Nova Scotia

Why it may take more than an apple a day to keep the doctor away

New research out of Nova Scotia's Annapolis Valley shows today's cultivated apples are far heavier and sweeter than their ancestors, but they don't have nearly as many antioxidants.

Quest to breed sweeter apple may have come with surprising side effect, says researcher

Sean Myles is an associate professor at Dalhousie University's agriculture faculty. He says understanding how apples have changed over the years is important to improving cultivation in future. (Submitted by Sean Myles)

New research out of Nova Scotia's Annapolis Valley shows today's cultivated apples are far heavier and sweeter than their ancestors, but they aren't as good for you.

Using Canada's Apple Biodiversity Collection, an orchard that houses more than 1,000 apple varieties in the valley, researchers measured different traits, including flowering time, harvest date and size.

"We can kind of see evolution in action and observe," says Sean Myles, an associate professor with Dalhousie University's agriculture faculty.

"What are the differences between the apples that our ancestors used to enjoy a thousand years ago and the apples that we enjoy today?"

Some of the key findings are that today's cultivated apples are 3.6 times heavier and 43 per cent less acidic than wild apples.

Myles said the biggest finding is the level of phenolics (bitterness) in the apples. It is this trait that plays a role in the antioxidant content of an apple.

He said a sign of an apple with high phenolic content is one that browns quickly when it is cut open.

Why today's apples have less antioxidants

Myles, who can't eat apples because of an allergy, said breeders have tried to improve apples in the last couple hundred years by making crosses. He said it's possible that in making crosses to make them brown less, this has resulted in apples with lower phenolic levels, which has meant reduced antioxidants.

"It's also possible that we've been selecting against that bitterness, so in the search for the big, gigantic sugar bomb apples that a lot of people enjoy, we sort of selected out that bitterness by selecting for apples that are lower in phenolic content," said Myles.

He said it's not uncommon to see a threefold reduction in phenols in apples over the last 200 years.

"I think the new saying should be, like, you know, two apples a day will keep the doctor away," said Myles, who added that apples have nutritional benefits other than antioxidants.

Myles is shown at the orchard that houses Canada's Apple Biodiversity Collection. Besides the modern apples you'd find at a grocery store, the orchard has trees containing the ancestral species of the apple: Malus sieversii. (Submitted by Sean Myles)

He said it's important to know how apples have changed over time in order to improve apple production in future. The biodiversity collection can help with that.

If there's a move toward crossing apples to have higher antioxidant levels at the expense of sweetness, that shouldn't necessarily be viewed as a negative, he said.

"There's no reason to believe that these things need to be necessarily tradeoffs with each other, as you can have an extraordinarily high-acid apple as long as it's really well balanced with the sugar and the other components," said Myles.