Can N-acetyl Cysteine Prevent Kidney Damage?

Kidney cells are particularly vulnerable to damage which may come from things in the environment, or from within our own body. So today I thought I’d write about the nutritional supplement N-acetyl cysteine or NAC that has been shown to protect the kidneys from damage. 

What is N-acetyl cysteine?

N-acetylcysteine or NAC is a nutritional supplement that comes from the amino acid cysteine which can be found in most high-protein foods and is also produced endogenously by the body.

NAC was introduced in the 1960s as a mucolytic drug used to thin mucous in conditions like cystic fibrosis. After that, it was discovered that NAC is an effective antioxidant that increases the production of glutathione in the body prompting its use as an antidote to acetaminophen/paracetamol overdose and toxicity to protect the liver and kidneys from damage. 

Image from: Bioconcepts.com.au

Therapeutic actions of NAC:

•     Antioxidant
•     Anti-inflammatory
•     Mucolytic 
•     Boost immune function
•     Supports liver detoxification
•     Mitochondrial support
•     Neurological support
•     Promotes fertility
•     Supports mental health
•     Protects thyroid function
•     Lowers homocysteine
•     Improves insulin sensitivity
•     Lowers blood pressure

As you can see, NAC supplementation has many different actions within the body, but its antioxidant activity is probably the most well-known and most beneficial.

Now, before I explain the antioxidant effects of NAC, I just wanted to do a quick recap of the relationship between the kidneys and oxidative stress.

What is oxidative stress?

Kelly FJ. Oxidative stress: its role in air pollution and adverse health effects. Occup Environ Med. 2003 Aug;60(8):612-6. PMID: 12883027.

Oxidative stress is simply described as a physiological event where free radicals have damaged cells of the body and is well known to be involved in the development and progression of kidney disease, as well as the development of other complications seen in kidney disease including cardiovascular disease, anaemia, malnutrition and lowered immune function.

Ordinarily, antioxidants in the body ‘quench’ these free radicals, however, if the production of these antioxidants decreases, or the production of free radicals is sped up, the body just can’t meet demands. 

The kidneys are especially vulnerable to oxidative stress and damage from free radicals and prooxidants produced within the body. 

It makes sense then that boosting antioxidant levels within the body is one way to protect the kidneys from damage. 

Antioxidant effects of NAC

NAC itself has direct antioxidant activity but primarily acts as a precursor to glutathione which is known as the ‘master’ antioxidant and found in every cell of the body.

Glutathione is frequently depleted in people with kidney disease which sets the stage for higher levels of oxidative damage and inflammation within the body. Supplementing with NAC increases glutathione levels by about 30%.

NAC’s strong antioxidant actions mean it helps to protect against damage in the cells, reduces inflammation, helps with the detoxification of chemicals, drugs, environmental pollutants and heavy metals and has beneficial effects on the immune system. 

How does NAC protect the kidneys?

1. Antioxidant actions- protect against damage to the cells in the kidney by quenching free radicals and through downregulating inflammatory pathways.

2. Improved renal haemodynamics- improves renal haemodynamics through its vasodilatory actions. What this means is that it improves blood flow to the kidneys which increases the amount of oxygen delivered. Changes in renal haemodynamics and reduced oxygen delivery is one of the contributing factors to both acute and chronic kidney disease.

3. Improved detoxification- NAC has also been shown to help the body detoxify some heavy metals and protect the kidneys and liver from damage from heavy metals, medications, pesticides, diesel fuel and chemotherapy.

One example of NAC protecting against kidney injury is its use as a preventative treatment prior to the administration of radiographic contrast dyes. 

Radiographic dyes are used in diagnostic testing such as CT scans and angiography and are linked to the development of acute kidney injury and kidney damage particularly in people with diabetes and pre-existing kidney disease. 

Numerous studies have shown that when NAC is given before contrast dyes in people with renal impairment it has been shown to reduce the incidence of acute kidney injury by improving renal haemodynamics and reducing oxidative tissue damage. 

Immune actions

One of the other actions of NAC that I wanted to highlight is its role in boosting immune function and its antiviral activity. 

NAC boosts immune function by improving the function of white blood cells and natural killer cell activity. Natural killer cells are a type of white blood cell that identify and remove infected cells and cancer cells from the body. Studies have also shown that NAC reduces the viral load by stopping viral replication in a number of viruses.

NAC supplementation has been shown to significantly decrease the frequency of influenza-type episodes as well as reduce the severity of symptoms. So, not only are you less likely to get the flu but if you do, the symptoms aren’t as severe and don’t tend to last as long. 

In one study, supplementation with NAC was successful in significantly preventing most symptoms related to flu infection including symptoms in the respiratory tract such as runny nose, sore throat, mucous build-up and cough and general symptoms such as fatigue, headache and muscle aches. 

Another thing that was really interesting in the study was that only 25% of those in the group that were taking NAC developed any symptoms from infection with the influenza virus, whilst 75% of the placebo group were symptomatic. https://www.researchgate.net/publication/13989914_Attenuation_of_influenza-like_symptomatology_and_improvement_of_cell-mediated_immunity_with_long-term_N-acetylcysteine_treatment

Therapeutic Dose

The therapeutic dose of NAC is usually 600 mg-1200 mg a day and is best taken in divided doses. 

Cautions and Contraindications

 NAC should not be given alongside nitroglycerin as it may cause hypotension and severe headaches and may increase the anticoagulant activity of nitroglycerin. 

People with cystinuria, a genetic disorder that causes cysteine to precipitate in urine and cause kidney stones should not take NAC.  

And don’t forget…. 

Before introducing any new supplements, make sure you consult your healthcare provider. Because of NAC’s ability to lower blood pressure, it may increase the effect of anti-hypertensive medications so close monitoring of blood pressure is advised. 

So there you have it. I hope you’ve learnt something about the role of NAC supplementation in protecting the kidneys and boosting immune function. If you’ve found this article interesting or helpful please Share it with your friends and family.