Anytime a new fad diet or trendy food emerges, I like to do a thorough scientific literature review to see if there is any supporting data to back up the various health claims that are often made. I did this with coconut oil, and I’d like to do the same for an up-and-coming food trend that’s been gaining in popularity—activated charcoal.
Activated charcoal is produced by exposing a carbon-containing material, such as wood, coconut husk, bamboo, or peat, to extremely high temperatures. This process changes the material’s structure making it extremely porous, which in turn, increases its surface area and ability to absorb various compounds. It can be used to clean up chemical spills, filter drinking water, and purify air or alcoholic beverages, among other functions. Activated charcoal is sold as a powder, gel, or as tablets. It differs from the charcoal briquettes used for grilling, and the two should not be mixed-up, as charcoal briquettes are not safe to consume.
Activated charcoal can also be used for cases of acute poison ingestion, or for orally ingested drug/medication overdoses (although it doesn’t work for all poisons/drugs). For example, if you accidentally drink some household cleaner, you could quickly swallow some activated charcoal which would bind up the cleaner before it’s absorbed into your bloodstream and makes you ill. This, however, is time sensitive. If the toxic substance is absorbed before you ingest the activated charcoal, there will be little benefit. Studies show that the effectiveness of activated charcoal significantly decreases as the time between poison ingestion and activated charcoal ingestion increases (1). Even when consumed a half hour after poison ingestion, activated charcoal only absorbs about 50% of the poison—a percentage that continues to drop as the time difference increases. For this reason, and because it does not improve clinical outcomes, activated charcoal is not recommended for routine use in patients who have overdosed or ingested a poison (1-4).
While it is true that activated charcoal can absorb toxic substances in the gastrointestinal tract, this concept has recently been twisted by health gurus claiming that activated charcoal can “detox” the entire body. A simple Google search pops up dozens of “health websites” with posts like, “Top 10 Ways to Use Activated Charcoal for Better Health”. These websites also claim that activated charcoal can whiten your teeth, prevent hangovers, reduce cholesterol, improve kidney function, improve digestion/gas/bloating, and can be used for a “digestive cleanse”. These are all very catchy claims, but is there actually any science to back them up? Let’s find out.
Activated charcoal can bind to substances in the gastrointestinal tract, which are then excreted without being absorbed. However, there’s no evidence that it can pull any other harmful substances, such as environmental pollutants, from elsewhere in the body. The idea that consuming activated charcoal can help your body “detox” is a completely unsupported claim.
Activated charcoal can be used to clean metals and purify gold, but does it have the same effect on your teeth? I was only able to find one unpublished study looking into this (5). It found that activated charcoal may have the exact opposite effect—the fine black powder may darken teeth if it gets embedded in cracks and defects. Beyond this, there didn’t appear to be any harmful effect, so if you want to give it a try, go for it.
I couldn’t find any studies looking into whether activated charcoal prevents hangovers, and the websites that make this claim don’t cite any research. In theory, activated charcoal, if taken while alcohol is still in the stomach (before it’s absorbed), could prevent some alcohol from being absorbed, which may reduce the likelihood of a hangover the next morning. Through this same mechanism, it may also help prevent acute alcohol poisoning, but it should not be used if actual medical attention is needed. The best way to prevent a hangover would be to not drink so much in the first place.
A couple of studies suggest that activated charcoal can lower cholesterol levels by binding to bile salts in our gastrointestinal tract (6-9). However, these studies were small and a more recent study suggests that it has no effect (10). At high doses, activated charcoal may indeed help lower cholesterol, but the evidence is limited and a high-fiber, plant-based diet would be much more effective (and healthier).
Improve Kidney Function
Websites making this claim suggest that activated charcoal helps rid the body of substances that would normally be filtered out by the kidney, thus lessening the burden on them and improving their ability to function. Their supporting evidence is extremely weak and limited to a few rodent studies. The one human study I could find used activated charcoal along with a very low-protein diet in elderly patients with end-stage kidney disease who refused dialysis (11). The intervention appeared to work, but it was probably due to the low-protein diet (something known to place less of a burden on the kidneys), not the activated charcoal. This claim also falls into the “unsupported” category.
Improve Gastrointestinal Health
Charcoal biscuits were sold in England in the early 19th century as a means to reduce gas and bloating. The idea is that activated charcoal binds to gas-forming byproducts in our gastrointestinal tract, which in turn, reduces flatulence and bloating. A few studies suggest that activated charcoal can reduce unwanted gastrointestinal symptoms after consuming a gas-producing meal or substance (12-14). However, these studies were small, and other studies showed no effect (15). The overall data on activated charcoal and gastrointestinal health is weak, at best.
Activated charcoal may help lower cholesterol and can potentially reduce unwanted gastrointestinal symptoms, but the overall evidence is limited. Plus, the therapeutic dose used in many of these studies was far greater than what you might add to a smoothie or beverage, so don’t expect the same results. There is little to no evidence that activated charcoal will whiten your teeth, prevent hangovers, improve kidney function, or “detox” your body. Until more research is conducted, I recommend saving your money and opting out of this food trend. If you truly want to “detox”, I would encourage you to consume a plant-based diet, drink plenty of water, get adequate sleep, and exercise regularly.
Peace, love, heath
- Position paper: Single-dose activated charcoal.
- Gastrointestinal decontamination in the acutely poisoned patient
- The role of activated charcoal and gastric emptying in gastrointestinal decontamination: a state-of-the-art review.
- Position statement and practice guidelines on the use of multi-dose activated charcoal in the treatment of acute poisoning. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists.
- Activated Charcoal as a Whitening Dentifrice
- The adsorption of bile salts on activated carbon.
- Activated charcoal in the treatment of hypercholesterolaemia: dose-response relationships and comparison with cholestyramine.
- Effect of activated charcoal on hypercholesterolaemia.
- The mechanism of the hypocholesterolaemic effect of activated charcoal.
- No effect of activated charcoal on hyperlipidaemia. A double-blind prospetive trial
- Combination of oral activated charcoal plus low protein diet as a new alternative for handling in the old end-stage renal disease patients.
- Efficacy of activated charcoal in reducing intestinal gas: a double-blind clinical trial.
- Effects of orally administered activated charcoal on intestinal gas.
- Activated Charcoal Reduces Lactulose-Induced Breath Hydrogen in Patients with Excessive Gas and in Controls
- Activated charcoal: In vivo and in vitro studies of effect on gas formation