Garlic contains a complex cocktail of chemicals that may act to reduce the risk of cardiovascular disease.
Despite huge financial investment in pharmaceutical ‘research’, cardiovascular disease remains a leading cause of death in developed nations. The newest and most high-profile cardiac drugs are the profitable but useless statins, however, others white elephants include beta blockers, ACE inhibitors, calcium channel blockers, diuretics and thrombolytic agents. While pharmaceutical companies have been aggressively marketing these drugs in the name of profit, the mainstream medical community has been sycophantically trying to convince the public that the solution to deteriorating cardiac health caused by a poor quality diet, is consumption of damaging concentrations of metabolically poisonous substances. Logically, if modern cardiac drugs were effective in any way, we would expect to see improvements to the disease progression in those who take them. However, because these drugs do not address the cause, but only treat the symptoms, there is no improvement in patient health. In nearly all cases the side effects of the drugs cause further deleterious health consequences.
Despite the illogical absurdity of ‘treating’ a disease with substances that do not correct the abnormality that is the root cause, we are continually patronised by medical experts as to the efficacy of these drugs. Such experts seem to define ‘healthcare’ as ingestion of a metabolic poison to alleviate the symptoms of a disease until premature death. Elongation of the time to death, while taking expensive and potentially damaging chemicals, therefore appears to be the primary concern of the mainstream medical establishment. This despite the associated morbidity and deleterious social and economic effect of such a regimen. However, good health begins with personal responsibility, and thankfully a growing number of enlightened individuals are beginning to circumvent the scam that is modern allopathic medicine and instead are turning towards the nutritional sciences for guidance. Such individuals interested in remaining drug free while maintaining a healthy cardiac system, are highly recommend to incorporate the herb garlic into their diet.
Of all of the thousands of known herbs, garlic has to rank as one of the most overall beneficial to human health. Known to man for thousands of years, garlic is a natural medicine that is a true panacea for heart health. Garlic (Allium sativum) is a member of the onion family, Alliaceae, which includes other plants such as shallots, scallions, leeks and chives. These plants are all characterised by being high in flavonols and organosulfur compounds which are of interest to the nutritional sciences because they may have very useful healing properties. While researchers are still unclear as to the absorption and metabolism of many of the compounds in garlic, there is a consensus starting to emerge that demonstrates strong cardioprotective effects with regular consumption1, 2. As with red wine, the benefits of garlic appear to be due to synergistic action between the many constituent chemicals rather than the activity of a singly specific compound.
Of the chemicals known to be present in garlic, a number of possible active constituents have been identified. These include chemicals such as allin, ajone, cycloallin, S-allyl-L-cysteine, S-methyl-cysteine, S-ethylcysteine, S-1-proponyl-L-cysteine, S-allylmercapto-L-cysteine, fructosyl-arginine, and β-chlorogenin3. Many of these give garlic a characteristic odor and pungent taste, as they do with all the Alliaceae family vegetables. Crushing and cutting garlic converts these compounds into hundreds of organosulfur compounds. It is some or all of these components that are believed to give garlic its therapeutic properties on cardiovascular health. That many of the health promoting chemicals are only released upon crushing, in combination with their short-lived properties, is probably the main reason that fresh garlic is more beneficial that supplemental garlic capsules containing garlic oil. However, a number of active ingredients, particularly allicin, have been isolated and research does shows beneficial cardioprotective effects for these single compounds.
Much of the research surrounding garlic has focused on the cholesterol and lipid lowering effects, as garlic has shown some ability to lower blood cholesterol levels in humans. It is thought that some of the more water soluble constituents within the garlic may inhibit the enzyme squalene monooygenase and HMG-CoA reductase, both of which are involved in cholesterol biosynthesis. This in turn leads to a reduced level of blood cholesterol. However, blood cholesterol is not the cause of cardiovascular disease, but is only associated with it. It is important to understand that raised cholesterol levels in blood are a symptom of metabolic abnormality, but not the cause of it. Forcing down blood cholesterol through enzyme inhibition, which is how many drugs work, might not be an effective solution. Therefore, whether the cholesterol lowering effect of garlic is the reason for its ability to help cardiac health is debatable. In fact, other more plausible explanation exist for the cardioprotective benefits of garlic.
Recently, research has focused on high homocysteine levels as being an important risk factor in the development of cardiovascular disease and myocardial infarction. Homocysteine is a thiol (sulfur) containing amino acid, formed in all mammals from the amino acid methionine, which is ingested from protein in the diet. Homocysteine can itself be damaging to the body and so under optimal nutritional status, the body converts the homocysteine to other less dangerous compounds. This conversion is dependent on vitamin B6, vitamin B12 and folic acid. However, garlic has also been shown to be able to lower elevated levels of plasma homocysteine. A study published in the Journal of Nutrition in 20064, found that giving garlic extract to rats fed a diet deficient in folic acid, produced a 30 % reduction in circulating homocysteine levels. Another study in the Journal of Nutrition in 20065 demonstrated that garlic extract was able to reduce the adverse acute effects of high homocysteine levels.
Garlic has also been shown to prevent platelet aggregation in humans. Platelets are used by the body to produce clots which are important in preventing bleeding. However, if clots forms inside blood vessels and cause blockages, they can lead to myocardial infarction or stroke in the arteries of the heart or brain, respectively. Poor nutrition and stress can cause platelets to become more likely to form clots, and preventing aggregation of the platelets is an important step in cardiovascular health. A series of studies published in the Journal of Nutrition in 20006, 20017 and 20068 demonstrated that components of garlic work in a synergistic manner and exert multiple effects on the biochemical pathways involved in platelet aggregation. The exact mechanism of this action is unknown but is likely that garlic can interact with calcium signaling within the platelets themselves. In addition, research suggests garlic has a fibrinolytic activity and can break down clots once they have formed.
A number of other mechanisms by which garlic may protect from cardiovascular disease have also been investigated by researchers. Garlic is thought to possess antioxidant effects in humans which may prevent the oxidation of lipids within the blood. This may prevent damage the endothelial lining of blood vessels, something that is thought to lead to the formation of atherosclerosis and a subsequent narrowing of the arteries. The antioxidant effect may derive from the flavonol compounds in garlic. Garlic may also have a modulatory effect on the blood pressure, by a number of mechanisms. Firstly, through an effect on nitric oxide synthase (NOS) and endothelin-1, garlic is able to modulate blood pressure by allowing blood vessels to relax. This may relate to the antioxidant effects of the herb, as free radicals inhibit NOS and therefore reduce nitric oxide production. Secondly, garlic may work to inhibit the angiotensin-converting enzyme, which is responsible for raising the blood pressure by allowing production of angiotensin I.
The lack of side effects, in combination with the low cost, suggest that garlic is worth considering for the cardioprotective effects it offers. The exact form of garlic to consume is an important consideration because differences are reported between supplements and the various herbal preparations. Much of the research surrounding garlic has used aged garlic extracts (AGE). These extracts are prepared by soaking raw garlic in 15 to 20 % aqueous ethanol solution for up to 20 months at room temperature. Aged garlic extracts are available in supplement form from most health food suppliers. Because much of the research has been performed on this form of garlic it is sensible to use AGE in the diet. Studies have used a very wide range of amount of AGE from as little as 1.8 grams per day to as much as 10 grams per day. The higher dose is probably too much for most people, but even at this high level, the extract appeared to be quite safe.
However, although aged garlic extracts are an ideal adjunct to a healthy diet, incorporating the whole herb into cooking may add additional benefits. There is controversy surrounding the potency of some garlic supplements and it is at present not entirely clear which constituents of the garlic produce the beneficial effects. Garlic contains may chemicals, many of which have not been fully characterised. There is a chance therefore that some beneficial compounds have not been identified. In addition, some of the active ingredients in garlic are very short lived and are only released on crushing the garlic. Therefore, in order to ensure that the full benefits of the herb are attained, it is sensible to consume the whole herb. Because some of the chemicals are pungent they can cause changes to the smell of the breath. However, parsley is able to freshen breath after eating garlic, and so growing some parsley in a small herb garden for chewing after eating garlic is recommended if this is of concern.
