Curcumin Research

July 28, 2009 Written by JP    [Font too small?]

The distinctive yellowish color that is often associated with Indian and South Asian dishes is derived from Curcuma longa or turmeric. This rhizome (underground stem) is part of the ginger family, but it doesn’t possess the same pungent flavor or odor. Turmeric does however contain a group of antioxidant pigments known as curcuminoids. The primary curcuminoid is curcumin, a name often used interchangeably in alternative medicine when describing turmeric extracts.

In the culinary world, ground turmeric is the form of choice. But for medicinal purposes, concentrated and standardized extracts are preferred because whole turmeric only contains about 3% curcumin content. It is curcumin and certain related chemicals that is thought to be responsible for the vast array of health benefits ascribed to this revered rhizome. At this very moment, researchers are examining the potential of these phytochemicals in applications that include Alzheimer’s prevention and reversal, support of cardiovascular health, the repression of autoimmune conditions and cancer growth, and the promotion of a healthy digestive system. (1)

One of the most exciting areas of curcumin research involves its effects on the brain. Alzheimer’s disease and dementia are two of the most feared conditions associated with aging. Currently, there aren’t any truly successful conventional treatments that help reverse the consequences of these brain disorders. Perhaps that’s why scientists are working so hard to determine whether turmeric components may be part of the answer to making serious strides in this arena.

There is, however, a major obstacle to investigating curcumin. Decades worth of research indicate that this potential superstar has relatively poor bioavailability. Test tube studies reveal consistently positive results, but it’s just not absorbed very well by the body. Fortunately, newly developed forms of this herbal extract appear to sidestep this issue. (2,3,4)

A 2008 study published in the Journal of Clinical Psychopharmacology examined the effects of either 1 or 4 grams of specially processed curcumin in 22 Alzheimer’s (AD) patients over a 6 month period. The turmeric extract used in this research is known as BCM-95 and has been shown to increase the bioavaialability of curcumin several-fold over other previously tested turmeric extracts. This research demonstrated that blood levels of Abeta and vitamin E rose as a result of supplementation with BCM-95. Abeta plaque deposits are believed to be a major factor in the formation of AD. The authors concluded that the curcumin prompted a disaggregation (release) of Abeta from the brain and into the bloodstream. An increase in vitamin E was also noted. Some evidence suggests that vitamin E may also benefit those at risk for AD. (5,6,7,8)

Many other recent trials imply that curcumin has a multi-modal impact on AD and various dementia models. One avenue of research is the role that it plays in combating oxidative damage caused by heavy metals in the brain, such as aluminum and iron. Countering the deleterious effects of heavy metal toxicity has been shown to improve memory retention and slow the aging process of the brain in several animal trials. (9,10,11,12,13,14,15)

Other experiments suggest that curcumins brain boosting effects are partially the result of increased choline acetyltransferase activity. This is the primary target that many AD prescription medications attempt to address. Yet another way in which curcumin may support brain health is via improved blood flow. New research presented in the American Journal of Pathology implicates blood vessel constriction and the subsequent reduction in blood flow to the brain as a possible contributing factor to AD progression. Curcumin extracts have not only been shown to improve the viscosity of blood, but they may also reduce plaque build up in arteries which impedes proper circulation. (16,17,18,19)

The battle against cancer is perhaps an even more promising aspect of turmeric research. The past few months have provided some very important information for the nearly 6 million women in the US undergoing hormone replacement therapy (HRT). HRT has been implicated in an increased risk of breast cancer among postmenopausal women. Two new studies suggest that turmeric extracts may afford some protection against “progestin-accelerated breast tumors”. A group of rats that were fed curcumin, in addition to HRT, showed a delay in breast tumor growth, fewer total tumors and undesirable changes to breast tissue. A test tube experiment conducted on human breast cells also supports these current findings. (20,21)

One of the study’s authors concluded that, “Curcumin and other potential anti-angiogenic compounds should be tested further as dietary chemopreventive agents in women already exposed to hormone replacement therapy containing estrogen and progestin in an effort to decrease or delay the risk of breast cancer associated with combined hormone replacement therapy”. (22)

Apart from HRT related breast cancer risk, other trials from 2009 postulate a variety of ways by which curcumin may promote healthy mammary tissue and a cancer-free body in general. Collectively, these experiments point to changes in cell communication and genetic expression that discourage cancer cell growth and spread. Perhaps the most positive of these findings is that turmeric consistently shows an ability to selectively kill tumor cells while leaving healthy cells intact. (23,24,25,26,27)

Alzheimer’s disease/dementia and cancer may garner most of the headlines, but there’s a lot more going on in the world of curcumin research. Here are a few of the highlights I found on my last scientific literature field trip:

  • Digestive Health – Researchers at the University of Arizona just announced that curcumin may be a valuable aid in managing Inflammatory Bowel Disease (IBD). IBD collectively refers to two inflammatory conditions known as Crohn’s disease and ulcerative colitis. The effects of IBD generally include abdominal pain, diarrhea, fatigue, indigestion, intestinal damage and weight loss. It appears that curcumin modulates the immune system so that it won’t inappropriately attack the lining of the intestines. Recent evidence also suggests that turmeric may help combat unwanted bacteria, such as the cancer and ulcer causing H. pylori bug, and improve the transit of food through the digestive system. (28,29,30,31,32,33)
  • Multiple Sclerosis (MS) – MS is an autoimmune condition that impairs the ability of nerve cells in the brain and spinal cord from properly communicating with each other. Symptoms of this miscommunication can include fatigue, muscle stiffness and weakness, numbness or pain, poor balance and coordination and vision problems. The good news is that preliminary evidence suggests that curcumin may halt or even reverse a form of MS in mice (known as “autoimmune encephalomyelitis”). It’s also been noted that countries that frequently eat turmeric rich meals have a much lower incidence of MS. Lastly, stress is thought to be an exacerbating factor in MS progression. Curcumin extracts may play a role in blunting the effects of chronic stress. (34,35,36,37,38,39)

Source: Indian Journal of Pharmaceutical Sciences – Issue 4, 2009 (link)

The future of curcumin research appears bright as well. Some of the most encouraging trials of late have tested the synergistic pairing of curcumin with resveratrol (the “red wine molecule”) vs. cancer and as an addiction and obesity fighter. That same combination is showing great promise with regard to prostate cancer prevention as well. Two different concoctions of a) curcumin and fish oil; and b) vitamin D and curcumin are also generating buzz in the quest for a viable Alzheimer’s cure. Only time will tell whether these or other natural ingredient blends will provide results that are even greater than the sum of their parts. (40,41,42,43)

While much of the published evidence about curcumin is very hopeful indeed, there are still some vitally important questions that need to be addressed. For instance, the dosages and forms of curcumin used in many of these studies differ from one another. With such obvious disparities, how are we to know the proper way to apply the study findings in our own lives? One way to do so is to look at the dosages currently being used in a clinical setting. For instance, a trial that’s presently underway in patients with rheumatoid arthritis is utilizing 500 mg twice daily of the BCM-95 extract. But another study using this very same extract in those with cervical cancer lists a twice daily dosage of 3,600 mg. That’s more than a 7 times difference (1,000 mg vs. 7,200 mg)! (44)

The truth is that we just don’t know exactly how much curcumin is necessary to replicate the results found in the successful experiments. In fact, most of the trials listed here and elsewhere have been performed in diseased animal models or in test tube studies. But the few human studies that have been completed are optimistic enough to make curcumin one of the the most widely studied herb in modern medicine. This is no accident. There is a legitimate reason for all the excitement in both the natural and pharmaceutical sectors. At this point, however, we’re still left a bit in the dark. In future columns, I’ll do my best to report new findings that will hopefully shed more light on this important topic.

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

Be well!


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Posted in Bone and Joint Health, Memory, Nutritional Supplements

6 Comments & Updates to “Curcumin Research”

  1. Charles Colenaty Says:

    Healthy Fellow,

    I want to compliment you for writing such a clear, comprehensive, and informative article about curcumin. I trust that you wont mind if I add a few points. As you mention, curcumin’s bioavailability in humans is very low. Very, very low, in fact. The best estimate that I have found so far is about 0.1%. For rats it is about 5%. Some researchers report absence of curcumin in the blood stream even at doses as high as 10 grams, while others report that about 3,500 mgs does the trick. Direct indication of physiological results from curcumin seems to require about 8 grams (see the “Margaret’s Corner” blog). But there is one important exception. The immune cell responsible for rheumatic arthritis (Th17), among other autoimmune diseases, matures in the small intestine. Curcumin inhibits this process of maturation, and so research involving much smaller doses of curcumin have shown a reduction in symptoms.

    Nano versions of curcumin have recently become available that are advertised as having 10 times the bioavailability of normal curcumin. That is, 100 mgs of the nano version is comparable to one gram of regular curcumin. A noticeable improvement, but I think that more effectiveness is needed if we are to get up to the bioavailability of the rat — and that is what is needed to rack up practical results from curcumin.

    Your point about lack of knowledge about the effects of different dosage levels will become a very critical issue once high bioavailability level is achieved. The work with rats and mice indicates that curcumin has a hormetic effect, which means that while a small amount can produce a positive effect, a larger amount might either have no effect at all, or possibly a negative effect. And there is currently no information about this.

    There’s much more to say, but this comment is already loo long. Keep up the good work.


  2. JP Says:


    Thank you for your thoughtful comments. They’re much appreciated.

    Also of note is the potential of combining curcumin with phospholipids:

    Be well!


  3. sirvan abnous Says:

    thanks…..viry …..nice…..

  4. JP Says:

    Update 05/13/15:

    Indian J Endocrinol Metab. 2015 May-Jun; 19(3): 347–350.

    Turmeric use is associated with reduced goitrogenesis: Thyroid disorder prevalence in Pakistan (THYPAK) study

    Introduction: South Asian population has a particularly high prevalence of thyroid disorders mainly due to iodine deficiency and goitrogen use. There is no data available for prevalence of thyroid disorders in the general population living in nonmountainous regions of Pakistan.

    Materials and Methods: A total of 2335 residents of Pak Pattan, Punjab, Pakistan were interviewed about demographic, dietary, medical and environmental history as well as screened for goiter. Individuals of all ages and either gender were included.

    Results: Median age was 34 (10–88) years and 1164 (49.9%) were males. Median monthly income was 49 (3.9–137) USD. Six hundred and sixty-nine (28.7%) subjects had palpable goiter. 77.5% (n = 462) and 22.5% (n = 133) had World Health Organization Grade I and Grade II goiters respectively, further screened by measuring thyroid-stimulating hormone (TSH). In subjects with TSH <0.4 mg/dL, free T3 and free T4 levels were measured. In 185 goiter subjects when TSH was measured, 50% (n = 93) were euthyroid, 48% (n = 89) were hyperthyroid, and one subject each was hypothyroid and subclinically hyperthyroid. 29/89 hyperthyroid subjects underwent radionuclide scanning. Twelve subjects had heterogeneous uptake consistent with multinodular goiter, 12 subjects had diffuse uptake, two had cold nodules and two had hyperfunctioning single nodules. Goiter was significantly more common among females, unmarried individuals and individuals drinking tube well (subterranean) water. Goiter was less common among those who consumed daily milk, daily ghee (hydrogenated oil), spices, chilies, and turmeric.

    Discussion: In our study population, goiter was endemic with very high prevalence of hyperthyroidism. Turmeric use was association with reduced goitrogenesis. Further studies to assess iodine sufficiency, thiocyanate exposure and autoimmunity need to be conducted. Masses consuming high goitrogen diets should be educated to incorporate turmeric, spices and green chilies in their cooking recipes, to reduce the risk of goiter development. In addition, use of iodized salt in their daily diet cannot be overemphasized.

    Be well!


  5. JP Says:

    Updated 09/28/15:

    Complement Ther Med. 2014 Oct;22(5):851-7.

    Lipid-modifying effects of adjunctive therapy with curcuminoids-piperine combination in patients with metabolic syndrome: results of a randomized controlled trial.

    BACKGROUND: Dyslipidemia is an established feature of metabolic syndrome (MS) that is associated with an increased risk of atherosclerotic cardiovascular disease. Curcuminoids are natural products with anti-atherosclerotic and lipid-modifying effects but their efficacy in patients with MS has not yet been tested.

    OBJECTIVE: To investigate the effects of bioavailability-enhanced curcuminoids, as adjunctive to standard of care, on serum lipid concentrations in patients with MS.

    METHODS: Patients diagnosed with MS according to the NCEP-ATPIII criteria who were receiving standard of care were assigned to either curcuminoids (C3 complex(®); 1000 mg/day; n=50) or placebo (n=50; matched with drug capsules in shape and color) for 8 weeks. In order to improve the oral bioavailability, curcuminoids were co-administered with piperine (bioperine(®)) in a ratio of 100:1. Serum concentrations of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, small dense LDL (sdLDL), lipoprotein(a) [Lp(a)], and non-HDL-C were determined at baseline and at the end of 8-week treatment period.

    RESULTS: Curcuminoids were more effective than placebo in reducing serum LDL-C, non-HDL-C, total cholesterol, triglycerides and Lp(a), and elevating HDL-C concentrations. However, changes in serum sdLDL levels were found to be comparable between the study groups. The effects of curcuminoids on triglycerides, non-HDL-C, total cholesterol and Lp(a) remained significant after adjustment for baseline values of lipids and body mass index.

    CONCLUSION: Curcuminoids-piperine combination is an efficacious adjunctive therapy in patients with MS and can modify serum lipid concentrations beyond what is achieved with standard of care.

    Be well!


  6. JP Says:

    Updated 12/12/16:

    Inflammopharmacology. 2016 Dec 7.

    Antioxidant effects of curcuminoids in patients with type 2 diabetes mellitus: a randomized controlled trial.

    BACKGROUND: Oxidative stress has a key role in the pathogenesis of type II diabetes mellitus (T2DM) and its vascular complications. Antioxidant therapy has been suggested as a potential approach to blunt T2DM development and progression. The aim of this study was to assess the effects of supplementation with curcuminoids, which are natural polyphenolics from turmeric, on oxidative indices in diabetic individuals.

    METHODS: In this randomized double-blind placebo-controlled trial, 118 subjects with T2DM were randomized to curcuminoids (1000 mg/day co-administered with piperine 10 mg/day) or matching placebo for a period of 8 weeks. Serum total antioxidant capacity, superoxide dismutase (SOD) activities and malondialdehyde (MDA) concentrations were measured at baseline and after the supplementation period.

    RESULTS: Curcuminoids supplementation caused a significant elevation in serum total antioxidant capacity (TAC) (p < 0.001) and SOD activities (p < 0.001), while serum MDA levels were significantly reduced compared with the placebo group (p < 0.001). These results remained statistically significant after adjustment for potential confounders (baseline differences in body mass index and fasting serum insulin). CONCLUSION: The present results support an antioxidant effect of curcuminoids supplementation in patients with T2DM, and call for future studies to assess the impact of these antioxidant effects on the occurrence of diabetic complications and cardiovascular endpoints. Be well! JP

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