Although interfacing with clinical data can even make our heads spin at times, it’s important to have an understanding of what actually makes a good, viable study. Measurements: Unfortunately, many publications report the bioavailability of curcuminin without actually distinguishing between free form curcumin, curcumin metabolites, and total curcuminoids (curcumin, DMC, BDMC). This will inevitably skew what was actually measured in sample blood, versus what is reported in the corresponding publication. Don’t forget about our little friend Beta-glucuronidase either, seeing the use of this enzyme further skews results generating false values for Free Form Curcumin. For the sake of accuracy, simple
Curcumin is the bright orange colored major active compound extracted from the spice turmeric. Turmeric is a widely used condiment in South East Asia and is a favoured component of Indian curries. The spice has been used for centuries in both Indian and Chinese cuisine as a flavoring and coloring agent and as a food preservative.
Turmeric in Ayurvedic and traditional Chinese medicine (TCM)
Turmeric is a key ingredient in many frequently used Ayurvedic and TCM formulas. In fact, turmeric is the main ingredient used by almost every Indian household for ailments such as digestive disorders, liver complaints, parasites, diabetes, kidney disease and various types of inflammatory conditions including arthritis. It is also used topically for infections and in cosmetic preparations. Typically, the turmeric spice is added to hot milk with ghee (clarified butter) and given in copious amounts to anyone with a sprain or a swelling due to an injury.
Curcumin – The Active Ingredient
Curcumin, the major active ingredient in turmeric, is widely studied for its effects on diabetes, cataracts, osteoarthritis, kidney disease, liver conditions like cirrhosis and bile duct disorders, psoriasis, neurodegenerative conditions including Alzheimer’s and Parkinson’s, a host of cancers such as colon, breast, liver, prostate, bladder, skin and many others.Research on curcumin in universities all over the world is prolific; within the last thirty years, probably no other natural product has been the subject of more animal and human research than curcumin. Curcumin has been demonstrated to be a powerful antioxidant and anti-inflammatory agent in numerous scientific studies. More than twenty different pathways of cancer protection have been established. Recently, researchers have looked into why Ayurvedic physicians have used turmeric in their formulas for heart health.
Curcumin and Heart ResearchAnimal Studies on Curcumin and Heart Health
Researchers at the universities of Tokyo and Toronto independently suggested that curcumin may be beneficial for heart health. The Toronto researchers used an animal model that mimicked high blood pressure in humans (by deliberately reducing the flow of blood in the aorta- the large blood vessel) and found that those animals subjected to such conditions quickly developed an enlarged heart and subsequent heart failure. However, those animals subjected to the same conditions but given a daily dose of curcumin in their diet were protected from enlargement of the heart and did not end up having heart failure.1
Similarly, researchers in Tokyo using a different model of high blood pressure (they used animals that spontaneously developed high blood pressure due to salt in their diet) were also protected from heart enlargement and heart failure by having curcumin in their daily diet .2 Heart enlargement is a common feature of high blood pressure. The heart has to work that much harder to pump the blood, and like any other muscle when over exerted will increase in size, but in the case of the heart this isn’t good and is normally associated with poor health and increased risk of death.Both set of researchers were able to meticulously work out the protective mechanism of curcumin. In short, curcumin inhibits a key class of enzymes called the Histone Acetyl Transferases (HATs), that normally function to increase the expression of inflammatory proteins. This way, inflammatory damage, as well as enlargement of the heart and heart failure are reduced. The pathology of the animal’s heart shows that curcumin also protects against fibrosis or scarring of the heart tissue. Scarred tissue is damaged tissue and is thus unable to perform the normal physiological function, which in the case of the heart is as a pump.
Human Studies on Curcumin and Heart Health
Since 2008 when the two animal studies were published, some human clinical data has emerged supporting the use of curcumin for heart and blood vessel health. The first was a study from Thailand which looked at the effects of a curcumin mixture given to patients that suffered a recent heart attack following coronary artery bypass. There were 121 patients who were given 4 g of curcumin and who underwent various tests.3 The researchers found that curcumin decreased the incidence of future heart attacks by over two and half times compared to patients not receiving any curcumin. Furthermore, the incidence of left ventricular dysfunction (a measure of the damage to the heart) was significantly reduced again in the curcumin group, this time by nearly nine times. These results are hugely significant. Other biological markers of heart disease such as inflammation (C-Reactive Protein, CRP) were also greatly reduced. Another human study from Japan used a much smaller daily dose of curcumin, just 25 mg given to 11 postmenopausal women who were either exercising or not exercising were given the curcumin dose for eight weeks.4 The researchers looked at a specific marker of vessel health called Flow Mediated Dilation (FMD) which is a very sensitive marker and predictor of future cardiovascular events, with every 1% decrease in FMD being associated with a 12% increase of cardiovascular risk.A daily dose of 25 mg significantly improved FMD similar to the exercise group. In other words, curcumin provided the same health benefit as exercise. The researchers concluded that curcumin could act as an alternative for patients unable to exercise! A second follow-up study by the same Japanese group also reported a reduced left ventricular afterload (this is the pressure the heart has to pump against) compared to the group not taking curcumin.It is worth pointing out the large discrepancy between the 4 g per day in the Thailand study compared to the 25 mg in the Japanese study. Curcumin has poor bioavailability, that is, very little reaches the site of action due to a number of issues. Curcumin has poor solubility, low stability, rapid degradation by enzymes, as well as fast elimination from the body.
A More Bioavailable Curcumin Extract
The Japanese used a super bioavailable extract of curcumin with considerably higher bioavailability than the regular curcumin. Much attention has been devoted to improving bioavailability and thus reducing the daily dose. Current literature search suggests the formulation that has the highest bioavailability by far is the Longvida® product, over 100 times compared to regular curcumin. In contrast, the Japanese product used in the study is reputed to be about 30 times more bioavailable. The Longvida® curcumin was specifically developed by the scientists at UCLA (University of California in Los Angeles) after studying over two hundred different formulas. The unique delivery system used in Longvida® curcumin is called a solid lipid nanoparticle that not only improves the solubility and stability of the curcumin but also prevents degradation by the enzymes that normally help keep out any foreign substances.
Curcumin has been used by ayurvedic practitioners for centuries, but only recently have human studies been conducted and the mechanism been studied. This versatile molecule offers exciting possibilities in heart health and will be increasingly used in natural health products.
1. Li H et al. Curcumin prevents and reverses murine cardiac hypertrophy. J Clin Invest 2008; 118: 879-893
2. Morimoto T et al. The dietary compound curcumin inhibits p300 histone acetyltransferace activity and prevents heart failure. J Clin Invest 2008; 118: 868-878
3. Womgcharoen W et al. Effects of curcuminoids on frequency of acute myocardial infarction after coronary bypass grafting. Am J Cardiol 2012, 110(1):40-4
4. Akazawa, N et al. Curcumin ingestion and exercise training improves vascular endothelial function in postmenopausal women. Nutr Res 2012; 32: 795-977
5. Sugawara J et al. Effect of endurance exercise training and curcumin intake on arterial hemodynamics in postmenopausal women: a pilot study. Am J Hypertension 2012; 25: 651-656