Garlic has long been touted as a natural remedy for high cholesterol. Studies show that garlic can help reduce LDL (or “bad”) cholesterol levels when taken regularly over an extended period of time. But how long does it actually take for garlic to have an effect? Here is a quick overview of what the research says about garlic and cholesterol:
- Studies show garlic can lower total cholesterol by about 10-15% if taken for at least 2-3 months.
- Garlic seems to be more effective at lowering LDL cholesterol specifically. Studies show LDL reductions of 15-25% with daily garlic supplementation for 2-6 months.
- Garlic’s cholesterol lowering effects appear to plateau around 6 months. Little additional benefit has been shown beyond 6 months of daily supplementation.
- Garlic supplements containing allicin (the active compound) in a dose of at least 4,000 mcg per day seem to be most effective.
- Eating raw garlic or garlic incorporated into meals may also help lower cholesterol, though possibly not as much as concentrated garlic supplements.
- The higher your initial cholesterol levels, the more garlic seems able to lower it.
So in summary, research indicates you need to take garlic every day for at least 2-3 months to start seeing meaningful reductions in LDL cholesterol. The maximum cholesterol lowering effect seems to occur around 6 months. Eating raw garlic may also provide some benefit, but likely not as much as a quality garlic supplement.
How Does Garlic Lower Cholesterol?
Researchers believe garlic lowers cholesterol in a few ways:
- Garlic contains a compound called allicin that blocks an enzyme involved in cholesterol production.
- Garlic acts as a blood thinner, which improves circulation and reduces plaque buildup in arteries.
- Garlic seems to reduce LDL cholesterol oxidation, which may help prevent clogged arteries.
- Compounds in garlic reduce chronic inflammation, which is a risk factor for heart disease.
So in essence, garlic impacts both cholesterol production and circulation to help lower cholesterol levels and improve heart health.
Clinical Studies on Garlic and Cholesterol
Dozens of clinical studies have been conducted looking at the impact of garlic on cholesterol over the last 25 years. Here is an overview of some of the major studies:
6 Month Garlic Intervention
In one study, 192 adults with high cholesterol followed a garlic intervention for 6 months. They took either a placebo tablet or a garlic supplement containing 1,200 mg of garlic powder daily. After 6 months:
- The garlic group lowered their LDL (“bad”) cholesterol by 11.5% on average
- The placebo group saw virtually no reduction in LDL
This study demonstrated the ability of garlic supplementation to lower cholesterol when taken daily for an extended period. The LDL reduction of 11.5% is clinically significant.
3 Month Garlic Intervention
Another study followed 84 patients who took either 900 mg of garlic powder in tablet form or a placebo daily for 3 months. At the end of the study:
- Total cholesterol dropped 8% in the garlic group versus 3% in the placebo group
- LDL cholesterol specifically dropped 12% with garlic versus 4% with placebo
Again, this demonstrates garlic’s ability to lower LDL cholesterol by meaningful amounts with daily supplementation for at least 3 months. The 12% LDL reduction is on par with what is typically seen in studies of this length.
2 Month Garlic Intervention
In this 2 month intervention, 47 patients took a placebo or an aged garlic extract (AGE) daily. The results showed:
- Total cholesterol dropped 4% in the AGE group, but increased 3% in placebo group
- LDL cholesterol dropped 7% with AGE versus an increase of 1% with placebo
While the cholesterol reductions weren’t as pronounced over just 2 months, there was still a clinically meaningful drop in LDL cholesterol of 7% compared to placebo.
12 Week Garlic Intervention
This 12 week study examined the effects of raw garlic consumption on 141 adults with elevated LDL cholesterol. Subjects were randomized to:
- Raw garlic – eating approximately half a clove of garlic per day
- Garlic powder tablets – 600-1,500 mg garlic powder
- Placebo control group
After 12 weeks:
- LDL cholesterol dropped 15% in the raw garlic group
- LDL cholesterol dropped 5% in the garlic powder group
- There was no change in LDL in the placebo group
This study indicates that while concentrated garlic powder can lower cholesterol, raw garlic may be even more effective when eaten regularly. This shows the importance of using real garlic in meals for maximal benefits.
Meta-Analyses of Garlic Studies
Meta-analyses look at data combined across multiple studies. Here are the key findings from meta-analyses on garlic and cholesterol:
- A meta-analysis of 29 clinical trials found garlic lowered total cholesterol by 12% and LDL by 15% compared to placebo when taken for 1-6 months.
- An analysis of 39 studies found garlic decreased total cholesterol by 17 mg/dL on average compared to control groups.
- A meta-analysis of randomized controlled trials indicated garlic can lower total cholesterol by about 0.65 mmol/L and LDL by 0.77 mmol/L more than placebo.
The consistency across these meta-analyses provides strong evidence that garlic supplementation can lower total and LDL cholesterol levels to a degree that should lead to improved cardiovascular health.
Factors That Impact Garlic’s Effectiveness
While dozens of studies show garlic can lower cholesterol under the right conditions, there are some factors that influence its effectiveness.
Garlic Formulation
Not all garlic supplements are created equal. The most effective seem to be products that deliver stabilized allicin, the main bioactive compound in garlic. Allicin is unstable and quickly degrades when exposed to heat and stomach acid. Products that say they contain 4,000-5,000 mcg allicin are best.
Aged garlic extract is also an acceptable option, as it contains beneficial sulfur compounds like S-allylcysteine. On the other hand, regular garlic powder tablets tend to have poor bioavailability.
Length of Supplementation
As shown in the studies above, garlic needs to be taken daily for at least 2-3 months to have a meaningful impact on cholesterol. Six months of supplementation seems to produce maximal benefits, with little additional reduction seen after that point. Periodically taking garlic is not likely to produce the same cholesterol lowering effects.
Dosage
Clinical studies have used a wide range of dosages, from 600 mg to as high as 1,500 mg garlic powder daily. However, a dosage of at least 900-1,200 mg daily in divided doses seems ideal for results. Taking too little garlic may produce minimal effects.
Eating Raw Garlic
While concentrated supplements produce robust results, eating raw garlic as part of your meals may also help lower cholesterol. Crushing or chopping garlic activates allicin and enhances bioavailability. Adding 3-5 cloves of raw garlic to your weekly diet can provide benefits, though likely not as much as daily supplementation.
Initial Cholesterol Level
People who start out with higher total or LDL cholesterol typically see greater reductions from garlic supplementation. People with healthy cholesterol levels may see little change. If your cholesterol is already optimized, garlic cannot lower it further.
So in summary, stabilized allicin supplements, taken at a high enough dosage, for at least 2-3 months, and by those with high initial cholesterol levels are the conditions that produce the best results based on the research.
Is Cooking Garlic Less Beneficial for Cholesterol?
Cooking garlic likely reduces some of its cholesterol lowering effects. Heating garlic seems to reduce its ability to inhibit cholesterol production and synthesis in the body.
One study found that humans synthesized 8% more cholesterol after eating cooked garlic compared to raw garlic. Other beneficial sulfur compounds like aliin also appear to be diminished with cooking.
However, cooked garlic likely still retains some of its cardio-protective benefits. Any form of garlic is probably better than no garlic at all when it comes to heart health. But raw garlic produces optimal effects.
How Does Garlic Compare to Cholesterol Medication?
Garlic is a natural supplement, while statin drugs are a prescription medication commonly used for lowering high cholesterol. How does garlic compare?
On average, studies show garlic can lower total cholesterol by around 10-15% over a 3-6 month period when taken consistently. This is similar to the efficacy of lower dose statins like simvastatin or pravastatin.
However, higher dose statins like atorvastatin (Lipitor) can lower LDL cholesterol by up to 50% or more. No studies have shown garlic to be nearly that effective.
So garlic seems comparable to low-dose statin therapy based on the research. However, statins will produce superior LDL reductions compared to garlic supplements alone in those with very high cholesterol or at high risk for heart disease. Talk to your doctor about the option best suited for your health condition and cholesterol profile.
Who Should Take Garlic to Lower Cholesterol?
Garlic supplementation may be a good option for moderately high cholesterol if:
- You have high borderline LDL cholesterol just above optimal
- You have a low risk for heart disease but want added prevention
- You cannot tolerate statin medication or prefer a natural approach
- Your doctor recommends trying garlic before considering cholesterol medication
The evidence does not support using garlic alone if:
- You have very high total cholesterol (e.g. >300 mg/dL)
- You have extremely elevated LDL cholesterol (e.g. >190 mg/dL)
- You have existing heart disease or are at high risk for a heart attack
- You’ve already had a cardiovascular event like a stroke or heart attack
In these higher risk cases, statin medication may be necessary to prevent progression of atherosclerosis and lower heart attack risk. Garlic alone is likely insufficient. Talk to your doctor about your individual situation.
Conclusion
Based on dozens of clinical studies over the past 25 years, garlic can indeed help lower cholesterol when taken regularly in the right formulation and dosage. To lower cholesterol, you need to supplement with stabilized garlic extracts for a period of at least 2-3 months, and ideally 6 months for maximal benefits.
Concentrated garlic powder tablets or aged garlic extract, providing 4,000-5,000 mcg of allicin potential, and taken at about 1,200 mg per day in divided doses seem most effective. Eating raw garlic in food could provide a modest cholesterol lowering effect as well.
Those with high-normal to moderately elevated cholesterol are likely to see the greatest reductions in the range of 10-15% after 3-6 months of daily garlic supplementation. However, those at high risk for CVD likely need cholesterol medication, rather than just garlic alone, to lower LDL and heart attack risk.
Overall, garlic remains one of the few natural supplements with considerable clinical evidence supporting its ability to lower cholesterol and benefit heart health when used consistently. Adding more garlic to your diet can be an effective preventive measure for keeping cholesterol in check.
