Nearly six in 10 American Protestants oppose genetic engineering of food when it is described as moving genes between different species.
Just more than half of Roman Catholics also worry about this human intervention in genetics, while Jews in the United States support the scientific innovation by 55 percent, according to a survey released Thursday.
The poll, conducted by the University of Virginia's Pew Initiative on Food and Biotechnology, also found mixed attitudes in the religious population -- while it worried about gene tampering, it equally believed "man has been empowered by God to use science to improve life."
Biotechnology can be used to give such crops as corn and rice resistance to insects or disease, or to produce larger fish. It has been called a solution to hunger by some, but others say it is science "playing God" to make "Frankenfood" with health risks.
"The debate over this technology has largely centered on the science issues, but there is clearly an ethical side to it as well that is shaping American hearts and minds," said Michael Rodemeyer, executive director of the university's project.
The poll surveyed 1,117 American adults this month and was conducted by Zogby International. The margin of error was five points for Protestants, six points for Catholics, seven points for Jews and nine points for Muslims.
The survey found that on the question of people being "empowered by God" to use science, 62 percent of Jews agreed as did 61 percent of Muslims, 55 percent of Catholics and 54 percent of Protestants.
Respondents identifying themselves as "born again," or evangelical, Protestants opposed genetic engineering in food by 62 percent. Among all Protestants, 57 percent were opposed to technology that can "move genes from one species of organism and put them into another" organism, a process that may mix plant and animal genes.
Women were more likely than men to oppose biotechnology, whether they worked inside or outside the home, the survey said.
The survey noted that "playing God" was a common slogan in the biotechnology debate, so it asked Americans what that phrase meant to them.
The most common interpretation was that "playing God" meant that a few in science or business would have power to control the technology and decide who gets the benefits.
Other options, with mixed emphasis given by each religious group, were a lack of humility, a loss of religious stewardship of creation, and undermining the purity of organisms.
A final choice was that "playing God" meant scientists had set up a "false priesthood." This was not a popular interpretation, but was more popular with Muslims (18 percent) than with Christians (12 percent) or Jews (7 percent).
In a statement with the survey, University of Pennsylvania bioethics professor David Magnus described the opposition to genetically modified foods as widespread.
But he said it may arise not from a risk-benefit concern, but over the "playing God" worry, which Britain's Prince Charles used in stirring Europe's protest against biotechnology.
Public worry about the technology stems from a mixture of this intuitive "wisdom" and lack of knowledge about the science, Mr. Magnus said.
"Hope remains that public discussion of values in these debates can allow for the appropriate progress of science and technology." he said.