The new study, published in Nutrition & Metabolism, deepens our understanding of the heart health benefits of anthocyanins, pigments found in many fruit like black raspberries, blueberries, blackberries, and blackcurrants. The water-soluble vacuolar pigments may appear red, purple, or blue depending on the pH. They belong to a parent class of molecules called flavonoids.
"These results are of public health importance because intakes of flavonoids associated with these findings are easily achievable in the habitual diet and make a significant contribution to the knowledge base needed to refine the current, rather general, fruit and vegetable dietary recommendations," wrote researchers from the University of East Anglia and King's College London.
Color may be key to spotting foods that fight free radicals, said Roberta Anding, an American Dietetic Association spokeswoman and a nutritionist at Texas Children's Hospital in Houston. Daily consumption of berries may have a significant and statistical outcome on inflammatory markers within the body.
Chinese scientists report that 320 mg per day of purified anthocyanins, equivalent to about 100 g of fresh blueberries and blackcurrants, for 24 weeks were associated with significant reductions in platelet chemokine levels, which correlated to lower levels of inflammatory markers in people with elevated cholesterol levels.
"Platelet chemokines are involved in inflammatory reactions, immune responses, and other aspects of the development of atherosclerosis," explained researchers from Sun Yat-sen University.
"In the present study, we first demonstrated that the plasma levels of the platelet chemokines CXCL7, CXCL5, CXCL8, CXCL12 and CCL2 were significantly decreased in hypercholesterolemic subjects after anthocyanin supplementation for 24 weeks.
"Furthermore, we found that the decreased levels of some platelet chemokines after anthocyanin treatment were closely correlated with the serum lipid and inflammatory molecule levels.
"These results indicated that anthocyanins exerted beneficial effects on the platelet chemokine levels, serum lipids and inflammatory factors, thereby inhibiting atherosclerosis."
The Chinese researchers recruited 146 people aged between 40 and 65 and randomly assigned them to consume either 320 mg of purified anthocyanins or placebo for 24 weeks.
Results showed that a number of platelet chemokines decreased after anthocyanin intake, including CXCL7 (12.3% decrease versus a 4% increase in the placebo group), CXCL5 (10% decrease vs 2% increase), CXCL8 (6% decrease vs. 0.7% increase), CXCL12 (8.1% decrease vs. 5.4% increase) and CCL2 levels (11.6% decrease vs. 12.8% increase.
"Interestingly, the decreases in the CXCL7 and CCL2 levels were both positively correlated with the decreases in the serum low-density lipoprotein-cholesterol (LDL-C), high-sensitivity C-reactive protein (hsCRP) and interleukin-1Beta (IL-1Beta) levels after anthocyanin supplementation for 24 weeks," said the researchers.
In addition, lower CXCL8 levels were correlated with increased HDL-Cholesterol levels, and with lower levels of soluble P-selectin (sP-selectin).
"These findings indicate a potential mechanism by which anthocyanins exert protective effects on the cardiovascular system, achieved through the comprehensive regulation of platelet chemokines, lipid metabolism and inflammation, in which platelet chemokines may play pivotal roles."