Amazing Acai Appears to Alleviate Atherosclerosis
Lee Swanson Research Update
The study, published in Atherosclerosis, presents evidence to suggest that the athero-protective effect of the acai juice is in part due to reduced breakdown of lipids (lipid peroxidation), which may be due to increasing the levels and activity of two antioxidant enzymes.
The research also supports the possibility that acai juice may exert protective effects against the development of atherosclerosis by inhibiting pro-inflammatory compounds called cytokines, through regulating inflammatory mediators.
"We provide direct experimental evidence that a diet containing an acai juice at the dose of five percent developed significantly less atherosclerotic lesions," said the researchers, led by Dr. Xianli Wu from the University of Arkansas for Medical Sciences.
The authors said the study "provides the first reported indication that acai juice protects against atherosclerosis," adding that the results "clearly indicate that acai juice significantly reduced lipid peroxidation."
"Reducing lipid peroxidation through boosting antioxidant enzymes and inhibiting pro-inflammatory cytokine production are proposed as major underlying mechanisms for the athero-protective effects of the acai juice tested in these experimental in vivo models," the researchers explained.
Dr. Wu and his colleagues explained that cardiovascular disease is the leading cause of death, not only in the United States "but also in most of the industrialized world." They added, "It has long been recognized that a diet rich in fruits and vegetables may have beneficial effects on cardiovascular diseases, largely attributed to their antioxidant and anti-inflammatory properties."
However, the researchers noted that in vivo experimental evidence to support the consumption of specific fruits and vegetables in reducing the risk of cardiovascular disease based on plausible mechanisms "remains scarce."
The new study investigated the athero-protective effects of acai juice in a mouse model. Markers of oxidative stress were found to be significantly lower in the serum and liver of acai-juice-fed animals.
Results from analysis of 17 genes related to oxidation/antioxidant enzymes also showed that expression of two antioxidant enzyme genes, glutathione peroxidase (GPX) and glutathione reductase (GSR)—considered important antioxidant enzymes in vascular systems—were significantly up-regulated in the aorta of acai-juice-fed mice.
The activities of GSR in serum and liver and GPX in serum were also reported to increase in acai-juice-fed mice. "Hence, these two antioxidant enzymes may act synergistically to reduce lipid peroxidation," Wu and his co-workers suggested.
Serum antioxidant enzyme PON1 (associated with HDL and implicated in the prevention of LDL lipid peroxidation) was also found to be elevated in acai-juice-fed mice.
In further experiments, mice fed acai juice for five weeks were reported to have significantly lower serum levels of the pro-inflammatory cytokines IL-6 and TNF-a.
"Not only did acai juice reduce basal levels of these two pro-inflammatory cytokines, it also increased the resistance of secretion of these two cytokines by macrophages in response to inflammatory stimuli such as LPS," the authors said.
The authors of the research are from the USDA Arkansas Children’s Nutrition Center, the Department of Physiology and Biophysics, the Department of Immunology at University of Arkansas for Medical Sciences and AIBMR Life Science, Inc.
Atherosclerosis; Published online ahead of print.
June, 2011