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OCTOBER/NOVEMBER 2001 - Garlic - Allium sativum
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"O, he is as tedious
As a tired horse, a railing wife;
Worse than a smoky house: I had rather live
With cheese and GARLIC in a windmill, far,
Than feed on cates and have him talk to me
In any summer-house in Christendom".
Keeping the Plants Alive is written by Isla Burgess; Pictures are by WhaleGrave Photos.
The Old Ways...
There are several other references to garlic in Shakespeare
Mopsa must be your mistress: marry, garlic,
To mend her kissing with!
Wint. IV/4/162
And, most dear actors, eat no onions
nor garlic, for we are to utter sweet breath; and I
do not doubt but to hear them say, it is a sweet
comedy. No more words: away! go, away!
Mids IV/2/43
The Duke
yet would have dark deeds darkly answered; he would
never bring them to light: would he were returned!
Marry, this Claudio is condemned for untrussing.
Farewell, good friar: I prithee, pray for me. The
duke, I say to thee again, would eat mutton on
Fridays. He's not past it yet, and I say to thee,
he would mouth with a beggar, though she smelt brown
bread and garlic: say that I said so. Farewell.
Meas. III/2/195
...and they are all to do with the odorous nature of this ancient asian plant with a 4,500 year history as medicine.1
The odour is also the subject of the first paragraph in Culpeppers profile2 ‘The offensiveness of the breath…will lead you by the nose to the knowledge hereof, and direct you to the place where it grows in gardens, which kinds are best and most physical'.
Other old references range from garlic being used ‘to clear the arteries' Dioscorides, 1st century, to ‘..it being a remedy for all diseases and hurts (except those which itself breed)' and ‘it provokes urine and women's courses,…kills worms in children, cuts and avoids tough phlegm, purges the head, helps the lethargy..cramps, convulsions or other cold diseases'. Culpepper.2
So what can we discern from ‘the nose', from watching it grow over time, from touch, smell and taste?
Garlic makes certain of its survival by reproducing by both bulbils and cloves.
It also produces seed which are often not very fertile.
Garlic has a good resistance to diseases.
Garlic is not often the food for other insects and animals.
The tough papery cover of its clove is also an added protection.
Consider this. If it is such a strong survivor and is so protective of itself then perhaps it will convey these qualities when eaten?
The smell? Pungent? Yes Sulphurous? Yes.
The taste? Hot? Yes. Stimulating? Yes.
And this. If it is so heating then it maybe unsuitable for the person who is already ‘hot' in temperament or who has a ‘hot' condition unless it is a fever.
Does it increase saliva? Yes
Does it increase appetite? It certainly makes your stomach active a little while after eating it.
And this. So it would improve digestion of foods?
These are some of the ways we can think about plants before we read what everyone else has to say.
And this. Is this the way our herbalist ancestors worked? Did they have an extraordinary understanding, an intimate connection with every plant they used?
The New Ways...I have often heard it said that if there was a pharmaceutical drug that acted in all the ways garlic does, it would be hailed as a miracle.
Along with Hypericum and Ginkgo, garlic is one of the most researched plants scientifically and by 1996 there were at least 1,808 chemical, pharmacological, clinical and epidemiological studies investigating the activities of garlic, published.3
One can only guess that in the last five years this would have at least doubled.
Not only is it popular among the researchers, others are hard at work creating a myriad of dishes to tempt even the most reluctant Garlic lover. There are at least four Garlic Festivals, a restaurant that has garlic in all of its dishes, even desserts, and in the Gourmet Alley in Gilroy, California, the home of the famous garlic festival, the chefs use literally tons of garlic per year in their dishes.
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What plant?
Garlic, Allium sativum, is a member of the Liliaceae or Lily family, characterised in this plant by its corms, simple leaves with parallel veins.
The pointed and flat based cloves (part of the stem) are covered in a multi-layered membranous coat.
Pinkish or white flowers appear along with the bulbils in an umbel.
Does a stronger odour mean a better medicine as Culpepper suggests? From the research it would suggest that it is so.
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What Part and When To Harvest?
The whole plant can be eaten but it is the dry whole corms that are the best medicine.
The tradition of ‘planting on the shortest day and harvesting on the longest', is a good guide but in my experience garlic is usually ready to harvest a month later. When the tops start to die back, bend them over and wait until they dry off.
Don't bury the cloves too deep when planting, pointed end up about 3cm or 1inch deep, and 15cm or 6inches apart.
Dry well after the corms are dug.
How and when to use?
Traditionally according to Culpepper and Dioscorides garlic was a
· diuretic - increases urine output
· emmenagogue - stimulates uterine activity
· anthelmintic - expels worms
· mucolytic - breaks up mucous
· stimulant - increases functional activity
· warming - increases circulation
and it reduced atherosclerosis.
Today it is considered to be
· anti-microbial - anti-bacterial and anti-viral
· anthelmintic
· anti-inflammatory - reduces inflammation
· hypotensive - reduces blood pressure
· hypolipidemic - lowers blood lipid levels
· cholagogue - stimulates bile production
· anti-tumourogenic - reduces tumour growth
· expectorant - removes excess mucous from the lungs
· diaphoretic - promotes perspiration
· anti-thrombotic - reduces the clotting ability of the blood
· nutritive contains valuable vitamins and minerals ( Vit A, B1, C, and E. Minerals Selenium, germanium, sulphur, calcium, magnesium, copper, potassium, zinc and some iron).
· hypocholesterolemic. - reduces LDL 4
This impressive list reflects the research and a medical herbalist will prescribe it for people with a wide range of conditions affecting the cardio-vascular, respiratory and gastro-intestinal systems.
Conditions for which garlic is often prescribed:
Cardio-vascular system
· hypertension
· hypercholesterolemia
· hyperlipidemia
· atherosclerosis
and other conditions associated with clotting.
Respiratory system
· any infectious conditions
· catarrhal conditions
· bronchitis.
Gastro-intestinal conditions - again any infections or intestinal dysbiosis.
There are also reports that garlic increases Natural-Killer cells, (assimilating cells may be a less war-like description), and the potential to affect both tumour and other cancerous cells.4
How to Prepare?
There are such a range of preparations on the market today yet most writers that are not associated with promoting a product agree that unprocessed corm is the most active.
Garlic, like all plants has a complex chemical makeup. The sulphur compound alliin, which is released if the garlic is crushed, chewed, minced or bruised, is acted on by the enzyme allinase and very quickly converted to allicin and then into a range of active secondary products.
The effectiveness then of a preparation depends on the processing.
Preparations available.
Garlic powder. If dried with care, these will contain virtually the same substances as fresh garlic (fresh meaning the whole corms dried for storage).
Garlic oil capsules. These contain little alliin but contain other sulphides.
Aged Garlic (AGE). Eg. Kyolic. Some reviews suggest ageing garlic to produce an odourless product reduces all sulphur compounds or modifies them.3,5
Steam distilled oil. Consists almost entirely of one of the secondary compounds, diallyl sulphides.
So what activity is attributed to what constituent?
Anti-viral?
Four enveloped viruses were found to be inactivated by allicin so the fresh and dried preparations would be the most effective. 6
Steam distilled and oil macerated products showed no effect nor did the Japanese aged garlic.6
Anti-bacterial?
Again it is thought that allicin may be the active constituent, so again the fresh and dried preparations would be best.
Cardio-vascular effects.
There are so many studies and analyses of studies that one could only comment that any preparation will be effective. See Research review.
Preparations at home
I have two favourite preparations, Garlic Honey and Lemon/Garlic/Ginger drink.
Garlic Honey
Carefully remove the outer skin of approximately 12 cloves. Roughly chop and cover immediately with honey. Manuka honey is my favourite because of its added anti-bacterial action.
Leave for 2-8 hours and take 1 tablespoon several times daily at the onset of a cold or sore throat or to relieve catarrhal conditions.
Lemon/Garlic/Ginger drink
Squeeze the juice of a lemon into a large cup and grate some of its rind.
Add two cloves of chopped garlic, a slice of finely chopped fresh ginger or a teaspoon of dried powder, a pinch of powdered cayenne and a tablespoon of honey.
Fill the cup with near boiling water, cover and infuse for a few minutes then drink the liquid and eat the solid.
Again drink it at the first signs of a cold, sore throat or fever. It will promote perspiration.
A tasty treat
Leave garlic with their skins on, add to a dish of roasting vegetables for the last 10 mins of cooking, they are sweet and delicious.
How Much To Use?
Fresh Garlic
For acute conditions - 2-6 almond sized cloves daily.
1 clove is fine for a maintenance dose.
For other conditions, 2-3 almond sized cloves daily.
Garlic oil
Follow directions on the label and use for cardio-vascular conditions.
The British Herbal Pharmacopeia states that 4-12mg of alliin is a daily dose, or 400-1200mg of powder, 2-5g fresh bulb, 2-5mg garlic oil.
Safety
Garlic and other Medication
Some caution should be taken with therapeutic doses of garlic if a person is on other forms of ‘blood-thinning' medication such as warfarin or aspirin.
Garlic and Surgery
It should also be stopped 10 days prior to surgery due to the increase in the time it takes for blood to clotting. It is likely that it only has a short term effect on blood clotting of around 12 hours, so this is a precaution only.
Garlic and Pro-biotics
If a person is using pro-biotic foods then garlic should be taken at least three hours either side of this as it will reduce the levels of lactobacillus and other bacteria.
Garlic and Lactation
It should probably not be used in the early weeks of breastfeeding as babies can be upset by it, it is a case of trying it to see if it OK for each individual.
Other
Some people feel a little nauseous after eating garlic and most of these have had either hepatitis or glandular fever. Others don't like the smell on their skin or breath. Chewing a little parsley will help the breath, and the skin odour will go away after garlic has acted on the body for awhile.
Research Review
There are many analyses of the trials and research papers written about garlic, and then there are the meta-analyses and the reviews of the meta-analyses and discussions about these. Are they unbiased and is the one that claims that they aren't, unbiased and so it goes on?
In 1996 Garlic The Scientific and Therapeutic Application of Allium sativum L. and Related Species by Heinrich P. Koch and Larry D. Lawson was published, reviewing the literature to that date. Briefly the following actions of garlic were supported by clinical trials;
· decreased platelet aggregation and thrombi formation
· anti-oxidant activity (preventing atherosclerosis)
· enhanced fibrinolysis (dissolving coagulated blood)
· decreased levels of low density lipo-proteins (LDL) and cholesterol
· increased high density lipoproteins (HDL)
· hypotensive
· anti-biotic (allicin) - they note that heating at high temperatures reduces the anti-biotic effect.
· anti-fungal effects
· anti-viral
· anti-cancer based on epidemiological studies on prevention of stomach and bowel cancer
More recently, Mills and Bone 5, provide an excellent review up to 1998. The clinical trials and reviews they cover discuss the following effects of garlic;
· lipid lowering effects (results of two supportive metaanalyses and two negative clinical trials)
· anti-atherogenicity
· anti-hypertensive - hypotensive (modest but significant reduction)
· anti-thrombotic
Since then the trials and papers written continue.
Summary of a selection of papers written this year about garlic and its actions.
What surprised me was that the same actions are still being tested in regard to the cardiovascular system with the following results;
Anti-oxidant health effects of aged garlic extract.
Although additional observations are warranted in humans, compelling evidence supports the beneficial health effects attributed to AGE, i.e. reducing the risk of cardiovascular disease, stroke, cancer and aging. 8
Suppression of LDL oxidation by garlic.
Short-term supplementation of garlic in human subjects has demonstrated an increased resistance of LDL to oxidation. These data suggest that suppressed LDL oxidation may be one of the powerful mechanisms
accounting for the anti-atherosclerotic properties of garlic.12
Aged garlic extract, a modulator of cardiovascular risk factors: a dose-finding study on the effects of AGE on platelet functions.
AGE exerts selective inhibition on platelet aggregation and adhesion, platelet functions that may be important for the development of cardiovascular events such as myocardial infarction and ischemic stroke. 13
Efficacy of garlic supplementation in lowering serum cholesterol levels.
The latest clinical research suggests that consumption of garlic powder does not play a significant role in lowering plasma lipid levels when in conjunction with a low-fat, low-cholesterol diet. Additional well-controlled, long-term studies that explore dosage and preparation type are necessary to confirm the efficacy of garlic in lowering cholesterol levels and to fully understand garlic's potential role in CVD.15
Effect of dietary garlic (Allium Sativum) on the blood pressure in humans--a pilot study.
This study shows that individuals whose blood pressures are on the lower side are more likely to consume more garlic in their diets. (Statistically significant for systolic blood pressure only). This was a pilot study and more elaborate trials are recommended to prove this association. 17
On Cancer
Mechanisms by which garlic and allyl sulfur compounds suppress carcinogen bioactivation. Garlic and carcinogenesis.
Overall, a host of studies provides compelling evidence that garlic and its organic allyl sulfur components are effective inhibitors of the cancer process. 9
Ajoene, a natural product with non-steroidal anti-inflammatory drug (NSAID)-like properties?
These data suggest that ajoene works by a mechanism of action similar to that attributed to non-steroidal anti-inflammatory drugs. This finding may add a novel aspect to the biological profile of the garlic-derived natural product ajoene which might be important for understanding the usefulness of garlic for chemoprevention of gastrointestinal carcinomas. 10
The influence of heating on the anticancer properties of garlic.
These studies suggest that heating (microwave or oven) destroyed garlic's active allyl sulfur compound formation, which may relate to its anticancer properties.11
Garlic consumption and cancer prevention: meta-analyses of colorectal and stomach cancers.
In the meta-analyses of colorectal and stomach cancer, high intake of raw or cooked garlic may be associated with a protective effect against stomach and colorectal cancers. 16
On anti-microbial activity
Allylsulfide constituents of garlic volatile oil as anti-microbial agents.
Six different mixtures of garlic distilled oils containing diallyl disulfide (DDS) and diallyl trisulfide (DTS), have been assayed against a number of yeasts (C. albicans, C. tropicalis and B. capitatus), gram-positive bacteria (S. aureus and B. subtilis) and gram-negative bacteria (P. aeruginosa and E. coli). Results obtained support a specific anti-fungal more than an anti-bacterial activity and implicate DDS as the active constituent.14
In-vitro anti-microbial activity of four diallyl sulphides occurring naturally in garlic and Chinese leek oils.
The in-vitro anti-microbial activity of garlic oil, Chinese leek oil and four diallyl sulphides occurring naturally in these oils against Staphylococcus aureus,
methicillin-resistant S. aureus (MRSA), three Candida spp. and three Aspergillus spp. (total of 276 clinical isolates) was studied. Diallyl disulphide, diallyl trisulphide, diallyl tetrasulphide and the oils rich in these sulphides may have a role in the prevention or treatment of infections.19
On perioperative care.
Herbal medicines and perioperative care.
Echinacea, ephedra, garlic, ginkgo, ginseng, kava, St John's wort, and valerian are commonly used herbal medications that may pose a concern during the perioperative period. Complications can arise from these herbs' direct and pharmacodynamic or pharmacokinetic effects. Direct effects include bleeding from garlic, ginkgo, and ginseng; cardiovascular instability from ephedra; and hypoglycemia from ginseng. Pharmacodynamic herb-drug interactions include potentiation of the sedative effect of anesthetics by kava and valerian. Pharmacokinetic herb-drug interactions include increased metabolism of many drugs used in the perioperative period by St John's wort.18
Recent Statistics
An estimated US$61.2 million dollars worth of garlic supplements sold in the US market in the year to Jan 7th, 2001.7
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References
1. Ernst Prof. E., How Garlic Protects Your Heart. Amberwood Publishing 1996.
2. Culpepper Nicholas, Complete Herbal and English Physician. Meyer Books, 1990.
3. Commission E Mongraphs.
4. Fisher C. Painter G., Materia Medica of Western herbs for the Southern Hemishere. 1996
5. Mills S. Bone K., Principles and Practice of Phytotherapy. Modern Herbal Medicine. Churchhill Livingstone. 2000.
6. Weber N, Anderson D, North J, Murray B, et al. In vitro virucidal effects of Allium sativum extract and compounds. Planta Medica 1992;58:417-423
7. American Botanical Council and The Herb Research Foundation. HerbalGram. 51
8. Borek C.Antioxidant health effects of aged garlic extract. Department of Community Health and Family Medicine, Nutrition and Infectious Diseases Unit, Tufts University School of Medicine, Boston, MA 02111, USA.
9. Milner JA.Mechanisms by which garlic and allyl sulfur compounds suppress
carcinogen bioactivation. Garlic and carcinogenesis. Adv Exp Med Biol 2001;492:69-81
10. Dirsch VM, Vollmar AM. Ajoene, a natural product with non-steroidal anti-inflammatory
drug (NSAID)-like properties? Biochem Pharmacol 2001 Mar 1;61(5):587-93
11. Song K, Milner JA. The influence of heating on the anticancer properties of garlic.J Nutr 2001 Mar;131(3s):1054S-7S
12. Lau BH.Suppression of LDL oxidation by garlic. Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
13. Steiner M, Li W.Aged garlic extract, a modulator of cardiovascular risk factors: a dose-finding study on the effects of AGE on platelet functions. J Nutr 2001 Mar;131(3s):980S-4S
14. Avato P, Tursil E, Vitali C, Miccolis V, Candido V. Allylsulfide constituents of garlic volatile oil as antimicrobial Phytomedicine 2000 Jun;7(3):239-43
15. Spigelski D, Jones PJ. Efficacy of garlic supplementation in lowering serum cholesterol evels. Nutr Rev 2001 Jul;59(7):236-41
16. Fleischauer AT, Poole C, Arab Garlic consumption and cancer prevention: meta-analyses of colorectal and stomach cancers. Am J Clin Nutr 2000 Oct;72(4):1047-52
17. Qidwai W, Qureshi R, Hasan SN, Azam SI Effect of dietary garlic (Allium Sativum) on the blood pressure in humans--a pilot study J Pak Med Assoc 2000 Jun;50(6):204-7
18. Ang-Lee MK, Moss J, Yuan CS. Herbal medicines and perioperative care. JAMA 2001 Jul 11;286(2):208-16
19. Tsao SM, Yin MC. In-vitro antimicrobial activity of four diallyl sulphides occurring naturally in garlic and Chinese leek oils. J Med Microbiol 2001 Jul;50(7):646-9
Reflections
Good food, Good medicine, Companion Plant, the focus of Festivals, Books, Thousands of Studies and the ‘Heart' of a good meal, quite miraculous for a plant scorned ‘…for we are to utter sweet breath…'
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