Introduction

Inflammation occurs when the body tries to fight an infection or a disease, and it is characterised as part of our body’s defence mechanism. Inflammation can cause symptoms such as redness, swelling, and pain, which can make the condition worse.

There are some medications that can help to fight inflammation, however, instead of overloading the body with drugs, there are natural tools that can either be used in combination with the medicine to speed up the treatment or fight inflammation on their own. These natural methods can even be used as a precaution for the future. One example of those natural tools is garlic, which is home to many bioactive compounds, and has been shown to be beneficial. 

History of garlic

Allium sativum L., often known as garlic, is a cultivated member of the Amaryllidaceae family and is valued for its culinary and functional qualities, due to its many health advantages.¹ With a rich history spanning centuries, garlic has been valued for its distinctive flavour and therapeutic properties.²  Its use goes back thousands of years; the Sumerians, the Egyptians, and even the athletes competing in the first Olympics in Greece acknowledged its ability to increase strength.³

Garlic was suggested in ancient Chinese and Indian medicine to treat leprosy, improve digestion, and fight against parasite infestation. In the Palaeothilic era, attention was drawn to garlic due to its many uses. It was suggested as a treatment for arthritis, tooth pain, ongoing coughs, constipation, infections and even for snake and insect bites. Because of all these highlighted health benefits that garlic carries, it has become of interest to scientists who are focusing on its immune strengthening abilities, antimicrobials, anti-cancer and anti-inflammatory activities. 

As we learn more about the many uses of garlic, its historical significance and contemporary scientific interest continue to coexist harmoniously, confirming garlic's value as a resource for both culinary and medical applications.²

Garlic's bioactive compounds

Garlic is regarded as a beneficial spice due to its wide range of nutritive components, fibre, and phytochemicals. 

It has high levels of:

• Potassium 
• Phosphorus Zinc
• Sulphur

Moderate levels of:

• Selenium
• Calcium
• Magnesium 
• Manganese
• Iron

 And low levels of:

• Sodium

• Vitamins A and C
• Vitamin  B-complex

Over the past few years, a great deal of attention has been given to its primary bioactive components, which include:

• Polyphenols
• Flavonoids
• Flavanols
• Tannins 
• Saponins 
• Polysaccharides 
• Sulphur-containing compounds (like allicin)¹

What is inflammation and what is its role in disease?

Inflammation plays a role in the defence mechanisms of our body. It is the mechanism by which the immune system identifies and removes dangerous and foreign stimuli and starts the healing process. One can experience acute or chronic inflammation.⁴

• Acute inflammation can be brought on by toxic chemicals, microbial invasion, or tissue injury from trauma. It begins quickly, gets worse quickly, and its manifestations, such as cellulitis (a common bacterial skin infection) or acute pneumonia, may last for a few days. The period of two to six weeks between acute and chronic inflammation is known as subacute inflammation.⁴
• Slow, prolonged inflammation that lasts for several months or years is known as chronic inflammation. The cause of the injury and the body's capacity for healing and recovery generally influence the degree and consequences of chronic inflammation.⁴ 

When inflammation occurs, there is a specific group of signalling proteins produced by immune cells, such as white blood cells or macrophages, to help in the immune response. These proteins are called inflammatory cytokines and they have an important role in regulating immune responses and inflammation. Inflammatory cytokines are split into two groups: pro-inflammatory cytokines, which tend to worsen the disease, and anti-inflammatory cytokines, which eliminate the inflammation.⁵

Garlic’s anti-inflammatory effect on various conditions

Inflammation can result from various conditions, like cancer cardiovascular diseases, infections, and many other diseases. In order to fight inflammation, there are different therapeutic approaches and also natural tools, like garlic, that can be used to ease symptoms and improve health. The first step for our body to fight infections is taken by the immune cells, which produce cytokines and lead to inflammatory effects. Various foods are able to boost the immune system to help with the process of fighting the infection. It is evident that garlic can strengthen the immune system by regulating cytokine production (as mentioned above, cytokines can worsen the state of inflammation). Garlic has the power to create an anti-inflammatory response by lowering the biomarkers that contribute to inflammation, enhancing immune cells’ activity, and even lowering the severity of flu and cough.¹

Garlic’s effect on cardiovascular disease

Inflammation plays a big role in cardiovascular disease (CVD), which can develop as a result of ongoing diseases like diabetes, obesity, hypertension (high blood pressure), or metabolic syndrome. Garlic has been shown to be beneficial in the treatment of CVD as it can decrease inflammatory cytokines and regulate oxidative stress, which goes hand in hand with certain conditions like atherosclerosis ( plaque formation in the vessels associated with CVD). Specifically, in diabetes, where oxidative stress is an important marker that contributes to this disease, garlic, with its sulphur compound, can eliminate hyperglycemia (increase blood sugar levels) by enhancing the antioxidant responses of the body.¹ Moreover, garlic can lower blood pressure, prevent atherosclerosis, decrease cholesterol levels, and help in dealing with so many other factors that lead to inflammation.³ This nutrient is also advised to be a part of our diet even if we are not struggling with any particular disease since it can act as a safeguard for our immune system by making it stronger and lowering the chances of having any health problems in the future.¹

Garlic’s effect on osteoarthritis

Osteoarthritis (OA) is a debilitating progressive disease of bone joints, and once again, proinflammatory cytokines are one of the markers that worsen the situation. However, garlic, with its therapeutic properties, helps to ease the symptoms that people experience with this condition. It also acts as an anti-inflammatory by reducing the production of pro-inflammatory cytokines and oxidative stress.¹

Garlic’s effect on cancer 

Garlic carries some anti-cancer effects as well. Through conducted studies, it has been found that garlic can be beneficial in fighting cancer since it protects our DNA from active carcinogens (agents that can promote the development of cancer), decreases the mass of the tumour, disintegrates carcinogens, and controls the overall immunological response of the body.^3,6

Garlic’s effect on infections 

Antibiotics may be a great way to treat infections, but there is concern about the antibiotic resistance some microorganisms have acquired. Do not be fooled by microorganisms, even though they seem small, they are very smart as they tend to find a way to become resistant to medication and continue to thrive in our bodies, causing nasty symptoms when we get an infection. For this reason, scientists have turned their attention to spices, like garlic, which have antimicrobial properties and inhibit foreign species from trying to make a home in our organism. Garlic, through its allicin compound, can hack the microorganism’s mechanism by putting a stop to its growth and the negative effects it can have on our body, as shown in some studies.^1,3

Mechanisms of garlic's anti-inflammatory effects

It is still uncertain how garlic’s therapeutic mechanism works on diseases since it is a complex process, however, there have been some theories introduced. 

• Since it acquires organosulfur compounds, they can act as anti-inflammatory markers by regulating pathways that promote pro-inflammatory cytokines, and thus it can lower inflammation.³ 
• With sulphur compounds like allicin, which have antioxidant activity, it reduces oxidative stress, which plays a big role in developing diseases like CVD, cancer, and neurodegenerative disorders.³ 
• It inhibits platelet aggregation, which is when platelets (components of our blood that help with clotting) stick to one another when there is an injury in the vessels and create blood clots, and it promotes vasodilation (the widening of blood vessels). As a result, it reduces the risk of CVD, by lowering blood pressure, and cholesterol and improving blood flow.
• It can destroy the cell membrane of microorganisms, which leads to their death when infection occurs.³ 

So garlic, which is a simple herb that is common in our diet, can actually be really beneficial for our health.³ 

Summary 

Garlic, a very famous spice in both the culinary and medical worlds, offers multiple health benefits. With its bioactive compounds, like allicin and organosulfur compounds, it has antioxidant and anti-inflammatory activity. Research has found garlic’s potential in fighting different diseases. For example, in cardiovascular disease, garlic can eliminate inflammatory markers, regulate oxidative stress, and decrease blood pressure and cholesterol levels, thereby reducing the risk of developing atherosclerosis. In osteoarthritis, it can alleviate the symptoms by lowering inflammation and oxidative stress that are linked with joint degeneration. Moreover, garlic has anti-cancer properties by protecting DNA, preventing tumour growth, and regulating the immune response against cancer cells. Lastly, garlic’s antimicrobial activities are also highlighted since allicin can inhibit the growth of the microbe and fight infections. Generally, garlic, with its multiple mechanisms to fight against disease and prevent the risk of having one in the future, makes it an important addition to our diet.