One in 10 people over 40 in the UK are now living with type 2 diabetes, which is a condition that causes too much sugar in your blood. However, there is one common vegetable that can lower blood sugar levels by 50 percent – and which could see “potential use” in treating patients with diabetes.
People with type 2 diabetes are unable to produce enough insulin from their pancreas to regulate blood sugar, which means their blood sugar can reach dangerously high levels.
However, 2015 findings presented at The Endocrine Society’s 97th Annual Meeting in San Diego revealed that the extract of an onion bulb can “significantly lower” high blood sugar and total cholesterol levels when given with the anti-diabetic drug metformin.
Lead study author Anthony Ojieh of Delta State University in Abraka, Nigeria, said at the time: “Onion is cheap and available and has been used as a dietary supplement. It has potential for use in treating patients with diabetes.”
The researchers tested the theory on rats. In total, three groups of rats with medically induced diabetes were given different doses of the onion extract to see if it would enhance the drug’s effect.
The doses were 200 mg, 400 mg and 600 mg per kg body weight. The researchers also gave the drug and the onion to three groups of non-diabetic rats with normal blood sugar.
The study showed that of the diabetic rats, those given 400 mg and 600 mg per kg of body weight, “greatly reduced” their blood sugar levels by 50 percent and 35 percent, respectively, compared to a baseline level.
The onion extract also lowered total cholesterol levels in diabetic rats, with 400 mg and 600 mg having the greatest effects.
The study also found that the onion extract led to weight gain among the non-diabetic rats, but not in the diabetic rats.
“Onions are not high in calories,” explained Ojieh. “However, it appears to increase metabolism and thus increase appetite, leading to increased feeding.
“We need to investigate the mechanism by which onion led to the reduction in blood sugar. We do not yet have an explanation.”
This article was amended on 5 September 2022 to reflect that this study was published in 2015. It originally stated that the results had been presented at a meeting in 2022.