Garlic Extracts For Good Health

Garlic cloves with one peeled away from the main stem on a black background.
Garlic Bulbs. Photo By Carlos Porton. Courtesy of

Garlic (Allium sativum L.) has long been regarded as a healthy vegetable. It is a member of the Lily family (Liliaceae). For many ancient peoples it was both food and medicine. We know of Egyptians, Greeks, Romans, Chinese and Babylonians all using garlic and its extracts to treat a range of ailments. Garlic was used to treat wounds – a practice long followed into the Second World War.  It has long been thought that the pungent component, allicin is the main compound responsible for many of its health benefits including lowering blood  sugar levels. Garlic also contains other nutrients and vitamins: vitamins C and B6, selenium and manganese.

Garlic possesses antidiabetic, antihyperglycemic, cardioprotective, antihypertensive, antilipiperoxidative, antiviral, antilice, antifilarial, antiinflammatory, antioxidant, and antidyslipidemic activity (Badole et al., 2013).

Nutrition Facts (per 100g)

Calories- 149
Total Carbohydrate-33g
Dietary Fiber-2g 8% RDA
Total Fat-0.5g
Protein-6.5g 13% RDA
Vitamin C-31mg 52% RDA
Thiamin-0.2mg 13% RDA
Riboflavin-0.1mg 6% RDA
Niacin-0.7mg 4% RDA
Vitamin B6-1.2mg 62% RDA
Pantothenic Acid 0.6mg 6% RDA
Calcium-180mg 18% RDA
Iron-1.7mg 9% RDA
Magnesium-25mg 6% RDA
Phosphorus-155mg 15% RDA
Potassium-400mg 11% RDA
Zinc-1.2mg 8% RDA
Copper-0.3mg 15% RDA
Manganese-1.7mg 84% RDA
Selenium-14.2mcg 20% RDA


Garlic extracts have been shown to have antidiabetic benefits especially in type-2 diabetes. In one rat study, an ethanolic extract was administered to either normal or rats treated with streptozotocin which made them diabetic (Eidi et al., 20

06). Levels of garlic extract given were varied between 0.1, 0.25 and 0.5 g/kg body wt. The extract was compared with an antidiabetic drug, glibenclamide (600 micrograms/kg) and the garlic was more effective. It appears an ethanolic extract is effective at reversing the effects of diabetes- certainly in rodents.

In terms of the mechanism, it is thought that in clinical studies, the components in garlic lower blood glucose levels by competing with sites for insulin in the liver (Badole et al., 2013). This leads to an increased production of insulin. It has been shown in research on both animals and humans that people eating garlic have ‘better control’ of their blood sugar levels and to be a therapy for treating diabetes. Whilst much of this benefit is ascribed to allicin, there are many sulphur-containing compounds which have a benefit.

Garlic And A Reduction In Cancer

Eating garlic is associated with a reduction in cancer risk although not all cancers. At the experimental cell level, extracts and individual components block the growth of experimentally induced tumours from various tissues – uterus (Hussain et al., 1990), colon, breast and skin (Milner, 1996; 2001). 

Cholesterol Lowering Benefits

Modest reductions in total cholesterol levels  were possible based on a study of 29 high-quality clinical studies which assessed performance on 1,794 subjects (Reinhart et al., 2009). Garlic was mainly consumed in the form of garlic powder in many of these studies. 

One meta-analysis of 39 trials shows that garlic can also reduce total serum cholesterol levels and low-density lipoprotein cholesterol, especially in those with a high starting blood cholesterol content (above 200mg/dL). Garlic needs to be consumed for longer than 2 months for any modest benefit to be seen (Reid et al., 2013).

Amongst nutritionists, the jury is still out on whether garlic truly has a strong impact on reducing cardiovascular disease !


Whilst hypercholesterolemia is associated with an increased risk of heart disease, there are many other aspects which need to be tackled as part of a treatment to improve cardiovascular health.


Badole, S.L., Ghule, A.E., Wagh, N.K. (2013) Chapter 15 – Antidiabetic Activity of Allium Sativum. In: Bioactive Food as Dietary Interventions for Diabetes. pp. 157-161

Eidi, A., Eidi, M., Esmaeili, E. (2006) Antidiabetic effect of garlic (Allium sativum L.) in normal and streptozotocin-induced diabetic rats. Phytomedicine 13 (9-10) pp. 624-629

Essman, E.J. (1984) The Medical Uses of HerbsFitoterapia, 55 pp. 279289

Hussain, S.P.Jannu, L.N. and Rao, A.R. (1990Chemopreventive Action of Garlic on Methylcholanthrene-Induced Carcinogenis in the Uterine Cervix of MiceCancer Letter., 49 pp. 175180

Milner, J.A. (1996) Garlic: Its Anticarcinogenic and Antitumorigenic PropertiesNutr. Rev., 54A82S86

Milner, J.A. (2001A Historical Perspective on Garlic and CancerJ. Nutr., 1311027S1031S.

Rahman, M. S. (2007). Allicin and other functional active components in garlic: health benefits and bioavailability. International Journal of Food Properties10(2), pp. 245-268

Ried, K., Toben, C., & Fakler, P. (2013). Effect of garlic on serum lipids: an updated meta-analysis. Nutrition reviews71(5), pp.. 282-299

Reinhart, K. M., Talati, R., White, C. M., & Coleman, C. I. (2009). The impact of garlic on lipid parameters: a systematic review and meta-analysis. Nutrition Research Reviews22(1), pp. 39-48.

Sahebkar, A., Serban, C., Ursoniu, S., & Banach, M. (2016). Effect of garlic on plasma lipoprotein (a) concentrations: a systematic review and meta-analysis of randomized controlled clinical trials. Nutrition, 32(1), pp. 33-40.

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