As a graduate student working towards my Ph.D. in Molecular Biology at an esteemed U.S. university, the last thing I expected to hear touted for its beneficial effects on cancer and many other diseases was turmeric. I had grown up in India where the spice turmeric was regarded, somewhat over-zealously in my opinion at the time, as the ultimate panacea for all ailments. Sore throat? Turmeric boiled in milk was what the doctor ordered. Digestive upset? A turmeric-infused rice and lentil porridge was a must, and so on and so forth. Old wives tales, I had smugly thought. It can't be true that a single spice cures everything! You can imagine my amusement and surprise then when scientists and doctors around the world were suddenly focused on curcumin, a bioactive component of turmeric, for its miraculous medicinal properties.
MEET THE GOLDEN SPICE
Turmeric is the underground stem (or rhizome) of the plant Curcuma longa of the ginger family. Fresh turmeric rhizomes look like ginger with a hint of orange on the skin. Upon slicing, it becomes apparent why turmeric is called the Golden Spice or Indian Saffron! A fiery, almost fluorescent orange flesh greeting the eye, fresh turmeric has an earthy, peppery and vibrant aroma and flavour. Most turmeric, however, is consumed in powdered form, in which it has a slightly bitter and mustard-like fragrance.
SCIENCE BASED HEALTH BENEFITS OF TURMERIC
A query for turmeric on Pubmed, a search engine for all biomedical research articles, yields 3000+ results over the last 70 years. Modern science is frantically seeking to understand why this miracle spice has dominated the traditional medicine cabinet for centuries and here is what it has discovered.
Turmeric Blocks Inflammation
Curcumin, the bioactive compound in turmeric, blocks a molecule, NF-kappaB, which is the master conductor in the orchestra of inflammation (1). This important player acts as a transcription factor, in that it binds to DNA and activates the expression of many genes that encourage inflammation, like cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) (2). (Interestingly, COX-2 is also the target of ibuprofen, a widely used over the counter anti-inflammatory medication!). Via the inhibition of NF-kappaB and cellular signalling molecules like Protein Kinase C (3), curcumin blocks the cascade of inflammation. You may be wondering why this is a bad thing - isn't inflammation part of our natural defence system? A good thing after all?Here's the catch. While some inflammation is a critical part of our body’s ability to fight infections and heal itself, unchecked, chronic inflammation is like damaging wildfire and the basis of many chronic diseases including cancer, heart disease, diabetes, arthritis Alzheimer’s, Parkinson’s and even depression (4). Curcumin’s suppression of inflammation, therefore, is very likely the basis of its beneficial effects on various ailments.
Turmeric Fights Cancer
The most vigorously studied benefit of turmeric and specifically, curcumin, is in cancer. With much of the evidence limited to animal studies, a few human trials are underway. The ability of curcumin to thwart cancer has been linked to its inhibition of NF-kappaB (discussed above) (5). Research has shown that curcumin can slow cancers of various organs including the lung, breast, skin and colon (6). Given its poor absorption (7) into the blood stream, it may be more promising for cancers of the esophagus and gut where it can exert its benefits without having to be absorbed. It's also important to keep in mind the limitations of dietary curcumin as a therapeutic given the high doses required* (8). Experts advocate its dietary use more for prevention rather than the treatment of cancer, reason enough to embrace it in our kitchens.
Turmeric Improves Brain Health
Curcumin in turmeric enhances the synthesis of a very important omega-3 fatty acid called docosahexaenoic acid (DHA) in the body (8). DHA is pivotal for brain health and low levels are associated with cognitive defects, anxiety and depression. DHA is either obtained through the diet, with fish oil being the best source, or can be synthesised, albeit inefficiently, from a precursor molecule called alpha-linolenic acid, found in vegetarian sources like flax seeds and walnuts. Researchers found that curcumin exposure increased DHA production in the brain and reduced anxiety levels in animals. The authors therefore conclude that vegetarian or diets low in fish may benefit from more turmeric to increase DHA production in the brain. It’s best to combine turmeric with black pepper to improve its bioavailability, as explained below* (9).
Turmeric Heals The Gut
Curcumin in turmeric increases the levels of a protein in the gut called Intestinal Alkaline Phosphatase (or IAP) that forms tight junctions between the cells lining the digestive tract, keeping them strong and intact and preventing a leaky gut** (10). Curcumin also promotes bile secretion by the gall bladder to aid digestion (11) and has prevented gas and bloating in a small human trial (12)
Turmeric Reduces PTSD And Anxiety
Post traumatic stress disorder (PTSD), characterised by the activation of fear-based memories, affects about 8% of the US population, yet treatment options are limited. In one study using a well established model for PTSD in rats, a diet enriched in curcumin impaired the consolidation and activation of fear memories and affected the expression of genes involved in PTSD (13) leading the researchers to suggest its use in combination with other therapies for PTSD and anxiety disorders.
Turmeric Fights Depression, Parkinson's And Alzheimer's Disease
Several studies in animals have reported anti-depressant, anti-Alzheimer's and anti-Parkinson's effects of curcumin (14). These benefits are most likely linked to the anti-inflammatory properties of curcumin as there is a strong link between high levels of inflammation and various neurological diseases (15). More recently, small studies in humans have also shown promising results for curcumin for depression. In a study on 56 individuals with major depressive disorder who were treated with a placebo or curcumin for 8 weeks, the curcumin-treated group saw a significant reduction in several mood-related symptoms (16). Larger trials are necessary but these studies suggest a potential role for curcumin, either alone or in combination with existing medications, for depression. Limitations include the poor bioavailability of curcumin which can be enhanced with new formulations or the addition of piperine from black pepper.*
Here's to more of the Golden Spice in our family's food, for the sake of our health and taste-buds!
*Limitations of curcumin as a therapeutic agent are as follows:
- Curcumin, has very poor 'bioavailability'. It is rapidly cleared from the stomach and the liver after consumption, before it has a chance to get into the bloodstream to exert its effects on the body.
- The bioavailability of curcumin is improved by black pepper. The addition of piperine, the active compound in pepper, improves the ability of curcumin to get into the bloodstream and other organs of the body. If one wants to benefit from turmeric in food, it's wise to combine it with black pepper, as is often done in Indian and Thai curries.
- In most studies, purified curcumin is administered at very large doses to see beneficial therapeutic effects on disease. The New York University Medical School estimates that 1200 - 1800 mg of curcumin a day are required to see therapeutics effects. An average Indian (who consumes a lot more turmeric than anywhere else in the world) ingests about 120 mg of curcumin a day. If you have an actual disease you want to treat with curcumin, you will need to consider supplements to achieve high enough amounts (after consulting with your physician). The good news is that curcumin is well tolerated at very high doses with minimal side effects, except for people with gallstones who should be careful when using curcumin or turmeric in large quantities.
**Leaky Gut
A healthy digestive tract has an intact lining of tightly-knit cells that prevent food and toxins from entering the blood stream. When this gut lining becomes leaky (literally, rife with holes), which can happen for a plethora of reasons, mostly related to diet and lifestyle, the foods, chemicals and toxins we ingest can enter the bloodstream right away and are perceived as threats by our immune system. This, in turn, leads to increased inflammation which has been shown, over and over again, to be the basis of many chronic diseases, including eczema, psoriasis, asthma, Alzheimers, depression and even diabetes.
Kanchan Koya, Ph.D. combines her Doctorate in Molecular Biology from Harvard Medical School and her training from the Institute of Integrative Nutrition to elevate our health with science and flavour. She is a Certified Health Coach and Founder of Spice Spice Baby, which brings to light the science-based benefits of spices and inspires their use in babies’, kids’ and families’ foods in simple and delicious ways. For recipes, science of spices, nutrition tips and inspiration for your family’s health, visit Spice Spice Baby