I recently came across a study published in 2014 that found the common kitchen spice, turmeric and its prime constituent curcumin, had a surprisingly effective effect on cancer stem cells (CSCs).
Why this information was not made more public than the medical newsletter Cancer Letters is clear only when I consider that there is no “real” money to be made from a root that has been used as a spice for hundreds of years.
Nixon signed the National Cancer Act in 1971. Since then, over a hundred billion dollars of taxpayer money has been spent on research and drug development in an attempt to eradicate the disease. Trillions more are spent by the cancer patients themselves and through insurance. But after more than four decades of waging full-scale conventional (surgery and chemo) and nuclear (radiotherapy) war against cancer, one in every four Americans will be diagnosed with cancer each year.
I’ve long known about curcumin as an anti-inflammatory and use it daily for my osteoarthritis, as well as for the central nervous system inflammation that is part of myalgic encephalomyelitis, the ME part of ME/CFS. But let’s talk about cancer in this post.
CSCs Are The Mother Of Cancer
Conventional models of cancer (the mutation theory) assume that the majority of the cancer cells within a tumor possess the ability to grow and self-renew to differing degrees. The CSC model proposes that CSCs, actually a minor population of all cancer cells, are the tumor growth engine. CSCs undergo continuous self-renewal and have the ability to change into different types of cancer cells, just like other human stem cells. No other cancer cell type has this capability.
In other words, CSCs are at the top of all cells within the tumor and are the “mother” of the various daughter cells that make it up. Furthermore, most of the cells derived from CSCs are not lethal. Therefore, chemotherapy, radiation, and surgery aimed at removing these “daughter” cells are wasted. The goal is to eradicate the stem cells, not the relatively harmless cancer cells they create.
In the study, conventional treatment with chemotherapy and radiation (tested by a rodent model with a 2-year experimental window to evaluate treatment efficacy and safety) was unable to identify the CSC-mediated cause of post-treatment tumor recurrence. This recurrence, which in humans can take decades after initial treatment to manifest, is usually more invasive and resistant to conventional treatment.
Although it’s possible to reduce (debulk) a tumor with surgery, chemotherapy, and radiation, CSC populations were often missed or even enriched as a result. When the tumor regrew it often results in the rapid death of the patient. Unfortunately, most of us are only too aware of family and friends who “survived” one cancer only to succumb, years later, to metastasis of cancer cells.
Turmeric and curcumin extract have been and continue to be extensively researched for their ability to kill various cancer cell lines. The number of published studies is so abundant that it is disheartening that so many people who need safe, effective and affordable treatments are not given any information about it.
Curcumin Is Ideal Cancer Therapy
Emerging evidence suggested that the dietary agent curcumin exerted its anti-cancer activities via targeting cancer stem cells of various origins such as those of colorectal cancer, pancreatic cancer, breast cancer, brain cancer, and head and neck cancer. https://www.ncbi.nlm.nih.gov/pubmed/24851881
The study identified a number of ways in which curcumin provides an ideal CSC therapy, including:
- Regulating CSC self-renewal pathway. Curcumin appears to influence at least three self-renewal pathways within cancer stem cells, namely, Wnt/b-catenin, sonic hedgehog 89 (SHH), and Notch. The authors list 12 difference cancer cell lines which curcumin appears to positively affect.
- Modulating microRNA. These are short, non-coding RNA sequences that regulate approximately a third of the human genome. Curcumin degrades or inactivates cells by binding to messenger RNA (mRNA) within the cell. The way curcumin alters the expression of microRNAs in cancer stem cells suggests a strong suppression of tumor formation.
- Direct anti-cancer activity. Curcumin has the ability to selectively kill cancer cells versus healthy cells and works with conventional chemotherapy agents, thereby making them more effective and, in some cases, less harmful.
“Curcumin, as well as its modiﬁed forms (analogs or nanoparticle-encapsulated formulations), has shown great potential to inhibit CSCs in several types of cancer both in cell cultures and in mouse models, including glioma, breast, colorectal, pancreatic, brain, and esophageal cancers. Some analogs (e.g., CDF) and formulations (e.g., nanotechnology-based formulation) have exhibited improved efﬁcacy against CSC-like cells and greater growth-inhibitory capacity in tumors.”https://www.ncbi.nlm.nih.gov/pubmed/24851881
There are over 800 studies on turmeric/curcumin in the national published medical research database, known as PubMed. The safety and tolerability of all the available human research on curcumin in human cancer studies found no cause for concern. Curcumin, in addition to being a natural Ayurvedic remedy for thousands of years, is well tolerated and caused no signiﬁcant toxicity in clinical trials.
Unfortunately, none of the research I cited earlier identified the amount of curcumin used in cancer therapy. However, I found guidance on this site. https://integrativeoncology-essentials.com
Pharmacologically, curcumin has been found to be safe. Human clinical trials indicated no dose-limiting toxicity when administered at doses up to 10 g/day. All of these studies suggest that curcumin has enormous potential in the prevention and therapy of cancer. https://www.ncbi.nlm.nih.gov/pubmed/12680238
According to Brian D. Lawenda, MD, an integrative oncologist trained at Massachusetts General Hospital and the Helms Medical Institute at Stanford-UCLA, and founder of IntegrativeOncology-Essentials, curcumin is considered to be a safe supplement, food additive and spice (by the U.S. FDA.)
Side Effects and Interactions
That said, Dr. Lawenda noted a number of potential side effects, drug interactions, and contraindications that you should know about:
- Curcumin may cause an upset stomach. Dosages of 6g daily have been associated with minor flatulence and a yellowing of the stool. I take between 1,500 and 3,000 mg/day in two divided doses. I especially noticed this when my irritable bowel syndrome was raging on the diarrhea side. After probiotic therapy that replenished my microbiome, I no longer see this.
- There is a risk of exacerbating existing gallbladder disease. Curcumin causes smooth muscle contractions, which will make it painful if you have stones in the bile duct.
- May increase the risk of bleeding (due to platelet inhibition) when combined with other medications or botanicals like aspirin, anticoagulants (blood thinners), antiplatelet drugs, non-steroidal anti-inflammatory drugs (ibuprofen, naproxen, Motrin ®, Ale®), Gingko biloba, garlic, saw palmetto.
May cause uterine stimulation (caution is recommended during pregnancy)
- May decrease the effectiveness of cancer drugs like cyclophosphamide and camptothecin.
- People with GI disorders or predisposed to kidney stone formation should also use this supplement with caution.
How Do You Take It?
Oral curcumin is poorly absorbed from the bowel. However, the absorption can be increased when it is given with piperine (an extract from black pepper.) Simply adding piperine to curcumin has been shown to increase curcumin absorption by 2000%!
Taking curcumin with meals can increase its absorption (especially fatty/oily foods: olive oil, avocado, fish oil, milk, seeds, etc.)
Newer formulations of curcumin are available with greater absorption characteristics (i.e. complexed with piperine, nanoparticles, liposomal formulations, etc.) Watch out for curcumin supplements that do not contain the amount listed on the bottle.
Consumer Labs tested 22 products and recommends only four that met or exceeded their minimum requirements–like containing the amount listed, and not containing heavy metals or insect fragments. Two of the recommended brands are not available on Amazon, but are listed in their review (see link at the start of this paragraph). The brands they, and I, recommend are: Doctor’s Best High Absorption Curcumin and NOW Curcumin.
Curcumin is rapidly cleared from the blood (within 1-4 hours of ingestion, most of it is cleared.) To maintain blood levels of curcumin, it is best to take it in divided doses throughout the day. Dr. Andrew Weil, a well-respected integrative medicine practitioner, recommends taking curcumin derived from whole turmeric three times per day.
Unfortunately, we don’t know the optimal dosing. That said, doses from 500-3600 mg of curcumin per day have been used in recent studies.
For cancer prevention, Life Extension recommends 400-500 mg per day. During and after cancer treatment, they suggest 800-3,000 mg per day (divided dose, with meals containing some form of fat).
If you want to take turmeric instead of curcumin, here’s how to do it. One tablespoon of dried turmeric powder weighs 6.8 grams. The average amount of curcumin (by weight) in turmeric powder is 3.4%. So, 1 tablespoon of turmeric powder is equal to 6.8 grams x 3.4% = 0.231 grams or 231 milligrams. Therefore, if you want to take 500 milligrams of curcumin per day, you will need to consume approximately 2 tablespoons of dried turmeric powder.
As with any supplement, please first discuss your interest in using curcumin with your oncology team or primary care provider before you start taking it.