Nourishing the Liver (repost but good)
- * Marilyn Sterling, R.D., is a freelance writer, consultant and
practicing nutritionist in northern California.
Nourishing the Liver
By Marilyn Sterling, R.D.
Is there any way to prevent cirrhosis? Could nutrition help? With
hundreds of thousands of people at risk, these should be urgent
public health questions. The only "cure" for cirrhosis is a $400,000
liver transplant, so finding a way to prevent cirrhosis could save
many lives, not to mention billions of dollars. Unfortunately,
society invests most of its health care dollars in treatment rather
than prevention research. On the bright side, there are some
intriguing clues about the development of cirrhosis. People who
already have liver damage, however, have complicated metabolic issues
and need personalized diet therapy from a registered dietitian. Here
are some avenues that may help heavy alcohol drinkers or people with
chronic hepatitis avert cirrhosis development: Limit iron intake
because hepatitis viruses thrive in iron-rich environments. An iron
surplus impairs many aspects of immune function including T
lymphocyte proliferation and maturation. Also, iron catalyzes damage
byoxidants. While iron deficiency is common among women who
menstruate, older women and men often have an excess because they
don't excrete as much. Limiting iron intake weakens hepatitis and
increases the chance of successful interferon therapy.1 Patients with
hepatitis C might want to avoid molasses, liver, iron-enriched
cereals,food cooked in iron pots, multivitamins containing iron, as
well as limit their intake of meat-all of which contribute excess
iron. Vitamin C increases iron absorption, so supplements or foods
high in vitamin C should not be taken with meals. Increase intake of
choline, an amino acid that is part of the phospholipid lecithin.
Alcoholism causes a relative choline deficiency in the liver by
decreasing the enzyme methionine synthetase, which is necessary for
choline production. A choline deficiency, which promotes liver
damage, can be corrected with lecithin supplements. Choline
increases the activity of the enzyme hepatic collagenase, which
breaks down collagen, preventing cirrhosis. In an experiment on
primates, baboons were fed high-alcohol diets for eight years. Most
developed cirrhosis. However, no members of a group provided with
lecithin supplementation during the experiment developed cirrhosis.
Large-scale trials are now under way to see if lecithin has the same
protective effect in humans.2-5 Reduce fat intake. Evidence from one
study showed this helped hepatitis C patients who drank alcohol.
Those patients who ate high-fat, low-protein and low-carbohydrate
diets were more apt to progress to cirrhosis.6 One reason could be
that unsaturated fatty acids are prone to oxidation, which is
dangerous to a damaged liver. This might also explain why one animal
experiment found cirrhosis was reversed in animals consuming
saturated rather than unsaturated fats(i.e., butter rather than
sunflower oil). While intriguing because cirrhosis is often
considered irreversible, no research has been conducted in humans in
regard to cirrhosis and fat-type consumption. Limiting fat shouldn't
be taken to extremes,however. People do need to meet their intake
requirement for essential fatty acids.7 In fact, another experiment
on monkeys showed that those with diets low in essential fatty acids
and low in antioxidants were more apt to develop alcoholic
Take Vitamin E to help maintain high levels of
glutathione-particularly important for people with hepatitis or other
liver problems.9,10 Glutathione (GSH), an antioxidant present in the
liver, is the body's key protector against the oxidizing compounds
that lead to cirrhosis. By maintaining GSH levels, vitamin E
supplementation may help protect against cirrhosis. In one study,
almost 50 percent of people with hepatitis C who did not respond to
interferon therapy improved dramatically with 800 IU of vitamin E
daily.11 Just because vitamin E helps protect the liver, however,
does not mean all antioxidants are equally helpful in liver-related
problems. Vitamin A, for example, can build to toxic levels in
Supplement with amino acids such as (SAMe)S-adenosyl-L-methionine and
N-acetyl cysteine (NAC) to help maintain glutathione. Scientists are
interested in these amino acids because they may counter the altered
biochemistry found in patients with liver disease, such as the
glutathione decrease caused by alcohol and hepatitis.
S-adenosyl-L-methionine prevented alcohol-induced glutathione
depletion in a baboon study.13 It is now being tested on humans but
is quite expensive. In a study of people with hepatitis C, 600 mg
daily of NAC enhanced the effectiveness of interferon therapy.14
However, another study did not confirm this finding.15 Regardless,
NAC protects against damaging oxidant-producing immune factors called
cytokines and chemokines released in the liver in response to
heavy-metal exposure.16 Some researchers predict that future
treatment of hepatitis C will depend on antioxidant therapies such as
NAC.17 Eat cabbage or any cruciferous vegetable. These can enhance
the liver's ability to detoxify. Substances that harm the liver act
synergistically. Alcoholics, for example, are more susceptible than
nonalcoholics to other liver toxins, and people with hepatitis cannot
tolerate alcohol. Therefore,it is important for people who are at
risk of cirrhosis to avoid toxic chemicals and ensure their bodies'
capacity for detoxification is maximized.
Here is where the cabbage family shines. The cruciferous vegetables
activate the liver's cytochrome P450 detoxification chain. Even more
exciting, researchers have recently found that brussel sprouts
stimulate the liver's Phase II enzymes-the first dietary component
shown to affect this important detoxification system. The cruciferous
vegetable family includes broccoli, cauliflower, kale, mustard
greens, radish, bok choy and brussel sprouts. Prevention vs. The Cure
For decades we have accepted that cirrhosis is not preventable, but
by putting together what we now know about the liver, there is hope.
Relying on costly, unpleasant interferon and antiviral therapy
followed by exorbitantly expensive, often unsuccessful liver
transplants is not a rational way to approach the growing cirrhosis
epidemic. The focus should be on cost-effective nutrition therapies
to slow or prevent cirrhosis in the first place.*
In addition to dietary modifications and nutritional supplements,
there are a variety of herbs with scientific evidence of
liver-supportive actions. Milk Thistle (Silybum marianum), also
called St. Mary's thistle or mariana thistle, is the best-known liver
tonic, having been described in herbals since the late 1600s. Its
most active constituent, silymarin, is a powerful antioxidant that
inhibits harmful oxidants and prevents formation of leukotrienes, one
type of dangerous oxidant produced by the immune system. Silymarin
not only prevents glutathione depletion but actually increases
quantities of it.It also has the ability to stimulate protein
synthesis in the liver.1-3 Artichoke (Cynara scol mus) leaves are
another liver remedy. Recent animal tests show supplementation with
artichoke prevented a liver toxin from causing oxidation, thus
preventing glutathione destruction.4 The active compound, cynarin, is
found in highest concentrations in the leaves. Chlorogenic acid and
other antioxidants are also present. Licorice Root(Glycyrrhiza
glabra), in the form of the injectable active principle glycyrrhizin,
a saponin glycoside, has been used for liver problems in Japan for 20
years. Controlled trials have shown that glycyrrhizin use in chronic
hepatitis is associated with improvement in liver enzymes. Liver
biopsies confirmed that the liver cells of those taking the compound
vs. a placebo were healthier.5,6
Diet for a Healthy Liver
Certain nutritional factors keep the liver operating smoothly and
induce detoxification through enzymatic pathways:
* Garlic, legumes, onions and eggs all (sulfur-rich foods) enhance
sulfation, which makes toxins easier to excrete.
* Broccoli, brussel sprouts and cabbage enhance glutathione
conjugation, a complex process of converting fat-soluble toxins to
water-soluble ones for easier excretion.
* Green leafy vegetables rich in folic acid, whole grains and legumes
rich in vitamin B6, and animal products or supplements providing
vitamin B12 ensure adequate methylation, which inactivates estrogens
and increases both bile and lipid flow.
* Nutritional yeast, whole grains, cabbage, citrus fruits and peppers
provide the B vitamins and vitamin C necessary for acetylation, which
helps the body eliminate sulfa drugs.
* Artichokes, beets, carrots,dandelion and herbs such as cinnamon,
licorice and turmeric are also useful in maintaining liver health.
Source: Murray M, Pizzorno J. Encyclopedia of Natural
Medicine. Rocklin (CA): Prima Publishing; 1998. p 114-23.
1.Hayashi H, et al. Improvement of serum aminotransferase levels
after phlebotomy in patients with chronic active hepatitis C and
excess hepatic iron. Am J Gastroenterol 1994;89:986-8.
2.Trotter JF, Brenner DA. Current and prospective therapies for
hepatic fibrosis. Compr Ther 1995 Jun;21(6):303-7.
3.Lieber CS. Alcohol and the liver: 1994 update. Gastroenterology
4.Chawla RK, et al. Biochemistry and pharmacology of
S-adenosyl-L-methionine and rationale for its use in liver disease.
Drugs 1990;40(3 Suppl):98-110.
5.Cabre E, Gassull MA. Nutritional support in liver disease. Eur J
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6.Corrao G, Ferrari PA. Exploring the role of diet in modifying the
effect of known disease determinants: application to risk factors of
liver cirrhosis. Am J Epidemiol 1995 Dec 1;142(11):1136-46.
7.Nanji AA, et al. Dietary saturated fatty acids down-regulate
cyclooxygenase-2 and tumor necrosis factor alpha and reverse fibrosis
in alcohol-induced liver disease in the rat. Hepatology 1997
8.Pawlosky RJ, et al. The effects of low dietary levels of
polyunsaturates on alcohol-induced liver disease in rhesus monkeys.
Hepatology 1997 Dec;26(6):1386-92.
9.Comporti M, et al. Glutathione depletion: its effects on other
antioxidant systems and hepatocellular damage. Xenobiotica 1991
10.Houglum K, Venkataramani A. Pilot study of the effects of
d-alpha-tocopherol on hepatic stellate cell activation in chronic
hepatitis C. Gastroenterology 1997 Oct;113(4):1069-73.
11.von Herbay A, et al. Vitamin E improves the aminotransferase
status of patients suffering from viral hepatitis C: a randomized,
double-blind, placebo-controlled study. Free Radical Res 1997
12.Russell RM. The impact of disease states as a modifying factor for
nutrition toxicity. Nutr Rev 1997 Feb;55(2):50-3.
13.Lieber CS. Susceptibility to alcohol-related liver injury. Alcohol
14.Beloqui 0, et al. N-acetyl cysteine enhances the response to
interferon-alpha in chronic hepatitis C: a pilot study. J Interferon
15.Cimino L. Effect of N-acetyl-cysteine on lymphomonocyte
glutathione and response to interferon treatment in C-virus chronic
hepatitis. Italian J Gastroenterol Hepatol 1998 Apr;30(2):189-93.
16.Dong W, et al. Toxic metals stimulate inflammatory cytokines in
hepatocytes through oxidative stress mechanisms.Toxicol App Pharmacol
17.Bonkovsky HL. Therapy of hepatitis C: other options. Hepatology
1997 Sep;3(1 Suppl):143S-51S. Liver-Friendly Herbs
1.Flora K, et al. Milk thistle (Silybum marianum) for the therapy of
liver disease. Am J Gastroenterol 1998 Feb;93(2):139-43.
2.Salmi HA, Sarna S. Effect of silymarin on chemical, functional and
morphological alteration of the liver: a double-blind controlled
study. Scandinavian J Gastroenterol 1982;17:417-21.
3.Boari C, et al. Occupational toxic liver diseases. Therapeutic
effects of silymarin. Min Med 1985;72(2):679-88.
4.Gebhardt R. Antioxidative and protective properties of extracts
from leaves of the artichoke (Cynara scolymus L.) against
hydroperoxide-induced oxidative stress in cultured rat hepatocytes.
Toxicol Appl Pharmacol 1997 Jun;144(2):279-86.
5.van Rossum TG, et al. Review article: glycyrrhizin as a potential
treatment for chronic hepatitis C. Ailment Pharmacol Ther 1998
6.Yamamura Y, et al. The relationship between pharmacokinetic
behaviour of glycyrrhizin and hepatic function in patients with acute
hepatitis and liver cirrhosis. Biopharm Drug Dispos 1995
7.Arase Y, et al. The long-term efficacy of glycyrrhizin in chronic
hepatitis C patients. Cancer 1997 Apr 15;79(8):1494-500.
8.Takahara T, et al. Effects of glycyrrhizin on hepatitis B surface
antigen: a biochemical and morphological study. J Hepatol 1994
9.Wang JY, et al. Inhibitory effect of glycyrrhizin on NF-kappaB
binding activity in CCl4 plus ethanol-induced liver cirrhosis in
rats. Liver 1998 Jun;18(3):180-5.
Marilyn Sterling, R.D., is a freelance writer,
consultant and practicing nutritionist in
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