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“Let food be thy medicine, and medicine be thy food.”
The father of Western medicine, also known as the ancient Greek physician Hippocrates had prescribed garlic to treat a variety of medical conditions. Number of studies have been conducted to confirm the beneficial health effects of garlic. Apart being known to boost the function of the immune system and combat sickness, garlic has also acquired the status of ‘traditional’ remedy for hypertension (high blood pressure) and high cholesterol.
The who, what, why and how of high blood pressure
Cardiovascular diseases like heart attacks and strokes are the world’s biggest killers. According to Australian Bureau of Statistics National Health Survey, 1 in 4 men had measured high blood pressure compared with 1 in 5 women. Many people developed high blood pressure when they are in their late 30’s or early 40’s, and it occurs more frequently as people age. Children are also at risk developing high blood pressure due to obesity epidemic.
The blood pressure is defined as the force of blood pushing against the walls of arteries as the heart pumps blood. So, when the blood flows through blood vessels at a higher than normal pressure, it forms a situation known as high blood pressure. Your blood pressure is considered high if it’s higher than 130/80 (1).
Early detection of high blood pressure is essential as it’s always termed as the “silent killer”, showing no symptoms, and putting one at an increased risk for heart disease, heart failure and stroke.
Is managing your high blood pressure with medication a good idea?
Medication can lower blood pressure effectively, however, it’s worth considering the pros and cons of taking medication. Research from University of Alabama at Birmingham has shown that although high blood pressure medications are beneficial, it is risky to wait for the condition to develop and then treat it to a controlled level. Their study also has shown that high blood pressure medication can increase stroke risk by 33%. Thus, the way to curb the problem is to prevent high blood pressure in the first place, according to George Howard, Dr. P.H., a professor in the Department of Biostatistics in the UAB School of Public Health (2).
Garlic can improve heart health
The wealth of scientific literature supporting the garlic consumption on lowering blood pressure, prevention of atherosclerosis, reduction of serum cholesterol and triglyceride, inhibition of platelet aggregation and increasing fibrinolytic activity has been reported (3). A study published in Experimental and Therapeutic Medicine has found that consuming garlic extract for two months can lower blood pressure and decrease arterial stiffness for people with high blood pressure. Garlic works by reducing lipids in the blood, and thus lower the risk for plaque build up in the cardiovascular system (4).
The most biologically active component in garlic, known as allicin, has the antioxidant properties that helps to lower cholesterol level and hence regulating blood pressure and blood sugar levels. Allicin is formed when Alliin comes into contact with the enzyme Alliinase when raw garlic is chopped, crushed or chewed. Oxidative stress is one of multiple molecular mechanisms involved in the etiology of high blood pressure, which results from increased production of reactive oxygen species (ROS) and diminished bioavailability of nitric oxide (NO). Nitric oxide plays an important function in vasodilation, which helps to relax the inner muscles of the blood vessels and increase circulation. Increased levels of ROS can activate the expression of NF-kB, resulting renal injury and hypertension.
Allicin has been reported to exert angiotensin-II-inhibiting and vasodilating effects. Gamma-glutamyl-S-allycysteine (GSAC) also contribute to the effects by inhibiting ACE and inducing endothelium-dependent and independent relaxation. Angiotensin-II precipitates hypertension by promoting sodium and water retention, enhancing vasoconstriction and triggers the growth of vascular smooth muscle cell (VSMC), which interact with myosin to produce contraction. Thus, inhibiting ACE is an attractive approach for antihypertensive therapies (5).
Cultivated garlic bulb vs wild garlic
Some studies have shown that wild garlic has a greater effect than regular garlic on blood pressure. Wild garlic (Allium ursinum) was reported to reproduce many of the beneficial findings compared to common cultivated garlic (Allium sativum) derived from the bulb. Wild garlic contains 2 times more of the active compounds than cultivated garlic. Besides that, concentration of antioxidants is greater in wild garlic, as well as magnesium, adenosine, ajoenes and phosphorus. Wild garlic also appears to affect circulating cholesterol and HDL concentration more than cultivated garlic at lower concentrations (6).
Lifestyle also plays an important role in treating or prevent high blood pressure, such as watching your waistline by adopting a healthy diet and exercise regularly. Controlling your blood pressure should be part of a healthy living plan and lifelong task. High blood pressure can cause other health complication such as kidney disease. Taking care of your health and you can help control the silent killer.
References:
1. Australian Bureau of Statistics. Dec 2018. Hypertension and measured high blood pressure. Retrieved from: https://www.abs.gov.au/statistics/health/health-conditions-and-risks/hypertension-and-measured-high-blood-pressure/latest-release
2. Science Daily. Blood pressure medications can lead to increased risk of stroke. May 2015. Retrieved from: https://www.sciencedaily.com/releases/2015/05/150529193554.htm#:~:text=Howard%20says%20the%20risk%20of,risk%20of%202.5%20times%20higher.
3. Bayan L, Koulivand PH, Gorji A. Garlic: a review of potential therapeutic effects. Avicenna J Phytomed. 2014;4(1):1-14.
4. Ried K. Garlic lowers blood pressure in hypertensive subjects, improves arterial stiffness and gut microbiota: A review and meta-analysis. Exp Ther Med. 2020;19(2):1472-1478. doi:10.3892/etm.2019.8374
5. Shouk R, Abdou A, Shetty K, Sarkar D, Eid AH. Mechanisms underlying the antihypertensive effects of garlic bioactives. Nutr Res. 2014 Feb;34(2):106-15. doi: 10.1016/j.nutres.2013.12.005. Epub 2014 Jan 6. PMID: 24461311.
6. Clouatre D. European Wild Garlic. The Better Garlic. San Francisco CA: Pax Publishing, 1995, pp. 1–38.