Garlic Guide: Nutrition Facts, Health Benefits, Cooking With It, and More

Medically Reviewed
a garlic bulb, which has many health benefits
Garlic gets its pungent smell from its sulfur-containing compounds.Nailia Schwarz/Stocksy

While often known for its addition to Italian foods, garlic seems to be used in virtually all cuisines as a strong flavoring agent. The bulbs are also sometimes used for medicinal purposes, to ease health conditions while preventing chronic health problems.

Learn more about the ins and outs of this popular spice, and see how it could fit into your own diet and lifestyle.

What Is Garlic, and Where Does It Come From?

Garlic (Allium sativum) is an age-old spice that’s made from a bulbous plant. But before it became the cooking staple it’s known as today, garlic had a rich history of cultivation, medicinal benefits, and consumption. It’s thought that garlic originated in India and Egypt around 5,000 years ago, and some historical documents suggest it was used in China about 4,000 years ago. The species of garlic found in this region are often referred to as “wild garlic” because of their indigenous nature. (1) Garlic was also mentioned in Biblical texts, as well as ancient Greek materials. (2)

Historically, garlic was used primarily for its medicinal components. In ancient civilizations, people used it in hopes of increasing their strength. Indeed, some historical documents note that ancient Greeks used garlic as a performance-enhancing boost for the Olympics. (2)

What’s particularly interesting about garlic is that it was concurrently used by different civilizations and cultures for similar benefits, all without contact between these cultures. (2) Still, the garlic grown in the United States isn’t like the “wild garlic” found in Asia and the Middle East. It most closely resembles the varieties first harvested in Europe nearly 1,000 years ago. (1) But garlic was also found to grow in the wild by indigenous civilizations in North America, where it was used in teas for medicinal purposes. (2) Garlic was introduced to Great Britain in 1548, (3) and the bulbs became popular in American culture by the late 19th century. (2)

Today, an estimated 10 million tons of garlic are produced worldwide. (1) While used as a food-flavoring agent, garlic is still considered as a “natural antibiotic” by many cultures. (3) In the 21st century, garlic continues to be a common seasoning in foods and packaged goods, but its potential medicinal properties are also gaining more appreciation in Western cultures.

Garlic Nutrition Facts: Calories, Carbs, and More

While garlic is a low-calorie food, it’s not particularly rich in the daily nutrients you need. But as per the U.S. Department of Agricultures (USDA)?MyPlate?guidelines, it is on the list of healthy ingredients you can include in your diet.

Nutritionally speaking, garlic is most useful as a spice or as a way to bring out the flavors of other healthy foods, like vegetables. The following nutrition facts for garlic from the USDA are based on a serving estimate of 1 teaspoon (tsp): (4)

  • Calories: 4
  • Protein: 0.18 grams (g)
  • Fat: 0.01 g
  • Carbohydrates: 0.93 g
  • Fiber: 0.06 g
  • Natural sugars: 0.03 g
  • Calcium: 5 milligrams (mg)
  • Iron: 0.05 mg (0.03 percent daily value, or DV)
  • Magnesium: 0.7 mg
  • Potassium: 11 mg
  • Vitamin C: 0.9 mg (1 percent DV)

Garlic is also thought to be a source of amino acids (the building blocks of proteins) and enzymes, which can help your body build muscles and protect your gut health, respectively. (3)

What Are the Health Benefits of Eating Garlic? A Look at What Research Suggests

Historically, garlic was used for the following medicinal purposes: (3)

  • Appetite stimulant
  • Blood pressure regulator
  • Colic
  • Constipation
  • Cough
  • Depression
  • Diarrhea
  • Fever
  • Infections
  • Intestinal parasites
  • Menstrual symptom relief
  • Muscle pain relief
  • Rheumatism
  • Seasickness
  • Skin diseases
  • Strength-building
  • Wounds

Today, research supports some of these medicinal benefits, but most studies remain inconclusive overall. Research primarily supports garlic’s potential antibacterial benefits, as well as its ability to help control cholesterol-causing lipids in the blood. Garlic also has antioxidants, which may help prevent free radicals that contribute to chronic illnesses, such as heart disease and cancer. (3)

Some of the most promising research on garlic’s health benefits pertains to cholesterol and high blood pressure. (5) But the research on these effects is limited. The National Center for Complementary and Integrative Health describes conflicting studies on the effects of garlic supplements on cholesterol. In some small studies, garlic supplements were shown to lower blood cholesterol within three months. In other studies, though, garlic had no effects on cholesterol whatsoever. (6,7)

While garlic may provide antioxidants that are shown to potentially help ward off certain types of cancer over time, such benefits are tied to eating garlic — garlic supplements don’t have the same effects. (5) Some of the most widely studied cancer effects from garlic include cancers of the colon, stomach, breast, esophagus, and pancreas.

Nevertheless, a meta-analysis from 2015 suggested that more research is needed to determine whether garlic and similar veggies, such as onions and leeks, can play a role in preventing cancer. Scientists also don’t know how much garlic people need to consume to see benefits. (8)

Another potential benefit of chewing on garlic is boosting heart health. This is compared with swallowing garlic or extracts that have not been chewed. (9)

Can Garlic Help You Lose Weight? A Glance at the Research Available

Some people tout garlic as a weight loss aid, too. But most of the studies on garlic’s effects on weight have been conducted on rodents, not humans, so more studies are needed.

One study found that garlic may help reduce body weight and fat accumulation in obese mice on a high-fat diet. (10) And another study, which involved rats with hypertension, high cholesterol, and high insulin levels that were being fed a diet with high fructose corn syrup, suggested that commercial garlic products helped promote weight loss. (11)

But a study of adults with obesity showed those who took a supplement that contained garlic, caffeine, ginger, and other herbs observed modest weight loss of 4.2 pounds,?while those who took a placebo lost 0.9 pounds on average after eight weeks. It’s not clear whether the weight loss was attributed to any single ingredient, a combination of ingredients, or only lifestyle habits. (12)

Instead of relying on garlic as a weight loss tool, it’s best to follow tried-and-true weight loss methods that include a healthy diet and an active lifestyle. The American Heart Association recommends between 30 and 60 minutes of moderate-intensity exercise per day if you’re looking to lose weight. (13)

How to Select and Store Garlic for the Best Quality and Taste

Garlic is used in a variety of ways for eating. The most traditional method is buying whole garlic bulbs and mincing or slicing them for cooking. You’ll want to look for bulbs that are white without brown or black spots. The bulbs should also be firm with no soft spots or loose cloves. If you don’t want to cut or mince garlic cloves, you can also buy ready-to-use minced garlic,?garlic oil, or garlic powder. (5,8) Be aware that the more processed the garlic, the less aroma and flavor there is — your choice all depends on your personal preferences.

If you’d like to take garlic supplements, be sure to speak with your doctor first. After you get the all-clear, you can find them in the form of capsules and soft-gels. Garlic is also available as an essential oil that can be diluted with carrier oil and applied to your skin. (5,8)

Tips for Cooking With Garlic in Your Home Kitchen

Garlic has an intense smell, thanks to its sulfur-containing compounds. These glycosides are only emitted upon peeling the bulbs and either cutting or crushing them. (3) Raw garlic is sliced or minced before being added to your favorite dishes. You can also sauté garlic cloves in olive oil or roast them in the oven.

To help avoid making a mess, you can opt for already-minced garlic. You can use a teaspoon at a time to add to your favorite recipes, and then you’ll need to store the jar in the refrigerator to keep the product fresh. You may even find pre-minced garlic in the frozen foods section in the form of individual cubes. Garlic powder is another option that offers more of a spicy flavor.

Can Eating Garlic Help Prevent or Shorten the Common Cold?

During cold and flu season, some people swear by eating or chewing garlic, or even taking more garlic supplements. It’s thought that the antioxidant content in garlic may help boost your immune system so that you get sick less often. (8) But garlic alone may not be enough to prevent you from getting sick, and preliminary studies conclude that garlic doesn’t help prevent colds. (5,15) While you might gain other health benefits from eating garlic, you shouldn’t rely on the bulbs solely as a way to prevent you from getting sick.

Are There Any Side Effects or Health Risks to Eating Garlic?

For most people, it’s safe to eat garlic liberally. (5) But it’s also possible to have an allergy or sensitivity to these bulbs. Spice allergies aren’t as common as other food allergies, but you may be at a higher risk if you’re also allergic to birch pollen. If you have an allergy to garlic, you could also have allergies to other related spices. (16)

Signs of an allergic reaction to garlic may include hives, facial swelling, and breathing difficulties. A nonallergy food sensitivity to garlic may cause gas, bloating, and other gastrointestinal discomfort. (17)

Also, eating garlic or taking garlic supplements can cause the following side effects in some people: (5)

  • Heartburn
  • Bad breath
  • Burning sensations in your mouth and throat
  • Upset stomach
  • Body odor
  • Diarrhea
  • Nausea or vomiting
  • Ulcers

Chewing or eating raw garlic may increase such effects, as well as having garlic on an empty stomach. (8)

Eating garlic in moderation is unlikely to interfere with medication, but taking garlic supplements may. Garlic supplements may interfere with HIV drugs and anticoagulants because of an increased risk of bleeding. (5) Bleeding risks can also occur if you’re undergoing surgery. (8)

Take care when using garlic essential oils on your skin. These can cause eczema, burns, and irritation if used incorrectly. Also, do not ingest essential oils. (8)

Garlic Top Sellers on Amazon

While most of the benefits of garlic are associated with eating the actual cloves, supplements may help in some situations. If your doctor has recommended garlic supplementation, talk to them about the following best-rated products:

Editorial Sources and Fact-Checking

  1. The Origins and Distribution of Garlic: How Many Garlics Are There? U.S. Department of Agriculture. March 3, 2020.
  2. Rivlin RS. Historical Perspective on the Use of Garlic. Journal of Nutrition. March 2001.
  3. Petrovska BB, Cekovska S. Extracts From the History and Medical Properties of Garlic. Pharmacognosy Review. January–June 2010.
  4. Garlic, Raw. U.S. Department of Agriculture. April 1, 2019.
  5. Garlic. National Center for Complementary and Integrative Health. December 2020.
  6. High Cholesterol and Natural Products: What the Science Says. National Center for Complementary and Integrative Health. February 2019.
  7. Cholesterol-Lowering Supplements May Be Helpful. Mayo Clinic. November 10, 2022.
  8. Nicastro?HL, Ross SA, Milner?JA. Garlic and Onions: Their Cancer Prevention Properties.?Cancer Prevention Research. March 2015.
  9. Jabbari A, Argani H, Ghorbanihaghjo A, Mahdavi R. Comparison Between Swallowing and Chewing Garlic on Levels of Serum Lipids, Cyclosporine, Creatinine, and Lipid Peroxidation in Renal Transplant Recipients. Lipids in Health and Disease. May 19, 2005.
  10. Lee MS, Kim IH, Kim CT, Kim Y. Reduction of Body Weight by Dietary Garlic Is Associated With an Increase in Uncoupling Protein mRNA Expression and Activation of AMP-Activated Protein Kinase in Diet-Induced Obese Mice. Journal of Nutrition. November 2011.
  11. Elkayam A, Mirelman D, Peleg E, et al. The Effects of Allicin on Weight in Fructose-Induced Hyperinsulinemic, Hyperlipidemic, Hypertensive Rats. American Journal of Hypertension. December 2003.
  12. Dietary Supplements for Weight Loss. Mayo Clinic. March 1, 2022.
  13. Losing Weight. American Heart Association.
  14. Deleted, November 5, 2022.
  15. Flus and Colds: In Depth. National Center for Complementary and Integrative Health. November 2016.
  16. Other Food Allergens. Food Allergy Research and Education.
  17. Garlic Side Effects. Drugs.com.
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