Effect of cranberry extract on lipids
Researchers from the Taichung Veterans General Hospital, in Taiwan examined the effect of cranberry ingestion on cholesterol in Type 2 diabetic patients taking anti-diabetes medicine.
First, the details.
- 30 adults with type 2 diabetes were randomly assigned to take cranberry extract or placebo for 12 weeks.
- Changes in cholesterol, diabetes control, components of the metabolic syndrome (eg, blood pressure), C-reactive protein, and urinary albumin excretion were measured.
- Neither the researchers nor patients knew the treatment given — double-blind.
And, the results.
- LDL (bad) cholesterol decreased significantly in the cranberry group compared to the start of the study and compared to the placebo group.
- Total cholesterol and total:HDL (good) cholesterol ratio also decreased significantly in the cranberry group vs placebo.
- There were no changes in diabetes control or in any other parameters.
The bottom line?
The authors concluded, “Cranberry supplements are effective in reducing atherosclerotic cholesterol profiles, including LDL cholesterol and total cholesterol levels, as well as total:HDL cholesterol ratio, and have a neutral effect on glycemic control in type 2 diabetic subjects taking oral glucose-lowering agents.”
The scientific literature on this issue is divided. Others report increases in HDL cholesterol during consumption of low-calorie cranberry juice cocktail for 4 weeks. While still others have reported no changes in cholesterol after drinking cranberry juice for 2 weeks.
Writing on Medscape, Profs. Mark Hamer and Gita Mishra, from University College London, in the UK tell us, “The mechanism of LDL-cholesterol lowering by cranberry extract… remains unclear. It is possible that certain flavonoids in cranberries, such as tannins, may increase hepatic uptake of cholesterol through the induction of LDL-receptor expression in hepatocytes, or intestinal absorption of cholesterol may be reduced via the binding of cranberries to bile acids.”
A PubMed search since the first posting of this summary revealed no new studies.
6/2/09 19:02 JR