Artichokes (Cynara cardunculus var. scolymus), originating in the Mediterranean, have been used for centuries for their potential medicinal properties. Often considered a vegetable, artichokes are a type of thistle rich in fiber, antioxidants, and other nutrients. Artichoke leaf extracts are used in herbal medicines as a hepato-protectant and choleretic and reportedly also have anti-carcinogenic, anti-oxidative, anti-human immunodeficiency virus, and antibacterial effects. Artichoke extract, which contains high concentrations of compounds found in the plant, is also increasingly popular as a supplement. While some believe artichoke leaf extract offers numerous health benefits, including promoting weight loss, or even "cleansing" the liver. This article delves into the available research on artichoke extract, focusing on its potential role in weight loss and other aspects of health.
Nutritional Profile of Artichokes
Artichokes are packed with powerful nutrients. Each cup, or 170 grams (g), of cooked artichoke contains:
- Calories: 90
- Carbs: 20 g
- Fiber: 10 g
- Protein: 5 g
- Fat: 0.6 g
- Folate: 151 μg
- Copper: 0.216 mg
- Magnesium: 71.4 mg
- Vitamin C: 12.6 mg
- Niacin: 1.88 mg
- Riboflavin: 0.151 mg
- Potassium: 484 mg
- Phosphorus: 124 mg
- Vitamin B6: 0.138 mg
Artichokes are low in fat while rich in fiber, vitamins, minerals, and antioxidants. Exceptionally high in folate and vitamin C, they also supply essential minerals, such as magnesium, phosphorus, and potassium. These delicious thistles come with only 90 calories per cooked cup (170 g) and around 5 g of protein, above average for a plant-based food. Artichokes are also rich in a variety of antioxidants.
Artichoke leaves contain various phenolic compounds (about 7.13%) including chlorogenic acid (about 4.71%), cynarin (about 1.62%), luteolin (about 0.42%), cymaroside (about 0.25%), and 1-caffeoylquinic acid (about 0.13%) [10,11]. Among them, luteolin (LU), which is a member of the flavonoids (a subclass of flavones), exists in vegetables and fruits such as celery, parsley, and peppermint.
Weight Loss and Obesity
Obesity or adiposity, which is rapidly increasing in both industrialized and non-industrialized countries, is a global epidemic that is constantly recognized as a health problem [1]. The World Health Organization estimated that among adults worldwide approximately 13% were obese and 39% were overweight in 2014. Obesity is defined as an imbalance between energy intake and energy expenditure [2]. Adipose tissues play an important role in the improvement of insulin resistance by regulating glucose and lipid metabolism as well as energy balance [3].
Read also: The Role of Enzymes in Digestion
One study investigated the effects and possible underlying mechanisms of long-term supplementation with dietary luteolin (LU)-enriched artichoke leaf (AR) in high-fat diet (HFD)-induced obesity and its complications (e.g., dyslipidemia, insulin resistance, and non-alcoholic fatty liver disease) in C57BL/6N mice. The mice were fed a normal diet, an HFD, or an HFD plus AR or LU for 16 weeks. In the HFD-fed mice, AR decreased the adiposity and dyslipidemia by decreasing lipogenesis while increasing fatty acid oxidation, which contributed to better hepatic steatosis. LU also prevented adiposity and hepatic steatosis by suppressing lipogenesis while increasing biliary sterol excretion. Moreover, AR and LU prevented insulin sensitivity by decreasing the level of plasma gastric inhibitory polypeptide and activity of hepatic glucogenic enzymes, which may be linked to the lowering of inflammation as evidenced by the reduced plasma interleukin (IL)-6, IL-1β, and plasminogen activator inhibitor-1 levels. Although the anti-metabolic syndrome effects of AR and LU were similar, the anti-adiposity and anti-dyslipidemic effects of AR were more pronounced.
In a study on mice, AR significantly decreased the BW after week 6 and consistently suppressed it except at week 14 (Figure 1A,B). In the HFD group, the food intake was significantly decreased while the food efficiency ratio (FER) was markedly increased when compared with the ND group (Figure 1C,D). Supplementation with AR or LU significantly decreased the FER relative to that in the HFD group (Figure 1D). The WAT weights were significantly higher in the HFD group than in the ND group. Both AR and LU significantly lowered the mesenteric, interscapular, visceral (sum of epididymal, perirenal, mesenteric, and retroperitoneal WAT) and total WAT (sum of visceral, subcutaneous, and interscapular WAT) weights in the HFD group (Figure 1D). Moreover, morphological observations revealed that the epididymal adipocyte size in the AR and LU groups was smaller than that in the HFD group (Figure 1F).
The expression levels of lipid metabolism-related adipocyte genes were regulated by AR and LU supplementation. AR significantly increased not only the mRNA expression of adipocyte genes involved in both FA uptake and lipogenesis (i.e., CD36, LPL, SREBP1, and SREBP2) but also those related to FA oxidation (i.e., ADRB3, CPT1, PGC1β, and UCP1) relative to the levels in the HFD group (Figure 1G). LU also markedly elevated the adipocyte mRNA expression of both lipogenic genes (CD36, SREBP1, and SREBP2) and hydrolytic genes (ADRB3, CPT1, CPT2, and COX8B) relative to the levels in the HFD group (Figure 1G). Notably, AR significantly increased the expression of ADRB3 relative to that in the LU group.
Appetite
Some studies have investigated the effects of Artichoke Extract and its ability to reduce food intake, usually in combination with Phaseolus Vulgaris (White Kidney Bean Extract), where Artichoke appears to be ineffective while the latter is somewhat effective at reducing food intake.[12] This inefficacy with Artichoke Extract has been noted elsewhere.[13] The combination of the two extracts has been shown to reduce food intake in obese (BMI greater than 35) persons without highly abnormal health parameters.
Cardiovascular Health
Cholesterol
Artichoke extract appears to induce secretion of cholephilic compounds bile canaliculi,[15] which then leads to accumulation of bile acids in the intestines.[1] This increase of bile acids in the intestines has been demonstrated (in rodents) to be the cause of cholesterol reducing effects associated with artichokes.
Read also: Effectiveness of the GOLO Diet
In rats given 100, 200, or 400mg/kg Artichoke extract (80% bioactives), bile flow into the intestines appears to be increased in a dose-dependent manner. In human interventions, a study of 18 moderately hyperlipidemic patients consuming the juice made from artichoke leaves (20mL; 2.5% fiber, 0.7% glucydes) in conjunction with a standard hypolipidemic diet for 6 weeks reported an increase in triglycerides associated with treatment only and a decrease in total cholesterol and LDL-C that occurred in both groups (due to the diet intervention).[18]
In comparison to this low dose study, one study using a 450mg Extract capsule (25-35:1 concentration) four times daily (1,800mg total) in persons with high cholesterol (7.3mmol/L or more) was associated with an 18.6% reduction in total cholesterol, 22.9% reduction in LDL-C, and no significant influence on either HDL-C (despite the ratio being improved) or Triglycerides.[19] A third study (double-blind) with 1280mg Artichoke extract also suggests cholesterol reducing properties with 75 adults with high cholesterol over 12 weeks, but only the difference between artichoke (4.2% reduction) and placebo (2% increase) was significant; the reduction of total cholesterol from baseline to final was not significant, nor was any alteration in LDL-C, HDL-C, or triglycerides.[20] This latter study used 1280mg of a 4-6:1 extract, so it is possible it was underdosed. Only one study has currently noted increases in HDL-C with 500mg Artichoke extract,[21] which is in contrast to previous studies using both lower[18] and higher[19][20] doses. Appears to have potential to reduce circulating cholesterol levels, but relative to other compounds the body of literature is quite small.
The plasma TG, TC, HDL-C, non HDL-C, and AI levels were significantly higher while the HDL-C to TC ratio (HTR) and ApoA-I levels were significantly lower in the HFD group than in the ND group (Table 2). Supplementation with AR significantly decreased the plasma in FFA, TG, TC, and non HDL-C levels (Table 2).
Blood Pressure
Artichoke extract may aid people with high blood pressure. Several reviews have found that artichoke supplementation could significantly reduce systolic and diastolic blood pressure in people with high blood pressure levels. It is not fully understood how artichoke extract reduces blood pressure. However, some research suggests that it promotes the enzyme eNOS, which plays a role in widening blood vessels. Artichokes are also a good source of potassium, which helps regulate blood pressure.
Liver Health
Artichoke leaf extract may protect your liver from damage and promote the growth of new tissue. It also may increase the production of bile, which helps remove harmful toxins from your liver. In one study, artichoke leaf extract decreased inflammation and liver cell death in mice with nonalcoholic fatty liver disease (now called metabolic dysfunction-associated steatotic liver disease). Studies in humans also show positive effects on liver health. For example, one 2018 trial in 90 people with non-alcoholic fatty liver disease revealed that consuming 600 milligrams (mg) of artichoke extract daily for 2 months led to improved liver function. Other reviews have found that artichoke supplementation could reduce liver enzyme levels. Elevated liver enzymes often indicate inflammation or damage to the liver. One study in persons with high cholesterol has noted decreases in liver enzymes associated with high dose (1,800mg of a 25-35:1 concentrated extract) of artichoke, where over 45 days a decrease was seen for y-GT (25.8%), AST (17.3%), and ALT (15.2%) with no influence on GLDH.[19]
Read also: The Truth About Keto Fusion Pills
The hepatic and fecal TG, cholesterol, and FA levels were markedly higher in the HFD group than in the ND group (Figure 2A, B). Supplementation with LU significantly decreased the hepatic TG, cholesterol, and FA levels and increased the fecal cholesterol and FA contents relative to the levels in the HFD group (Figure 2A,B). AR significantly decreased the hepatic cholesterol and FA levels while it tended to increase the level of fecal cholesterol excretion relative to the levels in the HFD group (Figure 2A,B). Hepatic morphological observations revealed that the sizes and numbers of hepatic lipid droplets were significantly lower in the AR and LU groups than in the HFD group (Figure 2C). The AR and LU groups had significantly reduced hepatic PAP enzyme activity and increased hepatic CPT activity when compared with the enzyme activity levels in the HFD group (Figure 2D). Analysis of the hepatic gene expression levels showed that AR and LU supplementation increased the mRNA expression of ABCG8 and ABCG5 in the mice with DIO.
In a study, changes in cellular activity demonstrated that ALE protects hepatocytes from lipotoxic stress.
Digestive Health
Artichokes are a great source of fiber, which can help keep your digestive system healthy by promoting friendly gut bacteria, reducing your risk of certain bowel cancers, and alleviating constipation and diarrhea. Artichokes contain inulin, a type of fiber that acts as a prebiotic. In one 2010 study, consuming 10 g of inulin derived from globe artichokes led to improvements in the composition of the gut microbiome after 3 weeks.
Artichoke extract may also provide relief from symptoms of indigestion, such as bloating, nausea, and heartburn. Irritable bowel syndrome (IBS) is a condition that affects your digestive system and can cause stomach pain, cramping, diarrhea, bloating, constipation, and flatulence. In one older study in people with IBS, consuming artichoke leaf extract daily for 6 weeks helped ease symptoms. What’s more, 96% of participants rated the extract equally as effective as - if not better than - other IBS treatments, such as antidiarrheals and laxatives. A 2004 study in 208 people with IBS discovered that 1-2 capsules of artichoke leaf extract, consumed daily for 2 months, reduced symptoms by 26% and improved quality of life by 20%.
In the colon, Inulin (a dietary fiber extracted from species of Artichoke) is able to proliferate the bacteria in the colon.
Interactions with Glucose Metabolism
One animal study from 2017 found that certain compounds in artichoke could reduce blood sugar and improve cholesterol and triglyceride levels in rats, which could be due to its antioxidant effects. In another small study, artichoke extract supplementation enhanced blood sugar management and improved several other aspects of metabolic health - such as cholesterol levels and waist circumference - after 8 weeks. What’s more, a review of nine studies concluded that artichoke and artichoke products could significantly reduce fasting blood sugar levels in humans.
Interactions with Cancer
Animal and test-tube studies note that artichoke extract impaired cancer growth. One in vitro study using the MDA-MB231 breast cancer cell line noted that the polyphenols of Artichoke (1/1 water/ethanolic extract of mostly caffeoylquinic acids) was able to induce 60% apoptosis at 600uM concentration over 24 hours; lower but significant degrees of cytotoxicity were seen in n BT549, T47D, and MCF-7 cancer cell lines but not MCF10A normal breast epithelial cells.[30] 400uM abolished cell proliferation in MDA-MB231 cells over 6 days and reduced the invasive potential of these cells, and these effects were thought to be mediated via the chlorogenic acid content of Artichoke.[30] Certain antioxidants - including rutin, quercetin, silymarin, and gallic acid - in artichokes are thought to be responsible for these anticancer effects.
Interactions with Oxidation
The anti-oxidant potential of artichoke appears to be less than that of turmeric (dietary source of curcumin) but more than that of rosemary and dandelion root.
Interactions with Sexuality
The active luteolin compounds are thought to be pro-erectile due to PDE5 inhibition, the mechanism of action of Viagra.
Safety and Potential Side Effects
Consuming artichoke extract is generally considered safe, with few side effects reported. Artichoke extract is not generally recommended for children and people who are pregnant or nursing, as there is a lack of research on its safety for these populations. Similarly, people with certain health conditions - including severe liver or kidney disease - should not take artichoke extract unless advised by a doctor. Some people may be allergic to artichokes or artichoke extract. The risk may be higher for anyone allergic to plants from the same family, including daisies, sunflowers, chrysanthemums, and marigolds. Artichokes are safe when eaten as food. Artichoke supplements can cause a reaction in people who are allergic to marigolds, daisies, and other similar plants. There is no recommended dose for artichoke leaf extract in any form. The amounts used in research vary from 250 to 2,700 mg per day. Due to the lack of safety research, artichoke leaf extract should not be used in children, people who are pregnant or breastfeeding, or those with chronic medical conditions.