Glutathione: The Body’s Master Antioxidant (and How To Make More Of It)

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A Diagram Showing All the Cells Within the Human Body.

Glutathione is one of the most critical compounds for human health.

It helps to protect our body from oxidative damage, and it has anti-aging, anti-carcinogenic and anti-inflammatory properties. 

In fact, glutathione supports nearly every process in our body.

Put simply; those with higher glutathione levels are healthier and much likelier to stay that way.

This article will explain what glutathione is, the benefits it has, and how we can make more of it through our diet.

What Is Glutathione?

Diagram Showing the Molecular Structure of Glutathione (GSH)

Known as the body's "master antioxidant," glutathione plays a critical role in our health.

However, it is not like the type of antioxidant we ingest from berries and green tea.

While we can get some glutathione from foods, we mainly produce glutathione internally through the synthesis of specific amino acids (protein). 

These amino acids are cysteine, glutamate and glycine (1).

To increase our glutathione levels, we need to create the optimal conditions to support its synthesis.

Structure of Glutathione

Regarding its structure, glutathione is a 'tripeptide'.

A 'peptide' is a type of compound that contains a chain of multiple amino acids, and 'tri' means three.

So, a 'tripeptide' is three amino acids (glutamate, cysteine and glycine) linked in a chain and connected by chemical bonds.

What is the Role of Glutathione?

Firstly, glutathione exists in two different states within our body;

  • L-Glutathione: otherwise known as 'Reduced glutathione' (GSH)
  • Glutathione disulfide: also called 'Oxidized glutathione' (GSSG)

'Reduced Glutathione'

Our body naturally produces 'reduced glutathione.'

This form of glutathione has an additional electron attached to it, and this electron can be "donated" to inflammation-causing free radicals to "neutralize" them (2).

In plain English; glutathione can give bad compounds an electron to make them behave better and stop causing oxidative damage.

'Oxidized Glutathione'

Once glutathione loses its extra electron, it becomes 'oxidized.' 

However, through the use of various co-enzymes, our body can recycle oxidized glutathione back into reduced glutathione.

On the negative side, when our body is in a state of chronic stress, this ability to recycle glutathione falls. 

For this reason, the total concentration of oxidized glutathione to reduced glutathione can give an important insight into cellular levels of oxidative stress (3).

As an example, people living with HIV often have low levels of glutathione.

Overtraining also tends to have this effect, which is one reason why excessive amounts of physical activity can eventually cause harm (4, 5).

Moderate levels of exercise, on the other hand, are very healthy.

Key Point: Glutathione is our body's 'master antioxidant' and it is largely responsible for the effectiveness of our immune system.

Key Benefits of Glutathione

Now that we know how this antioxidant works; what does glutathione do in the body?

Glutathione is involved in many biological processes, and here we will examine some of the essential functions it has.

1. Liver Health and Fatty Liver Disease

Diagram Showing the Different Stages of Liver Damage From NAFLD.

Firstly, it is easy to find various articles on juice detoxes to "cleanse" and "purify" our body.

While fruit has some benefits (juice: not so much), our body already has a perfectly good detoxification system called the liver. If the liver can't function properly, then some blended juice certainly will not help.

However, something that will help the liver is glutathione, since it plays a crucial role in liver health.

Non-alcoholic fatty liver disease (NAFLD) is, unfortunately, a rising epidemic.

Currently, NAFLD affects a concerning 20-30% of the population in Western countries (6). 

Notably, lower glutathione levels are typical in chronic liver diseases, which decrease the liver's defense systems (7).

On the positive side, recent research shows that increasing glutathione levels through high-dose intravenous administration improves various markers of liver health (8, 9, 10). 

Key Point: Increasing (and recovering) glutathione levels improves markers of liver health in patients with liver disease.

2. Supports the Healthy Growth and Repair of Every Cell

Diagram Showing How Cell Death Through Apoptosis Happens.

Glutathione helps every cell in our body to grow and repair healthily.

As part of this, glutathione has a vital role in cell apoptosis (11).

Apoptosis refers to the programmed death of cells in our body, and despite how it sounds, this is a good thing.

For example, we have billions of cells in our body, and many of these get damaged over time.

Apoptosis removes these damaged cells from our body and thus prevents them from potentially causing problems in the future.

To illustrate the importance of apoptosis; our body relies on it for the destruction of cancer cells (12).

Importantly, research demonstrates that glutathione plays a crucial regulatory role in activating the apoptosis process (13, 14).

Key Point: Glutathione has an important part in the apoptosis process and supports the healthy growth and repair of our cells.

3. May Improve Insulin Sensitivity

A Picture Showing 'Insulin Resistance' Written On a Board.

Lower levels of glutathione increase the rate of damage from oxidative stress, and unhealthy lifestyle habits, as well as aging itself, can be a cause of this.

For these reasons, in people suffering from insulin resistance, lower levels of glutathione are particularly undesirable.

Some recent research investigated what happens when we raise the glutathione levels of individuals with insulin resistance or type 2 diabetes.

Interestingly, the study demonstrated that (15);

  • Oxidative stress levels are higher when glutathione is low
  • Raising glutathione levels in elderly glutathione-deficient people increases their fat oxidation (fat-burning) rate to a level similar to young people.

It is also notable that newly diagnosed type 2 diabetics appear to have statistically significant lower rates of glutathione than non-diabetics (16).

Key Point: Higher levels of glutathione appear to be important for insulin sensitivity.

4. Reduces Oxidative Stress Levels

A Diagram Showing How Glutathione Repairs Free Radicals Through Electron Donation.

Many different factors that can cause oxidative stress in the human body.

Some of these include sleep deprivation, poor diet, the accumulation of heavy metals such as mercury, and many more (17, 18).

In other words; our whole lifestyle can impact upon levels of oxidative processes and cause damage to our cells, lipids, and DNA.

One of the critical roles of glutathione is to help attenuate this damage through its free-radical scavenging activity (19). 

Studies consistently link low glutathione levels with chronic illnesses, and when glutathione levels are low, oxidative stress appears to be higher (20, 21, 22).

Key Point: Low levels of glutathione are common in a variety of chronic illnesses. Conversely, high levels of glutathione signal that the body's immune processes are working well.

5. Reduces Inflammation (and Risk of Chronic Disease)

A Word Picture Saying 'Inflammation' In the Center.

Given the benefits glutathione has on detoxification systems and in fighting free radical damage, it makes sense that it has anti-inflammatory benefits.

For example, a wide variety of research demonstrates that glutathione inhibits or significantly reduces inflammatory processes (23, 24, 25).

One such example is the role that glutathione plays in our lung health. Specifically, low glutathione levels are strongly associated with lung abnormalities and make our lungs more prone to inflammation and free radical damage (26, 27).

Additionally, it is worth remembering that chronic inflammation plays a role in the etiology of numerous chronic diseases.

Given that glutathione is the body's master antioxidant, high levels of it are desirable for practically every bodily system.

Key Point: Glutathione has important anti-inflammatory properties.

How Can We Increase Glutathione Levels?

Since glutathione has great importance for our overall health, is there any way we can increase our levels of it?

The two main ways of boosting glutathione levels are through the food we eat and supplementation.

Dietary Factors

As previously discussed, our body naturally produces glutathione, but we can help by giving it more of the required precursors to build it.

To put it another way; by increasing our consumption of foods which contain cysteine, glutamine and glycine, we will be giving our body more of the raw materials it needs to make glutathione.

We can also find pre-formed glutathione in certain foods.

Supplementation

Firstly, most of the previous evidence had suggested that the oral bioavailability of glutathione is poor. 

Further, a randomized, double-blind, placebo-controlled clinical trial appeared to back this up; in tests on 40 participants, there was zero effect on markers of oxidative stress and glutathione status (28).

However, recent research - including randomized, controlled trials - demonstrates that newer supplement forms of glutathione are effective (29, 30, 31).

A recent clinical trial demonstrates that the oral liposomal form of glutathione (available here) works well (32).

Liposomal glutathione works by encapsulating the glutathione in a small kind of bubble/capsule. This bubble is called a liposome, and it is designed as a vehicle to allow compounds to survive digestion.

Key Point: It is possible to boost levels of glutathione through diet and supplementation.

Foods High in Glutathione and Its Precursors

A Whole Uncooked Chicken On a Wooden Board.

To increase our glutathione levels through diet, we have to ask what foods contain glutathione?

Additionally, we can split these foods into two categories;

  • Foods that provide pre-formed glutathione 
  • Food which contains glutathione precursors

10 Foods Rich in Glutathione

Based on the National Cancer Institute's Health Habits and Food Frequency Questionnaire tables, the following ten foods are some of the most abundant dietary sources of glutathione.

Each of these foods lists the total glutathione (and precursors) content per 100 grams.

While the majority of these are animal-based foods, some vegetables and nuts are also high in the compound.

1. Asparagus (28.3 mg per 100 g)

Alongside other sulfur-rich vegetables, asparagus is a very concentrated source of glutathione, and it provides 28.3 mg per 100 grams.

Other cruciferous vegetables such as broccoli, brussels sprouts and cabbage are also high in glutathione.

2. Avocado (27.7 mg per 100 g)

Avocados are a fantastic fruit that contains all sorts of beneficial nutrients.

A typical avocado has more monounsaturated fat than a tablespoon of olive oil, more fiber than 100 grams of grains, more potassium than bananas, and lots of vitamins and minerals (33). 

We can also add glutathione to the list; avocados are one of the most significant dietary sources.

3. Potato Chips (27.1 mg per 100 g)

Yes, potato chips.

But hold on...

Through a combination of potatoes (which are high in glutathione anyway) and the deep-frying oil, potato chips have a high glutathione content.

However, they are an unhealthy food as a result of the ultra-processing and frying process, and the fact they contain glutathione is no reason to eat them. 

If you like potatoes, eat them whole.

4. Veal (23.9 mg per 100 g)

Picture of Uncooked Veal Meat Next To Some Lettuce.

For those who do not know veal, it is the meat of a calf rather than an older cow.

In addition to the glutathione content, veal is very nutritious and contains a wealth of micronutrients, and it is a particularly good source of B vitamins (34).

5. Pork Chop (23.6 mg per 100 g)

Pork chops are one of the world's favorite cuts of pork, and they are reasonably nutritious too. 

Pork chops are an excellent source of amino acids and contain significant amounts of glycine and glutamate (35).

6. Boiled Ham (23.3 mg per 100 g)

Pork, in general, is an excellent source of glutathione. 

Boiled ham contains slightly less than pork chops, likely due to lower amounts of glycine (36).

7. Chicken Liver (18.8 mg per 100 g)

It may not be an everyday kind of food, but chicken liver is incredibly nutrient-dense and supplies a vast range of micronutrients.

It is also high in glutathione and provides 18.8 mg per 100 grams (37).

8. Hamburgers (17.5 mg per 100 g)

Healthy food doesn't have to be expensive, and hamburgers contain virtually the same nutrients as more costly cuts of beef.

They also provide a decent 17.5 mg of glutathione per 100 grams (38).

9.Beef (13.4 mg per 100 g)

It doesn't quite match up to pork concerning glutathione content, but beef still provides 13.4 mg per 100 grams (39).

Additionally, beef is very nutrient-dense and contains lots of essential vitamins and minerals in significant concentrations.

10. Walnuts (13.1 mg per 100 g)

Walnuts are a nutritious nut that also supplies a good amount of glutathione; 13.1 mg per 100 grams (40).

Aside from this, walnuts are also rich in omega-3 fatty acids and a wide range of minerals. 

Note of Caution

The only thing this data shows is the most concentrated sources of glutathione.

Importantly, this does not automatically infer the food is healthy.

For instance, just because potato chips (through a combination of the potatoes and oil) contain high amounts of glutathione, it does not mean they are a healthy choice.

Glutathione content can be an additional consideration after thinking about the overall nutritional value of food. However, it should not be the primary determinant.

Where Can We Get Dietary Glycine?

Many foods contain the amino acids (cysteine and glutamate) that are glutathione precursors.

However, it is harder to find significant sources of glycine.

One reason for this is that glycine mostly occurs around the connective tissues in animal foods.

As a result, foods such as chicken (with the skin) and bone-in, fatty and gelatinous cuts of meat are high in glycine.

Key Point: A wide range of foods contain a dietary source of glutathione, especially meat and sulfur-rich green vegetables.

Final Thoughts

Glutathione is an incredibly important compound that sits at the center of our internal antioxidant system.

This antioxidant has numerous health benefits, and maintaining high levels helps to protect our body from oxidative stress.

Although our body produces this antioxidant internally, there are certain foods we can eat to boost these glutathione levels.

Fortunately, this is a simple matter of eating whole foods such as meat and vegetables.