Adding fuel to the debates over the merits of organic food, a comprehensive review of earlier studies found substantially higher levels of antioxidants and lower levels of pesticides in organic fruits, vegetables and grains compared with conventionally grown produce.

“It shows very clearly how you grow your food has an impact,” said Carlo Leifert, a professor of ecological agriculture at Newcastle University in England, who led the research. “If you buy organic fruits and vegetables, you can be sure you have, on average, a higher amount of antioxidants at the same calorie level.”

However, the full findings, to be published next week in the British Journal of Nutrition, stop short of claiming that eating organic produce will lead to better health.

“We are not making health claims based on this study, because we can’t,” Dr. Leifert said. The study, he said, is insufficient “to say organic food is definitely healthier for you, and it doesn’t tell you anything about how much of a health impact switching to organic food could have.”