Over the next few articles, I will be exploring some important cardiovascular (circulatory system) themes. On checking, I was surprised to discover that in 15 plus years of writing this column I had never dedicated one to globe artichoke (Cynara scolymus, also called Cynara cardunculus var. scolymus).
We all know that the cooked unexpanded flower heads are a delicious addition to our meals, but herbal clinicians (especially in Europe) prize the leaves for a number of therapeutic uses as well, including elevated cholesterol and poor digestion. These applications are all backed up by clinical trials.
Boost bile production and aid digestion with artichoke
Let’s look at its benefits for digestion first. One of the key properties of globe artichoke is its ability to stimulate bile production by the liver (known as choleretic activity). In fact, it’s the best clinically proven herb for doing this.
The increase in bile flow after intraduodenal administration of standardized globe artichoke extract was investigated in a randomized, placebo-controlled, double-blind pilot study using a crossover design. Twenty healthy male volunteers were given a single dose of six capsules, each of which contained 320mg of 4.5 to 5:1 globe artichoke extract (equivalent to 1.5g of leaf and providing 0.2mg of cynarin). The amount of bile released into the duodenum was the primary variable measured and a maximum effect from the globe artichoke extract was achieved after one hour.
Significant and clinically relevant differences were still apparent three hours after it was administered, whereas bile secretion fell in the placebo group. This effective period of approximately 120 to 150 minutes was regarded as satisfactory to favourably influence digestion and intestinal motor function when the herb is given after a meal. No side effects were observed.1
Better bile flow reduces nausea, constipation and indigestion
An increase in bile flow will help digestion, especially of fats. Consequently, nausea after a fatty meal will be reduced. It will also have a mild laxative effect in people who are constipated due to a sluggish liver. This has been put to the test in a number of clinical trials for globe artichoke. For example, in a multicentre trial, patients with symptoms such as nausea, constipation, dyspepsia (indigestion) and functional gallbladder conditions were treated with a globe artichoke extract. The average dose corresponded to about 7g per day of leaf. After six weeks of treatment, results for 170 patients were analysed.
Improvements in symptoms were most marked for nausea and vomiting (improvement in 95% of cases), nausea (85%), abdominal pain (75%) and cramping right-sided pain (25%). In addition, problems such as flatulence and fat intolerance were favourably affected. There was also a significant reduction in mean total cholesterol from 267 mg/dL to 228 mg/dL (6.9 to 5.9 mmol/L).2
Globe artichoke eased irritable bowel symptoms
Globe artichoke can also help irritable bowel syndrome. More than 500 healthy people with self-reported dyspepsia, as assessed via the Nepean Dyspepsia Index and the State-Trait Anxiety Inventory, were randomly allocated 320 or 640mg per day of globe artichoke extract for months in an open study.3 In both dosage groups there was a significant reduction of all dyspeptic symptoms, with an average reduction of 40% in the Global Dyspepsia Score. Health-related quality of life was also significantly enhanced in both groups.
A follow-up analysis of the data was later done to assess the subset of patients with irritable bowel syndrome (IBS) symptoms, namely alternating constipation and diarrhoea, and mucus in stools.4 Two hundred and eight adults were identified as meeting the criteria for IBS, and analysis revealed that there was of 26.4% after treatment, with a shift away from alternating constipation and diarrhoea.
Total cholesterol plummeted nearly 23%
As mentioned above, the most popular use of globe artichoke in Europe is to lower elevated blood cholesterol levels. This is also probably related to its effects on the liver. The first clinical trials date back to the 1950s, the most recent one was published in 2013. Looking at some of the more recent studies, a randomized, double-blind, placebo-controlled trial evaluated a globe artichoke dry extract (equivalent to 45 to 63 g per day of fresh leaf) for six weeks in 143 hypercholesterolemic patients.5 Total cholesterol and LDL-cholesterol decreased from baseline by 18.5% and 22.9%, respectively.
Adults with mild to moderate hypercholesterolemia randomly received globe artichoke extract (equivalent to about 6.4g per day of dried leaf, containing 32mg of caffeoylquinic acids including cynarin and chlorogenic acid) or a placebo for 12 weeks.6 The mean body mass index (BMI) for both groups was above the ideal range of 20 to 25 kg/m2 and the majority participated in light or moderate exercise and had a moderately stressful lifestyle. Treatment with globe artichoke resulted in a small but significant decrease in plasma total cholesterol (4.2%), compared with an increase observed in the placebo group.
HDL cholesterol levels significantly increased
In a 2013 Italian study, a randomized, double-blind, placebo-controlled trial was undertaken in 92 overweight people with primary mild hypercholesterolemia.7 They took 500mg per day of an artichoke leaf extract or a matching placebo for eight weeks. Treatment with globe artichoke significantly increased HDL-cholesterol by 10%, and decreased total and LDL-cholesterol by 6% and 15%, respectively.
Of course, there is an ongoing debate about whether lowering LDL-cholesterol is always the first priority to reduce cardiovascular risk (heart attacks, strokes), especially when statin drugs are used to achieve this clinical endpoint. Hence, it is important above that the globe artichoke also increased protective HDL-cholesterol. The herb has been shown to improve other health measures linked to a high cardiovascular risk.
These favourable effects were demonstrated in a study of 18 moderately hyperlipidaemic patients given 20ml per day of frozen artichoke leaf juice for six weeks.8 Endothelial dysfunction (the health of blood vessel walls) was evaluated by ultrasound measurement of brachial flow-mediated vasodilation (FMV) and by the determination of several blood plasma markers, such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin. After globe artichoke, there was a reduction in total and LDL-cholesterol, and decreases in VCAM-1 and ICAM-1. Brachial FMV increased, while controls did not exhibit significant changes in any of these measures.
To your better health,
Nutrition & Healing
Vol. 8, Issue 3 – March 2014
Full references and citations for this article are available in the downloadable PDF version of the monthly Nutrition and Healing issue in which this article appears.