Some of the old stories of garlic's healing properties have doubtful validity, but many of its claimed health benefits have been backed up by modern scientific research. There are two main medicinal ingredients which produce the garlic health benefits: allicin and diallyl sulphides.
Garlic is a sulphurous compound and in general a stronger tasting clove has more sulphur content and hence more potential medicinal value. Some people have suggested that organically grown garlic tends towards a higher sulphur level and hence greater benefit to health. Whether or not that is in fact the case, in my experience it certainly has the best taste.
Benefits
Various garlic health benefits have long been claimed and the "stinking rose" treatment has been used extensively in herbal medicine (phytotherapy) down the centuries. It's been considered by many to be a herbal "wonder drug", with a reputation in folklore for preventing or treating everything from the common cold and flu to the Plague!
Much of that is at best unproven, however there are some very positive garlic health facts that are now widely accepted. Amongst the most interesting potential applications are suggestions that garlic might be able to assist some people in the management of blood pressure cholesterol levels.
Modern science has shown that garlic is a powerful natural antibiotic, albeit broad-spectrum rather than targeted. The bacteria in the body do not appear to evolve resistance to the garlic as they do to many modern pharmaceutical antibiotics. This means that its positive health benefits can continue over time rather than helping to breed antibiotic resistant "superbugs".
Studies have also shown that garlic - especially aged garlic - can have a powerful antioxidant effect. Antioxidants can help to protect the body against damaging free radicals. There are claims that fermented black garlic contains even higher antioxidant levels than normal cloves.
Some people who want the claimed health benefits without the taste prefer to take garlic supplements. These pills and capsules have the advantage of avoiding garlic breath.
Side-Effects
Even garlic isn't a perfect. Apart from garlic breath there are other possible side effects, especially if used to excess. Use common sense and don't overdo it.
Raw garlic is very strong, so eating too much could produce problems, for example irritation of or even damage to the digestive tract.
There are a few people who are allergic to garlic. Symptoms of garlic allergy include skin rash, temperature and headaches. 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.
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.
Garlic makes a wonderful health supplement for many people but the so-called "garlic cure" is no substitute for the basics: sensible eating and appropriate exercise. Garlic should be seen as part of a healthy lifestyle - not as an alternative to it. Always consult your doctor first regarding any medical condition.