Milk Thistle

http://www.liversupport.com/info4.htm

 

The Encyclopedia of Popular Herbs

 

Milk Thistle

 

 

Excerpt

 

The following information on Milk Thistle is from The Encyclopedia of

Popular Herbs, Your Complete Guide to the Leading Medicinal Plants.

The book was published by Prima Health (Copyright 2000). The authors

are Robert S. McCaleb, Evelyn Leigh, and Krista Morien.

 

Dr. Andrew Weil says of the book, " Both practitioners and patients

will find this guide to popular herbal remedies useful. It is

authoritative and readable. " Christopher Hobbs, L.Ac, and renowned

herbalist and author says, " Of all the many recent books on herbal

medicine, The Encyclopedia of Popular Herbs stands out as the one that

is the best blend of evidence-based, rigorously researched herbal

medicine, along with specific and practical guidelines for 21st

century home health care. "

 

 

Milk Thistle

Silybum Marianum Asteracae

PART USED: Seed

PRIMARY USES

Liver health

Protection against harmful chemicals, drugs, and pollution

Digestive aid

Acute and chronic hepatitis

Alcoholic and other liver damage

Gallbladder symptoms

 

Prickly thistles may not be as " approachable " as softer plants, but

appearances can be deceiving. Not only does this group of plants

contain no poisonous members, but many thistles have the ability to

protect our livers against harmful substances, including poisons

present in our daily environment.

 

The thistle that stands out most in this regard is Milk Thistle. This

remarkable plant has earned a worldwide reputation as an antioxidant

and liver protectant that can even help repair and regenerate injured

liver cells.

 

As the word liver suggests, maintaining the health of this essential

organ is key to the overall quality of life. The liver, the body's

second largest organ, processes nutrients, drugs, toxins, and any

other substance entering the body through the intestines, lungs, or

skin. Savvy Europeans have long recognized this, taking Milk Thistle

extract as a daily form of health insurance against pollution,

over-the-counter drugs such as acetaminophen, and even the

self-inflicted damage of overindulgence in rich foods and alcohol. In

Germany, Milk Thistle extracts accounted for over $180 million in herb

product sales during 1998.

 

Health practitioners also prescribe Milk Thistle to treat a variety of

problems you might not normally connect with liver health, including

poor digestion, female hormonal problems, constipation, mood

disorders, hemorrhoids, varicose veins, atherosclerosis (hardening and

narrowing of the arteries), and skin conditions such as psoriasis and

acne. Today, regular use of Milk Thistle extract can be considered a

modern necessity every bit as important as a healthful diet, exercise,

rest, and the most common vitamin supplements.

 

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HISTORY

 

Milk thistle has been used to support liver health for more than 2,000

years. As early as A.D. 23, Pliny the Elder recommended a mixture of

Milk Thistle juice and honey for improving digestion by stimulating

the flow of bile. During the sixteenth century, the British herbalist

Gerard called Milk Thistle " the best remedy that grows against all

melancholy diseases. " Melancholy (what we might call depression today)

gets its name from the Greek words for " black bile " and was

historically treated with liver herbs as well as mood-enhancing

plants. During the seventeenth century, British herbalist Nicholas

Culpeper prescribed Milk Thistle seeds for jaundice (yellow

discoloration of tissues due to excessive amounts of bile),

gallstones, and obstructions of the liver and spleen.

 

Milk thistle became popular in American medicine around the turn of

the twentieth century, when the Eclectic physicians (a prominent group

of American doctors who practiced at that time) adopted it as a

treatment for varicose veins, menstrual problems, and liver and kidney

ailments. The plant gradually fell out of favor later in the

century—except in Germany, where herbs have always enjoyed widespread

acceptance. During the 1970s and 1980s, German scientists began

testing the plant to validate its many centuries of application as a

liver herb. Today, Milk Thistle is a popular treatment in Germany for

many liver problems, including hepatitis and cirrhosis. Intravenous

silymarin (a complex of important Milk Thistle constituents) is also a

life-saving emergency room treatment used throughout Europe in cases

of poisoning.

 

Like its cousin the globe artichoke (Cynara scolymus), Milk Thistle

has a long history as a delicious and nutritious food. When boiled,

young Milk Thistle flowerheads look and taste much like a savory

artichoke. All parts of the plant are edible, including the roots and

young stalks and leaves. To incorporate the benefits of Milk Thistle

seeds into your daily diet, herbalist Christopher Hobbs suggests

making a seasoning salt by soaking Milk Thistle seeds overnight,

draining the water, grinding the seeds into a powder using a coffee

grinder, lightly toasting them in the oven, and then mixing them with

salt or other spices.1 Milk thistle seeds are high in protein and the

essential fatty acid linoleic acid, a healthy fat that can help reduce

chronic inflammation, balance the female menstrual cycle, and improve

heart health.

 

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INTERNATIONAL STATUS

 

Milk thistle seeds are approved in the German Commission E Monographs

as a supportive treatment for inflammatory liver conditions such as

cirrhosis, hepatitis, and fatty infiltration caused by alcohol and

other toxins.2

 

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BOTANY

 

Herbalist Michael Moore describes Milk Thistle as " a bulldog with a

spiked collar " because of the plant's prickly appearance. The plant

grows to heights of 5 to 10 feet and is dangerous looking-right down

to the sharp spines on its reddish purple flowers. Milk thistle's

common name comes from the white markings on the leaves, its milky

white sap, and its traditional use by nursing mothers to increase

lactation. The humble plant is closely related to other common

thistles, including blessed thistle (Cnicus benedictus), which has

similar medicinal properties but is not as well researched.

 

Milk thistle is native to Europe, southern Russia, Asia, and North

Africa. When the English colonists brought it to North America, the

plant quickly became a common weed in many parts of the United States.

Today, large fields of Milk Thistle are cultivated in Texas and

Argentina, with an eye toward developing cultivation methods that

yield the highest amounts of silymarin. If you decide to grow Milk

Thistle in your own garden, watch out! The plant lives up to its

reputation as a weed, spreading easily on its many parachute-like

seeds. Milk thistle is an annual or biennial and favors sunny

locations and well-drained soils, though it generally tolerates

harsher conditions. The seeds can be harvested in July or August after

the flowers have blossomed.

 

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BENEFITS

Protects the liver from damage by guarding liver cell membranes

 

Acts as a powerful antioxidant in the liver, stomach, and intestines

 

Helps repair and regenerate liver cells by stimulating protein synthesis

 

Aids digestion and elimination by stimulating the flow of bile (needed

to break down fats)

 

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SCIENTIFIC SUPPORT

One of the best-studied herbs, Milk Thistle has been the subject of

more than 300 clinical and laboratory trials. In cases of acute

hepatitis, Milk Thistle extract helps people recover more quickly and

prevents the condition from becoming chronic. Improvement is often

apparent within 5 days, and even greater benefits are seen after 3

weeks. Milk thistle is also useful for treating chronic hepatitis when

taken over a period of 3 to 12 months. Studies show that it can help

reverse liver cell damage, normalize elevated levels of liver enzymes,

and improve symptoms such as abdominal discomfort, decreased appetite,

and fatigue. Standard therapy for hepatitis usually involves the drug

alpha-interferon, which has many unpleasant side effects, including

flu-like symptoms, fatigue, and irritability. Research has also

demonstrated that Milk Thistle can slow the advancement of cirrhosis

(chronic liver damage) and increase life span in people with

cirrhosis, particularly alcoholics.

 

Preliminary research shows that Milk Thistle may help prevent

gallstones by reducing cholesterol levels in the bile. In one study, a

daily dose of 420 mg of silymarin taken for I month led to a reduction

of bile cholesterol in people with a history of gallstones and

gallbladder surgery. 3

 

Exciting breakthrough research suggests possible antioxidant benefits

in another area: non-melanoma skin cancer. A number of preliminary

laboratory investigations indicated that silymarin could reduce the

rate of tumor formation and tumor size at all three stages of

development-initiation, promotion, and complete carcinogenesis.

Silymarin's effects were most dramatic in the later stages of skin

cancer. Clinical studies are necessary to determine how these results

apply to humans. 4

 

Another area of current research is Milk Thistle's possible

anti-allergenic effects. In vitro research indicates that silymarin

and silybin may help prevent allergic reactions by inhibiting the

release of histamine from mast cells in animals and from blood

basophils in humans.

 

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SPECIFIC STUDIES

Liver Protection:

 

Clinical Study (1994)

 

Silymarin provided protection against the toxic effects of long-term

treatment with psychotropic drugs (used in mental illness) in a

randomized, double-blind, placebo controlled clinical study of 60

people. Before the study began, all of the participants had been

taking the psychotropic drugs phenothiazine or butyrophenone, or both,

for at least 5 years. Subjects were divided into four groups for the

3-month trial: group I took psychotropic drugs and a high dose of

silymarin (800 mg per day), group 11 took psychotropics with placebo,

group III took silymarin only (800 mg per day), and group IV took

placebo. Silymarin provided liver protection to group I by reducing

blood levels of malondialdehyde (MDA), an indicator of liver damage

that increases during long-term treatment with psychotropics. Not

surprisingly, the decrease in MDA levels was even greater in the group

taking silymarin alone (group III ). Patients in group II continued to

experience rising levels of MDA, whereas those who took placebo had

declining MDA levels until the psychotropics were reinstated. There

were no adverse effects associated with Milk Thistle treatment. 6

 

Active Cirrhosis:

 

Clinical Study (1992)

 

Silymarin was just as effective as the bile acid ursodeoxycholic acid

(UDCA) in improving symptoms of active cirrhosis in a randomized,

controlled, crossover study involving 21 people. During the 6-month

trial, subjects took either 420 mg of silymarin or 600 mg of UDCA

daily. In the UDCA group, liver function improved significantly,

measured as a 30 percent drop in serum aspartate amino transferase

(AST) levels and a 22 percent drop in alanine amino transferase (ALT)

levels. Serum levels of gamma-glutarnyltranspeptidase (y-GT) also

demonstrated a beneficial decline. Those in the silymarin group had a

15 percent drop in AST and a 23 percent decline in ALT levels, with no

change in y-GT levels.

 

During the second half of the study, 20 of the 21 original

participants took either combined treatment (UDCA and silymarin) or no

treatment. Combination therapy caused a beneficial decrease in liver

enzymes over a 12-month period. On the other hand, those who received

no treatment experienced a rise in mean levels of serum transminases

and y-GT, similar to pretreatment values. No side effects were

reported for UDCA or silymarin.

 

Lastly, researchers tested UDCA in relation to hepatitis C virus

(HCV). They found that UDCA was not as effective in lowering ALT and

AST levels in people who were positive for anti-HCV antibodies,

compared to those who were negative for these antibodies. The

researchers concluded that both UDCA and silymarin are safe and

effective in treating active cirrhosis of the liver. However, UDCA

treatment should be restricted to people who test negative for

anti-HCV antibodies. 7

 

Cirrhosis:

 

Clinical Study (1989)

 

Long-term treatment with silymarin significantly increased survival

rates in a randomized, double-blind, placebo-controlled study of 105

people with cirrhosis. Subjects took either 420 mg of silymarin daily

or placebo during the study, which lasted for approximately 41 months.

Over a 4-year period, the mortality rate in the placebo group was

twice that of the silymarin group. Silymarin showed the greatest

benefit in those with alcohol-related cirrhosis. There appeared to be

no difference in the results of liver function tests (transminases,

bilirubin, SGGPT, and other liver enzymes) between the two groups. No

side effects were reported.8

 

How It Works:

 

Milk thistle prevents toxins from entering the liver by guarding the

organ's numerous doorways-the membranes of liver cells. By slowing the

rate at which the liver absorbs harmful substances, the toxins are

excreted through the kidneys before they can cause liver damage.9 The

most dramatic example of this is Milk Thistle's ability to block

poisons from the deathcap, mushroom (Amanita phalloides), one of the

most notorious liver toxins known to humans. In a group of 49 patients

with Amanita poisoning, physicians rated the results " amazing " and

" spectacular, " after patients were given injections (20 mg/kg daily)

of silybin, a major constituent in Milk Thistle. All of the patients

survived, even though they were treated 24 to 36 hours after

poisoning, when liver and kidney damage had already occurred. The

death rate in emergency rooms from Amanita poisoning is usually 30 to

40 percent.8 Milk thistle acts in a similar fashion to detoxify other

synthetic chemicals that find their way into our bodies, from

acetaminophen and alcohol to heavy metals and radiation.9

 

Much of Milk Thistle's protective effect is due to the flavonoid

complex silymarin, which acts as a powerful antioxidant, combining

with and thus neutralizing harmful free radicals that result from

normal metabolic processes and from the breakdown of toxic substances.

At least 10 times as potent as vitamin E, silymarin also helps

increase levels of two additional antioxidants, glutathione and

superoxide dismutase (SOD).11 A laboratory study showed that silymarin

may increase glutathione content in the liver and intestines by up to

50 percent.12 Silymarin also increases the activity of SOD in

erythrocytes (red blood cells) and lymphocytes (white blood cells)

formed in the lymphatic tissue in patients with liver disease.13

Because silymarin is a potent antioxidant in the stomach and

intestines, it may also have a role to play in treating inflammatory

conditions such as colitis and ulcers. 14

 

When damage has already been done, Milk Thistle aids the liver in

repairing injured cells and generating new ones. It does this by

stimulating protein synthesis through the enzyme RNA polymerase I.

Protein is a basic building block of cell walls, cell structures, and

enzymes that are vital to all body processes. Recent evidence

(molecular modeling) suggests that the constituent silybin may be

responsible for stimulating protein synthesis, because it imitates a

steroid hormone. Silybin increases protein synthesis by up to 25 to 30

percent, compared with controls.9 Milk thistle's regenerative ability

is essential for treating serious conditions such as chronic

hepatitis, cirrhosis, and toxic fatty deposits in the liver.

 

Recent evidence suggests that silymarin may be just as important for

kidney health. Silymarin concentrates in kidney cells, where it aids

in repair and regeneration by increasing protein and nucleic acid

synthesis. One study showed that it increased cell replication by 25

to 30 percent. 9

 

Of the many compounds that make up the silymarin complex, silybin and

silychristin are the two most potent ones, according to current

pharmacological studies.9

Unfortunately, these compounds are relatively poorly absorbed by the

gastrointestinal tract. Some studies suggest an absorption rate of

just 20 to 50 percent, which explains why it is so important to take

standardized Milk Thistle extracts to ensure high concentrations of

the active ingredients.15

Some manufacturers claim that combining Milk Thistle with

phosphatidylcholine increases absorption.

 

(Note from webmaster: this is the form found in Maximum Milk Thistle™

at http://www.LiverSupport.com. Check the clinical studies on the site

for more information.)

 

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MAJOR CONSTITUENTS

Silymarin (a flavonoid complex that includes silybin, silychristin and

silydianin)

 

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SAFETY

Milk thistle has been safely used as a food herb and medicine for

centuries.

 

Side effects: No side effects have been reported during clinical

trials. Milk thistle may initially have a mild laxative effect in

certain people because of its stimulating effects on bile secretion.2

 

Contraindications: Milk thistle is considered safe for use during

pregnancy and has a long history of use by nursing women.16 People

with diabetes who are taking Milk Thistle should carefully monitor

their blood glucose and may require reduction in standard

antihyperglycemic agents.

 

Drug interactions: None known.

 

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DOSAGE

 

Standardized milk thistle products are strongly recommended to ensure

therapeutic levels of silymarin. There is no research on Milk Thistle

as a tincture or tea. In any case, Milk Thistle does not make an

effective tea because the main constituents do not dissolve easily

into water. For maintaining overall health, begin with the full dosage

of Milk Thistle for 6 to 8 weeks, followed by a reduction to 280 mg

daily. Those with liver problems should continue the full dosage for

at least 4 to 8 weeks. Long-term therapy may be required in serious or

chronic cases.

 

Standardized capsules/ tablets: 420 mg silymarin, divided into two to

three doses a day

 

Tincture (unstandardized): 10 to 25 drops up to three times a day

 

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STANDARDIZATION

 

Milk thistle is typically standardized to contain 70 to 80 percent

silymarin.

 

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REFERENCES

1 . Hobbs C. Milk Thistle: The Liver Herb. Capitola, CA: Botanica

Press, 1992.

 

2. Blumenthal M, Busse W Goldberg A, eds.The Complete German

Commission E Monographs. Austin, TX: American Botanical Council;

Boston: Integrative Medical Communications, 1998.

 

3. Nassuato G, lemmolo RM, Strazzabosco M, et al. Effect of silybinin

on biliary lipid composition: experimental and clinical study. Journal

of Hepatology 1991; 12(3): 290 295.

 

4. Katiyar SK, Korman NJ, Mukhtar H, et al. Protective effects of

silymarin against photocarcinogenesis in a mouse skin model. Journal

of the National Cancer Institute 1997; 89(8): 556-566.

 

5. Miadonna A, Tedeschi A, Leggieri E, et al. Effects of silybin on

histamine release from human basophil leucocytes. British Journal of

Clinical Pharmacology 1987; 24: 747-752.

 

6. Palasciano G, Portincasa P, Palmieri V, et al. The effect of

silymarin on plasma levels of malon-dialdehyde in patients receiving

long-term treatment with psychotropic drugs. Current Therapeutic

Research 1994,55(5): 5 37-545.

 

7. Lirussi F, Okolicsanyi L. Cytoprotection in the nineties:

experience with ursodeoxycholic acid and silymarin in chronic liver

disease. Acta Physiologica Hungarica 1992; 80(1-4): 363-367.

 

8. Ferenci P, Dragosics B, Dittrich H, et al. Randomized controlled

trial of silymarin treatment in patients with cirrhosis of the liver.

Journal of Hepatology 1989; 9: 105-113.

 

9. Sonnenbichler J, Sormenbichler 1, Scalera F. Influence of the

flavonolignan silybinin of Milk Thistle on hepatocytes and kidney

cells. In: Lawson L, Bauer R, eds. Phytomedicines of Europe: Chemistry

and Biological Acti viV. Washington, DC: American Chemical Society, 1998.

 

10. Farkas L, Gabor M, Kallay, F, eds. Flavonoids from natural red

resins. Proceedings of the International Biqflavonoid Symposium,

September 6-9, 1981. Amsterdam, Oxford, and New York: Elsevier

Scientific, 1982.

 

11. Hikino H, Kiso Y, Wagner H, et al. Anti-hepatotoxic actions of

flavonolignans from

 

Silybum marianum fruits. Planta Medica 1984; 50:248-250.

 

12. Valenzuela A, Aspillag3a M, Vial S, et al. Selectivity of

silymarin on the increase of the glutathione content in different

tissues of the rat. Planta Medica 1989; 55: 420-422.

 

13. Muzes G, Deak GY, Lang 1, et al. Effect of the bioflavonoid

silymarin on the in vitro activity and expression of superoxide

dismutase (SOD) enzyme. Acta Physiologica Hungarica 1991; 78(l): 3-9.

 

14. Brown D. Phytotherapy review and commentary: silymarin educational

monograph. Townsend Letter for Doctors November 1994;1282-1285.

 

15. Robbers JE, Tyler VE. TyIer`s Herbs of Choice: The Therapeutic Use

of Phytomedicinals. New York and London: The Haworth Press, 1999.

 

16. McGuffin M, Hobbs C, Upton R, et al., eds. American Herbal

Products Association Botanical Safety Handbook. Boca Raton, FL: CRC

Press, 1997.

 

17. Velussi M, Cernigoi AM, Viezzoli L, et al. Silymarin reduces

hyperinsulinemia, malondialdehyde levels, and daily insulin need in

cirrhotic diabetic patients. Current Therapeutic Research 1993; 53

(5): 533-545.

 

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