And More Chocolate!!!

It just keeps getting better for you dark chocolate lovers! Another study has shown positive results for dark chocolate and the management of kidney disease. Turns out the eating dark chocolate helps with managing blood pressure through modifying blood vessels in the kidneys. Below is the study results.

Dark chocolate is rich in cocoa, a substance with anti-oxidative and antihypertensive properties. The effect of dark chocolate on renal hemodynamics (the constriction and dilation of blood vessels in your kidneys) is not well understood. The aim of this randomized, placebo-controlled study was to investigate whether dark chocolate induces changes in blood pressure and renal perfusion (the flow of blood through the kidneys) as assessed with Doppler ultrasound – both at rest and during sympathetic stimulation (activation of the sympathetic nervous system through exercise) – compared to cocoa-free white chocolate.

Seventeen healthy volunteers aged 42±14 years (47% women) were randomized to eat one dose of 1g/kg of dark chocolate (70% cocoa) or 1g/kg of white chocolate. The renal resistive index (RRI), which is a representation of the resistance to allow filtration of the blood vessel within the kidneys, was measured just before and two hours after chocolate consumption. Blood pressure, heart rate and cardiac output were all measured as part of the study. At each time point, a 3-minute handgrip test was performed as the sympathetic stimulus; during the handgrip, supplementary RRI values were measured. Two weeks later, the same exams were repeated with the other type of chocolate.

Dark chocolate intake decreased the RRI from 0.62±0.04 to 0.60±0.04 (p=0.039), whereas RRI did not change after the intake of white chocolate (before: 0.62±0.05, after: 0.62±0.04, p=0.47). Dark chocolate had no effect on BP in participants consuming >50g chocolate/week, whereas SBP increased from 115±17 to 122±15 mmHg (p=0.02) in non-regular chocolate eaters. Handgrip exercise lowered the RRI from 0.62±0.04 to 0.57±0.05 (p=0.001) and prolonged acceleration times (from 48.2±8.2 to 57.8±14 msec, p=0.009), while increasing BP, heart rate and cardiac output. In participants aged ≥35 years, the effect of handgrip exercise on RRI was attenuated by dark chocolate ingestion.

The consumption of dark chocolate led to an acute reduction in RRI, suggesting dilation of the blood vessels within the kidney, whereas white chocolate had no effect. Blood pressure only increased in non-regular dark chocolate eaters, suggesting that regular dark chocolate eaters are more accustomed to the BP-modifying effects of dark chocolate. When participants performed the handgrip exercise it led to indications of reduced blood flow through the blood vessels. This effect was attenuated though by dark chocolate consumption in older participants, suggesting that dark chocolate counterbalances the sympathetically induced vasoconstriction, or reduced blood flow, in the kidney blood vessels in these volunteers.

So it appears that eating dark chocolate can have beneficial effects on the flow of blood through the blood vessels in the kidneys which could lead to better elimination of toxins from the blood stream. Enjoy!

1. The acute effect of dark chocolate on blood pressure and renal hemodynamics as assessed with doppler ultrasound in healthy volunteers.

   Gargiulo, Louise et al.

   Journal of Renal Nutrition, Volume 0, Issue 0