By Craig Weatherby
Last month, we summarized research linking the polyphenols in berries to cuts in heart risk factors, and protection against Parkinson's.
Certain kinds of berry polyphenols – the “antioxidant” compounds called anthocyanins – serve double duty as red-blue-purple pigments.
Why do we put “antioxidant” in quotes when referring to anthocyanins and related food-borne compounds such as carotenes?
Contrary to common belief and product claims, polyphenols do not exert substantial direct antioxidant effects in the body.
Instead, polyphenols and other food-borne “antioxidant” compounds benefit health via indirect, “nutrigenomic” effects on gene switches that help control the body's antioxidant and anti-inflammation systems.
Ample evidence shows that the flavanol-type polyphenols unique to cocoa and green tea aid artery health (Heiss C et al. 2005; Farouque HM et al. 2006; Wang-Polagruto JF et al. 2006; Balzer J et al. 2008; Heiss C et al. 2010)
Now, a new study from China adds clinical evidence that the anthocyanin-type polyphenols in berries
– also found in eggplant peel, black rice, grapes, and red cabbage – provide key cardiovascular health benefits.
Inflammation leads to clogged arteries
Chronic inflammation is brought about by poor diets and sedentary lifestyles.
The immediate cause of inflammation linked to unhealthy diets is “over-expression” of genes that promote inflammation or “down-regulate” the body's own protective mechanisms.
Growing evidence implicates chronic inflammation in obesity, insulin resistance, dementia, diabetes, osteoporosis, arthritis and cardiovascular disease.
Inflammation promotes cardiovascular disease, in part by causing oxidation of LDL cholesterol and making blood “stickier”… effects that lead to buildup of arterial plaque.
Accordingly, medical researchers are keen on identifying food-borne compounds that exert indirect anti-inflammatory effects … including omega-3 fatty acids, carotenoids, and polyphenols.
Trial finds berry pigments curbed artery-attacking inflammation
The trial was conducted by researchers from China's Sun Yat-Sen University and Shaoguan University (Zhu Y et al. 2012).
They recruited 150 people with high cholesterol levels to participate in a randomized, double-blind, six-month-long trial.
The subjects were randomly assigned to one of two groups, each of which took assigned capsules daily:
After six months, the people in the anthocyanin group showed sharp reduction in blood levels of three pro-inflammatory proteins (cytokines): CRP, sVCAM-1, and IL-1beta.
Doctors test blood levels of these proteins – especially CRP – to gauge people's risk for atherosclerosis … and consequent coronary heart disease.
Increased production of sVCAM-1 and other “cell adhesion molecules” promotes development of arterial plaque.
And studies suggest that abnormal lipid (cholesterol and triglyceride) blood levels increase CAM production.
The Chinese team recorded these beneficial reductions in the Anthocyanin Group, versus the Placebo Group:
CRP dropped 22 percent, vs. 2.5 percent in the placebo group.
sVCAM-1 dropped 12.3 percent, vs. 0.4 percent in the placebo group.
IL-1beta dropped by 12.8 percent, vs. only 1.3 percent in the placebo group.
The Anthocyanin Group also enjoyed improvements in their cholesterol profiles:
In contrast, LDL levels rose by 0.3 percent and HDL levels fell by 0.9 percent in the placebo group.
As the Chinese team noted, “This is the first report that long-term supplementation with purified anthocyanins can inhibit the inflammatory response in hypercholesterolemic [high-cholesterol-level] subjects.” (Zhu Y et al. 2012)
They also conducted a cell study showing that decreases in these three inflammatory markers were greater when cells were exposed to the anthocyanin mixture versus individual anthocyanin compounds.
As they wrote, “This suggests that the various anthocyanins in the mixture may synergistically operate to inhibit the inflammatory response. Further, these in vitro [test tube] findings support our observations in human subjects that anthocyanins can remarkably regulate the levels of inflammatory cytokines in hypercholesterolemic subjects.” (Zhu Y et al. 2012)
And they drew a logical conclusion: “Hence, incorporating plant-based foods rich in different anthocyanin compounds in the diet is likely to be more beneficial than consuming a single anthocyanin supplement.” (Zhu Y et al. 2012)
These encouraging findings build on two prior studies, which found that berry anthocyanins improved people's artery functions and LDL/HDL cholesterol ratios (Qin Y et al. 2009; Zhu Y et al. 2011).
make great toppings for yogurt or cereal, and form the centerpiece of Chef Myra Kornfeld's Very Berry Power Smoothie
, which she demonstrates in a video.
Balzer J, Rassaf T, Heiss C, Kleinbongard P, Lauer T, Merx M, Heussen N, Gross HB, Keen CL, Schroeter H, Kelm M. Sustained benefits in vascular function through flavanol-containing cocoa in medicated diabetic patients a double-masked, randomized, controlled trial. J Am Coll Cardiol. 2008 Jun 3;51(22):2141-9.
Farouque HM, Leung M, Hope SA, Baldi M, Schechter C, Cameron JD, Meredith IT. Acute and chronic effects of flavanol-rich cocoa on vascular function in subjects with coronary artery disease: a randomized double-blind placebo-controlled study. Clin Sci (Lond). 2006 Jul;111(1):71-80.
Heiss C, Kleinbongard P, Dejam A, Perré S, Schroeter H, Sies H, Kelm M. Acute consumption of flavanol-rich cocoa and the reversal of endothelial dysfunction in smokers. J Am Coll Cardiol. 2005 Oct 4;46(7):1276-83.
Qin Y, Xia M, Ma J, Hao Y, Liu J, Mou H, Cao L, Ling W. Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjects. Am J Clin Nutr. 2009 Sep;90(3):485-92. Epub 2009 Jul 29.
Wang-Polagruto JF, Villablanca AC, Polagruto JA, Lee L, Holt RR, Schrader HR, Ensunsa JL, Steinberg FM, Schmitz HH, Keen CL. Chronic consumption of flavanol-rich cocoa improves endothelial function and decreases vascular cell adhesion molecule in hypercholesterolemic postmenopausal women. J Cardiovasc Pharmacol. 2006;47 Suppl 2:S177-86; discussion S206-9.
Zhu Y, Ling W, Guo H, Song F, Ye Q, Zou T, Li D, Zhang Y, Li G, Xiao Y, Liu F, Li Z, Shi Z, Yang Y. Anti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: A randomized controlled trial. Nutr Metab Cardiovasc Dis. 2012 Aug 17. [Epub ahead of print]
Zhu Y, Xia M, Yang Y, Liu F, Li Z, Hao Y, Mi M, Jin T, Ling W. Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individuals. Clin Chem. 2011 Nov;57(11):1524-33. doi: 10.1373/clinchem.2011.167361. Epub 2011 Sep 16.