To eat organic or not to eat organic — that is the question

February 25, 2016

It’s been an ongoing debate: Is organic food actually more nutritious than its traditionally grown counterpart? A few recently published studies may hold the answer as scientists have discovered evidence that organic production can boost key nutrients in foods and are part of a growing body of evidence documenting how farming methods can influence the nutritional content of foods.

Published this week in the British Journal of Nutrition, the study found that organic dairy and meat contains about 50% more omega-3 fatty acids than the non-organic versions.

A recent article explains that this is a result of animals foraging on grasses rich in omega-3s, which then end up in organic dairy and meats. These findings are based on data pooled from more than 200 studies, and previous research in the U.S. has pointed to similar benefits as well.

"Omega-3s are linked to reductions in cardiovascular disease, improved neurological development and function, and better immune function… So we think it's important for nutrition," study co-author Chris Seal, said in the article. That said, he added that organic meat and dairy contain far lower concentrations of omega-3s than what are found in fish such as salmon.

Another large meta-analysis published in 2014, also in the British Journal of Nutrition, found that organic crops — ranging from carrots and broccoli to apples and blueberries — have substantially higher concentrations of a range of antioxidants and other potentially beneficial compounds. That review included data from more than 300 studies.

The article states that organic crops had about 50% more anthocyanins and flavonols compared with conventional crops. Anthocyanins are compounds that give fruits and vegetables, such as blueberries, their blue, purple and red hues.

Consumption of these compounds is linked to a variety of benefits, including anti-inflammatory effects. Flavonol compounds — found widely in fruits and vegetables — have also been shown to protect cells from damage, which can help fend off disease.

So, what explains these boosts in antioxidant and other beneficial compounds in organic crops? As Seal explains, it comes down to stress.

Organic crops tend to be exposed to higher levels of stress — including insect attacks. In response, they form compounds to help combat the stress. For example, if a carrot fly lands on a carrot and starts to chew on it, what options does the plant have?

If it's a conventionally grown carrot, a pesticide can be applied to repel the pest. But in organic agriculture, that carrot has to fend for itself a bit more. So, the carrot produces compounds known as polyacetylenes, which taste bitter to the carrot fly. These polyacetylene compounds may help drive the fly away — and research in animals suggests, polyacetylene compounds may play a role in reducing inflammation and cancer risk in humans as well.

Another difference between organic and conventional crops is the way plants get nitrogen, the article explains. Conventional crops are given steady doses of nitrogen from synthetic fertilizer. In organic systems, which rely heavily on crop rotation and composting, there's typically less nitrogen available.

As a result, organic crops tend to grow more slowly, and produce more of what scientists call secondary plant metabolites. These compounds also may be health-promoting when we eat them. For example, a 2008 study of tomatoes conducted at the University of California found that organic tomatoes have almost double the concentration of a beneficial flavonoid known as quercetin, compared with conventional tomatoes grown on an adjacent field.

"Taken together, the studies on crops, meat and milk suggest that a switch to organic fruit, vegetables, meat and dairy products would provide significantly higher amounts of dietary antioxidants and omega-3 fatty acids," Carlo Leifert, a professor of agriculture at Newcastle wrote in a release about the new papers.

However, plenty of skeptics remain.

"Such small changes are unlikely to represent any nutritional or health benefit," Ian Givens, a professor of nutrition at the University of Reading, said in a statement on the new findings. Givens also points out that switching from conventional milk to organic milk would increase omega-3 intake by only very small margins.

In addition, an analysis by researchers at Stanford University published several years ago concluded there was no good evidence that organic fruits and vegetables were more nutritious overall.

Given the big picture, several of experts say that, from a health perspective, what you eat matters more than whether you choose organic or conventional. At a time when most Americans don't eat the recommended servings of fruits and vegetables, the more important step may be to add them to your diet — no matter what farming methods were used to grow them.

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Category: Food Safety