The health benefits of Turmeric

In this Article (Index)

Learn about the risks and benefits of this ancient Asian spice.

• What is Turmeric?
• Natural chemicals in turmeric
• Curcumin
• Turmeric oil
• Tumerin
• Turmeric in Traditional Medicine
• Arthritis
• Treatment and Prevention of Cancer
• Gut microbiome, curcumin, and intestinal permeability: Leaky gut
• Leaky Gut
• Irritable Bowel Syndrome
• Candida infections
• Ringworm
• Atherosclerosis and improved cholesterol
• Type 2 Diabetes
• Psoriasis
• Turmeric and its bioavailability
• Safety and dosage
• Turmeric Tea Recipe
• The Downside of Turmeric and Curcumin
• Turmeric conclusions

Turmeric

What is it?

Turmeric (Curcuma longa) is a plant related to ginger, native to Southeast Asia and the Indian subcontinent.

Its roots, known as rhizomes, have been used as a spice for cooking (it is the main component of curry powder) and in traditional medicine for millennia.

You will distinguish its slightly bitter yet sweet earthy flavor, with a soft pepper-like tang.

These rhizomes are either consumed fresh or as a powder -after being boiled, dried in ovens, and ground. They have a characteristic deep orange-yellow color.

This yellow color comes from its principal active ingredients, curcuminoids that are used to dye cloth, color food, and tint natural cosmetics.

Nowadays, it is also sold as a supplement in the form of tablets, extracts, teas, and capsules. It is also used as an antioxidant and to promote weight loss (1).

The natural chemicals found in Turmeric

Turmeric powder, as found in stores, is composed of (2):

• 60 - 70% carbohydrates
• 6 - 14% water
• 6 - 8% protein
• 5 - 10% fat
• 3 - 7% essential oils
• 3 - 7% minerals
• 2 - 7% dietary fiber
• 1 - 6% curcuminoids < These are the active ingredients

Volatile oils include d-α-phellandrene, d-sabinene, cineol, borneol, zingiberene, and sesquiterpenes. Turmeric's aroma is due to the presence of oils such as turmerone, arturmerone, and zingiberene.

Regarding minerals, 100 g of turmeric contains 0.26 g phosphorous, 10 mg sodium, 2500 mg potassium, and 47.5 mg iron.

It also has Vitamins: (values per 100 g): 0.9 mg thiamine (Vitamin B1), 0.19 mg Riboflavin (Vitamin B2), 4.8 mg niacin (Vitamin B3), and 50 mg ascorbic acid (Vitamin C).

It is a good source of omega-3 fatty acid and α-linolenic acid (2.5% content).

Turmeric's Phytochemicals

Phytochemicals are biologically active compounds produced by plants and are the active ingredients in natural remedies.

Curcumin

Turmeric contains 1 to 6% of curcuminoids such as curcumin, demethoxycurcumin, and bisdemethoxycurcumin.

Of these Curcumin is the main component (making up roughly 1.5 to 3% of commercial turmeric powder). Curry, which also has other ingredients, has a far lower curcumin content (approx. 0.3%).

Curcumin is a low-molecular weight polyphenol whose chemical name is (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), or diferuloylmethane for short.

It is an active ingredient that displays potent antioxidant, anti-inflammatory, and antimicrobial properties (3).

Turmeric oil

Turmeric also contains other compounds other than curcumin that may have similar properties to curcumin.

For instance, turmeric oil can enhance the bioavailability of curcumin and other turmeric components.

These include tumerin, tumerone, elemene -approved in China to treat cancer-, furanodiene, etc.

All of these are found in curcumin-free-turmeric and they also have anti-inflammatory properties (4).

Tumerin

Tumerin is another water-soluble active ingredient. It is also a potent antioxidant, antimutagen, and DNA-protectant. It is found in small amounts (0.1% of turmeric is tumerin) and is heat-stable (5).

Turmeric in Traditional Medicine

Turmeric is employed all across Southern Asia as an antiseptic to treat cuts, burns, and bruises (2).

Turmeric or "Indian saffron" has been used in Indian Ayurvedic medicine for over 4,000 years to treat conditions such as fatigue, pain, breathing problems -asthma-, allergy, liver disease, and rheumatism (1)(2).

In Thai traditional medicine turmeric is used to treat a rash, itching, and fungal infections like tinea and ringworm (6).

It is employed in Japanese (Kampo) and Chinese traditional medicine to treat digestive and abdominal ailments.

These traditional uses prompted formal research into its potential medicinal properties. We will see below that some studies have confirmed the health benefits of turmeric while others have not found any benefits at all.

Research into Turmeric's Health Benefits

Below is a list of research regarding the potential health benefits of turmeric.

• Arthritis
• Treatment and Prevention of Cancer
• Gut microbiome, curcumin, and intestinal permeability: Leaky gut
• Leaky Gut
• Irritable Bowel Syndrome
• Candida infections
• Ringworm
• Atherosclerosis and improved cholesterol
• Type 2 Diabetes
• Psoriasis

Arthritis

Hewlings & Kalman, (2017) (7) reported a six-week-long double-blind trial involving 40 subjects with knee osteoarthritis. They found that those treated with 500 mg per day of a curcuminoid (plus 5 mg of piperine -an active component of black pepper) showed significant improvements when compared to the placebo group: less pain, better physical function scores, but not in the stiffness score.

Turmeric extracts and curcumin can be recommended for alleviating the symptoms of arthritis, especially osteoarthritis. Hewlings SJ, Kalman DS., (2017) (4)

Hewlings and Kalman also revealed that doses of 1,000 mg⁄day of curcumin reduced symptoms of arthritis such as inflammation and pain as effectively as ibuprofen or diclofenac sodium (4).

Another study (8) found that curcumin's efficacy in treating rheumatoid arthritis was similar to that of the drug phenylbutazone.

Treatment and Prevention of Cancer

Animal studies involving mice have shown that curcumin had a protective - preventive effect in cancer development. It decreased the number of tumors when compared to control groups (3).

A study involving humans ratified this preventive anti-cancer effect, suggesting that "dietary turmeric can act as an effective anti-mutagen in smokers and can reduce the risk of lung cancer" (8).

These anti-cancer properties derive not only from curcumin but also from other non-curcuminoid compounds found in curcumin-free-turmeric (or CFT) (4).

Some of CFT's anticancer and anti-inflammatory compounds include turmerin, turmerone, elemene, furanodiene, curdione, bisacurone, cyclocurcumin, calebin A, and germacrone (9).

The mechanism by which curcumin protects against cancer may be due to its anti-inflammatory and antioxidant properties, as well as being an antiangiogenic that reduces the growth of blood vessels that feed tumors.

Regarding non-curcuminoids, they alter cellular signaling pathways, inhibit enzymes, and block cancer cell growth, provoking cell-death.

Gut microbiome, curcumin, and intestinal permeability: Leaky gut

Curcumin seems to have a positive effect on the intestinal microbiota. A study with rats found that eating a high-fat diet changed their gut microbiota's composition. But, when fed curcumin together with their high-fat meals, the composition of their intestinal microbiota changed back to that of the control group that was composed of lean rats eating a normal diet (10).

Leaky Gut

The cells that line the intestine form a "permeable" barrier that allows the body to absorb nutrients, water, and electrolytes and at the same time keep out harmful pathogens like bacteria, viruses, and fungi.

This barrier is a contact point between foreign particles -antigens- and the body's cells ("self"). The immune system is regulated by the delicate balance of the barrier's permeable cell junctions.

The intestinal microbiota regulates this barrier, and pathogens such as H. pylori, E. coli, or Salmonella can breach it. Stress, alcohol, and certain medications can also upset its balance.

Alterations of the intestinal permeability (also known as "leaky gut") can also be caused by high-fat diets.

A highly-permeable intestinal barrier is also linked to inflammation. Bacteria may lodge in the now leaky barrier and promote even more inflammation.

Curcumin has a positive influence on intestinal permeability

Several studies (10) show that curcumin inhibits the inflammatory response and lessens permeability by organizing proteins at the barrier's junction points.

Rats fed curcumin showed "improvements in the structure of tight junctions of the intestinal mucosa... and improved intestinal barrier function at multiple levels ... improved the histologic structure of intestinal mucosa." (10)

Irritable Bowel Syndrome

The causes of Irritable bowel syndrome (IBS) are unclear. A pilot study (8) used turmeric extract on IrBS symptoms in 105 healthy adults for eight weeks and reported that those taking one tablet with 72 mg daily experienced a 53% reduction of IrBS. Those taking two tablets had an even higher drop (60%). Both groups reported a marked decrease in symptoms.

Turmeric and other medical conditions

Its antioxidant, antibacterial, and anti-inflammatory properties have been studied for several medical or health-related issues:

Exercise-induced muscle soreness

Active volunteers who ingested 1 g of curcumin one and two days before the downhill running test experienced "significantly less pain in the right and left anterior thigh," they also had significantly less evidence of muscle damage and inflammation. The study concluded that "curcumin may be beneficial to attenuate exercise-induced muscle soreness." (7)

Ringworm

An antifungal cream containing 6% turmeric oil was found to be effective as a treatment against ringworm. The oil's major active ingredient, Ar-turmerone was far more effective than standard ketoconazole (6).

Candida infections

The yeast candida causes thrush or candidiasis in humans, a condition that curcumin is effective against. The antifungal activity of curcumin was notable (8): "curcumin was found to be more efficient than fluconazole in inhibiting the adhesion of many Candida species to human buccal epithelial cells."

Atherosclerosis and improved cholesterol

Accumulation of fatty residues (cholesterol) that thickens artery walls is a chronic disease that can be countered by lowering serum levels of cholesterol. The anti-cholesterol effects of curcumin were reported in a study that noted a drop of total cholesterol of 11.63%, and an increase in "good" HDL cholesterol by 29% (8).

This finding suggests that curcumin at an ingestion level of 500 mg per day can control atherosclerosis.

However, another randomized double-blind trial with 36 obese adults (they ingested 1 g of curcumin + 10 mg of piperine for 30 days) showed that there was no "significant influence on serum total cholesterol, LDL-C, HDL-C,... [or] body mass index (BMI) and body fat" when compared to the placebo group. The only positive effect was a significant reduction in triglyceride concentrations (1).

Probably the fact that this group involved obese subjects and the short duration of the trial led to this contradicting outcome.

Type 2 Diabetes

A double-blind, randomized study with 240 participants, found that 1.5 g per day of curcumin delayed the onset of Type 2 Diabetes in a prediabetes population after 9-month treatment.

Not one case of Type 2 diabetes was reported in the curcumin-treated group, while the placebo group reported a 16.4% prevalence of the disease (8).

Psoriasis

Although Gupta (2012) reported a very low response rate when treated with curcumin (CUR) (8), a statistical meta-analysis reviewing 26 studies (14) found that curcumin was an effective treatment: "...both CUR monotherapy and combination therapy improved Psoriasis Area and Severity Index (PASI) scores in patients compared to controls... CUR has excellent efficacy and broad potential to treat psoriasis in multiple ways. Its use also plays a crucial role in improving the psoriasis phenotype and reducing the inflammatory microenvironment. In conclusion, our findings suggest that CUR alone or in combination with other conventional treatments can effectively treat psoriasis."

Turmeric and its bioavailability

To obtain health benefits from a chemical complex the body has to be able to absorb it so that it becomes "available" via the circulatory system to the body's organs.

This process is known as "bioavailability".

Oral administration of a biologically active compound (pills, tablets. or as an infusion) usually decreases its bioavailability because it has to go through the digestive tract to be absorbed, suffering potential degradation in the stomach and the intestine, plus possible breakdown by the gut microbiome.

The absorption of turmeric's active ingredients is poor, and only a small fraction of the ingested compound reaches the bloodstream. To make matters worse it is rapidly metabolized in the intestinal wall and the liver and eliminated (in urine or feces) (7).

The Black Pepper effect

However, the bioavailability of curcumin improves if taken together with piperine, an alkaloid that is the major active component of black pepper and long pepper.

Just 20 mg of piperine added to a 2 g dose of curcumin increased its bioavailability by 2,000%, a 5 mg dose of piperine duplicated the absorption of a 2 g dose vs. a control group. (7, 3, 11).

Safety and Dosage for an optimal effect

Doses of 1.1 to 8 g of curcumin per day (1,125 to 8,000 mg) are effective in slowing cancer progression (3). However, considering that turmeric powder contains 1.5 to 3% curcumin, to achieve those doses of curcumin you would have to consume between 38 and 533 g of turmeric powder per day. Considering that one tablespoon contains around 7 grams, this is equivalent to ingesting roughly 5½ to 76 tablespoons of turmeric powder each day!

This is not feasible: how do you fit all that powder into your diet? And what about the safe daily ingestion recommendations?

Side effects and safety of Turmeric

The JECFA (The Joint United Nations and World Health Organization Expert Committee on Food Additives) and EFSA (European Food Safety Authority) have established an Allowable Daily Intake (ADI) for curcumin:

• Up to 3 mg/kg body weight.

A person weighing 180 lb. (82 kg) could ingest up to 245 mg, a value that is well below the "anti-cancer dose" mentioned further up (1.1 to 8 g).

The side effects for ingesting higher doses are headache, diarrhea, rash, and nausea (All of which have been reported on doses ranging from 450 to 12,000 mg per day) (7).

The FDA has declared turmeric and its active component (turmeric oleo extract) as GRAS (Generally Regarded As Safe) for use in foods, without setting any maximum daily intake values (2).

The National Center for Complementary and Integrative Health (NCCIH) (2020) (1) cautions "Turmeric may be unsafe for use during pregnancy in amounts greater than those commonly found in food. Little is known about whether it’s safe to use turmeric in amounts greater than those commonly found in food while breastfeeding."

Incorporating Turmeric into your diet

But don't feel discouraged, some studies (2) have reported that as little as 1.5 grams of turmeric per day may have biological activity. This is equivalent to 1 teaspoon of turmeric powder.

Turmeric can be added to sweet dishes as a spice blend, with ginger and cinnamon. It can be added to spices used to prepare curry-based dishes.

Traditional Indian turmeric milk (milk, sugar, and turmeric) or tea is another tasty option. See the recipe below:

The Downside of Turmeric and Curcumin

But not all studies have found conclusive effects for curcumin or turmeric. Some have not found any, others only a limited effect similar to that of the placebo.

• Not antiinflammatory or antioxidant
• No antimicrobial effect on H. pylori
• No effect against Alzheimer's disease

No anti-inflammatory or antioxidant effect detected

A double-blind randomized study involving 62 overweight and obese women (BMI over 27), ages 40 to 75 years, affected with systemic inflammation, didn't find any differences in oxidative stress levels or inflammation between the group consuming red pepper spice or turmeric as a flavoring in foods when compared to the placebo group. (12).

This study used both spices at "culinary levels", so perhaps the dose was too low or bioavailability too poor to show any positive effect.

No antimicrobial effect on H. pylori

Curcumin displayed a limited anti-bacterial effect against ulcer-causing -and also stomach cancer-promoting- bacteria Helicobacter pylori (8).

No effect against Alzheimer's disease

A randomized, double-blind trial with 34 patients suffering from Alzheimer's disease showed that the "Mini-Mental State Examination" score of the curcumin ingesting group did not improve when compared to the placebo consuming one. Furthermore, their blood levels of Amyloid Beta Protein (A β40 - which forms the amyloid plaques that deposit in Alzheimer's patients' brains) were not affected by the curcumin treatment (8).

Critique and hope for turmeric

A team reviewing the pharmacological possibilities of curcumin, as an active ingredient in medical drugs (13) concluded that the different studies and clinical trials in animals, humans, and cell cultures are "much ado about nothing."

They were forthright about this, and the reason for their skepticism is turmeric's very poor bioavailability: "Certainly, the low systemic exposure levels reported in clinical trials do not support its further investigation as a therapeutic."

However, the authors offer a glimmer of hope by adding that "curcumin might provide benefit by acting on gut microbiota" (an effect that we have already mentioned further up), and, that food-borne phytochemicals with low bioactivity "can act via weak negative biological feedback mechanisms, escaping in vitro detection and blurring our understanding of mechanisms of action." (13)

This means that even though the active ingredients can't be detected they act upon the body in ways that have not yet been discovered.

The pharmaceutical industry's approach is to identify one active compound, purify it, and, if possible synthesize it, as it did with aspirin (originally obtained from willow tree bark) and anti-cancer drug Taxol® (from a pine tree) both are examples of natural phytochemicals.

However, this process eliminates other synergistic compounds that combine their effect with it, and enhance the activity of the main active ingredient.

This is the reason why the team concludes with a more encouraging comment when addressing the fact that most studies used purified forms of curcumin instead of the whole product - with all the other compounds that make up turmeric. They wrote "...we do not rule out the possibility that an extract of crude turmeric might have beneficial effects on human health." (13)

Turmeric, a healthy option

Turmeric, as a spice will add color and flavor to your dishes, and -with a pinch of black pepper- you may also harness some of its antioxidant and anti-inflammatory properties.

Try to include it in your diet as a tea, or sprinkle it on your salads.

It is a natural remedy with a long history and it does have chemoprotective effects. It is a non-pharma option for treating ringworm and different types of arthritis.