Sugawara J, Akazawa N, Miyaki A, et al. Effect of endurance exercise training and curcumin intake on central arterial hemodynamics in postmenopausal women: pilot study. Am J Hypertens. 2012;25(6):651-656.
This was a pilot study to test the hypothesis that combining regular endurance exercise with daily oral doses of curcumin would lower the age-related increase in left-ventricular (LV) afterload more than monotherapy with either intervention alone. This was tested through a randomized, double-blind, placebo-controlled parallel design study.
Forty-five postmenopusal women took part in the study. Selection criteria had excluded any potential participants who had overt cardiovascular disease; those taking cardiovascular acting medications, including hormone replacement therapy; and smokers. The participants were randomly assigned to one of four interventions:
- Placebo (n=11)
- Curcumin (n=11)
- Exercise + placebo (n=11)
- Exercise + curcumin (n=12)
It is reasonable to take this current study at face value and begin using curcumin in treatment plans aimed at improving cardiovascular status.
The curcumin used in this study is a specific, highly absorbable product in which the curcumin is dispersed in colloidal nanoparticles (Theracumin™). Each capsule contained only 25 mg of actual curcumin. Participants took 6 capsules per day so that those not in the placebo groups received 150 mg/day.
Exercise intervention consisted of exercise training 3–6 days/week for 8 weeks. Initially participants started out with low-intensity workouts. As exercise tolerance improved, intensity and duration of the workouts was increased to about 45 minutes per day, 4–5 days/week at 70–75% peak heart rate.
Extensive lab work was performed on all subjects in order to monitor changes in blood chemistry and heart function tests that included arterial pressure waveforms. Carotid and femoral arterial pulse waveforms were simultaneously recorded so that aortic blood pressure (BP) and augmentation index (AIx), an index of LV afterload, could be calculated.
At baseline there were no significant differences between the 4 groups, except that the exercise + curcumin group weighed more. After the interventions, brachial systolic BP (SBP) significantly decreased in both exercise-trained groups (P<0.05 for both), whereas aortic SBP significantly decreased only in the combined-treatment (ie, exercise + curcumin) group (P<0.05). Heart rate (HR) corrected AIx significantly decreased only in the combined-treatment group.
In order to understand the implications of this study, one must first understand what was being measured in these rather esoteric tests. Arterial pressure in the central region of the body, which is the aorta and carotid artery, is composed of the incident wave from the heart and the reflected wave from the periphery. Age-related aortic stiffening and impaired endothelial function may result in the early return of the augmented reflection wave from the periphery and therefore increase the LV afterload. These measurements give us a means to measure the elasticity of the blood vessels. The central AIx increases with age and is typically higher in women.
Coming back to the study at hand, recall that only those women in the study who both exercised and took curcumin saw improvement in this index. In simpler words, their vasculature became more elastic and a marker of cardiovascular aging improved.
Although this appears to be the first human randomized controlled trial to find this effect, a number of earlier animal studies suggest this sort of result might be expected.
A study published in the April 2012 issue of Hypertension Research reported that curcumin improved hemodynamic function and vascular elasticity in rats.1 A year earlier the same research group reported that curcumin protected rats against chemically induced hypertension. Curcumin and its metabolite, tetrahydrocurcumin, “suppressed the blood pressure elevation, decreased vascular resistance, and restored vascular responsiveness.”2 Given these and other studies, it is reasonable to take this current study at face value and begin using curcumin in treatment plans aimed at improving cardiovascular status. This study may have particular value in lobbying patients to exercise, as well as take supplements. The combination of exercise + curcumin in this pilot study was superior to either exercise or curcumin alone.
Unfortunately this study does not answer one important question: Which of the curcumin products currently being marketed as “highly absorbable” works the best? All of these new products are superior to the plain curcumin powders available only just a few years ago. A handful of papers tell us that this new form of curcumin increases absorption by about 20- to 30-fold compared to plain curcumin powder.3-5 We do not yet have a paper that compares the different products against one another.
- Nakmareong S, Kukongviriyapan U, Pakdeechote P, et al. Tetrahydrocurcumin alleviates hypertension, aortic stiffening and oxidative stress in rats with nitric oxide deficiency. Hypertens Res. 2012;35(4):418-425.
- Nakmareong S, Kukongviriyapan U, Pakdeechote P, et al. Antioxidant and vascular protective effects of curcumin and tetrahydrocurcumin in rats with L-NAME-induced hypertension. Naunyn Schmiedebergs Arch Pharmacol. 2011;383(5):519-529.
- Sasaki H, Sunagawa Y, Takahashi K, et al. Innovative preparation of curcumin for improved oral bioavailability. Biol Pharm Bull. 2011;34(5):660-665.
- Cuomo J, Appendino G, Dern AS, et al. Comparative absorption of a standardized curcuminoid mixture and its lecithin formulation. J Nat Prod. 2011;Apr 25;74(4):664-669. Epub 2011 Mar 17.
- Gota VS, Maru GB, Soni TG, Gandhi TR, Kochar N, Agarwal MG. Safety and pharmacokinetics of a solid lipid curcumin particle formulation in osteosarcoma patients and healthy volunteers. J Agric Food Chem. 2010;58(4):2095-2099.