Benefits of Artichoke for Digestive Disorders
The artichoke plant is best known for its heart, the bottom part of its spiky flower bud that many of us have learned to appreciate as both a delicacy and a nutritious vegetable. However, other parts of this tall thistle-like plant, which never reach the dinner table, have proven to be even more beneficial for our health. Clinical studies show its large basal leaves to be effective for improving digestion and liver function, as well as cholesterol levels.
Since ancient times, humans have looked to nature for help to cure diseases. Up until modern times, most remedies were derived from the plant kingdom, and even today a large percentage of our current pharmaceutical drugs are based on plant extracts from various parts of the world. Many old herbal remedies, however, have fallen into oblivion with the development of modern medicine.
Artichoke extract is one of the few phytopharmaceuticals whose experiential and clinical effects have been confirmed to a great extent by biomedical research. Its major active components have been identified, as have some of its mechanisms of action in the human body. In particular, antioxidant, liver-protective, bile-enhancing, and lipid-lowering effects have been demonstrated, which correspond well with the historical use of the plant. More research is needed to determine in detail the mechanisms of action for these effects. However, there appears to be enough evidence to suggest a potential role for artichoke extract in some areas where modern medicine does not have much to offer.
Used as a food and a medical remedy as early as 400 BC, the artichoke plant has a long history. At the time, a pupil of Aristotle by the name of Theophrastus was one of the first to describe the plant in detail. Enjoyed as a delicacy, an appetizer, and a digestive aid by the aristocracy of the Roman Empire, it later seemed to fall into oblivion until the 1500s, when medicinal use of the artichoke for liver problems and jaundice was recorded. In 1850 a French physician successfully used extract of artichoke leaves in the treatment of a boy who had been sick with jaundice for a month and had made no improvement from the drugs used at that time. This accomplishment inspired researchers to find out more about the effects of this extract, and their research resulted in the knowledge we have today about the extract and its mechanisms of action.
Artichoke leaf extract is made from the long, deeply serrated basal leaves of the artichoke plant. This part is chosen for medicinal use because the concentration of the biologically active compounds is higher here than in the rest of the plant. The most active of these compounds have been discovered to be the flavonoids and caffeoylquinic acids. These substances belong to the polyphenol group and include chlorogenic acid, caffeoylquinic acid derivatives (cynarin is one of them), luteolin, scolymoside, and cynaroside.
Cynarin was the first constituent of the extract to be isolated in 1934. Interestingly, it is found only in trace amounts of fresh leaves but is formed by natural chemical changes that take place during drying and extraction of the plant material. Cynarin was originally believed to be the one active component of the extract. Today the whole complex of compounds is considered important, since it has not yet been completely clarified which component is responsible for each effect. It is claimed that neither cynarin alone, nor fresh plant material achieves the potency of the dried total extract (Kirchhoff 1994).
Chlorogenic acid, another major component of the artichoke leaf extract, has recently become known as a powerful antioxidant with exciting potential in many applications. Laboratory investigations are ongoing all over the world with promising findings for future clinical application in areas such as HIV, cancer, and diabetes.
Most of the modern research on artichoke has been done with the German artichoke extract Hepar-SL Forte, standardized to contain 3% caffeoylquinic acids. A new, even more potent extract, standardized at 15% caffeoylquinic acids--calculated as chlorogenic acid--is now available on the American market.
The original uses of artichoke (since ancient times) have been as an aid for indigestion and insufficient liver function. The mechanism of action, however, has been essentially unknown. Recent findings have provided a new foundation for our understanding and uncovered additional benefits of the extract, such as antioxidant and lipid-lowering effects.
Effects on the Gastrointestinal System
The importance of effective liver function for overall health, and proper gastrointestinal function in particular, is rarely emphasized in health discussions in the United States. One reason might be that there is neither laboratory evidence nor specific physical symptoms to reveal an overburdened liver in the beginning stages. The symptoms may be nonspecific, such as general malaise, fatigue, headache, epigastric pain, bloating, nausea, or constipation. Discomfort following meals and intolerance of fat are also notable indications of disturbances in the biliary system.
It is estimated that at least 50% of patients with dyspeptic complaints have no verifiable disease. Because of the liver's essential role in detoxification, even minor impairment of liver function can have profound effects. It is therefore important to take such chronic complaints seriously. In Germany and France, for example, physicians frequently prescribe herbal liver remedies, such as artichoke extract, with good results when presented with these chronic but nonspecific symptoms.
The proven basis for the beneficial effects of artichoke leaf extract on the gastrointestinal system is the promotion of bile flow. Bile is an extremely important digestive substance that is produced by the liver and stored in the gallbladder. The liver manufactures about 1 quart a day of bile to meet digestive requirements. It is secreted into the small intestine, where it emulsifies fats and fat-soluble vitamins and improves their absorption. Any interference with healthy bile flow can create a myriad of immediate digestive disorders, such as bloating.
Good bile flow is also essential for detoxification, which is one of the major tasks of the liver. The liver is constantly bombarded with toxic chemicals from the environment (i.e., the food we eat, the water we drink, and the air we breathe).
Bile serves as a carrier for these toxic substances, delivering them into the intestine for further elimination from the body. This is the major route for excretion of cholesterol. Bile’s promotion of intestinal peristalsis, which helps prevent constipation, is also helpful.
When the excretion of bile is inhibited (e.g., due to gallstones or gallbladder disease), toxins and cholesterol stay in the liver longer with damaging effects. Other common reasons for impairment of the bile flow within the liver itself are, for example, alcohol ingestion, viral hepatitis, and certain chemicals and drugs. In the initial stages of liver dysfunctions, laboratory tests, such as serum bilirubin, alkaline phosphatase, SGOT, LDH, and GGTP, often remain normal. It is not adequate to rely on these tests alone. Symptoms that may indicate reduced liver function are general malaise, fatigue, digestive disturbances, and sometimes increasing allergies and chemical sensitivities.
Excessive alcohol consumption is by far the most common cause of impaired liver function in the United States. It stimulates fat infiltration into the liver cells, causing fatty liver. Some livers are very sensitive to even minute amounts of alcohol; others are more tolerant. Research suggests that fatty liver condition is more serious than previously believed. It may develop to more advanced liver disease, such as inflammation, fibrosis, and cirrhosis.
Because of its long historical use for liver conditions, it seemed reasonable to investigate the artichoke plant scientifically. The first clinical studies were conducted in the 1930s with encouraging results. In the 1990s the interest has been intensified, and several excellent clinical studies have been conducted during the past few years.
Realizing the importance of adequate bile flow for health, German researchers set out to confirm the earlier findings of bile-promoting effect of the artichoke plant in a controlled, double-blind study on healthy volunteers (Kirchhoff 1994). The participants were given a 1-time dose of artichoke extract or placebo, and their bile secretion was measured over the following hours, using special techniques. The bile secretion was found to be significantly higher in the group that received the artichoke extract.
Another clinical study showed an improvement of symptoms in 50% of patients with dyspeptic syndrome after 14 days of treatment with artichoke leaf extract. The study involved 60 patients with nonspecific symptoms such as upper abdominal pain, heartburn, bloating, constipation, diarrhea, nausea, and vomiting. In the placebo group, as a comparison, improvements of less distinct quality were noticed in 38% of the participants (Kupke 1991).
Interesting results were also demonstrated in a large open label study of 417 participants with liver or bile duct disease. Most of these patients had long-standing symptoms, some of them for many years. They suffered from upper abdominal pain, bloating, constipation, lack of appetite, and nausea. These patients were treated with artichoke leaf extract for 4 weeks. After 1 week, about 70% of the patients experienced improvement of their symptoms, and after 4 weeks, the percentage was even higher (approximately 85%) (Held 1991).
Even more remarkable improvement was shown in another open label study (Fintelmann 1996) where 553 outpatients with nonspecific dyspeptic complaints were treated with a standardized artichoke leaf extract. The subjective complaints declined significantly within 6 weeks of treatment. Improvements in vomiting (88%), nausea (83%), abdominal pain (76%), loss of appetite (72%), severe constipation (71%), flatulence (68%), and fat intolerance (59%) were noted. Ninety-eight percent of the patients judged the effect of the extract to be considerably better, somewhat better, or equal to that achieved during previous treatment with other drugs. The dosage used in this study was 1-2 capsules, 3 times daily of the preparation Hepar-SL Forte. One capsule contains 320 mg of dry extract of artichoke leaves, standardized to provide 3% caffeoylquinic acid.
The study by Fintelmann (1996) not only confirmed the efficacy of the artichoke extract for dyspepsia, but also demonstrated a significant effect of the extract on fat (lipid) metabolism. The researchers found a significant decline in both cholesterol and triglyceride levels in the blood, which confirmed a discovery made as early as the 1930s.
Artichoke leaf extract is well tolerated and has few side effects in recommended dosages. The use of the artichoke plant as food in many countries over hundreds of years supports the safety of consumption. More important, however, is that several rigorous studies report the absence of adverse effects when using a standardized extract compared to the placebo. In a large safety study, only one out of 100 subjects reported mild side effects such as transient increases in flatulence.
Local eczematous reactions have been reported after occupational exposure and skin contact with the fresh plant or its dried parts. Such an allergy should be considered a contraindication for external use of the extract, although no reactions to orally ingested extract have been observed so far. Because of its bile-stimulating effect, the extract should not be taken by individuals with gallstones or other bile duct occlusion.
An artichoke extract is now available in the United States. While the German artichoke products, cited in most European studies, typically contain 3% caffeoylquinic acids, this artichoke extract is standardized to contain 15% caffeoylquinic acids, calculated as chlorogenic acid.
Artichoke leaf extract has proven to be a safe and natural way to maintain and improve general health because of its many applications to improve essential physiological functions. As a nutritional supplement and antioxidant, it can safely be used as an adjunct to conventional therapies.