Garlic and cholesterol: Can Kenyas favorite kitchen staple really protect your heart?

Cook with garlic. [File, Standard]

From a steaming plate of pilau to beef stew, sukuma wiki, and vegetable dishes, garlic is a familiar ingredient in many Kenyan kitchens.

Its strong aroma and distinctive taste can transform an ordinary meal into something memorable. But beyond its culinary appeal, garlic has also built a reputation as a natural remedy for a wide range of health problems.

For centuries, people have turned to the humble bulb for conditions ranging from infections and digestive problems to high blood pressure.

Today, garlic is increasingly being promoted as a natural way to improve heart health and lower cholesterol. It is also sold in concentrated forms, including powders, oils, extracts and supplements.

But can garlic really lower cholesterol?

The answer is more complicated than many health claims suggest.

Garlic’s potential health benefits are largely linked to its sulphur-containing compounds, particularly one known as allicin.

Interestingly, an intact garlic clove does not contain large amounts of allicin. The compound is formed when garlic is crushed, chopped or chewed.

The process breaks down the cells in the garlic, allowing different compounds and enzymes to react.

“When crushed, it reacts with the air to make allicin, which gives garlic its pungent smell, taste and potential health benefits,” says Dell Stanford, a senior dietitian at the British Heart Foundation.

Allicin begins forming within approximately 10 to 15 minutes after garlic is crushed.

Laboratory studies suggest that compounds in garlic may have antioxidant and anti-inflammatory effects. They may also influence cholesterol metabolism and blood pressure.

This is particularly important because high cholesterol is a major risk factor for cardiovascular disease.

Low-density lipoprotein (LDL), commonly referred to as “bad” cholesterol, can accumulate in the walls of arteries, contributing to the formation of fatty plaques.

Over time, these deposits can narrow or block blood vessels, increasing the risk of heart attack and stroke.

Although cholesterol is often associated with food, much of the cholesterol in the bloodstream is actually produced by the liver.

Researchers believe compounds in garlic may interfere with the production of cholesterol by affecting an enzyme known as HMG-CoA reductase.

This is significant because the same enzyme is targeted by statins, a group of medicines commonly prescribed to lower cholesterol.

Garlic may also reduce cholesterol absorption in the intestines and support the breakdown and removal of cholesterol from the body.

Research into garlic and cholesterol has produced mixed results.

Some studies have reported modest reductions in total cholesterol and LDL cholesterol among people who consume garlic or garlic-based products.

Other studies, however, have found little or no significant effect.

The differences may partly be explained by the many forms of garlic used in research.

Scientists have studied fresh garlic, garlic powder, garlic oil, extracts, supplements, aged garlic and black garlic. The doses and duration of treatment have also varied considerably.

The people taking part in the studies have not always been the same either.

“It’s a big leap from being able to demonstrate mechanisms in cells in laboratory studies to demonstrating meaningful benefits in humans,” Stanford says.

“Although garlic has been heavily researched, human studies use different forms of garlic, in different doses, for different lengths of time and in different numbers and types of people. This makes it very difficult to compare and interpret studies.”

Some research suggests garlic may have a greater effect on people who already have high cholesterol than on people whose cholesterol levels are within the healthy range

This means that the results of one study cannot necessarily be applied to everyone.

For people who want to benefit from garlic’s natural compounds, preparation may also be important.

Crushing or chopping fresh garlic allows allicin to form. However, heating garlic immediately may reduce the activity of some of its compounds.

This does not mean cooked garlic is unhealthy.

In fact, garlic remains a useful ingredient because it adds flavor to food and may help people reduce their reliance on excessive salt and unhealthy fats.

However, people should not assume that eating one whole clove of garlic daily will automatically lower their cholesterol.

Allicin is also unstable and can break down relatively quickly after it is formed.

The amount of active compounds that reach the body may depend on how the garlic is prepared, stored and consumed.

Other varieties, including aged garlic extract and black garlic, have also attracted the attention of researchers.

Some studies have explored their potential effects on blood pressure, inflammation, blood vessel health and arterial stiffness.

However, these products should not be confused with proven medical treatment.

Garlic supplements are widely marketed as products that support heart health, improve immunity and maintain healthy cholesterol levels.

But experts remain cautious.

“Although some studies suggest that garlic supplements have the potential to lower cholesterol levels, the evidence is too limited and inconsistent to recommend taking them for any health benefits,” Stanford says.

This is especially important for people living with high cholesterol.

Garlic supplements should not replace prescribed medication, medical monitoring or lifestyle changes recommended by a qualified healthcare professional.

A heart-healthy lifestyle includes eating more vegetables, fruits, legumes and whole grains, choosing healthier sources of fat, limiting excessive saturated fats and remaining physically active.

Regular cholesterol checks are also important, particularly for people with a family history of heart disease or other cardiovascular risk factors.

Using garlic, herbs and spices to improve flavor may help reduce dependence on excessive salt and unhealthy sauces.

But the idea that garlic is a cure for high cholesterol is not supported by sufficiently strong evidence.

“Cholesterol is needed in the body as a building block for vitamin D and steroid hormone production,” says researcher Ried. “You do not want to reduce your cholesterol levels too much, but rather maintain a healthy balance between HDL and LDL cholesterol.”

Garlic is undeniably a valuable ingredient and contains bioactive compounds that may support good health.

It may have modest benefits for cholesterol and cardiovascular health, particularly in certain forms and among people with raised cholesterol.