Type 2 diabetes, a condition characterised by fluctuating blood sugar levels, can wreak havoc on the body. However, making smart dietary choices can help manage these levels.

A groundbreaking study has discovered that a common vegetable could slash high blood sugar levels by up to half. Type 2 diabetes arises when the pancreas fails to produce enough insulin to regulate blood sugar levels, or the body's cells don't effectively utilise the insulin produced.

Insulin is vital for controlling blood sugar - the main type of sugar found in our blood. Without this control, blood sugar levels can soar to perilous heights.

Fortunately, an effective solution may be closer than we think. Research unveiled at The Endocrine Society's 97th annual meeting in San Diego showed that extract from onion bulbs, Allium cepa, significantly lowered high blood glucose (sugar) in diabetic rats when given alongside the anti-diabetic drug metformin, reports Surrey Live.

"Onion is cheap and readily available and has been used as a nutritional supplement," said lead investigator Anthony Ojieh, MBBS (MD), MSc, from Delta State University in Abraka, Nigeria. "It holds potential for use in treating patients with diabetes."

Mr Ojieh and his team gave metformin and varying doses of onion extract - 200mg, 400mg and 600mg per kilograms of body weight daily - to three groups of rats with medically induced diabetes to see if it would boost the drug's effects.

The study involved giving metformin and onion extract to three groups of non-diabetic rats with normal blood sugar levels for comparison. Two control groups, one non-diabetic and one diabetic, did not receive either metformin or onion extract.

Another two groups, one with diabetes and one without, were given only metformin and no onion extract. Each group had five rats.

Onion extract, at doses of 400mg and 600mg, significantly lowered fasting blood sugar levels in diabetic rats by 50 percent and 35 percent respectively, compared to their baseline levels before receiving onion extract, Mr Ojieh reported.

However, the onion extract caused an increase in average weight among non-diabetic rats but not diabetic ones. "Onion is not high in calories," said Mr Ojieh.

"However, it seems to increase the metabolic rate and, with that, to increase the appetite, leading to an increase in feeding."

Mr Ojieh continued: "We need to investigate the mechanism by which onion brought about the blood glucose reduction. We do not yet have an explanation."

The onion extract used in the experiment was made from a common onion bulb, like those found in local supermarkets. If this were to be used on humans, it would typically be purified so that only the active ingredients would be measured for proper dosing, added Mr Ojieh.

The NHS has advised: "A healthy diet and keeping active will help you manage your blood sugar level. It'll also help you control your weight and generally feel better."

They suggest incorporating a variety of foods into your diet to maintain blood sugar levels, including vegetables like onions. "Keep sugar, fat and salt to a minimum," the health service recommends.

If you have any health concerns, it's always best to consult with your local GP.