Garlic unpeeled: Why the pungent bulb is one the healthiest foods you can eat – and the secret hack to help it supercharge your immune system

Garlic is a real multi-tasker: it can lower blood pressure, tackle cholesterol, protect against seasonal viruses, and – if the legend of Van Helsing is to be believed – even ward off vampires. 

For such a tiny bulb, it really packs a huge punch, with every clove filled with flavour  and health-boosting antioxidants. 

It is naturally rich in vitamins C and B6, as well as manganese and selenium – trace minerals that our body needs for a multitude of vital functions including maintaining bone strength, creating collagen, thyroid health and bolstering the immune system.

But what really makes garlic a superfood is the presence of allicin, a sulphur-rich compound responsible for its plethora of health benefits… and divisive aroma.

Alexa Mullane, Registered Functional Nutritional Therapist and Health Coach, told the Daily Mail: ‘Garlic contains organosulfur compounds which have been proved to be beneficial to health, especially allicin which has antimicrobial, antioxidant and anti-inflammatory effects. 

‘It has been found to support immune function due to its effectiveness against bacteria (including drug-resistant strains), viruses, fungi, and parasites. 

‘It can also support cardiovascular health – research has found modest improvements in blood pressure and cholesterol levels with the use of garlic. The sulphur-rich compounds also support liver detoxification.’ 

Garlic, which is from the same ‘family’ as onions and leeks, has been grown and eaten for nearly 6,000 years. 

It originated in central Asia, near modern day Iran, Kazakhstan, Turkmenistan and Uzbekistan.

From there it spread to the Middle East, then the Mediterranean and then all over the world, heralded as both a flavour enhancer and medicinal ingredient.

It is one of the reasons why many people regard garlic as a ‘miracle cure’ for winter viruses, with some going as far to suggest that you should pop a clove or two when you feel a sniffle coming along. 

This, explains Ms Mullane, is one of the major myths about garlic which she is keen to quash. 

‘It definitely helps with infections due to its powerful antimicrobial compounds, however the immune system needs support from a balanced diet containing lots of colourful vegetables and fruits alongside good quality protein, sufficient fibre and healthy fats like omega-3 from oily fish,’ she said. 

‘This will give the body the building blocks it needs to support a healthy immune system. 

‘It is great to use garlic when you have a cold or flu to give additional acute support to the immune system but shouldn’t be relied on as the only cure.’

Garlic was introduced to Britain by the Romans, who found that our fertile soils offered the perfect conditions for the bulbs to thrive, and it has since become a staple ingredient in commercial and residential kitchens across the country. 

From pasta dishes to roast dinners, golden garlic bread to curries, it’s hard to find a dish that doesn’t include garlic in one way or another, and the majority of Britons aren’t complaining.

A recent YouGov poll saw it ranked as the seventh most favourite vegetable in Britain, with just 8 per cent of respondents saying they disliked it. 

Although it might not seem like it, there are hundreds of varieties of garlic but they generally fall into two main categories; hardneck and softneck. 

Hardneck garlic tend to be larger and have fewer cloves, and generally have more flavour. 

On the other hand, softneck garlic – which you would typically find at the supermarket – are smaller with more cloves and have a milder flavour.

‘There is also black garlic which is fermented and has a sweeter flavour, has a different sulphur makeup and is higher in antioxidants,’ said Ms Mullane.

‘There’s also elephant garlic – which is actually a species of leek – which is milder but not as nutrient-dense as the others.

‘Wild garlic is a cousin of culinary garlic and is found in shady woodlands in spring, and is ideal for foraging. 

‘The leaves are most commonly eaten rather than the bulbs, and it has a much milder flavour. It also contains allicin which is produced when the leaves are crushed or chopped.’

Below, with Ms Mullane’s expert input, we take a closer look at why garlic is a must-have addition to our daily diet – and the common mistakes people make when preparing and eating it.

Can you eat too much garlic?

The side-effects of over indulging in the savoury bulb vary from a hard-to-shift case of garlic breath and sweats, to debilitating stomach cramps – a complaint made by  people with irritable bowel syndrome (IBS) especially.

‘As with anything, you can have too much of a good thing, especially if eating raw garlic,’ says Ms Mullane. 

‘Eating too much could irritate the digestive tract and could cause pain or discomfort, heartburn or reflux, gas and bloating, and even bad breath and body odour as the body eliminates it. 

‘Eating a lot of garlic is usually not dangerous though and the gastrointestinal symptoms will pass.’

The problems come down to the allicin – the very compound which makes it a nutritional powerhouse – it is most potent in raw garlic, and it can irritate the stomach when not cooked. 

Furthermore, garlic can cause painful and embarrassing digestive chaos in other ways, too.  

They are rich in fermentable carbohydrates – known as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) – which can’t be broken down by the small intestine. 

Instead they move slowly through the digestive tract attracting water until they’re fermented by microbes in the large intestine, producing gas. 

Ms Mullane said: ‘People with IBS may find that symptoms are exacerbated because garlic contains fructans, a type of oligosaccharide, which is poorly digested and can cause bloating and gas when fermented by bacteria in the gut. 

‘People on the FODMAP diet should avoid garlic for this reason.

‘In some people, garlic can relax the lower oesophageal sphincter which allows stomach acid to flow back up into the throat, causing acid reflux.’ 

How to make garlic even healthier   

The next time you’re preparing dinner and it calls for a couple of cloves of garlic, don’t rush. 

Ms Mullane advises waiting for 15 minutes after crushing or chopping raw garlic before you add it to the dish, as it allows the bulb’s natural enzyme, alliinase, to kick in. 

She said: ‘The alliinase then reacts with alliin and creates allicin, the compound responsible for garlic’s health benefits.’

Clever food pairings can also harness some of garlic’s raw power. 

Healthy fats like extra virgin olive oil or avocado help to absorb the fat-soluble antioxidants present in garlic, making them easier for the body to absorb.

‘Antioxidants work better when consumed with other antioxidants to help them recycle each other,’ Ms Mullane said. 

‘To help recycle garlic’s sulphur-based antioxidants it’s a good idea to eat foods rich in vitamin C such as tomatoes, bell peppers and citrus fruits. 

‘So a garlicky tomato sauce for pasta, roasted peppers and garlic, or a dressing with garlic, lemon juice and parsley are all great combinations.’

Furthermore, eating garlic with other alliums like onions or shallots increases the overall organosulfur content and can make a meal even healthier.

Should you eat garlic raw or cooked?  

Both cooked and raw garlic offer benefits, but to use it as a medicinal remedy for a cold or flu, raw is best. 

Raw garlic has the highest allicin content and the most potent antimicrobial properties, but on the flipside it is most likely to cause gastrointestinal irritation and symptoms.

Ms Mullane explained: ‘Cooked garlic is much more gentle on the digestive tract and is still rich in antioxidants and healing properties. 

‘It also contains prebiotic fibres to feed the microbiome and has benefits for heart health. For overall health support, it’s great to include garlic in cooking regularly.’

Ms Mullane also urges caution about using pre-prepared garlic products over a simple clove you need to prepare by hand.

‘Sometimes preservatives are added to keep it fresh, it often has less flavour than fresh garlic and the processing often destroys the allicin and antioxidants so it may be lower in health-supporting properties,’ she explained. 

‘Garlic is so quick and easy to use that I would always choose fresh over pre-prepared.’ 

Cloves vs capsules  

Not everyone wants to eat garlic every day – perhaps due to concerns about bad breath or body odour, or simply because they don’t like the taste of it – hence the advancement of pills which contain just the immune system boosting element, allicin.

The suggested daily dose for garlic pills often falls between 600 and 1,200 mg, which is the same as roughly one or two cloves. 

However, while they are more convenient (and odourless), Ms Mullane will always opt for the fresh stuff. 

‘Whole garlic offers a whole host of beneficial compounds (like antioxidants) which are often lost when manufacturers isolate the allicin in supplements,’ she said.

‘Supplements also vary in quality and formulation. Eating garlic in its natural form in cooking or by itself is preferred.’

Garlic can interfere with some medications 

There is an element of fact in the legend of garlic’s vampire-repelling powers. 

Historically it was believed to be the perfect protection against mosquitos, with the smell and taste of the bulb on the skin and in the blood thought to be abhorrent to the biting midges. 

Ms Mullane explained that it definitely does have an effect on the consistency of the blood – and it’s why people on certain medications need to be wary of overindulging. 

‘Garlic has anti-platelet properties and so acts as a blood thinner. 

‘Because of this, garlic can enhance the effects of anti-coagulant medication like warfarin, and can also interact with anti-platelet medication like aspirin as well as some HIV medications and certain antihypertensives. 

‘Eating modest amounts of garlic in food is not usually an issue, but large amounts of garlic or supplements should be avoided with these medications.’