Health Benefits of N-acetyl Cysteine

N-acetyl cysteine (NAC) is a supplement form of cysteine. Your body doesn’t make it and it’s not found in foods, but it still plays an important role. Like cysteine, NAC bonds with glutamine and glycine to form glutathione, a powerful antioxidant. Glutathione performs many functions throughout your body, such as helping to maintain your immune system.

NAC supplements can help to fill the gaps in your natural cysteine levels, ensuring that you have what you need. 

Health Benefits

One of NAC’s most important jobs is to help your body replenish its glutathione stores. As one of your body’s most potent antioxidants, glutathione helps to get rid of cell-damaging free radicals. Reducing oxidative stress can help to lower your risk of developing chronic conditions such as heart disease, diabetes, and infertility. 

NAC does more than just aid in the production of glutathione. Other benefits of the nutrient include:

Detoxification of the Liver and Kidneys

NAC plays a role in the detoxification of your kidneys and liver. It can help to prevent potential side effects of drugs and environmental factors — such as exposure to heavy metals — that may impact these organs.

Improved Symptoms of Respiratory Issues

NAC supplements can help those with chronic obstructive pulmonary disease (COPD) by improving symptoms and managing lung decline. The supplement can also help to decrease the severity of wheezing and coughing in people with bronchitis. 

Improved Immune Health

There aren’t many studies on NAC and the immune system, but current research suggests that it and glutathione may help to improve your immune function. Most of the studies focus on NAC and people with human immunodeficiency virus (HIV).

Some research shows that the supplement may help to suppress HIV-1 reproduction. Test-tube studies also show that NAC may help to prevent the flu virus from replicating, possibly reducing its lifespan and symptoms. 

Research also suggests that NAC may help to improve insulin resistance, thereby helping to regulate blood sugar levels. Studies involved human subjects with polycystic ovary syndrome (PCOS), a hormonal condition that can affect women of childbearing age. 

Healthy Brain Function

NAC helps to replenish glutathione levels in the body. It also aids in regulating glutamate. These functions may help to improve brain health and benefit people with conditions such as Alzheimer’s and Parkinson’s diseases. 

Mental Health Management

NAC may help with psychiatric disorders and addictive behaviors. Some research shows that NAC can help improve symptoms of depression and bipolar disorder.

Other studies say that the supplement may help decrease symptoms of withdrawal and lower the risk of relapse in people with addictions. 

Reduction of Heart Disease Risk

Test-tube studies suggest that combining NAC and green tea may help to reduce damage caused by oxidized LDL-cholesterol, a risk factor for heart disease. NAC also helps to boost nitric oxide production, which can improve your blood flow and lower your heart attack risk. 

Improvement in Fertility 

NAC may help to improve fertility in both men and women. One study found that men supplementing with both NAC and selenium experienced an increase in semen quality. NAC may also help to improve fertility in women with PCOS. 

Why NAC is Specifically Useful in Lung Diseases like Asthma and COPD

Oxidative stress has been implicated in the pathogenesis and progression of Chronic Obstructive Pulmonary Disease (COPD). Both reactive oxidant species from inhaled cigarette smoke and those endogenously formed by inflammatory cells constitute an increased intrapulmonary oxidant burden. Structural changes to essential components of the lung are caused by oxidative stress, contributing to irreversible damage of both parenchyma and airway walls. The antioxidant N-acetylcysteine (NAC), a glutathione precursor, has been applied in these patients to reduce symptoms, exacerbations, and the accelerated lung function decline. This article reviews the available experimental and clinical data on the antioxidative effects of NAC in COPD, with emphasis on the role of exhaled biomarkers. An important part of the pulmonary antioxidant defense is located in the epithelial lining fluid (ELF). Vitamin C and vitamin E levels in ELF are depleted in smokers, but glutathione (GSH) levels are increased. These effects depend on the time-course of exposure to tobacco smoke. 

NAC has direct and indirect antioxidant properties. Its free thiol group is capable of interacting with the electrophilic groups of ROS (Redox signaling, which is a key modulator of oxidative stress induced by nonspecific insults of biological molecules generated by reactive oxygen species). This interaction with ROS leads to an intermediate formation of NAC thiol, with NAC disulfide as a major end product. NAC also exerts an indirect antioxidant effect related to its role as a GSH precursor. GSH is a tripeptide made up of glutamic acid, cysteine, and glycine. It serves as a central factor in protecting against internal toxic agents (such as cellular aerobic respiration and metabolism of phagocytes) and external agents (such as NO, sulfur oxide, and other components of cigarette smoke, and pollution). The sulfydryl group of cysteine neutralises these agents. In vitro, NAC acts as a precursor of GSH as it can penetrate cells easily and is subsequently deacylated to deliver cysteine. 

Treatment with NAC in humans alters the pulmonary oxidant–antioxidant imbalance. NAC 600 mg/day given orally shown to increase lung lavage glutathione (GSH) levels, thereby greatly improving lung function in chronic smokers and those suffering from asthma and COPD (Although asthma and COPD have many similarities, they also have many differences as well).