Organic food lovers may insist their produce, meat and milk are fresher, tastier, and better for the environment. But a new study suggests they aren't any more nutritious.

The study, commissioned by the Food Standards Agency (FSA), an independent department set up by the British government, found no significant differences in the nutrition content of organic food compared with conventionally made food.

The study was a systematic review, or meta-analysis, of dozens of studies on organic foods, published over the past 50 years, and was conducted by a team of researchers from the London School of Hygiene and Tropical Medicine.

The researchers say they found more than 52,000 articles on organic food, and narrowed them down to 162 studies analyzing the nutrient content of organic versus conventionally produced foods.

They found no evidence of a difference between organic and conventional crops in terms of their content of a number of nutrients, including:

• vitamin C
• magnesium
• calcium
• potassium
• zinc
• copper

Conventional crops were found to contain more nitrogen than organics, and organic crops had higher phosphorus and acidity content than conventional crops.

Among animal-source foods such as meat and milk, the researchers found no evidence of differences in nutrient content.

When nutritional differences were found, they were so small as to be insignificant, reported the paper's principal author, Dr. Alan Dangour, of the LSHTM's Nutrition and Public Health Intervention Research Unit.

"A small number of differences in nutrient content were found to exist between organically and conventionally produced crops and livestock, but these are unlikely to be of any public health relevance.

"Our review indicates that there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority."

The findings are published in the American Journal of Clinical Nutrition.

Gill Fine, FSA Director of Consumer Choice and Dietary Health, says the study does not mean that people should not eat organic food. "What it shows is that there is little, if any, nutritional difference between organic and conventionally produced food and that there is no evidence of additional health benefits from eating organic food."

"The Agency supports consumer choice and is neither pro nor anti organic food," Fine added.

The review did not look at look at pesticide and herbicide residues in organic and conventional food, nor did it seek to compare the taste of the products.

The FSA says it recognizes that there are many reasons why people choose to eat organic, including concerns about animal welfare on conventional farms and feedlots, or environmental concerns.

At least one group is dismissing the study. The Soil association, a British charity campaigning for organic food and farming, says the review excluded many worthy studies that may have led the researchers to different conclusions.

They also insist that the differences in nutrition that were identified were not insignificant, noting organic foods had higher levels of protein, beta-carotene, and flavonoids.