Carlos Solis
Garlic packs a punch of flavor — and people have long hoped it can do the same for health. For centuries folks have used garlic to fight infections, aid digestion, and generally boost well-being. Today garlic gets promoted for anti-inflammatory and anticancer properties, and many claim it can also help lower cholesterol.
What allicin is and why it matters
One of garlic’s active compounds is allicin. Whole, unbroken cloves don’t contain allicin: you have to crush or chop the garlic so the cells break and enzymes react with air — then allicin forms within about 10–15 minutes and gives garlic its sharp smell, taste, and potential benefits.
Dell Stanford, a senior dietitian at the British Heart Foundation, says lab studies show allicin and other garlic compounds act as antioxidants and anti-inflammatories and can moderately influence cholesterol metabolism and blood pressure.
One key mechanism is that allicin can inhibit the liver enzyme HMG-CoA reductase (HMGCR), the same enzyme targeted by statin drugs. Some garlic components may also reduce cholesterol absorption in the gut and help break down and eliminate cholesterol from the body.
Why study results are mixed
The main challenge in studying garlic’s effects is the huge variation in forms and doses. Human trials have tested fresh garlic, powders, extracts, oils, and supplements at different doses and durations and in different populations. That variety makes results hard to compare and interpret.
Allicin is also unstable and breaks down quickly, so getting an effective dose depends on how you prepare and consume the garlic. In other words, eating a raw clove every day is not necessarily the same as getting a therapeutic dose of allicin.
The available evidence suggests garlic’s effect on cholesterol may be clearer in people with high cholesterol and weaker in people whose levels are already normal.
How to use garlic
If you want to try garlic for potential heart benefits, pay attention to the form and preparation.
After you chop or crush fresh garlic, let it sit for 10–15 minutes to allow allicin to form, then add it to a salad or dressing. Cooking substantially reduces allicin activity.
Garlic capsules and extracts are widely available. Dell Stanford cautions that while some studies hint that garlic supplements can lower cholesterol, the evidence is limited and inconsistent, so supplements aren’t a proven replacement for treatment.
Quick takeaways:
- Garlic is a healthy, flavorful food, but don’t treat it as a substitute for medication.
- If your goal is to lower cholesterol, rely on a balanced diet and your doctor’s guidance: plenty of whole grains and fiber, unsaturated fats, and fish.
- Form matters: crushing fresh garlic produces allicin, but cooking destroys much of that compound.
- Aim to lower cholesterol only if your levels are high or your doctor recommends it; excessively low cholesterol can be harmful because the body needs cholesterol to make vitamin D and steroid hormones.
Feel free to add garlic to more meals — beyond the bold flavor, it contains bioactive compounds that may support health. Still, don’t view garlic or its supplements as a cure for high cholesterol. Long-term diet and lifestyle changes are more reliable for reducing heart disease risk.
Foods that help lower cholesterol include oatmeal, beans, whole grains, fruits and vegetables, unsaturated fats (olive or vegetable oils, nuts, seeds), and fatty fish. Talk with your doctor before taking any supplements, especially if you take statins or other medications.
Based on BBC Science Focus
Photo: Unsplash
