Allium sativum extract
Also known as: Allium sativum, Garlic, Aged garlic extract, Garlic oil
Overview
Allium sativum, commonly known as garlic, is a bulbous plant extract widely recognized for its diverse health benefits, primarily attributed to its organosulfur compounds such as allicin, alliin, S-allyl cysteine, and diallyl disulfide. It is categorized as a functional food supplement and is used for cardiovascular support, metabolic syndrome management, and antimicrobial applications. Research on garlic extract is considered moderately mature, with numerous randomized controlled trials and systematic reviews. While evidence is generally consistent, heterogeneity in study designs contributes to a 'Grade B' evidence quality. Aged garlic extract is often preferred due to the higher bioavailability of its key compound, S-allyl cysteine, compared to the transient allicin found in raw garlic.
Benefits
Garlic extract has demonstrated several evidence-based benefits. In individuals with NAFLD, meta-analyses show significant reductions in ALT (SMD -0.94, 95%CI -1.44 to -0.44) and AST (SMD -0.89, 95%CI -1.39 to -0.40). Regarding cardiometabolic health, a meta-analysis indicated a non-significant trend toward increased adiponectin levels (p=0.07). Garlic extract also exhibits antimicrobial properties, with studies showing a significant reduction in *S. mutans* colony-forming units (3.32 CFU reduction, 95%CI -4.39 to -2.26). Furthermore, animal studies suggest potential neuroprotective effects, including improved cognitive function in Alzheimer's disease models.
How it works
Garlic extract exerts its effects through several key mechanisms. It activates the Nrf2/ARE antioxidant pathway, enhancing the body's defense against oxidative stress. Additionally, it influences lipid metabolism via PPARγ-mediated pathways and inhibits the NF-κB inflammatory pathway, reducing inflammation. The bioavailability of garlic's active compounds varies; S-allyl cysteine, abundant in aged garlic extracts, boasts >90% absorption, while allicin, the primary compound in raw garlic, has <15% bioavailability due to its transient nature. These mechanisms collectively contribute to garlic's observed health benefits.
Side effects
Common side effects of garlic extract include breath odor and gastrointestinal discomfort, affecting more than 5% of users. Uncommon side effects, occurring in 1-5% of individuals, encompass allergic reactions and hypotension. Rare side effects, observed in less than 1% of users, include a theoretical risk of bleeding. Garlic extract can interact synergistically with anticoagulants, potentially increasing bleeding risk. It may also interact with HIV protease inhibitors via CYP3A4. Contraindications include preoperative patients and individuals with garlic allergies. Caution is advised for those on blood-thinning medications due to the potential for increased bleeding.
Dosage
The minimum effective dosage of aged garlic extract is typically 300-450mg, providing 1.5-2.4mg of S-allyl cysteine. The optimal range for standardized extracts is 600-1200mg per day. Short-term use has shown that dosages up to 2400mg/day are generally safe. It is recommended to take garlic extract with meals to minimize gastrointestinal side effects. Individual responses may vary, and it's advisable to start with a lower dose and gradually increase as needed. Due to potential interactions with blood-thinning medications, consulting a healthcare professional is recommended.
FAQs
How can I mitigate the odor associated with garlic supplements?
Enteric-coated tablets or aged garlic extracts can help reduce or eliminate the characteristic odor. These formulations are designed to break down in the intestines rather than the stomach, minimizing odor release.
How long does it take to experience the metabolic benefits of garlic extract?
The onset of metabolic benefits typically ranges from 4 to 12 weeks of consistent supplementation. This timeframe allows for the active compounds to exert their effects on lipid metabolism and inflammatory pathways.
Are fresh garlic and garlic supplements equally effective?
Aged garlic extracts are often preferred over fresh garlic due to the higher bioavailability of stable S-allyl cysteine. Fresh garlic contains allicin, which is transient and has lower bioavailability compared to S-allyl cysteine.
Is it safe to take garlic extract with other medications?
Garlic extract can interact with certain medications, particularly anticoagulants and HIV protease inhibitors. Consult with a healthcare professional before combining garlic extract with other drugs to avoid potential adverse effects.
What is the best time of day to take garlic extract?
It is generally recommended to take garlic extract with meals to minimize gastrointestinal discomfort. Consistent timing, such as with breakfast and dinner, can also help maintain stable levels of active compounds in the body.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8331287/ – This review provides a broad overview of garlic's chemical composition, pharmacological activities, and clinical applications. It highlights garlic's potential in treating various conditions, including cardiovascular diseases, cancer, and infections, while also discussing its safety profile and potential drug interactions. The review emphasizes the need for further research to fully elucidate garlic's mechanisms of action and optimize its therapeutic use.
- https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2023.1059106/full – This systematic review and meta-analysis investigated the effects of garlic supplementation on liver enzymes in patients with non-alcoholic fatty liver disease (NAFLD). The analysis of seven randomized controlled trials revealed that garlic supplementation significantly reduced ALT and AST levels, suggesting a potential therapeutic role in managing NAFLD. However, the authors noted substantial heterogeneity among the included studies, indicating the need for more standardized research.
- https://pubmed.ncbi.nlm.nih.gov/34273446/ – This systematic review of animal studies explored the neuroprotective effects of garlic and its bioactive compounds in Alzheimer's disease (AD) models. The review found that garlic supplementation improved cognitive function and reduced AD-related pathology in these models. The findings suggest that garlic may have potential as a therapeutic agent for AD, warranting further investigation in human clinical trials.
- https://biointerfaceresearch.com/wp-content/uploads/2021/01/20695837114.1210412119.pdf – This article discusses the antimicrobial properties of garlic and its potential applications in combating various infections. It highlights garlic's effectiveness against a range of bacteria, fungi, and viruses, attributing these effects to its organosulfur compounds. The article also explores the mechanisms by which garlic exerts its antimicrobial activity, including disruption of microbial cell membranes and inhibition of enzyme activity.
- https://ps.tbzmed.ac.ir/Article/ps-34399 – This study investigated the effects of garlic on Streptococcus mutans, a bacterium responsible for dental caries. The results showed a significant reduction in S. mutans colony-forming units (CFU) following garlic treatment, indicating its potential as an antimicrobial agent for oral health. The study suggests that garlic could be a natural alternative to conventional antimicrobial agents in preventing dental caries.