Introduction to the master of antioxidants – Glutathione

Highlight

• Glutathione is a molecule that is naturally produced in the liver and is distributed throughout the body. It is made of 3 amino acids – cysteine, glutamic acid, and glycine.
• It is known as the master of antioxidants.
• Changes in lifestyle and exposure to certain factors will change the level of glutathione in our body.
• Main functions of glutathione are:
  • Fighting against cell damages from free radical attacks
  • Detoxifies toxins, drugs, and heavy metals in the liver
  • Recycles vitamin C & vitamin E
  • Regulates vitamin D level
• Main sources of glutathione in food include liver, cruciferous vegetables, banana, rice, almond, carrots, and spinach.
• Eating a diet filled with glutathione-rich food is one of the common ways to increase our glutathione levels, though it can be tedious at times.
• Taking glutathione or its precursors in a supplemental form can be helpful especially for those who are leading a busy lifestyle. It helps you to know the exact amount you’re getting each day.
• Commonly used glutathione supplements can be found in the form of L-glutathione or N-acetyl-cysteine (NAC).

1. Introduction

You might have heard about glutathione from your relatives, friends, or from social media. They might have claimed it as a powerful antioxidant and some may even suggest you to take the supplemental form of glutathione to improve your immunity and help with your overall health. But do you know how it actually works in our body and do you really need them ?

2. What’s glutathione

Glutathione (GSH) is a naturally occurring molecule that is produced in the liver and distributed to all of our body cells through the bloodstream. This molecule is made up of 3 amino acids – cysteine, glutamic acid, and glycine, which are all also naturally present in our body.

Like other molecules in our body, glutathione level fluctuates when our body experiences certain types of changes. Some of the factors that take part in determining the level of glutathione in our body include:

• Diet
• Age
• Stress
• Medications
• Exposure to pollutants
• Infections
• Radiation
• Drinking & smoking habit
• Fitness activity

On top of that, the production of new glutathione in our body is also limited by the availability of cysteine – when cysteine is low, glutathione production is slowed down.¹ As humans grow older, get sick, and get exposed to various stress factors, the storage of glutathione in the cell depletes rapidly. This reduction will be upregulated mainly by increasing the availability of cysteine.¹

Higher level of glutathione is also associated with better physical health and less occurrence of illness and diseases. Matter of fact, GSH levels in human body have been discovered to correlate with telomerase activity, a key predictor of lifespan.² Which means, the more glutathione you have in your body, the longer your lifespan may be.

3. Main functions of glutathione

I. Scavenging free radicals & combating oxidative stress

Free radicals are molecules that contain single oxygen and are desperate to steal atoms from other molecules. They are also known as reactive oxygen species (ROS). When they steal an atom from a healthy cell, molecular changes occur in the cell. The reactivity of this molecule is dangerous and may cause various harmful reactions in our body if not removed.

It may seem impossible that one atom missing from a molecule may cause many health problems. But bear in mind that we are exposed to many situations that cause us to ingest free radicals such as exposure to sunlight, pollution, stress, smoking, heavy exercises, and radiation. On top of that, our body also naturally produces free radicals everyday as a byproduct of our regular metabolism. IN other words, our body is exposed to a lot of free radical sources on a daily basis.

Ideally in healthy individuals, free radicals will be scavenged by antioxidants in their body and a normal balance of free radicals and antioxidants can be achieved. However, due to the high amount of stress and pollution we are exposed to nowadays, we often produce more free radicals than our body can manage to scavenge at a time. This overload of free radicals causes oxidative stress – a condition resulting from damages on various parts of our body cells. Oxidative stress may lead to:

• Rapid internal & external aging
• Low immunity
• Cancers
• Impaired brain & organs functions
• Degenerative diseases
• DNA mutations
• Various chronic diseases

Antioxidants, especially glutathione, are responsible for stopping these free radicals from harming our cells by inactivating them. Glutathione’s powerful function is attributable to its cysteine group. It contains a sulphur chain (SH) that acts like a flytrap. Toxins and free radicals that are roaming around in our body get stuck onto this sulphur group, disabling them from causing any harm to our cells. Our body naturally increases the production of glutathione when we’re under stress or when we’re sick.

II. Detoxification of toxins and heavy metals

Glutathione is also important in detoxifying chemicals within the liver. It works by binding to drugs, toxin compounds, and heavy metals such as mercury to make it easier for excretion.¹ Due to its potent detoxifying effect, some people even take glutathione prior to drinking alcohol to reduce the severity of the side effects the next morning.

III. Vitamin C & E recycling¹

Part of the reason glutathione is called the master of antioxidants is due its role in the recycling of other antioxidants (vitamin C & vitamin E). After being used, antioxidants need to be recycled back to their active form to maintain an optimal level and a continuous supply of antioxidants in our body. 

Through a process called antioxidant recycling, used vitamin E is returned to its oxidized form with the help of vitamin C, and oxidized vitamin C is returned to its reduced form by glutathione. This series of recycling vitamin C & E allows our body to continuously fight free radicals at all times. In other words, without glutathione, all the other antioxidants may not be recycled back to their functioning forms.  

IV. Vitamin C & E recycling¹

Vitamin D plays many key roles in maintaining our health. Some of them are to maintain calcium balances in our body and bone, to regulate calcium absorption in the intestine, to regulate blood pressure, and to modulate the immune system. Deficiency in this vitamin will cause many health issues such as:

• Bone issues (osteoporosis, osteoarthritis)
• High blood pressure
• Neuropsychiatric disorders (depression, schizophrenia, neurodegenerative disorders)
• Cardiovascular disease
• Muscle weaknesses

Glutathione has the ability to affect the level of vitamin D in our body. It was found that supplementation of glutathione may help to improve vitamin D level in our blood and may also help to reduce the effects of oxidative stress in our body. In fact, in those who suffer from vitamin D deficiency, their vitamin D level can only be improved when the glutathione level is corrected. This means that taking vitamin D supplements may be less effective unless it was taken together with glutathione or glutathione precursor.³

4. Natural sources

We can obtain glutathione from various sources of food. Some glutathione-rich food are:

• Liver
• Cruciferous vegetables (broccoli, cauliflower, brussels sprouts)
• Rice
• Banana
• Sulphur-rich food (garlic, onion)
• Potatoes
• Peppers
• Almonds
• Avocados
• Spinach
• Melons
• Meat & dairy products
• Carrots

Glutathione is especially high in animal-based food products, mainly the liver. However, most dietary intake is not sufficient to supply the amount of glutathione that our body needs due to the increased requirement. This is especially true for people with certain health conditions and poor health habits. Moreover, it is difficult to estimate your daily intake since the amount of glutathione from food varies greatly and cannot be measured accurately.

5. Supplemental sources

Various types of supplemental glutathione are already available in the market these days. They came in many forms and formulations. One of the most common types is L-glutathione.

Once consumed, they will be broken down into their constituent amino acids – cysteine, glutamic acid, and glycine. As mentioned previously, cysteine is the limiting factor to the production of glutathione. Therefore, our body can only produce as much glutathione as the amount of cysteine existing in our body at one time.

To overcome this limitation, some supplements use glutathione precursors instead of the glutathione itself. One of the most commonly used molecules is N-acetyl-cysteine (NAC). When consumed, NAC will initiate the production of cysteine in our body which then triggers the production of glutathione, granted that glutamic acid and glycine are also present. Taking NAC in a supplemental form is considered to be one of the most effective ways at raising glutathione levels.¹    

Sulforaphane is another common glutathione precursor used in supplements. This molecule can be obtained from broccoli and its sprouts.

6. How do I improve my glutathione level?

The most common way to improve the antioxidant levels in your body is by eating a variety of food containing glutathione. However, keeping a tab of your daily dietary intake can be quite taxing and tiresome especially if you have a busy lifestyle.

Taking glutathione or its precursors in a supplemental form can be helpful in such cases. It also allows you to know and control the exact amount you’re getting each day. You may take a glutathione supplement in the form that you think is helpful for you including L-glutathione and NAC.

Commercial glutathione supplements are considered to be safe for daily consumption. Though it is advised for you to still consult your doctor and dietitian before taking any supplements to make sure they’re not affecting your medications or any treatment you’re undergoing.

References

1. Pizzorno, Joseph. “Glutathione!” Integrative Medicine: A Clinician’s Journal 13, no. 1 (February 2014): 8–12. Accessed June 21, 2021. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4684116/.
2. Borrás C, Esteve JM, Viña JR, Sastre J, Viña J, Pallardó FV. Glutathione regulates telomerase activity in 3T3 fibroblasts. J Biol Chem. 2004;279(33):34332-34335.
3. Jain, S. K., Parsanathan, R., Achari, A. E., Kanikarla-Marie, P., & Bocchini, J. A. (2018). Glutathione Stimulates Vitamin D Regulatory and Glucose-Metabolism Genes, Lowers Oxidative Stress and Inflammation, and Increases 25-Hydroxy-Vitamin D Levels in Blood: A Novel Approach to Treat 25-Hydroxyvitamin D Deficiency. Antioxidants & Redox Signaling, 29(17), 1792–1807. https://doi.org/10.1089/ars.2017.7462