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- Artichoke (Cynara scolymus)
- Hypercholesterolemia
- Cardiovascular Disease
| Date: 09-30-2008 | HC# 090161-361 |
Re: Efficacy of Artichoke Leaf Extract in Reducing Plasma Cholesterol Concentrations
Bundy R, Walker AF, Middleton RW, Wallis C, Simpson HCR. Artichoke leaf extract (Cynara scolymus) reduces plasma cholesterol in otherwise healthy hypercholesterolemic adults: A randomized, double blind placebo controlled trial. Phytomed. 2008;15: 668-675.
High plasma levels of total cholesterol are associated with
cardiovascular disease—the primary cause of death in the United Kingdom. The
World Health Report estimates that approximately 8% of disease in developed
countries is caused by elevated cholesterol levels and that greater than 60% of
coronary heart disease (CHD) is due to total blood cholesterol levels greater
than 3.8 mmol/L. More than 10 years ago, the Department of Health in the United
Kingdom reported an inverse association between CHD and dietary intakes of
antioxidants. Since then, the intakes of several fruits and vegetables, tea,
red wine, and cocoa have been shown to reduce the risk of CHD. Extracts from
the leaves of one such vegetable, the globe artichoke (Cynara scolymus), have traditionally been used in Europe as a digestive
aid and to improve the health of the urinary tract. Pharmacological research
has shown that artichoke leaf extracts (ALEs) have hypocholesterolemic and
antioxidant properties. The proposed mechanisms for these properties are a
reduction in cholesterol synthesis via the inhibition of HMG CoA reductase, an
increase in cholesterol excretion, and the inhibition of LDL oxidation. The
primary objective of the present study was to evaluate the effect of ALE
consumption on lipid levels in hypercholesterolemic but otherwise healthy
adults. The secondary objective was to evaluate well-being.
Seventy-five adults with a plasma total cholesterol level of 6.8 to 8.0
mmol/L were enrolled in this randomized, double-blind, placebo-controlled
study, which was conducted at the Hugh
Sinclair Unit of Human Nutrition (Reading, United Kingdom). The subjects were
randomly assigned to take either 1280 mg of ALE (Cynara Artichoke, Lichtwer
Pharma Ltd., Marlow, United Kingdom) or a matched placebo, daily for 12 weeks.
At baseline and at the end of the study, the patients completed a well-being
questionnaire (Psychological General Well-Being Index), had blood samples
drawn, and had weight, height, and blood pressure measured. Concentrations of
triglycerides and total, high-density-lipoprotein (HDL), and
low-density-lipoprotein (LDL) cholesterol were measured in plasma. The data
were analyzed on an intention-to-treat basis, and any adverse events
experienced by the subjects were recorded.
Plasma total cholesterol decreased from baseline in the ALE group by
approximately 4.2% (from a mean ± SD of 7.16 ± 0.62 to 6.86 ± 0.68 mmol/L) but increased in the placebo
group by approximately 1.9% (from a mean ± SD of 6.90 ± 0.49 to 7.03 ± 0.61 mmol/L), after 12 weeks. An analysis of
variance indicated a 6.1% difference in plasma total cholesterol between the
groups at 12 weeks (P = 0.025). No significant differences in triglyceride, HDL,
or LDL cholesterol concentrations were observed between groups. Two adverse
events were reported in each group, which were deemed to be unrelated to the
study treatment. No significant differences in well-being were observed between
groups; however, well-being improved significantly in the ALE group (by 9.9%)
and in the placebo group (by 11.0%) over the course of the study (P <
0.001). The mean ± SD scores were 92.1 ± 14.9 and 91.7 ± 12.3 for the
ALE and placebo groups, respectively; both scores were within the range
indicating a positive well-being.
The results indicate that consumption of 1280 mg ALE daily for 12 weeks
had a modest but favorable statistically significant effect on plasma total
cholesterol levels in hypercholesterolemic adults, although the effect was not
as strong as observed in a previous similar study. Differences in the quantity
and type of extract used and in the lifestyle characteristics of the subjects –
which contribute to "the apparent positive health status of the study
population" – are likely explanations for the differences in the magnitude
of the response observed between the 2 studies. The authors conclude that
"this study provides further evidence that ALE may help reduce plasma
total cholesterol in adults with mild to moderate hypercholesterolemia."
—Brenda Milot, ELS |