An apple a day can keep high blood pressure and hypertension away, as long as you don't remove its peel, scientists say.

Scientists in Canada have found that it is more effective than other "superfoods" including green tea and blueberries as a source of antioxidants and chemical compounds called flavonoids that combat the potentially life-threatening condition.

For the outer layer contains up to six times the amount of chemical ingredients that can combat potentially life threatening high blood pressure.

Apples have long been known as natural source of antioxidants and chemical compounds called flavanoids, all of which are good for the heart, the 'Telegraph' reported.

But peeling apples first before eating means missing out on most of the health benefits, said researchers from Nova Scotia in Canada.

Scientists tested the peel and the fleshy fruit of apples separately on samples of an enzyme called ACE which is known to cause hypertension and high blood pressure in humans.

The peel was significantly much more effective in inhibiting ACE in living organisms, the researchers from Nova Scotia Agricultural College told the journal Food Chemistry.

Researchers in Nova Scotia tested the peel and the fleshy fruit of apples separately.

The peel was found to be up to six times more effective, according to the team's results in the journal Food Chemistry.

The researchers from Nova Scotia Agricultural College said: "Apples are one of the most popular and frequently consumed fruits in the world."

"Apple peel is a rich source of flavonoids which provide numerous health benefits apple peel flavonoids inhibited the ACE, an enzyme associated with hypertension" they said.