Swedes eat more than twice as much vegetables today compared to 30 years ago, according to the Swedish Board of Agriculture, but the most the cheaper, most popular varieties often contain lower amounts of the naturally occurring chemical compounds called phytochemicals.
Phytochemicals are kind of the plant equivalent of our immune system and help plants stay healthy. These health benefits are then passed on to us when we consume the plants or the vegetables. One example of such a compound is lycopene, which is found in tomatoes and is what makes tomatoes red.
Today, typical tomatoes sold in the produce section of a Swedish grocery store could contain less than half as much lycopene as cocktail tomatoes or smaller organic tomatoes, according to Swedish Radio News.
Kimmo Rumpunen, a researcher and plant breeder at the Swedish University of Agricultural Studies, confirms that most of the fast-growing vegetables contain less phytochemicals and says that many vegetables today also contain lower quantities of these nutrients than they used to a few decades ago.
"It's true that some cultivars have become sort of diluted today because we add more water and fertilizer, and that may also generate lower quantities of these nutrients," says Rumpunen.
Sharon MacGregor, one of the managers at the agriculture group Monsanto, tells Swedish Radio News that companies are often forced to choose between developing produce that will give a high yield or produce that is more nutritious.
"If a variety has some additional characteristics such as nutrition then perhaps that might be offset by a lower yield or that it is more difficult to grow, and that might lead to that customers don't always get the most nutritious variety," MacGregor says.
Kimmo Rumpunen, however, says that the main problem is not that we are not getting the most nutritious varieties of fruits or vegetables, but that we are not consuming enough of either.
"We should eat about 500 grams of fruits and vegetables each day and consume about 350 grams a day, so we should focus more on increasing our consumption rather than just breeding more nutritious foods," says Rumpunen.
Rumpunen says that one tip if you want to pick out the most nutritious produce is to look for the fruit or vegetable with the deepest colour.
"Some of these compounds are associated with colour, so if you look for fruit with an intense or deep colour you will most likely get a fruit with high levels of phytochemicals. This is certainly true when it comes to red tomatoes, orange carrots and blue bilberries and blackcurrant," says Rumpunen.