Garlic is the most widely used medicinal plant in history. A member of the onion family, it is known for its antibiotic, antifungal and antiviral properties, and has been used by the Egyptians, Greeks, Romans and Chinese to help cure a variety of ailments from bronchitis and influenza to whooping cough.

Today, medical journals contain countless scientific studies investigating the ability of garlic to help fight infections, as well as provide potential benefits for diabetes, asthma and cancer sufferers.

Perhaps the most exciting discoveries to date have been that garlic can help protect against heart disease by thinning the blood and helping to lower cholesterol. If you have been indulging in high-fat foods over Christmas, this could be just the superfood you need.

Garlic contains allicin, a sulphur compound that gives it its pungent smell. Allicin encourages the elimination of cholesterol from the body and helps to reduce quantities of unhealthy fats. In countries where lots of fresh garlic is eaten, such as France and Italy, heart disease is less common than in the UK.

Researchers are also looking at the antioxidant effects of garlic, and its anti-ageing benefits, as well as how garlic can help to protect against the bacteria which cause stomach ulcers.

If you don't like the taste, real allicin products are the most effective supplements. Brands such as Allimax and Alliforce capture the allicin from fresh garlic and stabilise it.

As with most foods, fresh is still best. Add a clove to your salad dressing, rub toasted bread with it or make a fresh pesto sauce for pasta. Eating garlic during breast-feeding helps children become familiar with the flavour.

You should eat it as soon as possible after peeling, as its potency fades the longer it is exposed to light. Cooking the bulb also diminishes the healing properties, but it is still better to eat it cooked than not at all. If you don't want to smell of garlic afterwards, try chewing parsley or sucking a mint.