With so many man-made chemicals being released into our atmosphere, waterways, foods and medications today, you might wonder how your body even knows what to do with them. Relentless toxic exposures, poor diets, medication overuse, chronic stress and insufficient exercise compound our toxic burden and whittle away at our reserves. Fortunately, your body has wisely equipped itself with a natural detoxification system that relies primarily on one powerful antioxidant: glutathione.
Frankly, with today’s toxic onslaught, just about everyone benefits by boosting their glutathione levels — with food, supplements, or a few other tricks we’ll explore below.
Why is Glutathione the #1 Antioxidant in the Human Body?
When we think about increasing our antioxidant levels, we typically think of superfoods—but glutathione is different. Largely, your body must manufacture most of its own glutathione, requiring adequate amounts of three amino acids: cysteine, glutamate and glycine. Although some foods contain natural GSH, studies suggest relatively little of your glutathione reserves come from your diet because GSH doesn’t survive the digestive tract. This makes many oral glutathione supplements of questionable value. (We’ll get to that.)
To aid detoxification naturally, glutathione levels are the highest in your liver and kidneys, which are your body’s primary detoxification organs. Glutathione is important to your overall immune system, protecting your cells and mitochondria from the damaging effects of oxidative stress and helping keep inflammation at bay. As my friend and colleague, Dr. David Jockers, reports, every cell in your body faces as many as 10,000 free radical strikes per day—therefore, preventing damage is a formidable task. (1)
GSH is of particular importance for “Phase II detoxification,” where toxins are bound directly to glutathione (aka glutathione conjugation) so they can be eliminated from the body. However, GSH must sacrifice itself in the process—which is why you must continuously make more.
Glutathione is labelled the “master antioxidant” for its unique ability to “recycle” other antioxidants such as vitamins C and E, alpha lipoic acid and CoQ10, so they can be reused by your body. It follows that by increasing your GSH levels, you are effectively increasing many of your other antioxidants as well. (2)
What happens to Glutathione as we age?
Glutathione levels tend to decline as we age, therefore deficiency is common among the elderly (3), and among alcoholics and athletes who overtrain. Individuals with the lowest GSH levels are 30 percent more likely to have a heart attack than those with the highest levels. (4). Essentially, the more glutathione your body can make, the healthier you will be—and some research suggests, the longer you will live. (5, 6)
The problem is that your body faces a number of challenges in maintaining adequate glutathione levels, which may explain why so many people today are battling toxicity-related diseases. We are bombarded daily with thousands of man-made chemicals that continuously use up our glutathione reserves, and most of us don’t derive enough glutathione (or its building blocks) from our daily diets to keep up. Detoxification is further challenged by the fact that nearly half of us may be missing one or more of the genes necessary to manufacture GSH. What happens when we don’t have enough GSH?
Glutathione deficiency is linked to a number of serious illnesses such as cancer, neurodegenerative diseases including Alzheimer’s and Parkinson’s, cardiovascular and pulmonary diseases, arthritis, diabetes, cystic fibrosis, HIV infection and Chronic Fatigue Syndrome—and those are just for starters. (7, 8)
If we can’t get enough of this uber-important antioxidant from our diets, then how do we increase it? The answer to this question will be the focus of this article, but first let’s take a closer look at glutathione’s important functions in your body.
Glutathione Grabs Toxins and Gives Them the Boot
Glutathione is different from other antioxidants in that it’s intracellular, so it supports detoxification at the cellular level. (Extracellular, or systemic detoxification, is what people typically think of when it comes to detox … a kidney, liver, or bowel cleanse. Here, I’m talking about getting toxins out of your individual cells so that they can then be pulled from those systems.)
Although GSH plays a role in dozens of important biological operations, its benefits can generally be grouped into two broad categories: detoxification and immune support. (9)
By way of its plentiful sulfur, GSH can eliminate an impressive array of toxins (carcinogens, heavy metals, herbicides, pesticides, xenobiotics, radiation). It binds with them to form soluble compounds that can then be excreted through the urine or bile. Its sulfur atoms scavenge free radicals, transforming them into harmless compounds, such as water. For example, glutathione-mercury complexes are the primary way by which mercury is eliminated from your body. If you consume a great deal of fish, the total mercury retained in your tissues directly depends on your glutathione stores. (10, 11, 12)
This is why your body must continuously replenish its GSH by making more. If you become deficient, toxins can build up—a bit like overflowing dumpsters during a garbage strike.
The best example of glutathione’s unique binding power is illustrated by its role in the treatment of Tylenol (acetaminophen) overdose. Since cysteine is the limiting factor in how much glutathione your body can produce, overdose patients are given an IV containing the amino acid N-acetyl cysteine, or NAC, which triggers a sudden flood of glutathione production. This deluge of GSH to the liver flushes out the acetaminophen and can be the difference between life and death, between full recovery and living with a severely damaged liver.
Your brain is very susceptible to oxidative stress due to its high fat composition and oxygen requirements. Although your brain makes up only two percent of your body weight, it consumes 20 percent of your oxygen. Strong oxidation defenses reduce inflammation levels in the body—including the brain—and we know that brain inflammation is a factor in many neurodegenerative diseases. This may explain why glutathione deficiency is common in diseases such as Alzheimer’s and Parkinson’s. One meta-analysis detected a possible link between GSH deficiency and autism. (13)
Glutathione plays a role in countless biological operations, a few of which are outlined below. Keep in mind that these are just the tip of the iceberg.
- Maintains energy, strong athletic performance and recovery
- Reduces muscle pain
- Helps synthesize proteins, and aids transport of amino acid into and out of cells
- Sleep quality
- Skin health
- Helps regulate homocysteine
- Enhances immune function (leukotrienes, T-cells, macrophages, etc.)
- Makes medications more bioavailable; enhances efficacy and modulates side effects of chemotherapy and radiation (14)
- Induces cancer cell death (apoptosis) (15)
- Acts as cofactor (“helper”) in many enzymatic reactions
Boosting Your Glutathione Production Naturally
It is difficult to optimize GSH levels through diet alone. A large percentage of oral glutathione breaks down and oxidizes in your digestive tract, with only a small fraction making it into your bloodstream, tissues and cells.
Nevertheless, you can increase your glutathione levels to some degree by consuming foods rich in glutathione and its building blocks. A variety of foods, vitamins, minerals and herbs have been scientifically shown to work. We should be getting 250 milligrams of dietary GSH daily, but the standard American diet contains a paltry 35 milligrams. Researchers tested a variety of foods for their GSH content and drew the following conclusion in a report published in the journal Nutrition and Cancer:
Dairy products, cereals, and breads are generally low in GSH; fruits and vegetables have moderate to high amounts of GSH; and freshly prepared meats are relatively high in GSH. Frozen foods generally had GSH contents similar to fresh foods, whereas other forms of processing and preservation generally resulted in extensive loss of GSH. (16)
Cooking raw vegetables destroys nearly 100 percent of their usable GSH. Similarly, the glutathione stores available in meat, dairy, and eggs, are only significant when the foods are consumed raw. It’s unlikely you’ll be consuming large quantities of raw meat and eggs, but have no fear—it turns out the top ten glutathione-containing foods are actually plants: (17)
Other foods may boost your GSH levels by providing the nutritional building blocks to support your body’s own GSH production. Sulfur-rich cruciferous vegetables are great for this (broccoli, cauliflower, cabbage, etc.). (18) Others include garlic, onions, parsley, spinach, beets, curcumin (turmeric), cinnamon, cardamom and black cumin. High-cysteine foods are also beneficial. Raw dairy is the best source of cysteine, but also undenatured raw whey protein. (19) Not surprisingly, GSH is almost entirely absent in pasteurized dairy. On a side note, a ketogenic diet was shown to increase mitochondrial glutathione in rats, but human studies are lacking. (20)
Other nutritional compounds play important roles in glutathione synthesis—your body can’t make GSH without them:
- Vitamin C: Vitamin C is glutathione’s number one “crime-fighting cohort,” working with GSH to purge water-soluble toxins from your body. Vitamin C raises glutathione levels by helping your body manufacture it, and glutathione helps recycle vitamin C.
- Vitamin D (plus zinc): Vitamin D appears to increase glutathione production. In a rat study, GSH levels tripled when the rats were given vitamin D. However, the zinc-deficient rats did not make as much GSH as rats with adequate zinc. (21)
- Sulfur: Sulfur is a key compound in GSH, which is why cruciferous vegetables are so beneficial. MSM (methylsulfonylmethane) can be used for additional sulfur. In animal studies, MSM is shown to promote glutathione synthesis and upregulate the activity of glutathione enzymes.
- B vitamins: Vitamins B1, B2, B6 and B12 are required for synthesis of glutathione. Folate (B9) is able to divert cysteine preferentially towards glutathione and away from homocysteine.
- Selenium and Magnesium: Along with vitamin E, selenium is required for your body to manufacture GSH. The best source of selenium is Brazil nuts, and you only need two or three per day. Magnesium is also required for glutathione synthesis.
- Alpha lipoic acid (ALA): ALA is important for recycling GSH and restoring its levels after depletion. Food sources of ALA include organ meats and spinach, although the human body has difficulty extracting it from foods, so the majority must be produced.
- Green tea, fish oil, and resveratrol: These substances have been found to switch on the genes responsible for glutathione synthesis.
- Milk thistle: A source of silymarin, milk thistle stimulates the growth and regeneration of liver cells by helping prevent glutathione depletion in the liver.
Are There Any Glutathione Supplements Worth Taking?
Oral supplementation has been the subject of much debate as studies are inconsistent and technology is evolving. The studies showing effectiveness tend to involve higher doses and longer treatment duration. (22, 23) Intravenous GSH has been successful for some, but it’s less practical, expensive, and presents only a temporary fix. IV glutathione is better reserved for extreme situations—like getting a jump when your car battery is totally dead.
A while back, though oral GSH supplements and injections were found largely ineffective, recent biotechnology now gives us better options. Research supports the efficacy of the following four strategies for glutathione supplementation, so my recommendation would be to experiment and see what works best for you.
1. N-Acetyl Cysteine (NAC)
As already discussed, NAC is a precursor to glutathione. Research supports the effectiveness of NAC in upregulating glutathione levels, but the effect tends to be temporary with GSH levels dropping below baseline afterward. NAC also has some reported risks and side effects (nausea, diarrhea, muscle cramps, and others ref). NAC is probably the least optimal of the four supplements, but I’m including it for the sake of completeness.
Recommended Dosage: 400-1200 mg per day, in 2-3 dosages, with or without food.
2. Glutathione Intra-Oral Spray
Glutathione sprays have been shown as effective in increasing intracellular GSH levels. They are rapidly absorbed through oral mucus membranes, largely bypassing the digestive tract.
3. Liposomal Glutathione
Liposomal glutathione—meaning glutathione combined with liposomes—is an excellent option. The liposomes help the glutathione survive your digestive tract in order to make it to your cells. Be sure to avoid the varieties that use soy lecithin, opting for sunflower lecithin instead.
Recommended Dosage: 200-500 mg taken 1-2 times daily, away from food
4. Acetylated Glutathione
The acetylated form is quite similar to liposomal glutathione in that it also survives the gut and makes it into your cells, but it has an additional advantage. Acetylated GSH is cleaved by cellular enzymes, so utilizing it requires no energy expenditure by your body. My personal favorite is the S-acetylated form due its superior bioavailability compared to NAC and liposomal glutathione.
Recommended Dosage: 200-500 mg taken 1-2 times daily, away from food
Ultimately, the best way to determine which method works best for you is to test your body’s levels of GSH, before and after supplementation over a period of time.
One thing we know for sure: Exercise Boosts Glutathione
If you wish to boost your glutathione naturally, get off your butt. The first longitudinal study measuring the effect of exercise on glutathione levels found a positive connection—physical activity increased glutathione. A combination of cardio and weight training was most effective. (24)
The effect of exercise is not surprising when you consider it’s the number one way to increase the number of mitochondria in your muscles, for increased energy and ATP. Synthesis of macromolecules like GSH is energy-intensive. If your GSH is low, then chances are your cellular ATP is also low. Glutathione depletion can also cause ATP shortage, as was found by a study in Journal of Biological Chemistry. (25)
If you want higher glutathione levels without turning to a supplement, you have to get your body to make more, and this requires providing it with the right building blocks and ample energy to fuel the operation. Moving your body, improving your diet and reducing your toxic load are the best strategies for accomplishing the task.