Aug
12
2017

Curcumin And Cancer

Many clinicians give their attention to curcumin and cancer. It may not be used as a primary treatment, but may be added as an adjunct to other cancer treatments. Curcumin is the effective ingredient of the old Indian spice, turmeric. The question is how effective curcumin is against cancer? Is it safe to use? What is the evidence?

Frequency of cancer

According to the American Cancer Society there will be 1,688,780 new cancer cases diagnosed in 2017 and 600,920 cancer deaths will occur in the US.

Causes of cancer

Cancer can be caused in many different ways. Hidden in the many causes may be the possible solution to new cures.

  1. A lack of exercise may contribute to the development of cancer because of a lack of tissue circulation. And exercise will help to support your normal cell metabolism (explained below). Wrong foods may or may not have a contributory role regarding cancer development (a high sugar and starch diet causing insulin response, which changes the metabolism). The Mediterranean diet is an anti-inflammatory diet and has been credited to prevent a lot of cancers.
  2. Cancer can be caused by chemicals, called carcinogens. But it can also be caused by oncoviruses. It can be genetically caused, that’s why it tends to run more often in certain cancer prone families. But Warburg has researched the metabolism of cancer almost 100 years ago, even got the Nobel price for it in 1931 and yet the elusive cancer cure has not materialized yet. Otto Heinrich Warburg
  3. Following Warburg’s research Watson/Crick detected DNA in our cells. Ever since geneticists were fascinated by it. They also found that a cancer suppressive gene, regulated by the p53 gene could develop mutations and then cancer would occur: Tumor Suppressor Genes For decades this was the “in” thing. But in the last 5 to 10 years there is a revitalization of the original Warburg idea that one should concentrate on the metabolic differences between cancer cells and normal cells. This is starting to show some timid results.
  4. Cancer cells are more acidic from lactic acid and burn glucose for energy without requiring oxygen (anaerobic pathway), while normal cells burn glucose in the aerobic pathway in the mitochondria. This difference is important. Cancer cells were found to be more vulnerable to be killed by certain manipulations.
  5. Take cryoablation therapy for prostate cancer. Cryosurgery for prostate cancer. The more vulnerable cancer cells are preferentially killed over the normal cells through a local deep freeze method. Another example is phototherapy treatment of cancer that has been used for lung cancer and esophageal cancer. https://www.sciencedaily.com/rel… This method may be a lot more universally applicable than believed so far. A photosensitized dye is injected and later when normal cells have eliminated the dye, but the defective cancer cells are still containing the dye a laser beam is used to kills the cancer cells preferentially, absorbing the specific laser wavelength that is specific for the dye.
  6. Nobody knows which way cancer research is going. But I think it will be consumer driven: consumers want better cures, and when new methods appear that have better cure rates, these will be pushed forward while less effective methods will become history. I think that Warburg will be revitalized and new therapies will continue to be developed from this as I indicated.

Curcumin and cancer: malignant conversion

There are three development stages for any cancer to develop.

This was originally researched with skin cancer, but also confirmed with cervical cancer. It is called the “malignant conversion” that needs to take place before a normal cell has become a cancer cell. There are three stages.

  • Initiation
  • Promotion
  • Progression

This is important to know in the context of curcumin. Basic research has shown that curcumin interferes with all of these stages of tumor development, both in terms of prevention as well as in terms of being curative. Here is a link that points out the complex multiple steps of cancer growth that curcumin interferes with.

As can be seen from it, curcumin interferes with the initiation of multiple cancers, reduces inflammation, and interferes with angiogenesis and this reduces the amount of metastases that can form. But curcumin further interferes with proliferation of cancer cells, reduces invasion, prevents resistance and improves survival. The underlying molecular and genetic reasons for curcumin’s actions are all contained in that link.

Curcumin and cancer: research in tissue culture and animal experiments

When it comes to cancer research, you usually hear about in vitro culture experiments and animal experiments. This type of research is used to establish that there is an anti-cancer effect, that it is reproducible and non-toxic. The September issue of the 2016 Life Extension Magazine reviewed this in detail. It was entitled “How Curcumin Targets Cancer”.

But as a former clinician I am more interested in seeing cancer patients cured. This has to be verified by clinical trials first. When I looked through PubMed.com for objective evidence of the effects of curcumin in cancer patients, this type of information was more difficult to find. But in the following there are a number of examples that I did find.

Curcumin and cancer: clinical trials

1. Reduction of tumor necrosis factor-alpha

A 2016 meta-analysis of eight randomized studies investigated the effect of curcumin in patients with various inflammatory diseases including cancer. They found that curcumin consistently reduced tumor necrosis factor-alpha. In cancer patients this inflammatory substance is responsible for further cancer growth and developments of metastases.

2. Poor bioavailability of curcumin

A study with increasing amounts of curcumin showed poor absorption of curcumin into the blood. In this study dosages between 500 mg up to 12,000 mg per day of curcumin were given. 500 mg to 8000 mg of curcumin did not result in any positive serum level of curcumin. Only the higher dosages, 10,000 and 12,000 mg of curcumin were associated with positive curcumin levels in the blood serum. In order to have effects of curcumin, higher amounts have to be taken. Higher amounts of curcumin have been tested for toxicity and were found to be safe and were fairly well tolerated.

3. Precancerous colonic polyps reduced in number and size

A smaller study consisted of 5 subjects with familial adenomatous polyposis (FAP). This is an autosomal-dominant disorder where hundreds of colorectal adenomas develop in the lining of the colon. From these colorectal cancer can arise. Five patients received 480 mg of curcumin and 20 mg quercetin orally three times per day. After 6 months the number of polyps and the size had reduced by 60.4%.

4. Premalignant colonic lesions suppressed by curcumin

44 eligible smoker subjects received a baseline colonoscopy where aberrant crypt foci (ACF) were determined. ACI are the very first focal areas in the colon from which colon cancer develops. Smokers are known to have more of these lesions, which was the reason that smoker subjects were used for this trial. The patients received either a supplement of 2000 mg of curcumin or 4000 mg of curcumin for 30 days. These are fairly high doses, but they were used to overcome the poor absorption of curcumin. Colonoscopies were done again after one month of curcumin supplementation. 41 subjects completed the study. In the 4000 mg curcumin group the ACF numbers were reduced significantly by 40% compared to the 2000 mg group, which showed no reduction. The 4000 mg group showed a 5-fold increase of curcumin blood levels compared to baseline. There was no change in blood levels in the 2000 mg group.

5. Reduction of radiation dermatitis with radiation therapy in breast cancer patients

30 breast cancer patients were divided into an experimental group and a placebo group. All of them had a mastectomy first, which was followed by radiation therapy. The experimental group received 6 grams (2 grams three times per day) of curcumin during the time of radiotherapy following mastectomy. The severity of radiation dermatitis following radiotherapy was significantly reduced in the experimental group when compared to the placebo group. Only 28.6% had significant radiation dermatitis in the curcumin group versus 87.5% in the placebo group.

6. Chronic multiple myeloma patients

An Australian study involving chronic multiple myeloma patients found that curcumin at 4 Grams per day and even more so at 8 Grams per day stabilized the disease and improved kidney function.

7. Descriptive studies

Descriptive studies investigating the effect of various doses of curcumin have been done regarding breast cancer,  and advanced pancreatic cancer. But these clinical trials were all rather small.

8. Chemoprevention of cancer

A phase II trial enrolled 21 patients with end-stage pancreatic cancer patients. The only FDA approved treatments for this are gemcitabine and erlotinib, but this would normally only lead to clinical responses in less than10% of patients. In this study the investigators used curcumin to enhance the anti-tumor response of either gemcitabine or erlotinib. The study summary stated: “Oral curcumin is well tolerated and, despite its limited absorption, has biological activity in some patients with pancreatic cancer.” 2 of the 21 patients had stable disease for more than 18 months; one of the 21 patients had a brief tumor regression of 78%, but then relapsed and died.

9. Chemoprevention of cancer

Chemoprevention of cancer is discussed in this publication: There was specific reference made to prevention of prostate cancer and the opinion of the researchers was: “At present, there is no convincing clinical proof or evidence that the cited phytochemicals might be used in an attempt to cure cancer of the prostate.”

Curcumin And Cancer

Curcumin And Cancer

Conclusion

For years there have been reports to indicate that curcumin was a promising natural supplement that can improve cancer survival. There are poorly founded reports of effects of curcumin on colorectal cancer, pancreas cancer, prostate cancer, breast cancer, ovarian cancer and others. But on closer look the hype seems to come mostly from in vitro studies (tissue culture experiments) or from animal studies. Clinicians, however, demand well-constructed randomized clinical trials with clear research objectives before they can accept a new agent like curcumin to be effective. These clinical trials are missing! Instead there are many in-between trials of questionable quality as listed above.

There have been problems of bioavailability due to poor absorption of curcumin. To a certain extent this could be overcome by pushing the dosage to 6000 to 8000 mg per day. But a significant percentage of people (around 30%) suffered from abdominal cramps and nausea and had to discontinue these high doses of curcumin. Newer curcumin compounds have been developed, but at this point it is not known what the bioequivalent dosage is of these newer curcumin agents in comparison to the original curcumin dosages.

It is quite possible that new trials will one day be performed that may bring better news on survival rates of various cancer patients involving curcumin therapy. But in my opinion right now it is not yet prime time for curcumin!

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About Ray Schilling

Dr. Ray Schilling born in Tübingen, Germany and Graduated from Eberhard-Karls-University Medical School, Tuebingen in 1971. Once Post-doctoral cancer research position holder at the Ontario Cancer Institute in Toronto, is now a member of the American Academy of Anti-Aging Medicine (A4M).