WASHINGTON — Eating organic food, which costs more, may be better for the environment and the palate, but has little effect on the health of individuals, according to a new study.
Stanford University doctors dug through reams of research and concluded that there is little evidence that going organic is healthier, citing only a few differences involving pesticides and antibiotics.
Eating organic fruits and vegetables can lower exposure to pesticides, including for children — but the amount measured from conventionally grown produce was within safety limits, the researchers reported Monday in the journal Annals of Internal Medicine.
Nor did the organic foods prove more nutritious.
‘‘I was absolutely surprised,’’ said Dr. Dena Bravata, a senior research affiliate at Stanford and longtime internist who began the analysis because so many of her patients asked if they should switch.
‘‘There are many reasons why someone might choose organic foods over conventional foods,’’ from environmental concerns to taste preferences, Bravata stressed. But when it comes to individual health, ‘‘there isn’t much difference.’’
Her team did find a notable difference with antibiotic-resistant germs, a public health concern because they are harder to treat if they cause food poisoning.
Specialists long have said that organic or not, the chances of bacterial contamination of food are the same, and Monday’s analysis agreed. But when bacteria did lurk in chicken or pork, germs in the nonorganic meats had a 33 percent higher risk of being resistant to multiple antibiotics, the new study said.
That finding comes amid debate over feeding animals antibiotics, not because they are sick but to fatten them up. Farmers say it’s necessary to meet demand for cheap meat. Public health advocates say it’s one contributor to the nation’s growing problem with increasingly hard-to-treat germs.
Caroline Smith DeWaal, food safety director at the Center for Science in the Public Interest, counted 24 outbreaks linked to multidrug-resistant germs in food between 2000 and 2010.
The government has begun steps to curb the nonmedical use of antibiotics on the farm.
Organic foods account for 4.2 percent of retail food sales, according to the US Department of Agriculture. It certifies products as organic if they meet certain requirements including being produced without synthetic pesticides or fertilizers, or routine use of antibiotics or growth hormones.
Consumers can pay a lot more for some organic products but demand is rising: Organic foods accounted for $31.4 billion sales last year, according to a recent Obama administration report. that is up from $3.6 billion in 1997.
The Stanford team combed through thousands of studies to analyze the 237 that most rigorously compared organic and conventional foods. Bravata was dismayed that just 17 compared how people fared eating either diet while the rest investigated properties of the foods themselves.
Organic produce had a 30 percent lower risk of containing detectable pesticide levels. In two studies of children, urine testing showed lower pesticide levels in those on organic diets.