Artichoke Extract, the New Ally Against High Cholesterol

Known for its protective properties for the liver, artichoke extract is also an effective ally against high cholesterol. Here’s how it can help protect heart and artery health.

High cholesterol is one of the main cardiovascular risk factors. Lowering it allows those dealing with atherosclerosis (the buildup of cholesterol and other material in artery walls) to reduce both cardiovascular mortality and the incidence of dangerous events such as heart attacks. Moreover, even those who have not yet developed symptoms and signs of atherosclerosis can benefit from molecules traditionally used to lower cholesterol, such as statins. 

Despite the widespread use and known effectiveness of these drugs, not everyone likes the idea of taking them; in fact, more and more people lean toward non-pharmacological alternatives. Sometimes this desire comes from a personal inclination to avoid medication; other times from already using many other medicines. Some also report unpleasant side effects associated with statins (particularly muscle pain). There are also those who have cholesterol levels outside the norm but do not have a cardiovascular risk high enough for a doctor to prescribe medication. 

Until recently, the most common alternative was undoubtedly red yeast rice. However, recently, the use of its active principles (monacolins) in dietary supplements has faced strong restrictions. The reason is simple: monacolins, particularly monacolin K, are essentially natural statins. Their effectiveness in lowering cholesterol is unquestionable. 

Unfortunately, because they are so similar to recognized and regulated molecules, authorities decided monacolins should no longer be marketed and consumed as dietary supplements, with all that this entails including possible side effects. This does not mean there is no alternative to statins anymore, but rather that one should opt for tablets or capsules containing other ingredients with proven cholesterol-lowering properties. Among market offerings, artichoke extract standardized in chlorogenic acid and luteolin stands out without doubt. 

 Properties of artichoke extract 

Indeed, the beneficial properties of artichoke extract have long been known, and numerous studies have confirmed what centuries of medicinal use of this natural remedy suggested. The therapeutic effects of artichoke (Cynara scolymus) were already well-known in the 17th century. 

The 20th century provided evidence of its stimulating effects on the liver and gallbladder, adding more details: artichoke can also help lower blood sugar levels and – which is particularly relevant for those with high cholesterol – reduce both blood lipid levels and oxidative stress. Oxidative stress can modify cholesterol particles making them more dangerous; thus, the antioxidant effect of artichoke may help reduce cardiovascular risk. 

A review of scientific literature data, published in 2018 in Pharmacological Research, concluded that regarding blood lipid levels, the main effects of artichoke leaf extract supplementation are:

• the reduction of total cholesterol;
• the reduction of LDL (Low Density Lipoprotein), the form of blood cholesterol that increases cardiovascular risk if present in excessive amounts (commonly known as "bad cholesterol");
• the reduction of triglycerides, other lipids that, if present in excess, increase cardiovascular risk.

According to this analysis, a daily intake of 2-3 grams of artichoke leaf extract reduces LDL by between 8 and 49 mg/dL and total cholesterol by 12-55 mg/dL. The authors hypothesize that two active compounds are responsible for these and other effects beneficial to reducing cardiovascular risk: chlorogenic acid and luteolin. The effectiveness may depend on the concentration of these molecules; therefore, it is especially important to rely on standardized extracts (i.e., containing known concentrations) of these molecules. 

Chlorogenic acid and luteolin: how do they work? 

Chlorogenic acid is a phenolic compound found in various fruits and vegetables. Its effects on cholesterol levels depend on inhibiting the enzyme responsible for its synthesis, the same enzyme inhibited by statins (HMG-CoA reductase). Moreover, chlorogenic acid also inhibits several other enzymes involved in fatty acid synthesis and digestion of dietary fats. Luteolin is also found in many plant species. It is a flavonoid associated with the ability to inhibit cholesterol absorption at the intestinal level and reduce its synthesis, as well as antioxidant properties towards LDL. 

A study published in 2019 in Nutrients demonstrated the ability of an artichoke extract standardized in chlorogenic acid and derivatives (10-12%) and luteolin-7-glucoside and derivatives (2-4%) to improve cardiometabolic parameters in people with metabolic syndrome, a condition significantly increasing cardiovascular risk. The study involved 50 individuals with metabolic syndrome who took 150 mg per day of the artichoke extract standardized in chlorogenic acid and luteolin-7-glucoside for 6 months, while another 50 individuals with metabolic syndrome took a placebo for the same period. Analyses showed the extract’s effectiveness in reducing total cholesterol and LDL cholesterol levels, along with improvements in other important cardiovascular risk factors (including blood triglyceride levels) and liver health. 

The carotid intima-media thickness (an index of atherosclerosis) also improved after extract intake. Based on these results, the authors suggest taking an artichoke extract containing 10-12% chlorogenic acid and derivatives and 2-4% luteolin-7-glucoside and derivatives “as a valid and safe approach to preventing and managing cardiometabolic alterations”. 

Side effects and contraindications 

Artichoke extract is generally considered safe and free of side effects. Traditional use is mostly associated with mild diarrhea with abdominal cramps, nausea, heartburn, and other stomach discomforts. In some cases, medical evaluation is required; specifically, the European Medicines Agency (EMA) lists biliary duct obstruction, cholangitis, liver diseases, and gallstones as contraindications for traditional use. No definite contraindications have yet been established for standardized extracts, which in the Nutrients study caused only transient gastrointestinal symptoms, reported even more frequently in the placebo group. 

Caution should be exercised in cases of allergies to plants in the Asteraceae family, such as lettuce, since artichoke is closely related. One last curiosity: according to the 2019 Nutrients study, artichoke extract may also be useful for weight loss. 

Its intake has also been associated with reductions in waist circumference and body mass index. Not all artichoke supplements may be equally effective: here too, it is better to prefer those containing standardized extracts of chlorogenic acid (10-12%) and luteolin (2-4%). 

Sources

• Ben Salem M et al. Pharmacological Studies of Artichoke Leaf Extract and Their Health Benefits. Plant Foods Hum Nutr. 2015 Dec;70(4):441-53. doi: 10.1007/s11130-015-0503-8
• Brown JE and Rice-Evans CA. Luteolin-rich artichoke extract protects low density lipoprotein from oxidation in vitro. Free Radic Res. 1998 Sep;29(3):247-55. doi: 10.1080/10715769800300281
• Castellino G et al. Altilix® Supplement Containing Chlorogenic Acid and Luteolin Improved Hepatic and Cardiometabolic Parameters in Subjects with Metabolic Syndrome: A 6 Month Randomized, Double-Blind, Placebo-Controlled Study. Nutrients. 2019 Nov; 11(11): 2580. doi: 10.3390/nu11112580
• European Medicines Agency. Committee on Herbal Medicinal Products (HMPC). European Union herbal monograph on Cynara cardunculus L. (syn. Cynara scolymus L.), folium. Final. 27 March 2018
• Ibrahim MA et al. Hypercholesterolemia. [Updated 2022 Jun 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459188
• Miao M and Xiang L. Chapter Three - Pharmacological action and potential targets of chlorogenic acid. Advances in Pharmacology. Volume 87, 2020, Pages 71-88. doi: 10.1016/bs.apha.2019.12.002
• Nekohashi M et al. Luteolin and Quercetin Affect the Cholesterol Absorption Mediated by Epithelial Cholesterol Transporter Niemann–Pick C1-Like 1 in Caco-2 Cells and Rats. PLoS One. 2014; 9(5): e97901. doi: 10.1371/journal.pone.0097901
• Oliveira Santos H et al. The effect of artichoke on lipid profile: A review of possible mechanisms of action. Pharmacol Res. 2018 Nov;137:170-178. doi: 10.1016/j.phrs.2018.10.007