Here’s why eating garlic and on¬ions can prevent diabetes and more

by Evangelyn Rodríguez

Alliums are disease-fighting vegetables widely used as everyday food and traditional medicines. This incredible family of edible medicinal plants is com­posed of garlic, white and purple onions, leeks, chives, scallions and shallots. Ac­cording to studies, alliums contain unique compounds called organosulfur com­pounds and natural anti­oxidants called polyphenols that are responsible for their disease-fighting activities.

In a recent study, re­searchers at the Federal University of Technology  in Nigeria investigated the benefits of eating garlic, white onion and purple on­ion against serious conditions like diabetes and hyperten­sion. They confirmed these by looking at how extracts from the three alliums af­fect the activity of diabetes-related enzymes, such as a-amylase and a-glucosidase, and the hypertension-related enzyme, angiotensin-con­verting enzyme (ACE).

The researchers reported their findings in an article published in the Journal of Dietary Supplements.

Garlic, white onion and purple onion show an­tioxidant, antidiabetic and antihypertensive properties

Garlic and onions are spices commonly used in cooking. They also serve as ingredients in several tradi­tional delicacies in Nigeria that are known to contain plenty of polyphenols. To as­sess the beneficial properties of garlic, white onion and pur­ple onion, the researchers first obtained extracts from each and assessed their inhibitory effects on certain enzymes. They also conducted assays to determine the antioxidant capacities of the extracts.

ACE is the enzyme re­sponsible for converting an­giotensin I into angiotensin II, the hormone that increases blood pressure, as well as body water and sodium con­tent. Angiotensin II elevates blood pressure by constrict­ing the blood vessels; hence, chemicals that can inhibit the activity of ACE, which is re­sponsible for the production of angiotensin II, are used for the treatment of hypertension.

a-Amylase is the enzyme that breaks down starch and glycogen into glucose and maltose (two glucose mole­cules bound together). In hu­mans, this enzyme is produced by the salivary glands and the pancreas. a-Glucosidase, on the other hand, is responsible for breaking down carbohy­drates in the small intestine and facilitating the absorp­tion of glucose. Inhibiting the activity of this enzyme is one of the strategies cur­rently used to prevent the rise of blood sugar levels follow­ing a carbohydrate-filled meal.

The researchers reported that the garlic, purple onion and white onion extracts inhibited the activities of ACE, a-amy­lase and a-glucosidase in vitro in a concentration-dependent manner. At a half maximal in­hibitory concentration (IC50) of 0.59 mg / mL, the purple onion extract exhibited a higher inhibitory effect on ACE than the white onion extract (IC50 = 0.66 mg / mL) and the garlic (IC50 = 0.96 mg / mL) extract.

Meanwhile, the white on­ion extract showed a signifi­cantly stronger inhibitory effect on a-amylase at an IC50 of 3.93 mg / mL than the garlic extract (IC50 = 8.19 mg / mL) and the purple onion (IC50 = 8.27 mg / mL) extract. The garlic extract, on the other hand, showed a similar inhibitory effect (IC50 = 4.50 mg / mL) on a-glucosidase as the white and purple on­ion extracts. All three extracts also showed dose-dependent free radical scavenging ac­tivity and reducing power in the antioxidant assays.

Based on these findings, the researchers concluded that garlic, white onion and purple onion can be used to treat or prevent diabetes and hypertension, thanks to their ability to inhibit ACE, a-amylase and a-glucosidase activity, as well as lipid per­oxidation in the pancreas and the heart. (Natural News)