supplementing with essential amino acids (EAAs), especially alongside aerobic and resistance exercise, improves muscle protein metabolism and function and builds muscle mass and strength in healthy adults of all ages. But there’s also a rumor circulating that three of these EAAs, known as the branched-chain amino acids (BCAAs), can spike insulin levels and lead to insulin resistance. If that is indeed the case, then is supplementing with EAAs safe, especially for those with prediabetes or type 2 diabetes? In this article, we’re exploring the science behind the relationship between essential amino acids and insulin resistance, so that you can make a safe and informed choice.
What Is Insulin Resistance?
Your pancreas produces the hormone insulin to help your body either convert blood sugar (glucose) into immediate energy or store it in your muscles, liver, and fat cells for later use. This process kicks into gear after a meal, which causes blood sugar to rise. This in turn signals the pancreas to unleash insulin. Insulin travels to your cells and tells them to open up and let glucose in. Once inside your cells, glucose turns into energy or stays tucked away until energy is needed.
Without insulin, glucose stays trapped in your blood. Such is the case with type 1 diabetes (diabetes mellitus), an autoimmune disease that causes the immune system to destroy insulin-producing cells (beta cells) in the pancreas.
Type 2 diabetes is the end result of a condition called insulin resistance, in which muscle, liver, and fat cells become unresponsive to insulin’s urges. The pancreas responds by producing even more insulin in an attempt to encourage glucose uptake. The constant call for more and more insulin wears out beta cells in the pancreas. Eventually, they won’t be able to keep it up, and when that happens, prediabetes and type 2 diabetes take hold.
Causes of Insulin Resistance
Insulin resistance is more likely to develop alongside one of the following risk factors and predictors:
- Obesity (BMI of 30+)
- Sedentary lifestyle
- Metabolic syndrome (high blood pressure, high cholesterol, and triglyceride levels)
- High-carbohydrate diet
- Cardiovascular disease
- Gestational diabetes
- Nonalcoholic fatty liver disease
- Polycystic ovary syndrome
- Family history of diabetes
- If you are Latino, African American, or Native American
- If you are over 45
- If you take steroids, HIV medications, or antipsychotics
- If you suffer from sleep troubles such as sleep apnea
The current debate is whether BCAAs, which are associated with elevated insulin levels, should be on the list above. Let’s see what the science says.
What Are Essential Amino Acids?
Amino acids are the building blocks of protein, and essential amino acids are the type of amino acids your body cannot produce and needs you to supply via diet or supplementation. The nine essential amino acids are:
Three of these—leucine, isoleucine, and valine—are BCAAs, so called because of their unique side chain. These amino acids, particularly leucine, are known for stimulating muscle protein synthesis (the building of new muscle tissue) through the activation of the initiation factor mTOR.
People with insulin resistance and type 2 diabetes tend to have higher levels of BCAAs and their metabolites. This is due, in part, to insulin resistance, which speeds up protein breakdown in the muscles. As protein is broken down into its component amino acids, BCAA levels naturally increase. Type 2 diabetes also impacts branched-chain amino acid metabolism by inhibiting the gene expression of enzymes that stimulate BCAA catabolism (breakdown).
But do BCAAs spike insulin to a worrisome degree and contribute to the development of insulin resistance? Let’s see what the newest research has to say.
The Link Between Essential Amino Acids and Insulin Resistance
UCLA researchers wanted to find out if taking BCAA supplements would worsen insulin sensitivity in overweight or obese adults with prediabetes, which accounts for 30% of Americans.
Participants took either 20 grams of BCAAs or 25 grams of rice protein (which contained approximately 4 grams of BCAAs) for 4 weeks, took 2 weeks off, and then supplemented with protein powders an additional 4 weeks. Results showed that neither the BCAA powder or the rice powder negatively affected plasma insulin, glucose tolerance, or plasma amino acid levels. The verdict: taking BCAA supplements does not produce insulin-resistant subjects (1).
Previous studies show, however, that when taken to excess BCAAs can have a short-term effect on insulin receptors and stimulate insulin secretion. That’s why Amino Co scientists always emphasize that balance with supplementation is key. In order to achieve that balance it is important to take a complete host of EAAs.
A complete supplement of EAAs does not spike insulin levels. Take for instance, the latest 2020 study published in the journal Clinical Nutrition. Researchers wanted to see if taking EAAs with and without exercise negatively impacted insulin levels in non-diabetic older adults alongside moderate protein intake. They determined that in both instances EAAs were metabolically safe and had no negative consequence on insulin action (2).
If essential amino acids don’t negatively affect insulin levels, might they, perhaps, benefit them?
Science says...they do!
Taking a daily essential amino acid supplement has been proven to help improve insulin sensitivity in type 2 diabetes patients. In a double blind clinical trial, type 2 diabetes patients who supplemented with essential amino acids had significantly greater decreases in plasma glucose after 45 days without alterations to plasma insulin levels, which suggests improvements in insulin sensitivity (3).
A separate study in the Journal of Endocrinology, Diabetes, and Obesity showed that an essential amino acid supplement with a high proportion of leucine helps to reduce the risk of heart disease and metabolic syndrome by lowering triglycerides, LDL, and total cholesterol as well as improving blood glucose levels and insulin signaling (4).
Supplementing daily with essential amino acids also helps protect against sarcopenia, age-related muscle loss, that is accelerated in people with insulin resistance. Researchers tracked the effects of a daily dose of 11 grams of EAAs on glucose intolerant subjects for 16 weeks with no changes to diet or physical activity. Because the muscle-stimulating effects of amino acids are subdued in cases of insulin resistance, patients with glucose intolerance made the ideal test subjects. If benefit was shown in those instances, then people with normal insulin insensitivity would be expected to benefit to an even greater degree. Results demonstrate that supplementing with EAAs improves skeletal muscle mass, muscle strength, and physical function (5).
Taking EAAs as part of a diabetes care regimen has also been deemed safe and beneficial by the American Journal of Cardiology. Findings suggest that supplementing with an essential amino acid mixture improves glucose metabolism and insulin sensitivity in older type 2 diabetes patients (6).
Supplementing with EAAs for Insulin Resistance
Alongside dietary intake of protein, essential amino acids can be personalized in precise formulas to meet your changing metabolic needs and promote whole-body wellness.
The Amino Company has optimized the EAA profile in Life to target the metabolic needs of 40+ year olds and support key components of healthy aging, including maintaining a healthy body weight and blood sugar levels.
Essential amino acids have also been shown to have a favorable impact on triglyceride and cholesterol levels, as well as weight loss. Our patented EAA blend helps to strengthen the heart, increase blood flow, and maintain healthy blood pressure levels already in the normal range. In a clinical trial, Life improved participants’ lipid profiles by significantly reducing triglycerides, LDL, VLDL, and total cholesterol.
To learn more about how Life can support insulin sensitivity and your body composition goals, click here.