Who Shouldn’t Consume Curcumin or Turmeric?

Michael Greger M.D. FACLM · January 22, 2014 · Volume 16

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Just because something is natural and plant-based doesn’t mean it’s necessarily safe. Those who are pregnant, have gallstones, or are susceptible to kidney stones may want to moderate their turmeric consumption.

Discuss

Transcript

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Is Curcumin Safe?

Following flax and wheatgrass, turmeric is the third best-selling botanical dietary supplement, racking up $12 million in sales, and increasing at a rate of about 20%.

“Curcumin is…a natural plant product extracted from [turmeric] root,” used commonly as a “food additive popular for its [pleasant] mild aroma and exotic yellow color,” considered “[un]likely to cause side effects.” Just because something is natural, though, doesn’t necessarily mean it’s not toxic. Strychnine is natural; cyanide is natural. Lead, mercury, and plutonium are all elements—can’t get more natural than that. But, turmeric is just a plant. Plants can’t be dangerous. Tell that to Socrates.

“In considering the validity of the widely accepted notion that [complementary and alternative medicine] is a safer approach to therapy we must remind ourselves and our patients that a therapy that exerts a biologic[al] effect is, by definition, a drug, and can have toxicity. It cannot be assumed that diet-derived agents will be innocuous when administered as pharmaceutical formulations at doses likely to exceed those consumed in the diet…”

Safe Amounts of Turmeric

Traditional Indian diets may include as much as a teaspoon of turmeric a day, which is the equivalent of about this much fresh turmeric root. If you look at the doses of turmeric that have been used in human studies, they range from less then a 1/16th of a teaspoon a day, up to about two tablespoons a day, for over a month—whereas the curcumin trials have used up to the amount found in cups of the spice, around 100 times more than what curry lovers have been eating for centuries.

Still, without overt serious side effects in the short-term, at least. But, if you combine both high-dose curcumin with black pepper for that 2,000% bioavailability boost, that could be like consuming the equivalent of 29 cups of turmeric a day. That kind of intake could bring peak blood levels up around here, where you start seeing some significant DNA damage in vitro, at least.

So, just incorporating turmeric into our cooking may be better than taking curcumin supplements, especially during pregnancy. The only other contraindication cited in the most recent review was the potential to trigger gallbladder pain in people with gallstones.

Curcumin and Gallstones

If anything, curcumin may help protect liver function, and help prevent gallstones, by acting as a “cholecystokinetic agent”—meaning it facilitates the pumping action of the gallbladder, to keep the bile from stagnating. In this study, they gave people a small dose of curcumin, about the amount found in like a quarter-teaspoon of turmeric, and using ultrasound, were able to visualize the gallbladder squeezing down in response, with an average change in volume of about 29%.

Optimally, though, you’d want to like squeeze it in half, so they repeated the experiment with different doses. And, it took about 40 milligrams to get a 50% contraction. That’s about a third of a teaspoon of turmeric every day. On one hand, that’s great—totally doable. But, on the other hand, I’m thinking, wow, that’s some incredibly powerful stuff. What if you had a gallbladder obstruction? If you had a stone blocking your bile duct, and you eat something like that, that makes your gallbladder squeeze down hard, that could hurt like heck! So, patients with biliary tract obstruction should be careful about consuming curcumin. But, for everyone else, these results suggest that curcumin can effectively induce the gallbladder to empty, and thereby reduce the risk of gallstone formation in the first place, and ultimately, perhaps, even gallbladder cancer.

Turmeric and Kidney Stones

Too much turmeric, though, may increase the risk of kidney stones. As I mentioned in a previous video, turmeric is high in soluble oxalates, which can bind to calcium, and form insoluble calcium oxalate, which is responsible for approximately three-quarters of all kidney stones. So, “the consumption of [even] moderate amounts of turmeric would not be recommended for people with a tendency to form kidney stones.” Such folks should “restrict the consumption of total dietary oxalate to less than 40 to 50 mg/day,” which means no more than, at most, a teaspoon of turmeric. So, for example, those with gout are, by definition, it appears, at high risk for kidney stones. And so, if their doctor wanted to treat gout inflammation with high-dose turmeric, then that’s where curcumin supplements might come into play, because to reach high levels of curcumin in turmeric form would incur too much of an oxalate load.

If one is prescribed a supplement, how do you choose? The latest review recommends purchasing from Western suppliers that follow recommended Good Manufacturing Practices, which may decrease the likelihood of our buying an adulterated product.

Please consider volunteering to help out on the site.

Sources

Acknowledgements

Images thanks to Savagecats, Viosplatter, Wallyg, h-bomb and Cizauskas via flickr, and Andy king50 via Wikimedia. Thanks to Ellen Reid for her image-finding expertise, and Jeff Thomas for his Keynote help.

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Is Curcumin Safe?

Following flax and wheatgrass, turmeric is the third best-selling botanical dietary supplement, racking up $12 million in sales, and increasing at a rate of about 20%.

“Curcumin is…a natural plant product extracted from [turmeric] root,” used commonly as a “food additive popular for its [pleasant] mild aroma and exotic yellow color,” considered “[un]likely to cause side effects.” Just because something is natural, though, doesn’t necessarily mean it’s not toxic. Strychnine is natural; cyanide is natural. Lead, mercury, and plutonium are all elements—can’t get more natural than that. But, turmeric is just a plant. Plants can’t be dangerous. Tell that to Socrates.

“In considering the validity of the widely accepted notion that [complementary and alternative medicine] is a safer approach to therapy we must remind ourselves and our patients that a therapy that exerts a biologic[al] effect is, by definition, a drug, and can have toxicity. It cannot be assumed that diet-derived agents will be innocuous when administered as pharmaceutical formulations at doses likely to exceed those consumed in the diet…”

Safe Amounts of Turmeric

Traditional Indian diets may include as much as a teaspoon of turmeric a day, which is the equivalent of about this much fresh turmeric root. If you look at the doses of turmeric that have been used in human studies, they range from less then a 1/16th of a teaspoon a day, up to about two tablespoons a day, for over a month—whereas the curcumin trials have used up to the amount found in cups of the spice, around 100 times more than what curry lovers have been eating for centuries.

Still, without overt serious side effects in the short-term, at least. But, if you combine both high-dose curcumin with black pepper for that 2,000% bioavailability boost, that could be like consuming the equivalent of 29 cups of turmeric a day. That kind of intake could bring peak blood levels up around here, where you start seeing some significant DNA damage in vitro, at least.

So, just incorporating turmeric into our cooking may be better than taking curcumin supplements, especially during pregnancy. The only other contraindication cited in the most recent review was the potential to trigger gallbladder pain in people with gallstones.

Curcumin and Gallstones

If anything, curcumin may help protect liver function, and help prevent gallstones, by acting as a “cholecystokinetic agent”—meaning it facilitates the pumping action of the gallbladder, to keep the bile from stagnating. In this study, they gave people a small dose of curcumin, about the amount found in like a quarter-teaspoon of turmeric, and using ultrasound, were able to visualize the gallbladder squeezing down in response, with an average change in volume of about 29%.

Optimally, though, you’d want to like squeeze it in half, so they repeated the experiment with different doses. And, it took about 40 milligrams to get a 50% contraction. That’s about a third of a teaspoon of turmeric every day. On one hand, that’s great—totally doable. But, on the other hand, I’m thinking, wow, that’s some incredibly powerful stuff. What if you had a gallbladder obstruction? If you had a stone blocking your bile duct, and you eat something like that, that makes your gallbladder squeeze down hard, that could hurt like heck! So, patients with biliary tract obstruction should be careful about consuming curcumin. But, for everyone else, these results suggest that curcumin can effectively induce the gallbladder to empty, and thereby reduce the risk of gallstone formation in the first place, and ultimately, perhaps, even gallbladder cancer.

Turmeric and Kidney Stones

Too much turmeric, though, may increase the risk of kidney stones. As I mentioned in a previous video, turmeric is high in soluble oxalates, which can bind to calcium, and form insoluble calcium oxalate, which is responsible for approximately three-quarters of all kidney stones. So, “the consumption of [even] moderate amounts of turmeric would not be recommended for people with a tendency to form kidney stones.” Such folks should “restrict the consumption of total dietary oxalate to less than 40 to 50 mg/day,” which means no more than, at most, a teaspoon of turmeric. So, for example, those with gout are, by definition, it appears, at high risk for kidney stones. And so, if their doctor wanted to treat gout inflammation with high-dose turmeric, then that’s where curcumin supplements might come into play, because to reach high levels of curcumin in turmeric form would incur too much of an oxalate load.

If one is prescribed a supplement, how do you choose? The latest review recommends purchasing from Western suppliers that follow recommended Good Manufacturing Practices, which may decrease the likelihood of our buying an adulterated product.

Please consider volunteering to help out on the site.

Images thanks to Savagecats, Viosplatter, Wallyg, h-bomb and Cizauskas via flickr, and Andy king50 via Wikimedia. Thanks to Ellen Reid for her image-finding expertise, and Jeff Thomas for his Keynote help.

Doctor's Note

This is the last installment of a six-part video series on the power of spices in general, and turmeric in particular. I started out discussing the role spices play in squelching inflammation and free radicals in Which Spices Fight Inflammation? and Spicing Up DNA Protection. Then, out of the lab into the clinic, with attempts to test the ability of turmeric extracts to treat joint inflammation with Turmeric Curcumin & Rheumatoid Arthritis and Turmeric Curcumin & Osteoarthritis. My last video, Boosting the Bioavailability of Curcumin, discussed ways to improve the absorption of these anti-inflammatory and antioxidant compounds.

I wish there were more science on wheatgrass. I just had that one unhelpful anecdote in my video How Much Broccoli Is Too Much? There is good science on flax, though. See:

Those who are susceptible to kidney stones should try to alkalinize their urine by eating lots of dark green leafy vegetables (but then, shouldn’t we all :). See Testing Your Diet with Pee & Purple Cabbage.

Based on this new science on turmeric (lots more to come!), I now try to include it in my family’s daily diet.

For all our videos on the latest research on turmeric, visit our Turmeric topic page.

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