Turmeric (curcumin): A complete guide

Executive Summary

Turmeric and its active ingredients called curcuminoids offer anti-inflammatory, antioxidant, anti-cancer, anti-fibrotic, brain-protective, liver-protective, and heart-protective benefits.

It can benefit in many health conditions such as cancers, heart disease, type 2 diabetes, liver fibrosis and cirrhosis, Alzheimer’s disease, depression, chronic stress, anxiety and mood disorders, rheumatoid arthritis, ulcerative colitis and premenstrual syndrome.

For best benefits, you should consume 2,000 mg of curcumin a day, which is equivalent of 100 g of turmeric a day. The bio-availability of curcumin is very poor. A good curcumin supplement contains curcumin extract with certain technologies to enhance its absorption in the intestines by 20 to 100 times. Such a small 100-200 mg curcumin supplement can substitute 100 g of turmeric consumption a day.

I wanted to caption this article as ‘Curcumin: A Complete Guide‘. That is because the main bio-active ingredient of turmeric is curcumin, a compound known to be useful in many medical conditions. However, I was told that many people don’t know the word curcumin and search only for the benefits of turmeric.

General Knowledge

Did you know that the turmeric plant is actually a part of the ginger family that goes with a long name called Zingiberaceae?

Disclaimer: The information, including but not limited to, text, graphics, images, and other material, contained on this website is for informational and educational purposes only. No material on this site is intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified healthcare provider with any questions you may have regarding a medical condition or treatment before undertaking a new healthcare regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.

What is Curcumin?

Turmeric is a spice used in South Asia for thousands of years. Its bright yellow colour adds the trademark yellow colour to the spicy curries.

Turmeric is known in Ayurveda, the Indian medicine, for its immense benefits across the spectrum of health issues. Its benefits accrue mainly from its bio-active compounds called curcuminoids. There are four of them:

1. Curcumin;
2. Demethoxycurcumin;
3. Bisdemethoxycurcumin; and
4. Cyclocurcumin.

Curcumin forms 80% of curcuminoids. So a blend of all those four together is referred to as curcumin in the literature as well as in the food industry classification. So we will also refer to the entire basket of beneficial compounds of turmeric as curcumin. In that sense, read the title of this article as:
Curcumin: A Complete Guide.

Functions of Curcumin

Curcumin belongs to a beneficial plant compound group called polyphenols.

Anti-inflammatory Properties

Curcumin is highly anti-inflammatory. That means, it can reduce inflammatory chemicals in the body that can lead to various degenerative disorders.

Curcumin blocks toxic compounds that go by scary names such as cytokines, COX and LOX enzymes, and adhesion molecules. Remember that inflammation is involved in many body functions and manifests itself through various mechanisms, processes, and chemicals.

Antioxidant Properties

Antioxidants are substances that prevent or delay some types of cellular damage due to unstable molecules called free radicals. In the process, antioxidants also reduce the risk of developing inflammation. Thus, you can say that antioxidants prevent inflammation while anti-inflammatories reduce inflammation.

Curcumin has been found to be a very potent antioxidant in experiments done in test tubes. But it is unclear if it acts an antioxidant inside the human body. What is known is that it stimulates and increases the production of antioxidant compounds that are native to the body (called endogenous antioxidants).

Anti-Cancer Properties

Curcumin helps in many aspects of protection against cancer.

Cell DNA Damage

When a cell’s DNA is damaged, its life cycle is programmed to proceed in two ways:

1. If its DNA is repairable: the cell’s life cycle is stopped and it does not duplicate until its DNA is repaired; or
2. If its DNA is not repairable: the cell gets killed through a fascinating process called programmed cell death or apoptosis.

But some defective cells keep duplicating unrestrained if their apoptosis mechanism itself is damaged. That leads to cancer.

Curcumin plays a role in both cases. If the DNA is fixable, curcumin stops the cell’s lifestyle and does not let it duplicate. If the DNA is not fixable, curcumin helps trigger that cell’s death or apoptosis.

Cell Proliferation and Differentiation

For the growth of normal cells, two processes are needed:

1. Proliferation, which leads to an increase in the number of cells; and
2. Differentiation, which leads to preparation of cells for specialised tasks.

You can think of proliferation as a process by which all kids learn the same things in the school becoming good at basics such as maths and languages. However, in college, they are taught separate subjects and they become doctors, lawyers, accountants, and engineers, which is equivalent of the differentiation process.

If cells just proliferate and don’t get differentiated, you end up getting a lot of cells of only one type, which is effectively a cancerous tumour. Curcumin regulates the genes involved in the proper functioning of this differentiation mechanism, protecting against cancer development.

Cancer Metastasis

At some point, a few cancer cells gain the ability to leave the original site of tumour and move to another location. This causes the spread of cancer or metastasis. Curcumin blocks the process by which cancer cells acquire such ability to migrate to a new location.

Once cancer has spread to another location and that tumour has grown beyond a few millimeters, it needs its own blood supply to feed its growing needs for nutrients. Such tumours release chemicals that trigger the growth of new blood vessels in the new area. That process is called angiogenesis. Curcumin has anti-angiogenesis properties by which it can effectively choke the growth of the new tumour.

Anti-Fibrotic Properties

Chronic inflammation in the lungs or liver leads to fibrosis. Curcumin prevents the progression of such fibrosis.

The mechanism by which such fibrosis develops also causes early-stage kidney damage in diabetic patients. Curcumin, by blocking that process, also helps in preventing such renal damage in diabetes.

Brain-Protective (Neuroprotective) Properties

To protect our brain, the body has developed a special network of cells and blood vessels that keep many potentially harmful substances from reaching the brain. This is called the blood-brain barrier. It allows only a few nutrients to enter into the brain. In turn, many helpful antioxidants are also not able to reach the brain. Luckily, curcumin is able to cross the blood-brain barrier and so can help the brain with its protective actions.

Curcumin blocks certain processes in the brain that lead to Alzheimer’s disease, a condition involving memory loss. It also reduces inflammation that is caused inside the brain due to some degenerative processes.

Curcumin helps preserve an omega-3 oil called DHA, which is known be very beneficial in brain health. Curcumin also increases the DHA concentrations in the brain and the liver. For people don’t consume fish oil regularly, this may help protect against many brain disorders.

Liver-Protective (Hepatoprotective) Properties

Curcumin has extensive benefits for liver protection. It can prevent oxidative stress-related liver disease by lowering blood chemicals such as alkaline phosphatase, SGOT (AST), SGPT (ALT). It also increases the levels of internally present (called endogenous) antioxidants in the liver such as vitamin C, glutathione, and superoxide dismutase.

Heart-Protective (Cardioprotective) Properties

Curcumin has protective effects in heart conditions such as blockages (atherosclerosis), heart enlargement (hypertrophy), heart failure, stroke, heart attack (myocardial infarction) and heart-related diabetic complications.

Sources of Curcumin

As mentioned, curcumin is a part of the turmeric spice. Roughly 2% (regular) to 5% (high quality, organically grown) of turmeric is curcumin and its sibling curcuminoids. A typical teaspoon on turmeric is about 5 g or 5,000 mg in weight. So it has 150 mg of curcuminoids.

The main drawbacks of curcumin are:

1. Poor solubility;
2. Poor absorption in the intestines. So out of the curcumin ingested, very little is absorbed into the blood;
3. Quick metabolism after absorption. So it gets converted to other compounds in the blood; and
4. Rapid elimination from the blood and excretion.

The first two points cover bio-availability of curcumin, which is extremely low. So most of the ingested curcumin is eliminated through the stools. You cannot do anything about points 3 and 4, anyway.

Curcumin in high doses of even 8,000 to 12,000 mg a day are not found to have side effects. However, keep in mind that you don’t want to have that much as it has some effects on medicines you may be taking. Do check with your doctor before taking such high dose of curcumin.

On the other hand, with intake of less than 3,600 mg a day of curcumin, it could not be detected in the blood. And to confuse all of us, doses lower than that are found to help many medical conditions. So the question still remains as to how curcumin could help in them without getting absorbed in the blood.

A safe number to look for is about 2,000 mg of curcumin a day. Mind you, this number is of the regular curcumin present in the standard turmeric, which has very low bio-availability.

Supplementation of Curcumin

It is extremely hard to get 2,000 mg of curcumin a day from the normal turmeric consumption. So all those impressive articles asking you to drink a glass of turmeric latte a day are, frankly, dubious. Drink them because they taste good but you are not going to see too much benefit by drinking one teaspoon of turmeric a day.

You may see benefits of drinking such a cup of turmeric milk daily, if you do so regularly for many years. But by the time you find you have a medical problem, it is too late to address it by just drinking turmeric milk or eating a bit of turmeric through foods.

This is the exactly like the green tea fad. People drink one glass of green tea a day and expect it to stop their neurodegeneration. For the best benefit of green tea, you need to do what the wise Chinese have been doing for centuries: drink small 100 mL cupfuls multiple times a day. That will keep you healthy, if it is done over a few decades. But once you have a problem, you cannot do much by just starting to drink a cup of green tea a day.

To get 2,000 mg of curcumin, you will need to consume 100 g of turmeric a day, which is equal to 20 teaspoonfuls. That is too much to consume on a daily basis. So your only option is to have curcumin in a supplementation form with highly enhanced bio-availability.

Increasing Curcumin Bio-Availability

There are many proprietary technologies whereby the bio-availability of curcumin in a formulation can be increased by 4 to 180 times. For example, this is done by adding a black pepper extract compound called piperine, using vegetable oils, or using soy lecithin.

Consider a technology whereby you increase the curcumin bio-availability 20 times. So a 100 mg curcumin extract supplement with 20 times enhanced bio-availability will give you the same efficacy as a 2,000 mg curcumin of normal bio-availability that you get by ingesting 100 g of turmeric powder a day.

In my opinion, if one wishes to take curcumin for helping in a particular medical condition, one doesn’t have much choice other than taking a supplement with 20 times enhanced bio-availability of curcumin.

Benefits of Curcumin Supplementation

While there is a huge body of research about the role of curcumin in prevention and treatment of various medical conditions, the results are all over the place. That is expected in the early stages of research such as that is going on with curcumin.

Some trials are on animals, some others are done in a lab, and a few are done on actual human candidates. To understand a bit more about such nutrient trials, which are different in nature from the pharmaceutical trials, read on this website: How to understand the evidence from clinical trials of nutrients?

While I can give you the features of many clinical trials that have shown positive results and many more that have not shown any benefit, it will just be confusing to you. So I will simply mention a salient point or two for each medical condition. Kindly read up the corresponding paper given in the link, if you want to know more:

Cancer Prevention: Curcumin helps prevent cancer development in colon, stomach, liver, and oral cancers in animal trials. But we don’t know if it will do the same in humans.

Liver Fibrosis: Curcumin protects against alcohol-induced liver fibrosis.

Liver Cirrhosis: Curcumin alleviates liver sepsis (severe inflammation due to infection) and cirrhosis.

Heart Disease: Curcumin significantly increases blood nitric oxide levels in humans. This reduces the risk of heart disease as we age.

Heart Failure: Curcumin seems to help protect against heart inflammation and blockages.

Type 2 Diabetes: Since curcumin has antioxidant, anti-inflammatory, antioxidant and blood glucose-lowering properties, it may help prevent and treat type 2 diabetes. Curcumin also reduces insulin resistance.

Diabetic Neuropathy: A recent paper showed that curcumin can lower long-term damage caused by high blood glucose and reduce symptoms of diabetic neuropathy.

Diabetic Nephropathy: Curcumin may help in slowing the progression of diabetic nephropathy.

Alzheimer’s Disease: Curcumin prevents accumulation of beta-amyloid proteins in the brain. It also prevents the inflammation caused in the brain by such accumulation.

Depression: Curcumin reduced symptoms of depression.

Anxiety: Curcumin helped reduced some measures of anxiety.

Stress: Curcumin reversed some of the brain damage caused by chronic stress.

Rheumatoid Arthritis (RA): 500 mg a day of curcumin for eight weeks improved joint swelling, tenderness and other measures of severity in RA patients.

Ulcerative Colitis (UC): 3,000 mg a day of curcumin for one month put significantly higher percentage of patients into remission from UC.

Premenstrual Syndrome (PMS): Daily 200 mg of curcumin for 10 days significantly reduced the severity of emotional, behavioural, and physical symptoms of PMS.

My Views

I suggest that you try to connect the dots and see where the strength of curcumin is coming from. Many lifestyle diseases are actually diseases of dysfunctional inflammation. By bringing such uncontrolled inflammation into check, curcumin helps prevent, control, or treat them. For example:
• Ulcerative colitis is a disease of inflammation of the inner lining of the intestines.
• Rheumatoid arthritis is an autoimmune condition with inflamed joints.
• Type 2 diabetes and its complications are considered to be caused by oxidative stress and inflammation.
• Depression involves increased neuroinflammation;
• Mood disorders and anxiety involve inflammation;
• Alzheimer’s disease involves neuroinflammation caused by certain protein deposits in the brain; and
• Heart blockages and disease progress through an inflammatory process.

To Read More

• Oregon State University: Curcumin
• Frontiers in Pharmacology: Turmeric and Its Major Compound Curcumin on Health
• Everydayhealth: Turmeric (Curcumin): A Complete Scientific Guide
• Foods Journal: Curcumin: A Review of Its’ Effects on Human Health

First published on: 10th June 2022
Image credit: stockimagefactorycom – www.freepik.com
Last updated on: 13th July 2022