Leia Mulroy (Clinical Nutritionist)

N-Acetyl Cysteine, also known as NAC, is a derivative of the naturally occurring amino acid L-Cysteine.
NAC stimulates the production of a powerful antioxidant Glutathione, promotes detoxification, acts as a mucolytic, cardiovascular protectant, respiratory aid and long known antidote for paracetamol overdose. There are numerous studies to date showing promising results for other conditions such as polycystic ovarian syndrome, fertility, and degenerative conditions such as Parkinson’s and Alzheimer’s (3).
Below we will cover some of NAC’s main therapeutic indications.
Easy & Healthy Alternatives to Processed Foods

Cardiovascular Health

Oxidative stress is a major contributor of cardiovascular diseases with certain studies suggesting a beneficial role of antioxidants for these diseases. Oxidative stress can cause a dysfunction of the endothelium (the cells that line our blood vessels) and promote the progression of conditions such as atherosclerosis, high blood pressure, high cholesterol and coronary disease.
Boosting levels of the antioxidant glutathione via NAC could suppress the levels of oxidative stress and reduce inflammatory mediators that are the underlying drivers of these diseases (6).

Antioxidant and Immune Support

A balance occurs every day between our level of antioxidants and oxidant free radicals in the body. Inflammation and oxidative stress is generated when there is an imbalance between these antioxidants and oxidants. Factors that can throw out this balance include:

  • air pollutants
  • cigarette smoke
  • cosmetic and chemical inhalants
  • processed food
  • alcohol
  • chronic stress.

NAC is a precursor to one of the most potent antioxidant defence systems in the body, called Glutathione (1). Increasing glutathione levels in the body can combat the effects of these toxins and improve general well-being, reduce the effects of aging and prevent cellular damage.
Influenza, commonly known as the flu, is an infection of the nose, throat and lungs caused by the influenza viruses (4). The antiviral and anti-inflammatory mechanisms of NAC have been shown to inhibit replication of human influenza A viruses, reduce virus replication and virus-induced inflammation (5). This revels promising results in the use of NAC in the prevention and treatment of the flu in otherwise healthy and immuno-compromised individuals.

Respiratory Disorder

Normally the lungs exist in an oxygen rich environment sensitively balanced between the toxicity of oxidants and the protective measures of intra and extra cellular antioxidants. (2) Reactive free oxygen radicals are known to play an important role in the pathogenesis of various lung conditions such as asthma, idiopathic pulmonary fibrosis (IPF), adult respiratory distress syndrome (ARDS) or cystic fibrosis (CF). They can originate from internal processes or external exposures (e.g. ozone, cigarette smoke, asbestos fibres).
In conditions such as asthma, constant presence of inflammatory mediators and immune cells in airways result in airway hyper-responsiveness (AHR), which is clinically pictured as breathlessness, coughing and wheezing (7). A 2013 study tested the preventative effects of NAC in steroid resistant asthma and found that NAC reduced airway inflammation and decreased the airway hyper-responsiveness (8). High levels of oxidative stress are seen in patients with asthma and have been implicated as a driving force behind the inflammatory response. Therefore, antioxidants such as NAC that neutralize this oxidative stress in the airways might be of benefit and may restore corticosteroid sensitivity in asthmatic patients.

Ok…let’s recap!

N-acetyl cysteine is a derivative of the amino acid cysteine and is involved in the production of a powerful antioxidant called glutathione. One of the main drivers of metabolic diseases in the modern world is caused by a high level of inflammation and oxidative stress caused by day-to-day stressors such as pollution, chemicals, toxins, processed food and alcohol. Increasing out body’s levels of protective antioxidants such as glutathione, can reduce inflammation, support a healthy immune system and reduce symptoms and occurrence of metabolic conditions such as cardiovascular disease, respiratory disorders, and hormonal disturbances.

Research – References

  1. Zafarullah, M, Li, W.Q, Sylvester, J, & Ahmad, M, 2003, Molecular mechanisms of N-acetylcysteine actions, Cellular and Molecular Life Sciences CMLS, vol 60, Issue 1, pp 6-20.
  2. Gillissen, A, & Nowak, D, 1998, Characterization of N-acetylcysteine and ambroxol in anti-oxidant therapy, Respiratory Medicine, vol 92, Issue 4, pp 609-623
  3. Mokhtari, V, Parvaneh Afsharian, Ms, Shahhoseini, M, Mehdi Kalantar, S, Moini, A, 2017, A Review on Various Uses of N-Acetyl Cysteine, Cell Journal, vol 19, Issue 1, pp 11-17
  4. Government of South Australia, SA Health, www.sahealth.sa.gov.au
  5. Geiler, J, Michaelis, M, Nackzk, P, Leutz, A, Langer, K, Doerr, HW, Cinatl, Jr, 2010, N-acetyl-l-cysteine (NAC) inhibits virus replication and expression of pro-inflammatory molecules in A549 cells infected with highly pathogenic H5N1 influenza A virus, Biochemical Pharmacology, vol 79, Issue 3, pp 413-20
  6. DiNicolantonio, J, O’Keefe, J and McCarty, M, 2017, Supplemental N-Acetylcysteine and other measures that boost intracellular glutathione can downregulate Interleukin-1β Signalling: A Potential Strategy for Preventing Cardiovascular Events?” Open Heart, vol 4, Issue 2
  7. Rogers, D, 2007, Mucoactive agents for airway mucus hypersecretory diseases, Respiratory Care, vol 52, Issue 9, pp 1176-1197
  8. Eftekhari, P, Hajizadeh, S, Raoufy, MR, Masjedi, MR, Yang, M, Hansbro, N, Jing, J & Foster, P, 2013, Preventive effect of N-acetylcysteine in a mouse model of steroid resistant acute exacerbation of asthma, Excli Journal, vol 12, pp 184-192