They were the days before modern agriculture took over. When life was simpler. And is it possible the produce was better for us?

In 1951, Canada began analyzing the vitamin and mineral levels in fruits and vegetables. We compared those 1951 findings to the most recent government nutrient analysis to see if anything had changed.

Of the 25 fruits and vegetables we compared, many appeared to lose their nutritional value. Here are some examples:

• Broccoli lost 62 per cent of its calcium, which is essential for building healthy bones and teeth; 
•  Potatoes lost virtually all their vitamin A content, which is important for eyesight; An apple has lost nearly half of its iron, a component of healthy blood;
• Only one trace mineral, niacin, increased in all the produce.

In all, the three most important nutrients dropped in the majority of fruits and vegetables tested:

• 68 per cent lost vitamin A content;
• 76 per cent dropped in iron content;
• and 80 per cent lost calcium content.

Phil Warman, a professor of soil science at the Nova Scotia Agricultural College, examined CTV's data. He agreed that it appeared time has wrought changes.

"The chart implies that there has been quite a change in the last 50 years in the nutritional content of many fruits and vegetables," Warman said.

Comparing nutrient values over 50 years isn't the most scientific way to do this type of analysis. But he agrees it is the only data available, and it does suggest a drop in some nutrients.

Warman cautioned that scientists first need to confirm our findings, but he believes nutrition has never been a top priority for fruit growers.

"My guess is that we've changed varieties quite dramatically in the last 50 years," Warman said. "We've bred for certain characteristics. Not that we've bred out nutritional qualities, but no one has put the emphasis there."

That's largely because of consumer demand – we want our fruit shiny, our vegetables colourful. "The consumer wants something that looks good," Warman said. "They want something that handles well, and the wholesaler wants something that stores well and can be transported."

That demand has led to growers selecting varieties of foods that grow bigger faster. They also choose plant varieties that resist pests, and that produce consistently attractive fruits and vegetables.

Weight over content

Stuart Hill, with the School of Social Ecology at the University of Western Sydney in Australia, agrees that such considerations are major factors in what farmers choose to grow.

"As long as we reward growers primarily for weight of produce, they will naturally make all decisions to maximize weight," Hill told CTV News. "And the easiest way for plant breeders to increase yield is to increase the water content of produce -- thereby diluting the nutrient content."

"This is why early tomatoes contained 50 mg of vitamin C per gram, whereas modern cultivars commonly contain 5 mg -- a 10 times dilution," he added.

Some others suggest that modern farming techniques have stripped minerals from the soil. Minerals are micronutrients that man-made fertilizers can't replace, since they're based solely on nitrogen phosphorus, and potassium.

Soil scientists disagree with this thesis, and say modern farming techniques have generated more produce at cheaper prices, making fruits and vegetables available more readily across North America. This offsets any potential decline in nutrient content.

Still, the comparative data deserve a closer look, because they may hint at a previously uncovered trend in food growing.

"These data do raise the question of whether we are changing something in our production practices or breeding practices that should be examined," says Beverly Hale, a professor of Land Resource Science at the University of Guelph.

Dr. Khursheed Jeejeebhoy, a professor of nutritional sciences at the University of Toronto, believes the drops in nutrient contents are so low, they probably wouldn't affect an individual's overall health. And there are no signs of increasing nutrient deficiencies among Canadians.

"My view is that there is nothing to worry about," Jeejeebhoy said, "because the sources which are really rich in recommended nutrients are still quite rich in what they are supposed to have."

Indeed, the CTV/Globe analysis showed that grapes gained vitamin C content, as did red peppers and carrots. Carrots, a major source of vitamin A, saw levels of this vitamin rise by 135 per cent.

Some agricultural specialists suggest these crops rose in certain vitamins because growers are breeding for a deep rich colour, which often contributes to a rise in certain vitamins.

Other scientists question whether the decline in nutrients is real.

"Did they really go down," wonders Professor Len Piche of the University of Western Ontario, "or did we just have better techniques for analyzing those nutrients?"

Piche believes it's an important question because studies suggest half of Canadians don't eat the recommended five to 10 servings of fruits and vegetables each day. And if we are missing out on important nutrients, it could cause widespread health problems down the road.

"If there is a problem," Piche said, "I'm confident the government will take it seriously and do the necessary research and address it on behalf of all Canadians."

Global trends

Research in Britain suggested there was a decline in nutrient content there as well.

The trend worries nutritional scientist Virginia Worthington, who works out of Washington D.C., because research is constantly linking vitamins and minerals to disease prevention. For example, low levels of folic acid may contribute to heart disease.

"Vitamins and minerals interact. For example, vitamin C helps vitamin E to work. And vitamin E helps vitamin A. And vitamin C helps the body absorb more iron," Worthington said. "We don't know what the net effect could be. It could be that all these small drops in nutrients could have a much bigger effect when you take the interactions into account."

It also begs the question: if breeders can select varieties for size and yield, why can't they also grow more nutrient-rich fruits and vegetables?

Warman says it certainly is something that could be done.

"It seems to me to be a relatively easy thing to do -- to look at the varieties we have today and select those higher in nutritional values and let people know," Warman suggests. "As a consumer I would certainly pick something that has a higher nutritional value."

But Cathy Bakker, a graduate student at the University of Guelph, says breeders aren't interested in nutrition content – nor are consumers.

Neverthless, it's a connection she appears to have made. Bakker learned she could grow broccoli with higher levels of vitamin C, by using less nitrogen fertilizer.

"If you can grow broccoli that looks just as good with less nitrogen and more vitamin C that would be fantastic," Bakker said. "And I think there would be benefits for the consumers and benefits for the growers."