Reduces High Cholesterol

• In 2013 Nutrition Reviews published a comprehensive meta-analysis including 39 trials on the effects of garlic on blood lipids. The data showed that when garlic is used for at least 2 months it can significantly lower LDL cholesterol and total cholesterol by 8 percent – which is associated with a 38 percent reduced risk of heart attack in individuals 50 years of age. [Source]
• In 2006 The Journal of Nutrition published an animal trial which showed rats that received high doses of raw garlic (500 mg/kg/bw) saw profound reductions in glucose, cholesterol and triglyceride levels. The researchers note that these reductions in cholesterol may play an important role in preventing the onset of atherosclerosis. [Source]
• In 2016 The Journal of Nutrition published a 24-week animal study which tested the effects of aged-garlic extract on mice bred to have a very high incidence of atherosclerosis. Compared to a control group, mice in the aged-garlic extract group saw a significant reduction in atherosclerotic lesions as well as significantly lower total cholesterol and total triglycerides. [Source]
• In 2016 Phytomedicine published an animal study which found garlic to prevent the development of cholesterol-induced atherosclerosis through “direct anti-atherosclerotic activity.” [Source]
• In 2007 Lipids in Health and Disease published a 6-week clinical trial in which 400 mg of garlic containing 1 mg of allicin (the active substance in garlic) taken twice daily was compared to 650 mg of anethum (Dill) taken twice daily and a placebo for treating 150 patients with high cholesterol. The garlic group (50 patients) saw a 12 percent reduction in total cholesterol, a 17 percent reduction in LDL cholesterol and a nearly 16 percent rise in HDL (good) cholesterol, whereas dill showed no efficacy in reducing cholesterol. [Source]
• In 2008 the Journal of Atherosclerosis and Thrombosis published a 42-subject, double-blind, placebo-controlled trial in which 600 mg of Allicor (extended-release garlic tablets) was evaluated for its potential in reducing blood lipids in men with hypercholsterolemia (high cholesterol). After 12 weeks of treatment total cholesterol in the Allicor group was 11.5 percent lower than the placebo group and HDL cholesterol in the Allicor group was 11.5 percent higher than baseline. [Source]

Protection against DNA damage

• In 2005 Molecular and Cellular Biochemistry published a study in which 20 patients with hypertension and 20 individuals with normal blood pressure were given 250 mg of garlic per day for 2 months. The hypertensive group saw a moderate decrease in blood pressure and significant increase in vitamin levels and antioxidant status. There was also a significant reduction in  8-OHdG levels – a marker of oxidative stress and DNA damage. [Source]

Prevents the Common Cold

• On 2001 Advances in Therapy published a study including 146 volunteers who received either an allicin-containing garlic supplement or a placebo for a 12-week period between November and February (cold season). The garlic group contracted significantly fewer colds and recovered faster if infected, leading researchers to conclude that allicin-containing garlic supplements can help prevent common cold virus infections. [Source]
• In 2012 Clinical Nutrition published a 120-subject, double-blind, placebo-controlled study which tested 2.56 grams of aged garlic extract per day on the body’s immune response to the common cold virus. After 45 days the garlic group had greater concentrations of natural killer cells (white blood cells vital to immune function) and experienced reduced severity in cold symptoms. [Source]

Alzheimer’s

• In 2009 Phytotherapy Research published an in vitro study which showed that garlic inhibits Amyloidogenic proteins – proteins that are linked to neurodegenerative disorder such as Alzheimer’s. [Source]
• In 2007 Phytoherapy Research published an animal study in which mice that were predisposed to develop Alzheimer’s disease were fed aged garlic extract. The result was a decrease in memory deterioration which may suggest a potential role of aged garlic extract in preventing the progression Alzheimer’s disease. [Source]

Hypertension

• In 2013 the Pakistan Journal of Pharmaceutical Sciences published a 24-week study which compared 5 different daily doses (300, 600, 900, 1200 and 1500 mg) of garlic with both a placebo and atenolol (blood pressure reducing drug) for reducing blood pressure in 210 hypertensive subjects. Blood pressure readings taken at 0, 12 and 24 weeks showed that garlic reduced systolic and diastolic blood pressure in a dose and duration-dependent manner compared to both a placebo and atenolol. [Source]
• In 2016 the Journal of Nutrition published a meta-analysis which included 20 studies and 970 participants on the effects of garlic on blood pressure. The authors of the review concluded that garlic supplements have the potential to lower blood pressure in hypertensive individuals, to regulate elevated cholesterol levels and stimulate the immune system. [Source]
• In 2015 the Journal of Clinical Hypertension published a meta-analysis which included 17 trials from 1946 – 2013. Based on the data the authors concluded that garlic supplements are effective in reducing blood pressure, particularly in hypertensive individuals. [Source]
• In 2008 The Annals of Pharmacotherapy published a meta-analysis which analysed 10 studies. The authors concluded that garlic is associated with blood pressure reductions in hypertensive individuals but not in subjects with normal blood pressure. [Source]
• In 2013 the European Journal of Clinical Nutrition published a 12-week, double-blind clinical trial in which 79 subjects with hypertension were assigned to 1 of 3 daily doses of garlic or a placebo. Results showed that after 12 weeks 480 mg/day of aged garlic extract produced a significant reduction in systolic blood pressure when compared to a placebo. [Source]
• In 2015 Phytomedicine published a meta-analysis of 7 placebo-controlled studies which revealed garlic to possess a significant blood pressure lowering effect on both systolic and diastolic blood pressure, leading the authors to conclude that garlic is a safe and effective treatment for hypertension. [Source]
• In 2016 Integrated Blood Pressure Control published an 88-subject, double-blind clinical trial which found that 12 weeks of supplementation with aged garlic extract was able to reduce blood pressure in patients with uncontrolled hypertension when compared to a placebo. The authors also concluded that garlic extract has the potential to improve arterial stiffness and inflammation. [Source]