Whether organic foods offer significant health benefits has been hotly debated, but a new study provides fresh information that may change people’s minds about going organic.
The study, published in the British Journal of Nutrition, found that foods grown using organic methods have definite advantages over conventionally-grown foods. Not only do organic foods contain more nutrients and antioxidants, but they have much lower residues of pesticides.
A team of researchers at Newcastle University in England and around the world analyzed the results of 343 previously-published, peer-reviewed studies that compared organic and conventionally-grown fruits, vegetables, and grains. Most of the studies looked at crops grown in the same locale and on similar soils, reducing the possibility of factors that could lead to differences in nutritional values.
It appears that the way crops are produced does affect their nutritional content. Crops grown in the conventional manner are exposed to more synthetic nitrogen, which causes them to produce more sugar and starches at the expense of other nutrients and phytochemicals in the harvested plant.Avoiding exposure to pesticides is one of the primary reasons people choose organically grown food, and the study found that conventional foods were three to four times more likely to contain pesticide residues than organic foods.ADVERTISEMENT
The findings contradict those of a study published earlier this year.
Organic foods are grown with no synthetic pesticides. They produce concentrations of antioxidants, including more phenols and polyphenols, that are 18 to 69 percent higher than those of conventionally-grown produce. These compounds serve as natural pesticides and protection against disease in plants; they also help prevent heart disease, stroke, and some forms of cancer.
This increase in antioxidants means that people eating organically-grown fruits, vegetables, and grains get from 20 to 40 percent more antioxidants just by eating their normal diet. It's like eating two extra portions of fruits and vegetables per day, the researchers suggest.
Avoiding exposure to pesticides is another reason people choose organically grown food, and the study found that conventional foods were three to four times more likely to contain pesticide residues than organic foods, but that’s not to say that organic foods were pesticide-free. Pesticide residues were also present on organic crops, but the levels were 10 to 100 times lower.
An unexpected finding was the amount of cadmium, a heavy metal, found in conventionally-grown crops. They had about twice the amount of cadmium as organic crops, probably because some of the fertilizers used in conventional farming made cadmium more available to the plants.
So does this study settle the question about the superiority of organic foods? Only time will tell.
Despite the controversy — and despite their higher price tag — sales of organic food have grown continuously since national standards for organic production and processing were established in 2002, reaching $32 billion in 2013. It is expected that the US organic food market will increase 14 percent by the year 2018.