This content originally appeared on Everyday Health. Republished with permission.
By Becky Upham
Key Takeaways
Garlic has been used medicinally for thousands of years and has known anti-inflammatory benefits.
A large review of nearly 30 studies showed eating garlic daily or taking a garlic supplement led to improvements in blood sugar and cholesterol levels.
To see benefits similar to the review, you’d need to eat the equivalent of one or two fresh cloves per day.
Love garlic? Here’s a good reason to get more of it into your diet: Eating garlic may help improve cholesterol and blood sugar levels, according to a large new meta-analysis, published in the journal Nutrients.[1]
The current analysis pooled the results of 29 studies with a combined total of more than 1,500 participants. Investigators only included randomized control trials that compared garlic with a placebo control, which is the gold standard for any research design and means the meta-analysis is high quality, says Alyssa Kwan, RD, a registered dietitian working with people in the cardiovascular ICU and surgery units at Stanford Health Care in California.
A Large Body of Evidence Confirms Garlic’s Benefits
Overall, the findings agree with what previous studies have shown: Garlic leads to some decrease in A1C levels and a small reduction in LDL (or “bad”) cholesterol, says Matthew Badgett, MD, an integrative health physician at Cleveland Clinic in Ohio, who was not involved in the study.
Hemoglobin A1C is a blood test that shows a person’s average blood sugar level over the past two to three months.[2]
All the included studies that looked at A1C levels found a decrease in the group taking garlic, and the average LDL cholesterol reduction across the studies was 8.2 points, says Dr. Badgett.
That’s a modest benefit when it comes to lowering “bad” cholesterol, though many studies were likely too short to show the full benefit of garlic, he says.
“We often need to lower LDL from 150 to 200, to less than 70 in high risk patients, and sometimes even more,” says Badgett.
Garlic Has a Long History in Traditional Medicine
Garlic has been used for its medicinal properties for thousands of years, long before studies like this one were conducted, says Elisabetta Politi, MPH, RD, who works as a certified diabetes educator at Duke Health in Durham, North Carolina.
The plant is part of the allium family, which also includes onions, scallions, shallots, chives, and leeks. Vegetables in this family contain high concentrations of sulfur compounds, including allicin, alliin, and methyl allyl trisulfide, which contribute to the health benefits.
Previous research suggests that garlic can help improve blood pressure, reduce inflammation in conditions like arthritis, and fight fungal conditions like athlete’s foot.[3]
The Study Had Some Limitations
Overall, the analysis has some strengths and weaknesses that should be considered when viewing the findings, Badgett says.
For a meta-analysis, the number of participants was small — which is often a problem with supplement studies, because they usually don’t enroll a lot of people.
Additionally, the garlic supplements examined in the different trials are extremely variable, which weakens the analysis, and probably makes the benefit of garlic look weaker than it is, says Badgett.
“Do we really know if all the supplements had the amounts of garlic they claimed?” he asks. The U.S. Food and Drug Administration oversees supplements, but because of limited resources, the agency does not routinely analyze those products to make sure they contain what’s advertised on the label.[4]
Garlic May Help as Part of a Plan That Includes Lifestyle Changes and Medications
There’s clear evidence that garlic is safe, healthy, and yields some benefit. Without bigger lifestyle changes, though, it’s not likely to have a significant impact on your health, says Badgett.
“But it can be one small piece of an effective plan,” he says.
Kwan agrees that although the analysis suggests that garlic can be beneficial for improving cholesterol and blood sugar levels, more evidence, including larger studies, are needed to show that garlic is causing these benefits.
Which Is Better, Taking a Garlic Supplement or Eating Foods With Garlic?
There are many types of garlic, including garlic extracts, garlic compounds, garlic powder, raw garlic, and cooked garlic, says Badgett.
The participants consumed between 300 and 22,400 milligrams of garlic powder tablets. We can eat within that range at meals if we like garlic enough, he says.
“But the issue with eating garlic is that the study looked at daily consumption, and I rarely see people eat garlic consistently every single day,” says Badgett. People would be more likely to see consistent results by taking a daily supplement, he adds.
“For clients who don’t digest garlic well or don’t like the taste of it, I do recommend supplements. But because of the variations in supplement quality and the expense, I think using garlic powder in foods to get the equivalent amount may be preferable — if you like the taste and you tolerate it,” says Politi.
Expert Tips to Add More Garlic to Your Diet
To get the health benefits of garlic, you need to eat about 3 to 6 grams — or one to two cloves, if you like fresh — each day, says Brogan Taylor, RD, a registered dietitian at Banner Health in Phoenix, Arizona.
For her clients, Taylor recommends adding fresh garlic, chopped or crushed, to foods to reap all the potential benefits.
Garlic is also a great way to season foods if you’re trying to cut down on sodium, she adds.
Here are a few ideas to incorporate more garlic into your diet.
Chili, Soups, and Stews Add garlic to give extra flavor and added health benefits, says Taylor.
Proteins and Veggies Cook proteins like chicken or lean cuts of meat with garlic and when roasting or sautéing veggies, says Taylor. “It’s also a good flavoring to add to salad dressing and marinades.
Bread Who doesn’t love garlic bread? You can also add crushed tomato or your favorite marinara to make bruschetta, says Politi.
Pesto Raw garlic is essential in pesto sauce, which is made with olive oil, basil, Parmesan cheese, and nuts (usually pine nuts). It’s a simple and delicious Mediterranean pasta sauce that’s heart healthy, says Politi.
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Sources
Zhao X et al. Effects of Garlic on Glucose Parameters and Meta-Analysis on Randomized Controlled Trials. Nutrients. May 29, 2024.
Hemoglobin A1C (HBA1c) Test. MedlinePlus. September 6, 2022.
The Health Benefits of Garlic. Cleveland Clinic. May 1, 2022.
Questions and Answers on Dietary Supplements. U.S. Food and Drug Administration. February 21, 2024.