An aged black garlic extract was linked to significant and favorable reductions in diastolic blood pressure in a group of individuals with moderately elevated cholesterol levels compared to placebo in a preliminary clinical trial appearing in Nutrients.
 
Hypertension effects nearly a third of adults worldwide, and is a leading preventable risk factor for cardiovascular problems and all-cause mortality. Pharmactive the supplier of ABG+, the garlic extract used in the study, reports that with every 10 mm/Hg increase in blood pressure, the risks associated with cardiovascular disease and other heart conditions doubles among people between the ages of 40 and 89.
 
The randomized, double-blind, crossover-controlled study was conducted at the Saint Roan de Reus University Hospital in Barcelona, and recruited 67 adult hypercholesterolemic volunteers who had relatively high blood LDL levels. Health outcomes were measured as each participant took 250 mg of ABG+ or a placebo over the course of six weeks, with a three-week washout period before group crossover.
 
Subjects in both groups were also assigned a set diet that excluded foods known for anti-hypertensive and blood lipid-lowering benefits. At the end of each six-week interval, the participants who were taking the aged black garlic extract saw a reduced diastolic pressure by 5.85 mm/Hg on average compared to the placebo. The results were more significant in men than in women.
 
This is the first human clinical study conducted on ABG+, spurred by positive outcomes seen in previous animal studies suggesting that the ingredient has a potential cardioprotective role, with signs that it may help to balance blood lipids and enhance vascular function.
 
“A reduction of just 5 mm/Hg of diastolic blood pressure lowers substantially the risk of stroke and other vascular events,” Alberto Espinel, head of R&D for Pharmactive. “Aged black garlic has long been regarded as a culinary delicacy and integral component of the Asian diet, as well as a tool to maintain health. Empirical evidence is unfolding on the beneficial effects of black garlic on cardiovascular health. However, the magnitude of its effect depends on the amount and type of chemical compounds accumulated during the aging process and the ability to extract and preserve those compounds during processing.”
 
Standardization is Key
 
Pharmactive reports that aged black garlic’s bioactivity relies upon biochemical changes in which standardization is key. The savory ingredient is produced through an aging process which turns the garlic cloves dark and jellylike, which causes organosulfur compounds to diminish and significantly increases soluble polyphenols (predominantly S-allyl-L-cysteine (SAC)), flavonoids, and melanoidins. Researchers attribute the combined action of these antioxidants to the potential cardioprotective properties of the ingredient.
 
ABG+ is standardized to 1.25mg SAC per dose, and is produced through the company’s ABG Cool-Tech aging technique. The ingredient is then tested via high-performance liquid chromatography.
 
“SAC is virtually absent in fresh garlic, yet is synthesized and accumulated during aging under specific ambient conditions,” Espinel said. “The presence and concentration of active substances critically depend on the production process. Most commercial black garlic products on the market are intended just for their culinary properties and barely contain SAC. In other cases, SAC is produced in garlic by long industrial processes which included soaking the bulbs in organic solvents and the results are simply labeled as ‘aged garlic’. 
 
“This compromises the content of bioactives and is the reason the available studies of black garlic extracts show contradictory results and health capabilities. This is some of the first evidence emerging on the blood pressure-balancing effect of an ABG+ extract, as a natural alternative, in a population where the strategies of intervention are based on diet and maintaining a healthy lifestyle. Importantly, its positive effects were achieved following a simple protocol of consuming one ABG+ extract tablet daily.”
 
Julia Diaz, head of marketing for Pharmactive, said that future investigations into the potential role that this ingredient has in blood pressure management are being planned, and research suggests that ABG+ could be a complementary tool to use alongside first lines of treatment, such as the extensively-studied DASH or Mediterranean diets.