Organic food no more nutritious, study says | South China Morning Post
Organic produce and meat typically isn't any better for you than
conventional food when it comes to vitamin and nutrient content,
although it does generally reduce exposure to pesticides and
antibiotic-resistant bacteria, according to a US study.
"People choose to buy organic foods for many different reasons. One of
them is perceived health benefits," said Crystal Smith-Spangler, who
led a team of researchers from Stanford University and the Veterans
Affairs Palo Alto Health Care in California.
"Our patients, our families ask about, 'Well, are there health reasons
to choose organic food in terms of nutritional content or human health
outcomes?'"
She and her colleagues reviewed more than 200 studies that compared
either the health of people who ate organic or conventional foods or,
more commonly, nutrient and contaminant levels in the foods
themselves.
The foods included organic and non-organic fruits, vegetables, grains,
meat, poultry eggs and milk.
According to US Department of Agriculture standards, organic farms
have to avoid the use of synthetic pesticides and fertilisers,
hormones and antibiotics. Organic livestock must also have access to
pastures during grazing season.
Many of the studies used, though, didn't specify their standards for
what constituted "organic" food, which can cost as much as twice what
conventional food costs, the researchers wrote in the Annals of
Internal Medicine.
Smith-Spangler and her colleagues found there was no difference in the
amount of vitamins in plant or animal products produced organically
and conventionally – and the only nutrient difference was slightly
more phosphorous in the organic products.
Organic milk and chicken may also contain more omega-3 fatty acids,
but that was based on only a few studies.
More than one third of conventional produce had detectable pesticide
residues, compared with 7 per cent of organic produce samples. Organic
pork and chicken were 33 per cent less likely to carry bacteria
resistant to three or more antibiotics than conventionally produced
meat.
Smith-Spangler said it was uncommon for either organic or conventional
foods to exceed the allowable limits for pesticides, so it was not
clear whether a difference in residues would have an effect on health.
But others said more research is needed to fully explore the potential
health and safety differences between organic and conventional foods,
and it was premature to say organic foods aren't any healthier than
non-organic versions.
"Right now I think it's all based on anecdotal evidence," said
Chensheng Lu, who studies environmental health and exposure at the
Harvard School of Public Health.
