As astonishingly useful as curcumin is in treating cancer, it has its detractors – and some concerns about the curcumin have factual foundation. Here’s a list of common concerns about curcumin supplements from doctors, researchers, and well-informed cancer patients, with what the evidence says.
Curcumin undergoes extensive metabolic degradation in the intestines and in the liver. It’s not possible to achieve a clinically meaningful dosage in the bloodstream.
The fact that many clinical trials find significant effect suggests that the amount of curcumin the body needs is very, very small, in the range of nanograms per milliliter. However, it is correct that most formulations of curcumin are significantly degraded in the intestines and in the liver. Curcumin is poorly soluble in water, so simply putting curcumin in a capsule is not enough to ensure that it can pass from the contents of the small intestine into the bloodstream. Once curcumin has entered the body, its first stop is the liver, where most curcumin products are transformed by liver enzymes through a process called tagging from free curcumin into a curcumin-sugar combination know as curcumin glucuronide. “Tagged” curcumin is not as effective in the tissues where it is absorbed, and it is also more easily removed from the bloodstream by the kidneys.
There are several ways to get around these problems. The Sabinsa Company took a cue from Ayurvedic medicine, which traditionally combines turmeric (the source of curcumin) with black pepper (the source of piperine). Their Sabinsa C3 product escapes the tagging process so that more curcumin remains in its useful free form.
The makers of Merida figured out a way a product that stays more soluble in the small intestines so more is absorbed. And the makers of Longvida, also taking a cue from Ayurvedic medicine, figured out a way to combine curcumin with a fatty acid so that it is both more completely absorbed into the bloodstream and far less affected by liver enzymes.
You will get the best results with products made with Sabinsa C3, Merida, or Longvida curcumin. Other forms of curcumin are also beneficial, but you generally have to take more to get the same effect.
Not everyone who takes curcumin for cancer gets better.
This assertion is true. When you are in Stage IV of the disease, and you and your doctors have tried everything for your disease, it is a lot harder to get a good result from anything you do. Even if you have not yet reached late-stage cancer, curcumin is something you take in addition to your doctor-prescribed treatments so that you get a better result, not something you take so you can skip chemotherapy or radiation or surgery that your doctor believes is necessary. On the other hand, people who go out of remission but continue to take curcumin seem to have an easier time getting into remission yet again if they take all the measures they can to fight the disease.
Curcumin products interfere with the liver’s ability to detoxify cancer drugs.
In the case of products that combine curcumin from turmeric and piperine from black pepper, it’s the piperine, not the curcumin, that may pose a problem with certain medications. This black pepper compound interferes with the action of the liver enzyme CYP3A4, which processes paclitaxel, docetaxel, tamoxifen (Taxol), cyclophosphamide (Cytoxan), doxorubicin, irinotecan, and about 20 more common chemotherapy drugs. It is not a good idea to use any product that combines curcumin and piperine while you are on almost any kind of chemotherapy. It can slow down the liver’s detoxifying enzymes and increase side effects of the drugs. Noni juice and pomegranate juice also interfere with CYP3A4 and also should not be used during chemotherapy (if you have had chemo in the last week or you are scheduled to get chemotherapy in the next week).
However, curcumin itself also interferes with the detoxification process of some of other drugs. It interferes with the action of the CYP2C19 enzyme, which detoxifies cyclophosphamide (Cytoxan) and teniposide, as well as many antidepressants, Plavix (clopidogrel), proton pump inhibitors for acid reflux disease, and the anti-hormone drug nilutamide (Nilandron), used to treat prostate cancer. It interferes with the CYP2B6 enzyme, which processes cyclophosphamide (Cytoxan), ifosfamide (Ifex), and tamoxifen (Taxol), increasing their side effects, but it also increases that rate at which this enzyme breaks down ThioTEPA, making it less effective. The bottom line is, don’t take curcumin products the same weeks you take any kind of chemotherapy, and let your doctor and your pharmacist know you are using curcumin no matter what medication you take.
In doing my research for my book Minimal Medication, I had a series of blood tests both before and after taking CurcuBrain for 90 days. One reading stood out. Before I started taking CurcuBrain, I had unusually high iron levels. After I took the product for 3 months, I had borderline-low iron levels. Some other blood tests indicated that my body had responded to the product by making more of a protein called ferritin, which "neutralizes" iron so it cannot generate free radicals. That is beneficial for brain health, but it could be a problem if you have anemia. If you choose to take curcumin and you know you have low iron levels, make sure to have a blood test every 3 to 4 months to make sure your iron levels don't get lower. This is something you should be doing anyway, but it will help you and your doctor to be double-sure you aren't experiencing any side effects from curcumin.
Are There any Drug Interactions with Curcumin?
Curcumin changes the way the body detoxifies many chemotherapy agents. While curcumin many increase their effectiveness, it may also increase the side effects. (Curcumin reduces the impact of ThioTEPA. ) Generally speaking, if you take any prescription medication, you should let your doctor and your pharmacist know when you start taking curcumin.
Are There Any Side Effects from Curcumin?
High-dose curcumin (more than 1,000 mg a day) can cause mild stomach upset in a few people. In people who already have Alzheimer’s, there can be brief increased memory loss as it begins to work. The effect usually wears off in a week.
Are There Any Ways to Increase the Absorption of Curcumin?
The problem with curcumin is that it is hard for the digestive tract to absorb it. If you take curcumin in a pill form with cold water, less than 1 percent of the curcumin in the pill (about 0. 2 percent, to be precise) ever reaches the organs of your body.
Drinking a warm beverage or eating a hot meal before taking your curcumin might raise the percentage of curcumin in the supplement that finds its way out of your digestive tract to about 5 percent. However, if you aren’t going to consume hot food or beverages, then it is best to take your curcumin with a small glass (at least 4 ounces/120 ml) of cherry juice. When the juice reaches your small intestine, it raises pH and makes the curcumin more acceptable.
And if you take curcumin phytosome or liposome, the amount of curcumin your body absorbs is even higher, although not a whole lot It’s best to use products that are specifically formulated to be absorbable, such as those that contain C3 from Sabinsa or Longvida from Douglas Labs. Once the curcumin gets into your bloodstream, however, it still has to get inside cells. That's where beneficial drug interactions make a huge difference.
If you happen also to take aspirin, even a small dose such as the 81 mg baby aspirin, or any dose of ibuprofen, the cells in your body absorb curcumin at least 10 times faster than if you don't. (Acetaminophen, better known as Tylenol does not have the same effect. ) The synergistic effect of curcumin and aspirin or curcumin and ibuprofen is especially beneficial to colon cells.
Don't take more than the 81 mg dose of aspirin in a baby aspirin every day without consulting your physician, and, of course, don't take aspirin at all if you are allergic to it or your doctor has told you not to take aspirin. You don't need more 81 mg per day to get the fullest benefits of curcumin, and if you can't take aspirin or Ibuprofen, you can always just take more curcumin. Taking more aspirin is also OK.
Potential (Theoretical) Interactions with Prescription Drugs
What about prescription drugs? The simple fact is that, at the time of the writing of this book, there are no documented cases of interactions between curcumin and any prescription drugs.
A clinical study conducted in China, however, found that curcumin acts on the way the liver uses enzymes to accelerate the breakdown of caffeine, implying that taking curcumin results in taking the “buzz” off your morning cup of coffee faster. Curcumin also affects the way the liver uses two detoxifying enzymes called CYP1A2 and CYP2A6. It inhibits the action of the first enzyme but enhances the action of the second.
This basically means that curcumin potentially interacts with the same prescription drugs as grapefruit juice (and also black mulberry juice, star fruit, and pomegranate juice). There are no reports of problems from taking prescription drugs and curcumin in the medical literature, but just to be on the safe side, if your doctor tells you not to drink grapefruit juice with your medication, you should not take curcumin, either.