Artichoke extract, the new ally against high cholesterol

Known for its protective properties against 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 a major cardiovascular risk factor. Lowering it allows those struggling with atherosclerosis (the accumulation of cholesterol and other material in the artery wall) to reduce both mortality from cardiovascular causes and the incidence of dangerous events such as heart attack. Not only that, even those who have not yet developed the symptoms and signs of atherosclerosis can benefit from taking the molecules traditionally used to reduce cholesterolemia, statins. 

Despite the widespread use and now known effectiveness of these drugs, not everyone likes the idea of taking them; indeed, more and more people are leaning toward using non-drug alternatives. Sometimes their desire is driven by a personal propensity not to take drugs, other times by the fact that they already use many other medications. There is also no shortage of those who report the occurrence of unpleasant side effects associated with taking statins (in particular, muscle pain). And there are also those who, yes, have cholesterol values outside the normal range, but do not run such a cardiovascular risk that the doctor prescribes drug treatment. 

Until recently, the most popular alternative was undoubtedly fermented red rice. Recently, however, the possibility of using its active ingredients (monacolins) in the formulation of dietary supplements has come under severe restrictions. The reason for such measures is simple: monacolins, particularly monacolin K, are essentially natural statins. Not surprisingly, their effectiveness in reducing cholesterol is beyond doubt. 

Unfortunately, however, precisely because they are so similar to recognized and regulated molecules, the authorities in charge did not consider it appropriate that monacolines could continue to be marketed and taken as dietary supplements, with all that this also entails in terms of possible side effects. All this is not to say that an alternative to statins is no longer available, but to turn to tablets or capsules based on other ingredients with proven cholesterol-lowering properties. Among the offerings on the market,artichoke extract titrated in chlorogenic acid and luteolin undoubtedly stands out.  

 The properties of artichoke extract 

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

The 20th century has provided us with evidence of its liver- and gallbladder-stimulating properties, adding a few more details: artichoke may also help lower blood sugar (the level of sugar in the blood) and--a fact of most interest to those with high cholesterol--reduce both blood lipid levels and oxidative stress. The latter can change cholesterol particles, making them more dangerous; therefore, the antioxidant effect of artichoke could also help reduce cardiovascular risk. 

An analysis of data in the scientific literature, published in Pharmacological Research in 2018, concluded that with regard to blood lipid levels, the main effects of taking artichoke leaf extract are:

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

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

Chlorogenic acid and luteolin: how do they work? 

Chlorogenic acid is a phenolic compound found in several fruits and vegetables. Its effects on cholesterol levels depend on inhibiting the enzyme responsible for its synthesis, the same enzyme that is inhibited by statins (HMG-CoA reductase). Not only that, chlorogenic acid also inhibits a number of other enzymes involved in fatty acid synthesis and digestion of food-derived fats. Lutein is also present in many plant species. It is a flavonoid that has been associated with both the ability to inhibit intestinal absorption of cholesterol and reduce its synthesis, and antioxidant properties against LDL. 

A study published in 2019 in Nutrients demonstrated the ability of an artichoke extract titrated in chlorogenic acid and derivatives (10-12%) and luteolin-7-glucoside and derivatives (2-4%) to improve cardiometabolic parameters of people with metabolic syndrome, a condition that significantly increases cardiovascular risk. The study involved 50 individuals with metabolic syndrome taking 150 mg per day of the artichoke extract titrated to chlorogenic acid and luteolin-7-glucoside for 6 months and another 50 individuals, also with metabolic syndrome, taking a placebo for the same time. Analyses conducted demonstrated the extract's effectiveness in reducing total and LDL cholesterol levels, as well as improvements in other important cardiovascular risk factors (including blood triglyceride levels) and liver health. 

Intima-media thickness of the carotid artery (an index of atherosclerosis) was also found to be improved following intake of the extract. 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 in the prevention and management of cardiometabolic changes."  

Side effects and contraindications 

Artichoke extract is considered mostly safe and free of side effects. Traditional use is at most associated with mild diarrhea with abdominal spasms, nausea, heartburn, and other discomfort in the stomach mouth. Only in some cases does its intake require careful medical evaluation; in particular, the European Medicines Agency (EMA) lists bile duct obstruction, cholangitis, liver disease, and gallstones as contraindications to traditional use. In contrast, no definite contraindication has yet been defined for the titrated extract, which in the study published in Nutrients triggered transient gastrointestinal symptoms at most, which were even detected more frequently among participants taking placebo. 

Some care should be taken in case of allergies to plants belonging to the Asteraceae family, such as lettuce: artichoke is a close relative of theirs. One last curiosity: according to the study published in 2019 in Nutrients,artichoke extract could also be useful for weight loss. 

In fact, its intake has also been associated with reducing waistline and body mass index. Not all artichoke supplements, however, may be equally effective: again, best to prefer those containing an extract titrated in 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