The Downside of Curcumin Supplements

Supplement manufacturers often fall into the same reductionist trap as the drug companies. Herbs are assumed to have only one main active ingredient, so, as the thinking goes, if you can isolate and purify it into a pill, you can boost its effects. Curcumin is described as the active ingredient in turmeric, but is it the active ingredient or just an active ingredient? It is just one of many different components—more than 300, in fact—of the whole food spice.

“Only limited studies have compared the potential of turmeric with curcumin.” Some, however, suggest turmeric, the whole food, may work even better—and not just against colon cancer cells. As I discuss in my video Turmeric or Curcumin: Plants vs. Pills, researchers at the Anderson Cancer Center in Texas pitted both curcumin and turmeric against seven different types of human cancer cells in vitro.

The study found that curcumin kicks tush against breast cancer cells, but turmeric, the whole food, kicks even more. In addition to breast cancer, the researchers found that turmeric was more potent compared to curcumin against pancreatic cancer, colon cancer, multiple myeloma, myelogenous leukemia, and colorectal cancer cells, “suggesting that components other than curcumin can also contribute to anti-cancer activities.”

Most clinical studies treating diseases in people have used curcumin supplements, as opposed to turmeric, but none has tried using turmeric components other than curcumin, even though curcumin-free turmeric exhibits anti-inflammatory and anticancer activities.

“Although curcumin is believed to account for most activities of turmeric, research over the past decade has indicated that curcumin-free turmeric”—that is, turmeric with the so-called active ingredient removed—“is as effective as or even more effective than curcumin-containing turmeric.” There are turmerones, for example, in turmeric, which may exhibit both anticancer activities, as well as anti-inflammatory activities, but these turmerones are processed out of curcumin supplements. So, I assumed this review would conclude by stating we should stop giving people curcumin supplements and instead just give them the whole food spice turmeric, but instead the researchers proposed that we make all sorts of different turmeric-derived supplements!


That’s quite a rebut to reductionism. For more on this flawed nutritional philosophy, see my video Reductionism and the Deficiency Mentality.

Similar videos in this vein include:

Interested in learning more about turmeric and cancer? See:

And for more on turmeric and everything else:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

The Best Food for Acne

We hear a lot about traditional Chinese herbal medicine, but less about the herbs used in Japan. There is a root called Rhizoma coptidis that appears to have similar anti-acne activities to drugs like Accutane, a drug infamous for its side effects that has been since pulled from the market. But there are side effects to the root, too. A poor fellow took it to clear up his skin and as you can see in my video, let’s just say it made things  worse.

The anti-acne active component of the root is thought to be berberine. Is there any way to get the active ingredient in a safer plant? Yes, apparently: barberries, which I cover in my video Treating Acne with Barberries. You may remember barberries as being perhaps the most antioxidant-packed dried fruit available (see my video Better Than Goji Berries). You can find them cheap at Middle Eastern grocers, since they’re used to make a signature Persian rice dish. Their taste is described as “pleasantly acidulous,” which is just doctor-speak for sour. I love sprinkling them on my oatmeal just because I love their taste, but, evidently, they have played a prominent role in herbal healing for thousands of years around the world. They have been described rather flamboyantly in a pharmacology journal as an “herbal remedy [that] has no match in serving the human race.” And I just thought they were kind of tangy.

The problem with the herbal medicine literature is that there is often a long, impressive list of traditional uses, but little or no science to back them up. And what does exist is often either test tube or animal data that has questionable clinical applicability. Who cares, for example, if barberries “induce menstruation in a guinea pig” (except maybe the guinea pig)? So, you end up with drug companies injecting herbs into the penises of rabbits in hopes of coming up with the next Viagra, but they conduct few, if any, human studies.

I’ve seen petri dish studies over the years suggesting anti-cancer effects of barberries on human tumor cells in a petri dish or having anti-acne effects on hamsters, but there weren’t any such human studies… until, now.

Evidently, there had been anecdotal reports of acne clearing up after barberry juice consumption, so researchers decided to put it to the test in a double-blind, randomized, placebo-controlled clinical trial of fifty 12- to 17-year-olds with moderate to severe acne. Half got a sugar pill, and the other half got the equivalent of about a teaspoon of dried barberries three times a day for a month.

The results were remarkable. After four weeks on the placebo, as expected there was no change. The teens had just as many pimples as before. But in the barberry group, there was a 43 percent drop in the number of zits and about a 45 percent drop in the number of inflamed zits. That’s extraordinary. A spoonful of dried barberries costs about eight cents. Barberries have no reported side effects, and they are healthy for you anyway. The only potential concerns I could find were about eating them during pregnancy, and we don’t have good data on barberry consumption during lactation, so it’s best to stay away from barberries during breastfeeding as well until we know more.


For more on acne check out these older videos:

And a few new ones I just released this year:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

A Dietary Treatment for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic, episodic intestinal disorder characterized by abdominal pain and altered bowel habits. It affects 1 in 7 Americans, although most go undiagnosed. IBS can have a substantial impact on well-being and health, but doctors underestimate the impact the disease can have, particularly the pain and discomfort. Using some measures, the health-related quality of life of irritable bowel sufferers can rival that of sufferers of much more serious disorders, such as diabetes, kidney failure, and inflammatory bowel diseases. The first step toward successful treatment is for doctors to acknowledge the condition and not just dismiss the patient as just hysterical or something.

Another reason sufferers often don’t seek medical care may be the lack of effectiveness of the available treatments. There is a huge unmet therapeutic need. Since IBS has no cure, treatment is targeted to alleviate the symptoms. Typical antispasmodic drugs can cause side effects, including dry mouth, dizziness, blurred vision, confusion, and fall risk. New drugs now on the market, like Lubiprostone and Linaclotide, can cost up to $3,000 a year and can cause as side effects many of symptoms we’re trying to treat.

Antidepressants are commonly given but may take weeks or even months to start helping. Prozac or Celexa take 4 to 6 weeks to help, and Paxil can take up to 12 weeks. They also have their own array of side effects, including sexual dysfunction in over 70% of the people who take these drugs.

There’s got to be a better way.

Acupuncture works, but not better than placebo. Placebo acupuncture? That’s where you poke people with a fake needle away from any known acupuncture points. Yet that worked just as well as real acupuncture, showing the power of the placebo effect.

I’ve talked about the ethics of so many doctors who effectively pass off sugar pills as effective drugs, arguing that the ends justify their means. There’s actually a way to harness the placebo effect without lying to patients, though. We tell them it’s a sugar pill. Patients with irritable bowel syndrome were randomized to either get nothing or a prescription medicine bottle of placebo pills with a label clearly marked “placebo pills” “take 2 pills twice daily.” I kid you not.

Lo and behold, it worked! That’s how powerful the placebo effect can be for irritable bowel. They conclude that for some disorders it may be appropriate for clinicians to recommend that patients try an inexpensive and safe placebo. Indeed, sugar pills probably won’t cost $3,000 a year. But is there a safe alternative that actually works?

As you can see in my video, Peppermint Oil for Irritable Bowel Syndrome, nine randomized placebo-controlled studies have indeed found peppermint oil to be a safe and effective treatment for irritable bowel syndrome. A few adverse events were reported, but were mild and transient in nature, such as a peppermint taste, peppermint smell, and a cooling sensation around one’s bottom on the way out. In contrast, in some of the head-to-head peppermint versus drug studies, some of the drug side effects were so unbearable that patients had to drop out of the study. This suggests it might be a reasonable approach for clinicians to treat IBS patients with peppermint oil as a first-line therapy, before trying anything else.

The longest trial only lasted 12 weeks, so we don’t yet know about long-term efficacy. The benefits may last at least a month after stopping, though, perhaps due to lasting changes in our gut flora.

The studies used peppermint oil capsules so researchers could match them with placebo pills. What about peppermint tea? It’s never been tested, but one might assume it wouldn’t be concentrated enough. However, a quarter cup of fresh peppermint leaves has as much peppermint oil as some of the capsule doses used in the studies. One could easily blend it into a smoothie or with frozen berries to make something like my pink juice recipe. You can grow mint right on your window sill.

We doctors need effective treatments that “are cheap, safe, and readily available. This is particularly relevant at the present time as newer and more expensive drugs have either failed to show efficacy or been withdrawn from the market owing to concerns about serious adverse events.” Just like it may be a good idea to only eat foods with ingredients you can pronounce, it may be better to try some mint before novel pharmacological approaches, such the new dual mu-opioid agonist delta-antagonist drug with a name like JNJ-27018966.

I have some other mint videos: Enhancing Athletic Performance With Peppermint and Peppermint Aromatherapy for Nausea. Lemon balm is also in the mint family, so check out Reducing Radiation Damage With Ginger & Lemon Balm and Best Aromatherapy Herb for Alzheimer’s.

You can also sprinkle dried mint on various dishes. See Antioxidants in a Pinch.

What else might work for IBS? See Kiwifruit for Irritable Bowel Syndrome and Cayenne Pepper for Irritable Bowel Syndrome and Chronic Indigestion.

Irritable bowel symptoms can overlap with problems with gluten, so make sure your physician rules out celiac disease. These may be helpful:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: