What is garlic?
Garlic (Allium sativum) is a vegetable that can be eaten raw or cooked. It is also sold as a dietary supplement. Garlic contains several sulfur-containing phytochemicals that are metabolized when eaten and can affect cardiovascular health and inflammation.[1] These chemicals include allicin, diallyl disulfide (DADS), diallyl trisulfide (DATS), and S-allylmercaptocysteine (SAMC).
What are garlic’s main benefits?
Supplementation with garlic lowers circulating markers of oxidative stress[2][3] (e.g., malondialdehyde) and inflammation (e.g., C-reactive protein and TNF-α).[4][5][6] Supplementation with garlic can also reduce total cholesterol levels,[7][8] particularly in people with cardiovascular disease, and improve other measures of cardiovascular health (coronary artery calcium, carotid intima-media thickness, etc.).[9] However, its direct effects on cardiovascular morbidity and mortality are currently unclear.[9][10]
Observational studies also show that garlic consumption, through food or as a supplement, is associated with a lower risk of gastric and colorectal cancers.[11]
What are garlic’s main drawbacks?
Garlic consumption can cause “garlic breath” and body odor, which are typically most pronounced after eating raw garlic.[12] These side effects are also frequent-reported “adverse events” in clinical trials.[12][13][14] Some supplement formulations (e.g., aged garlic extract) are designed to minimize such odors.[15][16]
In rare cases, garlic may cause an allergic reaction.[12]
How does garlic work?
Metabolizing garlic’s sulfur-containing chemicals (i.e., allicin, diallyl disulfide, diallyl trisulfide, and S-allylmercaptocysteine) eventually produces hydrogen sulfide (H2S). H2S is not only responsible for the characteristic garlic odor, but is also a signaling molecule with direct effects on vascular tissue, nerve synapses, inflammatory processes, and more.[17] However, the sulfur-containing chemicals in garlic also have their own direct effects, activating several signaling pathways involved in anti-oxidant, anti-thrombotic, and anti-inflammatory mechanisms,[18][19] which explains garlic's role in cardiovascular health.[9] These chemicals also likely regulate the cell cycle in cancer cells, causing apoptosis (cell death),[11][20] which explains the potential role of garlic in lowering gastric and colorectal cancer risk.[11]
What are other names for Garlic
- Allium sativum
- Vegetable Viagra
- Da suan
- Camphor of the poor
- Lasun
- Stinking Rose
- Ail
- Ajo
- Tulbaghia violacea (Wild garlic or sweet garlic)
Dosage information
Most studies on garlic use a dosage range of 600-1,200mg a day, usually divided into multiple doses. The minimum effective dose for raw garlic is a single segment of a garlic bulb (called a clove), eaten with meals two or three times a day.
Aged garlic is a popular form of garlic to use for supplementation, since it does not have a fresh garlic scent. Garlic supplementation can also be done through food alone, though side-effects will include strong garlic-scented breath.
Microwaving garlic will partially destroy the beneficial components of the vegetable, but grilling and roasting will not damage the bioactives, provided the garlic is sliced or crushed beforehand. Garlic can be toxic if consumed in very high doses, so supplementation should never go beyond the following maximum dosages:
- 17.0 grams for a 150lb person
- 22.7 grams for a 200lb person
- 28.4 grams for a 250lb person
Frequently asked questions
Garlic (Allium sativum) is a vegetable that can be eaten raw or cooked. It is also sold as a dietary supplement. Garlic contains several sulfur-containing phytochemicals that are metabolized when eaten and can affect cardiovascular health and inflammation.[1] These chemicals include allicin, diallyl disulfide (DADS), diallyl trisulfide (DATS), and S-allylmercaptocysteine (SAMC).
Supplementation with garlic lowers circulating markers of oxidative stress[2][3] (e.g., malondialdehyde) and inflammation (e.g., C-reactive protein and TNF-α).[4][5][6] Supplementation with garlic can also reduce total cholesterol levels,[7][8] particularly in people with cardiovascular disease, and improve other measures of cardiovascular health (coronary artery calcium, carotid intima-media thickness, etc.).[9] However, its direct effects on cardiovascular morbidity and mortality are currently unclear.[9][10]
Observational studies also show that garlic consumption, through food or as a supplement, is associated with a lower risk of gastric and colorectal cancers.[11]
Garlic consumption can cause “garlic breath” and body odor, which are typically most pronounced after eating raw garlic.[12] These side effects are also frequent-reported “adverse events” in clinical trials.[12][13][14] Some supplement formulations (e.g., aged garlic extract) are designed to minimize such odors.[15][16]
In rare cases, garlic may cause an allergic reaction.[12]
Metabolizing garlic’s sulfur-containing chemicals (i.e., allicin, diallyl disulfide, diallyl trisulfide, and S-allylmercaptocysteine) eventually produces hydrogen sulfide (H2S). H2S is not only responsible for the characteristic garlic odor, but is also a signaling molecule with direct effects on vascular tissue, nerve synapses, inflammatory processes, and more.[17] However, the sulfur-containing chemicals in garlic also have their own direct effects, activating several signaling pathways involved in anti-oxidant, anti-thrombotic, and anti-inflammatory mechanisms,[18][19] which explains garlic's role in cardiovascular health.[9] These chemicals also likely regulate the cell cycle in cancer cells, causing apoptosis (cell death),[11][20] which explains the potential role of garlic in lowering gastric and colorectal cancer risk.[11]
Research Breakdown
References
- ^Tudu CK, Dutta T, Ghorai M, Biswas P, Samanta D, Oleksak P, Jha NK, Kumar M, Radha , Proćków J, Pérez de la Lastra JM, Dey ATraditional uses, phytochemistry, pharmacology and toxicology of garlic (), a storehouse of diverse phytochemicals: A review of research from the last decade focusing on health and nutritional implications.Front Nutr.(2022)
- ^Askari M, Mozaffari H, Darooghegi Mofrad M, Jafari A, Surkan PJ, Amini MR, Azadbakht LEffects of garlic supplementation on oxidative stress and antioxidative capacity biomarkers: A systematic review and meta-analysis of randomized controlled trials.Phytother Res.(2021-Jun)
- ^Moosavian SP, Arab A, Paknahad Z, Moradi SThe effects of garlic supplementation on oxidative stress markers: A systematic review and meta-analysis of randomized controlled trials.Complement Ther Med.(2020-May)
- ^Taghizadeh M, Hamedifard Z, Jafarnejad SEffect of garlic supplementation on serum C-reactive protein level: A systematic review and meta-analysis of randomized controlled trials.Phytother Res.(2019-Feb)
- ^Darooghegi Mofrad M, Milajerdi A, Koohdani F, Surkan PJ, Azadbakht LGarlic Supplementation Reduces Circulating C-reactive Protein, Tumor Necrosis Factor, and Interleukin-6 in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials.J Nutr.(2019-Apr-01)
- ^Mehdi Koushki, Nasrin Amiri-Dashatan, Yasin Pourfarjam, Amir Hossein DoustimotlaghEffect of Garlic Intake on Inflammatory Mediators: A Systematic Review and Meta-Analysis of Randomised Controlled TrialsPostgrad Med J.(2020 Feb 12)
- ^Maryam Kheirmandparizi, Pedram Keshavarz, Peyman Nowrouzi-Sohrabi, Mahnaz Hosseini-Bensenjan, Shahla Rezaei, Seyyed Mohammad Amin Kashani, Nazanin Zeidi, Reza Tabrizi, Abdolhamid AlkamelEffects of garlic extract on lipid profile in patients with coronary artery disease: A systematic review and meta-analysis of randomised clinical trialsInt J Clin Pract.(2021 Oct 9)
- ^Li S, Guo W, Lau W, Zhang H, Zhan Z, Wang X, Wang HThe association of garlic intake and cardiovascular risk factors: A systematic review and meta-analysis.Crit Rev Food Sci Nutr.(2022-Mar-29)
- ^Imaizumi VM, Laurindo LF, Manzan B, Guiguer EL, Oshiiwa M, Otoboni AMMB, Araujo AC, Tofano RJ, Barbalho SMGarlic: A systematic review of the effects on cardiovascular diseases.Crit Rev Food Sci Nutr.(2022-Feb-23)
- ^Stabler SN, Tejani AM, Huynh F, Fowkes CGarlic for the prevention of cardiovascular morbidity and mortality in hypertensive patients.Cochrane Database Syst Rev.(2012-Aug-15)
- ^Yangyang Wang, Ping Huang, Yufei Wu, Duanrui Liu, Mingyu Ji, Huanjie Li, Yunshan WangAssociation and mechanism of garlic consumption with gastrointestinal cancer risk: A systematic review and meta-analysisOncol Lett.(2022 Apr)
- ^Borrelli F, Capasso R, Izzo AAGarlic (Allium sativum L.): adverse effects and drug interactions in humans.Mol Nutr Food Res.(2007-Nov)
- ^Stevinson C, Pittler MH, Ernst EGarlic for treating hypercholesterolemia. A meta-analysis of randomized clinical trialsAnn Intern Med.(2000 Sep 19)
- ^Josling PPreventing the common cold with a garlic supplement: a double-blind, placebo-controlled surveyAdv Ther.(2001 Jul-Aug)
- ^Ana L Colín-González, Ricardo A Santana, Carlos A Silva-Islas, Maria E Chánez-Cárdenas, Abel Santamaría, Perla D MaldonadoThe antioxidant mechanisms underlying the aged garlic extract- and S-allylcysteine-induced protectionOxid Med Cell Longev.(2012)
- ^Amagase H, Petesch BL, Matsuura H, Kasuga S, Itakura YIntake of garlic and its bioactive components.J Nutr.(2001-Mar)
- ^Mancardi D, Penna C, Merlino A, Del Soldato P, Wink DA, Pagliaro PPhysiological and pharmacological features of the novel gasotransmitter: hydrogen sulfide.Biochim Biophys Acta.(2009-Jul)
- ^Li M, Yun W, Wang G, Li A, Gao J, He QRoles and mechanisms of garlic and its extracts on atherosclerosis: A review.Front Pharmacol.(2022)
- ^Sánchez-Gloria JL, Arellano-Buendía AS, Juárez-Rojas JG, García-Arroyo FE, Argüello-García R, Sánchez-Muñoz F, Sánchez-Lozada LG, Osorio-Alonso HCellular Mechanisms Underlying the Cardioprotective Role of Allicin on Cardiovascular Diseases.Int J Mol Sci.(2022-Aug-13)
- ^Mitra S, Das R, Emran TB, Labib RK, Noor-E-Tabassum , Islam F, Sharma R, Ahmad I, Nainu F, Chidambaram K, Alhumaydhi FA, Chandran D, Capasso R, Wilairatana PDiallyl Disulfide: A Bioactive Garlic Compound with Anticancer Potential.Front Pharmacol.(2022)
