Garlic - A Discussion Paper

Garlic Discussion Paper

I have been asked so often recently about Garlic that I thought it was about time I committed an answer to writing. What follows is a summary of Garlic from my own recent research on the subject.

In my opinion garlic makes a wonderful health supplement but the garlic ‘cure’ is no substitute for the basics: sensible eating and appropriate exercise. Garlic should be seen as part of a healthy lifestyle, not an alternative to it. This is not a medical website. Information is provided on a ‘best effort’ basis and does not constitute medical or even personal advice. It is essential to consult your doctor first regarding any medical condition, or indeed prior to embarking on any diet programme.

What is Garlic?

Garlic (Allium Sativum) is a plant with a very strong and bitter flavour which has been used for both culinary and medical purposes for hundreds of years. There are two main medical ingredients which produce the garlic health benefits: allicin and diallyl sulphides.

What are the Benefits of Garlic?

Garlic has long been considered a herbal "wonder drug", with a reputation for preventing everything from the common cold and flu to the Plague! It has been used extensively in herbal medicine (phytotherapy, sometimes spelt phitotherapy).

Some of the benefits have been scientifically demonstrated, others have not and remain officially in the realm of folklore. Obviously the efficacy or otherwise of any of these benefits described below will depend upon individual circumstances.

In general, a stronger tasting clove of garlic has more sulphur content and hence the more medicinal value it's likely to have. Some people have suggested that organically grown garlic tends towards a higher sulphur level and hence greater benefit to health. In my experience it certainly tastes better so I buy organic whenever possible whether or not it's best for my health.

Modern science has shown that garlic is a powerful natural antibiotic, albeit broad-spectrum rather than targeted. The body does not appear to build up resistance to the garlic, so the positive health benefits continue over time. It is also known to have wonderful anti-viral, anti-fungal and antioxidant properties. Antioxidants can help to protect the body against damaging "free radicals".

Amongst other things, garlic has been used to treat high cholestrol, parasites, respiratory problems, poor digestion, and low energy. Studies suggest that regularly eating garlic helps lower blood pressure, controls blood sugar and blood cholesterol, and boosts the immune system. It has also been found to reduce the risk of oesophageal, stomach, and colon cancer.

Note that although it is often argued that the medicinal properties and benefits of garlic are strongest when it is raw and crushed or very finely chopped, it is not recommended to take garlic in its raw form. This is because the enzyme necessary to produce allicin may be destroyed in the stomach before having any positive effect. For this reason, dried or powdered garlic tablets are more suitable to take advantage of garlic's immune-boosting qualities. Studies have shown that other forms of garlic such as cooked garlic, pickled garlic, and aged garlic are also beneficial.

A Little More Detail On Benefits and Uses of Garlic

A Natural Antibiotic

Of all garlic's reputed medicinal benefits, perhaps the best well known is its use as a natural antibiotic with reports going back through history. There are even stories of garlic being used to ward off the plague. It's not known how effective this was, however there is some evidence that anthrax is sensitive to garlic. Some people have even suggested that it might help in the fight against acne although that might be too much to hope for.

Garlic's antibiotic properties have been more extensively studied than some of its other reputed health benefits. Louis Pasteur examined garlic's use as an antibacterial back in the nineteenth century and showed how it killed bacteria under laboratory conditions. Numerous modern studies confirm that garlic has definite antibiotic properties and is effective against many bacteria, fungi and viruses. According to Wright State University garlic is approximately one per cent as potent an antibiotic as penicillin.

Researchers have compared the effectiveness of garlic with that of commercial prescription antibiotics. The result is often that garlic can be more effective as a broad spectrum antibiotic. However if a particular bacterium or virus is being treated a more specifically targeted antibiotic if available could be a more effective treatment than garlic.

One significant advantage of garlic is that the body does not seem to build up a resistance to it as it does to many modern antibiotics. This also makes it potentially effective against hospital superbugs.

The antibiotic properties of garlic are a direct result of the allicin produced from raw, crushed garlic. This is destroyed by age and cooking. Cooked garlic has virtually no antibiotic value although it still retains other benefits.

I do not recommend using garlic as a replacement for conventional medical antibiotics unless agreed with your doctor. Personally I treat any antibiotic properties of garlic as a bonus of eating it, not a reason to do so. However as more and more antibiotics are becoming almost useless due to over-prescription and side effects, garlic could one day have a part to play in modern medicine.

High Blood Pressure

Clinical studies have shown that people with high blood pressure who took garlic capsules daily for up to five months lowered their blood pressure levels as effectively as patients taking prescription blood pressure drugs. A suggested dosage is 600-900mg garlic capsules once daily. I did a little more research on this and my findings are detailed below.

High Cholesterol

Studies have shown that taking 600-900mg of garlic everyday lowers cholesterol levels and reduces arterial plaque formation by 5–18%. Therefore, an effective natural remedy is to take one garlic tablet or capsule (600-900mg) once per day. I delved a little deeper on this issue too and my findings are detailed below.

Allergies

Garlic is known to have antiviral properties, which may help the body fight against allergies. Simply take one tablet of garlic supplement each day 2 or 3 weeks before the usual allergy season begins.

Coughing

Garlic's antibacterial properties make it a worthwhile treatment for coughs and other throat irritations. Garlic may also reduce the severity of upper respiratory tract infections.

Diabetes

Garlic may regulate blood sugar levels by increasing the release of insulin in diabetics. Therefore an effective remedy is to take one capsule or tablet of garlic every day.

Toothaches

Garlic's antibacterial, analgesic, and anesthetizing properties can help cure toothaches. Simply put some garlic oil or a piece of crushed garlic clove directly onto the affected tooth and the gum for instant relief.

Warts

Garlic's ability to fight infections and bacteria makes it an effective cure for warts and other skin problems.Take a fresh clove of garlic and cut its tip off. Rub the cut area of the clove directly onto the wart for a few seconds. Repeat this each night before going to bed until the wart disappears. If you feel any kind of irritation or strong burning sensation, simply rinse the area with water.

Natural Insomnia Treatment?

Sleep is an essential part of life. We need it to remain physically and mentally healthy. The effects of sleep deprivation can be disastrous. Do consult your doctor. If we're having trouble sleeping then it would be nice to have something natural and inexpensive to help.

So, could garlic help us to sleep? Or is it more likely to keep us awake? The evidence is mixed. It has a reputation for doing both!

On the one hand garlic is generally classed as a "hot" herb and has been known as a stimulant. Some groups have even objected to garlic because of the "over-stimulation" it can produce by "inflaming" the passions. It has sometimes been considered an aphrodisiac, which would hardly seem to be suggestive of a sedative effect! Yet despite that garlic also has a reputation for helping people to get to sleep, even if they don't want to. Some people have claimed that eating garlic at lunch time can make it more difficult to concentrate in the afternoon. This contradiction was summed up by gourmet Curnonsky who wrote: "A garlic caress is stimulating. A garlic excess soporific." It seems that garlic might help you to get a good night's sleep, under certain conditions. For example, if you have a cold and are having trouble breathing then garlic might be able to assist. Garlic can help to dry up the nasal passages in some cases, improving breathing and helping to reduce snoring in some people. This can in turn ease sleep. Whether garlic works as a sleep aid under "normal" conditions is as yet unproven.

Some people suggest chopping a little garlic, infusing it in simmering milk for a few minutes then straining to produce a night-time drink. Check with your partner first!

Insect Repellent

There is a long history of using garlic to get rid of many insects. In particular, garlic has a reputation for protecting people from mosquito bites; some think that this could be the origin of the belief that vampires are scared of garlic. There are a number of commercial garlic sprays on the market, that effectively coat an area and produce a natural mosquito barrier. Garlic is more effective at repelling some species of mosquito than others. For this reasons many of the commercial preparations available include a number of different repellent ingredients such as catnip and soy as well as garlic.

It's not clear why garlic should be an effective natural mosquito repellent. It would seem that the powerful compounds such as allicin which garlic releases are inimical to mosquitos. They have therefore evolved to avoid garlic. Another possibility is that the strong smell of garlic overwhelms the mosquito's sense of smell and prevents them from finding their prey (us!). Whatever the mechanism, garlic's ability to repel a variety of pests has been proven scientifically. Its effect against mosquitos specifically is less well documented however there is much anecdotal evidence to support it.

If you wish to protect an entire area such as your garden, you could treat it with one of the commercially available garlic based sprays you can buy. For individuals, studies have shown that coating the body with a jelly based compound including garlic can keep mosquitoes away for some time. Obviously such a method, whilst effective against bites, has fairly major social side effects! (Warning: the allicin in garlic is very strong and can result in skin problems and allergic reactions. Consult your doctor).

Fortunately you probably don't have to go that far. There is strong anecdotal evidence that simply consuming more garlic can help to prevent mosquito bites. This is not simply a case of mosquitos being averse to garlic breath! If you eat a large amount of garlic then it actually seeps out through the pores of your skin. Some people think that this invisible layer of garlic oil might create a natural barrier cream.

Given the possible dangers from mosquito bites (West Nile virus etc) I don't recommend you rely on garlic alone!

Readers in Scotland will probably suffer from the infamous Scottish biting midges. Since many mosquito traps and sprays are also sold as midge repellents, and the famed mosquito magnet has been adapted as a "midge magnet", it's possible that garlic could also help to prevent in midge control.

Some Further Research On High Blood Pressure

High blood pressure is a potentially dangerous problem suffered by many people, often without them being aware of it. High blood pressure is in essence hypertension; the blood is being pumped through the system unusually fast and powerfully. This constant exertion of greater than normal force can damage the arteries, possibly leading in turn to kidney failure, heart attack and/or stroke. If you suspect you may have high blood pressure then it is essential that you discuss any symptoms with your doctor.

High blood pressure is usually divided by doctors into "essential hypertension" and "secondary hypertension". "Secondary hypertension" refers to when the high blood pressure is the result of a known factor such as kidney disease. "Essential hypertension" refers to the case where there is no obvious single cause of high blood pressure.

There are many factors that can contribute to essential high blood pressure, the most common of which are lifestyle related. Smoking and high levels of saturated fat intake can both contribute significantly to an elevated level of blood pressure. If your doctor doesn't identify a particular cause then he or she could well recommend diet and exercise as the best start. Losing some weight, lowering bad cholesterol levels and reducing salt intake can assist many people to lower their blood pressure levels. For others the preferred treatment will be medication.

So can garlic help? Garlic is not a substitute for prescription medicine or lifestyle changes, however it has long had a reputation for assisting with blood pressure management. The research data is not conclusive, however it does appear that there is some evidence to support the role of garlic in reducing systolic and diastolic blood pressure. It appears that the reputed beneficial effects of garlic on blood pressure come more from the garlic sulphides than from allicin. Unlike allicin, garlic sulphides are not destroyed by cooking. Garlic might also assist blood pressure indirectly by helping to manage cholesterol levels (see below). Finally, garlic can be used as a seasoning, thus reducing the need for salt.

If you think you have high blood pressure then you should consult your doctor first before considering any home diagnosis or treatment.

Some Further Research On Cholesterol

Cholesterol is a white, waxy substance found in the blood plasma and is essential to life. However, overly high cholesterol levels can have serious health implications on the cardiovascular system in particular leading to atherosclerosis. Excessive levels can be an indicator of increased risk of heart attack and/or stroke.

If you think you have a cholesterol problem it is essential you discuss it with your doctor.

Whilst all cholesterol was once considered harmful, it is now recognised that it comes in two distinct forms: one "good", the other "bad". High-density lipoproteins (HDLs) and low-density lioproteins (LDLs). Of these, HDLs are generally called "good" cholesterol whilst LDLs are "bad".

2005 UK recommendations (from the Joint British Societies - JBS2) are total cholesterol below 4.0mmol/l, "bad" cholesterol below 2.0mmol/l. Obviously these are general guidelines which may not be appropriate for everyone.

So what are the possible effects of garlic on cholesterol levels? Garlic has been reputed to assist the heart for centuries and has been used in herbal medicines for all manner of conditions. Garlic and cholesterol reduction are frequently mentioned together. Modern medical science suggests one reason garlic might reduce cholesterol: garlic is a proven antioxidant. This property might help to prevent LDLs from being oxidised. In this way the cholesterol build-up that clogs the arteries could perhaps be reduced by garlic.

In recent decades, numerous scientific studies have been conducted to test the claims that garlic can help lower cholesterol levels. These studies involve measuring the cholesterol and triglyceride levels of patients taking garlic supplements compared with a control group of patients taking a placebo. Unfortunately the results are not conclusive.

Some studies have shown a reduction in total cholesterol levels and/or LDL levels in those taking garlic. Other medical studies have shown no significant difference between the levels of those taking garlic and those taking a placebo. A study published in 2007 tested raw garlic and two popular garlic supplements (Garlicin and Kyolic). The study concluded that: "None of the forms of garlic used in this study, including raw garlic, when given at an approximate dose of a 4g clove per day, 6 d/wk for 6 months, had statistically or clinically significant effects on LDL-C or other plasma lipid concentrations in adults with moderate hypercholesterolemia."

So what is the verdict? Can Garlic Lower Cholesterol Levels? Whilst some individual studies have shown that garlic can be effective in reducing "bad" cholesterol (LDLs), the overall body of evidence is inconclusive. In particular the 2007 study appears to shed serious doubt on the reality behind garlic's reputation in this area. Thus it would be unwise to draw a definite conclusion that garlic can be used to combat "bad" cholesterol foods.

How then do we explain those studies that do show garlic works as a cholesterol treatment? Do we simply discard them as using flawed methodology? If, for the sake of argument, we assume there is some validity in those that found links, how do we explain the different findings? One possibility is that the efficacy of garlic in combatting cholesterol etc depends upon some other, unknown factor, for example the exact variety or manner of preparation of the garlic. Since this factor is unknown, it is not possible to design tests to eliminate it. Another possibility is that the reputed cholesterol lowering properties of garlic are effective only for specific subgroups of the population.

If you are concerned about elevated cholesterol levels then you should not turn to garlic as an alternative to medical treatment. Get advice from your doctor. However if your doctor approves then you might like to consider eating more garlic as part of a balanced diet "just in case". If nothing else it's a tasty alternative to salt.

What are the Side Effects of Garlic?

Garlic is a very powerful herb that is generally lauded as beneficial and health giving. However, partly because it is so powerful, there are risks associated with it. Remember that what helps one person may harm another.

For most individuals, garlic does not cause any serious side effects. However people who are allergic to garlic or who consume it in large quantities may suffer from stomach irritation, heartburn, or flatulence. Even if you don't have an explicit allergy to garlic, too much exposure to allicin (produced when garlic is crushed) can cause similar symptoms. Other symptoms of garlic allergy include skin rash, temperature and headaches. Garlic allergy has also been reported to exacerbate asthma symptoms, though this is more usually related to breathing in garlic dust rather than eating garlic.

All allergies can be potentially serious. If you suspect that you might be suffering from garlic allergy, or any other sort, food or otherwise, you should contact your doctor or a medically qualified clinic to arrange for testing.

Raw garlic is very strong, so even if you are not normally allergic or sensitive to garlic eating too much could produce problems, for example irritation of or even damage to the digestive tract. Also, garlic could potentially disrupt anti-coagulants, so it's best avoided before surgery. As with any medicine, always check with your doctor first and tell your doctor if you are using it.

Probably the most serious risk associated with garlic is botulism. Its sulphurous nature makes it a prime breeding ground for botulism (clostridium botulinum). Botulism is a nasty toxin that can result in major stomach illness sometimes leading to death. The worst danger from botulism comes if raw garlic is stored in oil at room temperature, or even for too long in the refridgerator. Never store raw garlic in oil at room temperature.

Important: Research published in 2001 concluded that garlic supplements "can cause a potentially harmful side effect when combined with a type of medication used to treat HIV/AIDS". More details are available on the NIAID website.

My personal rule of thumb for all foodstuffs is simple: If in doubt, don't eat it.

Better safe than sorry.

Where and How to Buy Garlic

Fresh garlic and garlic powder can be bought at regular grocery stores. Some people prefer to take garlic supplements. These pills and capsules have the advantage of avoiding garlic breath. Garlic supplements are available in the form of tablets, capsules, extracts, and oils and can be purchased at most health food stores.

Do Garlic Supplements Work? Do garlic supplements provide the health benefits of garlic? Is taking a dietary capsule good for your health or just a waste of money? As is so often the case, the answer is "it depends". Garlic supplements vary greatly.

The most potent medicinal compound derived from garlic is allicin and it is for this that most people turn to garlic supplements. The chemistry of allicin is complex; it is not present in natural garlic but is released when garlic is crushed. In addition, allicin is unstable and breaks down quickly. Producing garlic supplements that will release significant quantities of allicin is not easy. This might explain their price. There's no clear consensus on which products are best. One rule of thumb when buying garlic supplements is to check the label for the amount of allicin released. Use this information to compare different brands. Other figures such as "equivalent to x cloves" are not so important. The amount of allicin, if any, depends on the production method. Some people are sceptical that odourless capsules can contain any allicin, after all, it is the sulphorous compounds such as allicin that give garlic its smell in the first place.

Be aware that some garlic supplements list the amount of alliin they contain. That one letter difference is important. It isn't a spelling mistake! Alliin is a precursor compound to allicin and conversion rate between alliin and allicin is extremely variable. On its own an alliin figure is of little value.

Even without allicin, capsules might still be of value to some people because of the other sulphides they contain. In particular there has been a lot of research into the possible beneficial effects of aged garlic extract (AGE).

In summary, if you want to take nutritional garlic supplements, then to get the best medicinal benefits you should go for quality and always check the allicin level on the packet. Even without allicin content, garlic capsules might be of value to some people. Always check with your doctor, especially if you are taking other medication or are due to undergo surgery.

Oh and remember, in my opinion garlic makes a wonderful health supplement but the garlic ‘cure’ is no substitute for the basics: sensible eating and appropriate exercise. Garlic should be seen as part of a healthy lifestyle, not an alternative to it.

Your Friend and Coach

Adrian Lowther