I’m a big fan of EGCG (epigallocatechin gallate), a green tea catechin with many applications that I’ll enumerate below. I take it myself, and I recommend it to my patients and listeners.
Is it time to issue an urgent recall notice to my patients and followers? Am I inflicting irrevocable harm on them? I’d be the first one to revise my recommendations if there were a kernel of truth to the allegations.
The potential for liver damage is the biggest knock on EGCG, so I did a deep dive on the subject. Here’s my analysis:
Consider the source. Consumer Reports has conducted a virtual jihad against supplements for years. In lurid articles, they have continually bashed supplements with blanket statements like “Dietary supplements are not regulated the same way as medications. This lack of oversight puts consumers’ health at risk.” Their “experts” are uniformly inveterate supplement critics; never does Consumer Reports offer journalistic balance by giving a fair shake to responsible supplement advocates to tell their side of the story. To stack the deck against supplements, they include absurd ingredients like pennyroyal—a long-abandoned illicit abortifacient—in their “don’t take” list. No responsible natural health professional would recommend it, and no retailer would stock it. The last time I heard it referenced was in the famous Nirvana song “Pennyroyal Tea” (B-Side: “I Hate Myself and Want to Die”).
There have been reports of liver toxicity with green tea extracts—but these are exceedingly rare. It’s unclear why some people are susceptible. Could they have underlying liver disease? Might they concurrently have been taking medications notorious for causing liver stress, like Tylenol, statins, psych drugs, even birth control pills? Were they drinking inordinate amounts of alcohol? Were the supplements they took—often weight loss products—laced with other harmful ingredients? None of the research I reviewed provides definitive answers.
Concerned over sporadic reports of toxicity, the European Food Safety Authority (EFSA) conducted an assessment. They concluded that “there was no indication of liver injury for doses below 800 mg/day from green tea supplements”. A quick check of the green tea supplement I take and recommend to my patients shows it contains 700 mg per daily dose of two capsules, under the threshold.
A review by the US Pharmacopeia found 34 reports concerning liver damage associated with green tea extract use. Twenty-seven reports pertaining to liver damage were categorized as “possible causality” and a mere seven as “probable causality.” This out of literally thousands of toxicity reports. The review committee concluded that they were “unaware of significant safety issues that would prohibit monograph development.” By way of caution they stated “consumption of green tea concentrated extracts on an empty stomach is more likely to lead to adverse effects than consumption in the fed state.”
EGCG has been shown to be safe and effective for gestational diabetes. In one study, 404 women with gestational diabetes took 500 mg of EGCG per day or a placebo from the beginning of the third trimester until full term. Blood sugar and insulin sensitivity improved, rates of low-birth weight were reduced, and even the babies’ Apgar scores were better. I don’t advise green tea supplements for pregnant ladies because I’m extremely cautious about the use of botanicals when a baby’s well-being is at risk, but this study should offer reassurance about the safety of EGCG supplementation.
A list of EGCG’s additional proven benefits include:
Chemoprevention against many cancers, including cancer of the liver
Blood pressure reduction
Prevention of heart attacks and strokes
Neuroprotection (vs. Parkinson’s, multiple sclerosis, and Alzheimer’s)
Fat loss via thermogenesis and appetite suppression
So what are we to make of Consumer Reports’ alarmist warnings about green tea supplements? I would urge patients to continue supplementing EGCG under responsible management by nutritionally-oriented healthcare practitioners, but with the following caveats:
Be attuned to unforeseen rises in liver function tests, unexplained nausea or loss of appetite, or dark urine or jaundice while taking green tea supplements. If this happens, discontinue, and retest.
Avoid weight loss supplements that contain green tea, not as a solo ingredient, but when combined with other unfamiliar or suspect botanicals.
Don’t mega-dose with EGCG unless your health professional recommends it, say, for a serious cancer condition, and then only with frequent monitoring of your liver function.
Avoid EGCG if you have an underlying liver condition—except when undertaking a supervised trial of EGCG for non-alcoholic fatty liver disease as described above.
Avoid excess alcohol, Tylenol or acetaminophen-containing products, or other drugs that have hepatic toxicity while taking EGCG.
Take EGCG with food and not on an empty stomach.
EGCG may be helpful for blood sugar control in pregnancy, but moms-to-be would do better to drink up to two cups of green tea per day in lieu of supplements. The amount of caffeine that amount of tea would deliver has not been shown to harm the developing fetus.
And, finally, don’t turn to Consumer Reports for unbiased, science-based advice about nutritional supplements. Washing machines, electric tooth brushes, vacuum cleaners…maybe.
In my 40-year history in medicine, I’ve never endorsed a weight-loss product, because most don’t deliver—until now.
The science behind Calocurb and its active ingredient, Amarasate®, is so compelling that I can support it as a plausible alternative for curbing appetite and enhancing satiety to help you shed pounds.
Calocurb works by activating your body’s own appetite-regulating chemical messengers, including GLP-1, which signal specific areas of the brain to effectively manage hunger. It’s safe and effective, with no chemicals, synthetics, or caffeine—and it doesn’t cause jitters.
For a limited time, you can get 10% off your order by using code DH10.
LEARN MORE...
Like Us On Facebook
Leave a question for Dr. Hoffman day or night.The doctor is (always) in!
Our virtual voicemail is open 24/7, so there's no need to wait to submit your questions for Dr. Hoffman. Leave a message, and you may hear your question featured on the Intelligent Medicine radio program!