Health Benefits & Side Effects Of Turmeric

Turmeric has a rich history in traditional medicine.  There is evidence of its use in Indian medicine nearly 4,000 years ago, reaching China and  Africa hundreds of years later. It was the treatment of choice for a spectrum of ailments; arthritis, diabetes, colic and menstrual irregularity to name just a few [1]. It isn’t surprising that modern medicine has focused vast amounts of research on understanding how turmeric exerts these benefits on our health. Most of the bioactive effects of turmeric come from its main compound, curcumin.  This phenolic compound makes up around 2-5% of the spice; it’s also responsible for its bright yellow color [2].

Curcumin has most of its effects in the body due to it’s anti-inflammatory and antioxidant properties. It reduces the inflammatory response of the body to infection, making the damage to other organ systems less threatening [1]. This anti-inflammatory effect is perfectly demonstrated by its promise in treating rheumatoid arthritis, reducing morning joint stiffness and swelling when given in doses over a few weeks.

Turmeric usage and it's benefits

Schematic representation of traditional and modern use of turmeric (Gupta et al., 2012).

Turmeric’s antioxidant properties mean that when consumed, it reacts with ‘free radicals’  throughout the body. Free radicals are highly reactive, unstable molecules which easily damage the molecules in our body tissues.  Antioxidants reduce this damage by reacting with the free radicals instead, protecting the cells in our body. Evidence has shown that the amount of curcimun consumed by eating the average curry is enough to give the benefits of this antioxidant protection [3].

Digestive System Effects

The digestive organs are strongly targeted by curcumin because this is the first place it reaches when consumed in the diet. Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the digestive system. Curcumin is effective in reducing this inflammation in Crohn’s disease and ulcerative colitis: both types of IBD.

dietary polyphepnol curcumin

Dietary polyphenol Curcumin - (Rothwell et al.,2013).

 It also improves ‘gastric motility’, or the movement of our stomach and intestines, helping to move food quickly through digestion and reducing symptoms of Irritable Bowel Syndrome (IBS) [4]. It may have a positive effect on wound healing, speeding recovery from stomach ulcers. Even indigestion in those without IBD or IBS can be alleviated by consuming turmeric [3].

Anti-cancer Effects

Future research may allow turmeric to be used in the treatment of multiple types of cancer. Initial research has found that it may prevent stomach, liver, colon, skin, breast and oral cancer [1]. It prevents the mutation of normal cells into cancerous ones, and encourages ‘apoptosis’  in cancerous cells.  This is normal cell death which is essential to a healthy cell cycle. When apoptosis is suppressed, the tumor is able to grow. Phenolic compounds in general have also reduced the ability of cancers to spread to other body parts in studies.

Cardiovascular Effects

Many diseases involving the cardiovascular system, such as atherosclerosis, may be prevented by turmeric. It can cause blood vessels to relax, which reduces blood pressure. It also reduces levels of ‘bad’  LDL  cholesterol in circulation while increasing the ratio of ‘good’  HDL  cholesterol.  This shift discourages the build-up of fat within blood vessels. Oxidative stress is another major cause of atherosclerosis as it damages the walls of blood vessels; this is prevented by the antioxidant effects of turmeric [2].

Antimicrobial Effects

Turmeric also has strong antimicrobial properties. It inhibits bacteria growth and histamine production within the body, reducing their detrimental effect and our reaction to them. It even prevents pathogen growth (such as E.Coli) in the food itself before it is even consumed. It is antiviral in the liver, and even antifungal [4].

Neurological Effects

Turmeric’s anti-inflammatory effects may also explain why it can prevent neurological disorders such as  Alzheimer and Parkinson’s diseases. It protects against the degeneration of cell connections in the brain, encouraging normal cell death and maintaining a healthy structure of motor neurons. It may also help with the treatment of neurological disorders; treatment with curcumin improves the mood of those with depression [2]. Its extracts can protect levels of both serotonin and dopamine from decreasing; both of these chemicals are key to feelings of mood stabilization, happiness and pleasure.

Other Effects

These benefits of turmeric are only the tip of the iceberg. Human studies, though limited, have shown that it could be effective for treating acne, lupus, fibrosis and psoriasis [4]. It may improve memory, be a natural antibiotic and insecticide. It has a huge known range of effects on health, and more will likely be found in the future.

Dosage

The average intake of turmeric in  Asian countries is anywhere between 0.5-1.5g per day [3]. Dosage amounts for health benefits aren’t currently well understood. Initial studies have suggested anywhere between 8-60g of fresh turmeric root, three times per day, to reduce the symptoms of arthritis.  This needs to be studied in further detail but shows significant promise. Other studies have shown only 1.3-3g of turmeric root per day to reduce indigestion [3]. One clinical study showed that 3g of turmeric, spread throughout the day, sped the healing of peptic ulcers within weeks [2].

Side Effects of Turmeric Curcumin

So far, no negative side effects of turmeric use in medicine have been identified in studies. It doesn’t interact with other drugs.  Animal studies have tried giving much larger doses than the average intake, with no negative changes in the body noted [2]. Both turmeric and curcumin are also tolerated by adult humans at very high doses, with no toxic effects found. Curcumin, making up only a tiny percentage of the overall weight of turmeric powder, has been given to adults in doses of 10g per day with no negative effects [2].  These types of studies are not carried out on children so caution should be taken, but turmeric has been used in households for thousands of years. No studies so far have found any toxic effects, and the FDA  has declared it as ‘generally regarded as safe’.

This may be partly because curcumin is difficult for the body to absorb when turmeric is eaten normally. It doesn’t dissolve in water well, making it difficult to take from the digestive system, and it is rapidly metabolised and excreted. Future studies will focus on making the beneficial compounds more easily absorbed.  Turmeric has shown excellent health benefits in modern studies, helping to explain why it has been used effectively in traditional medicine for thousands of years.  As more research emerges, it will likely be used in the treatment of various diseases in the Western world.

References

[1] Hay, E., Lucariello,  A., Contieri, M., Esposito,  T., De Luca,  A., Guerra, G. and Perna, A., 2019.  Therapeutic effects of turmeric in several diseases:  An overview. Chemico-biological interactions, 310, p.108729.

[2] Chattopadhyay, I., Biswas, K., Bandyopadhyay, U., & Banerjee, R. K. (2004). Turmeric and curcumin: Biological actions and medicinal applications. Current Science, 87(1), 44–53. http://www.jstor.org/stable/24107978

[3] Prasad S,  Aggarwal BB.  Turmeric, the Golden Spice: From  Traditional Medicine to Modern Medicine. In: Benzie IFF, Wachtel-Galor S, editors. Herbal Medicine: Biomolecular and Clinical  Aspects. 2nd edition. Boca Raton (FL): CRC Press/Taylor & Francis; 2011. Chapter 13.

[4] Gupta SC, Sung B, Kim JH, Prasad S, Li S,  Aggarwal BB. Multitargeting by turmeric, the golden spice: From kitchen to clinic. Mol Nutr Food Res. 2013 Sep;57(9):1510-28. doi: 10.1002/mnfr.201100741. Epub 2012  Aug 13. PMID: 22887802.

Rothwell, J.A., Pérez-Jiménez, J., Neveu, V., Medina-Ramon,  A., M'Hiri, N., Garcia, L.P, Manach, C., Knox, K., Eisner, R., Wishart, D., Scalbert,  A. (2013). Phenol-Explorer 3.0: a major update of the Phenol-Explorer database to incorporate data on the effects of food processing on polyphenol content. Database, 10.1093/database/bat070. Full text (free access)