Curcumin; It is a yellow-orange substance obtained from the roots of the turmeric plant. It is also the main ingredient of curry spice, which is frequently used in meals, especially in Asian countries. Curcumin, which has an important place in traditional Indian and Chinese medicine for thousands of years, has been the focus of scientific studies for several decades, especially in the field of cancer. In the laboratory studies carried out so far, some positive results have been obtained regarding the anti-inflammatory and anticancer properties of curcumin. However, since these findings have not yet been confirmed by clinical studies, the effect on humans is not clearly known. Considering its advantages in terms of side effects, cost and accessibility and the positive results obtained from laboratory studies, it would not be wrong to say that curcumin is a substance worth studying. However, due to the lack of sufficient reliable evidence from clinical studies and the potential for drug interaction, it would be the best approach to avoid its use for medical purposes for now.
What is Turmeric (Curcumin)? What is its History?
Turmeric, also known as Indian saffron, is a perennial herbaceous plant belonging to the ginger family. Although it contains more than 300 active components, a substance with yellow-orange pigment properties obtained from its roots is the main biological active component of the plant on which its medicinal properties are based. This substance, which was called curcumin about 200 years ago, is also the main ingredient of curry spice, which is often used in cooking, especially in Asian countries. It is also used as a food colorant with the code E100. Curcumin has a history of more than 2500 years in Asia, especially in traditional Indian medicine. It has been used for thousands of years in various health problems such as wound healing, acne, burns, various skin diseases, eye infections, sinusitis, rheumatism, depression, stress, indigestion. The first scientific study on the use of curcumin in the treatment of diseases was published in 1937, and then in a study published in 1949, promising results were obtained regarding its antibacterial activity.
Curcumin; It has been studied on its effects against some mediator molecules, enzymes and factors, and its antimicrobial, anti-inflammatory effects, as well as some effects of regulating the immune system, protecting the kidneys-liver, and lowering blood sugar have been shown. Demonstrating its anti-inflammatory activity in some studies and the fact that inflammation is one of the factors that play a role in cancer has led to the idea that curcumin can be used in the prevention and treatment of cancer. In 1985, Dr. Kuttan’s laboratory studies have shown that curcumin may have anticancer activity, and research has focused on this area. Recently, the focus has been on its protective effect in cancer. Curcumin; It draws the ideal protective agent profile with its features such as low risk of side effects, low cost and easy accessibility. However, the low rate of absorption from the intestines, the high potential to interact with drugs, and the inadequacy of available evidence for its effectiveness are obstacles at this point.
In many laboratory studies, some anti-cancer properties of curcumin have been determined both in treatment and prevention. In the literature, there are many laboratory studies investigating the anti-proliferative effects of curcumin on various tumor cells. In one of them; Curcumin inhibited cell proliferation in uterine cancer cell lines. In another study on mice; Curcumin significantly inhibited proliferation in prostate cancer cells. Again, in a study on mice; After some of the mice were fed curcumin, the mice were injected with a cancer-causing substance in the esophagus, resulting in significantly lower cell proliferation markers in the curcumin-fed mice.
In a study investigating curcumin’s ability to prevent the spread of cancer; It has been observed that it inhibits the spread in prostate cancer cells. In yet another study; Curcumin has shown an inhibitory effect on the spread of breast cancer.
Some studies also evaluated the effects of using curcumin in combination with chemotherapy or radiotherapy. In two studies, one published in 2013 and the other in 2014; Curcumin increased the sensitivity of the chemotherapy drug 5-Fluorouracil in colon cancer cell lines. In another study published in 2014; In head and neck cancer cell lines, another chemotherapy drug increased the effectiveness of cisplatin. There is also a study reporting that it increases the effectiveness of cisplatin in ovarian cancer cells. In another study; It has been reported to increase the sensitivity of radiotherapy in lymphatic cancer.
One of the most studied anticancer effects of curcumin is protection. In one of these studies; It has been reported that curcumin can suppress the development of oral cavity cancer. In a study on mice; It has been stated that it may have a protective effect against colon cancer by preventing the development of polyps in the intestines.
There are very few clinical studies on the effects of curcumin in the prevention or treatment of cancer. These studies, too (with the exception of a few), are in the initial stages with a small number of cases. In one of the studies with a relatively high number of cases; It has been stated that curcumin given to 126 patients with colon cancer in the pre-surgical period reduces weight loss and improves health in general. In another study conducted with 199 patients with prostate cancer who were followed up after surgical intervention; In patients given a mixture of green tea, pomegranate, broccoli, and curcumin, the rate of increase in PSA (Prostate Specific Antigen) was 63.8% lower at 6 months post-treatment.
In some initial studies; Some positive results have been obtained in reducing the side effects and symptoms associated with radiotherapy. In an initial study conducted with the participation of 50 patients with head and neck cancer who received radiotherapy; A cream containing sandalwood oil and curcumin was effective in preventing radiation dermatitis (radiation-induced skin inflammation). In another similar study conducted on 30 patients with breast cancer who received radiotherapy; Curcumin reduced the severity of radiation dermatitis and skin peeling. In a study conducted with the participation of 62 patients with cancer-related lesions in the skin, genital area, breast or mouth; Curcumin provided relief in complaints.
In a study published in 2008 with the participation of 25 patients with advanced pancreatic cancer; one patient had a stable disease for more than 18 months; In one patient, the tumor shrunk by 73%. However, no positive response was obtained in other patients. In another clinical study; Curcumin was given in combination with the chemotherapy drug gemcitabine in 17 patients with advanced pancreatic cancer, but there was no positive result, and there was an increase in the complaints of 5 patients.
What are the side effects and risks of curcumin?
The US Food and Drug Administration (FDA) has defined curcumin as “generally safe”. As a matter of fact, no serious side effects directly related to the use of curcumin have been reported in the literature. However, there is strong evidence in the literature regarding drug interactions. There are studies on its interaction with many drugs, especially chemotherapy drugs. Studies have also been reported that drugs affect the enzymes involved in the metabolism. In another laboratory study; It has been stated that curcumin may reduce the effectiveness of chemotherapy drugs.
So what should be done then?
Results from animal studies and other laboratory studies indicate that curcumin may have particularly anti-inflammatory and anticancer properties. However, studies carried out in the laboratory environment or on animals, far from human physiology; not as valuable as clinical studies. As a matter of fact, clinical studies on the medical use of curcumin are also very few, so its effects on humans are not clearly known. Therefore, it is difficult to say that there is reliable evidence for the use of curcumin in any health condition. As a matter of fact, it has not yet been approved for use for any health condition. Although there are no reported serious adverse events related to the use of curcumin and curcumin-containing products, there are data on drug interactions, especially chemotherapy drugs. At this point, it is useful to avoid the use of this product for medical purposes for the time being.
