A long-awaited final report from the Food and Drug Administration concludes that foods from healthy cloned animals and their offspring are as safe as those from ordinary animals, effectively removing the last U.S. regulatory barrier to the marketing of meat and milk from cloned cattle, pigs and goats.
The 968-page "final risk assessment," not yet released but obtained by The Washington Post, finds no evidence to support opponents' concerns that food from clones may harbor hidden risks.
But, recognizing that a majority of consumers are wary of food from clones -- and that cloning could undermine the wholesome image of American milk and meat -- the agency report includes hundreds of pages of raw data so that others can see how it came to its conclusions.
The report also acknowledges that human health concerns are not the only issues raised by the emergence of cloned farm animals.
"Moral, religious and ethical concerns . . . have been raised," the agency notes in a document accompanying the report. But the risk assessment is "strictly a science-based evaluation," it reports, because the agency is not authorized by law to consider those issues.
In practice, it will be years before foods from clones make their way to store shelves in appreciable quantities, in part because the clones themselves are too valuable to slaughter or milk. Instead, the pricey animals -- replicas of some of the finest farm animals ever born -- will be used primarily as breeding stock to create what proponents say will be a new generation of superior farm animals.
When food from those animals hits the market, the public may yet have its say. FDA officials have said they do not expect to require food from clones to be labeled as such, but they may allow foods from ordinary animals to be labeled as not from clones.
Opponents express dismay
Opponents of the approval, including some concerned about the welfare of the clones themselves, expressed dismay upon learning about the FDA's intentions.
Joseph Mendelson, legal director of the Center for Food Safety, a Washington advocacy group that petitioned FDA to restrict the sale of food from clones, said his group is considering legal action.
"One of the amazing things about this," Mendelson said, "is that at a time when we have a readily acknowledged crisis in our food safety system, the FDA is spending its resources and energy and political capital on releasing a safety assessment for something that no one but a handful of companies wants."
Others countered that public opinion and politics should play no bigger role in the decision on clones than it should in the approval of a drug or a contraceptive.
"In fact, cloned animals have been studied much more than naturally produced animals," said Cindy Tian, who has analyzed milk and meat from clones at the University of Connecticut. "We have more data on them than for any other animal that we eat."
Release of the analysis was slowed for years by several forces, including the dairy industry, concerned about the potential impact on exports of U.S. whey solids, foreign sales of which are growing for use as a protein supplement.
In the past month, as an announcement neared, members of Congress, led by Sen. Barbara A. Mikulski (D-Md.), sought to delay approval through legislation.
Trade-related agencies including the Foreign Agricultural Service and the Office of the U.S. Trade Representative, which for years have struggled to get countries to accept U.S. gene-altered crops, also raised red flags.
A final blitz of meetings with FDA officials last week brought grudging acquiescence, insiders said. And it is possible, sources said, that even after the risk analysis is released, there will be calls for farmers to voluntarily refrain from selling products from clones until the trade issues can be resolved.
Challenges to assessing risk
To create its final risk assessment, the FDA gathered data on nearly all of the more than 600 U.S. farm-animal clones produced and hundreds of their offspring, as well as many from overseas. But it faced challenges in the process.
Those animals were made by scientists scattered among various universities and companies using different methods that in many cases were difficult to compare.
Moreover, many of those animals were not just clones but also had genes added to them for projects unrelated to food production.
In those cases, it was difficult for FDA reviewers to decide whether any problems were caused by those animals being clones or by their particular genetic alterations. (The FDA has said it will not approve gene-altered animals as food without additional tests for safety.)
Finally, there was the overarching problem of deciding which measures would best predict whether the food was safe. Most puzzling was whether to take into account the subtle alterations in gene activity, called epigenetic changes, that are common in clones as a result of having just one parent.
In the end, facing the reality that epigenetics have never been a factor in assessing the wholesomeness of food, agency scientists decided to use the same simple but effective standard used by farmers since the dawn of agriculture: If a farm animal appears in all respects to be healthy, then presume that food from that animal is safe to eat.
Scientists inside and outside the agency studied thousands of pages of veterinary reports describing weight, size, organ function, blood characteristics and other measures of clones and offspring. For cattle -- the animals for which the most data exist -- full health assessments were conducted for each of five different stages of the animals' life: fetal, newborn, juvenile, sexually mature, and old.
Newborn cattle often unhealthy
They concluded that newborn cattle are often unhealthy, probably because of epigenetic changes. They are usually extremely overweight and have respiratory, gastrointestinal and immune system problems. (Cloned pigs and goats are mostly healthy from the start.)
But those problems typically disappear within the first weeks or months of life as the animals somehow compensate. And since sick clones would not pass muster with food inspectors any more than sick conventional animals would, they pose no concern, the report says.
Studies of cloned farm animal behavior, including mating behavior, also showed them to be the same as ordinary animals. (One exception: On one farm, clones showed a peculiar preference not for the surrogate mother that gave birth to them but to the animal from which they were cloned.)
Scientists also looked at nutrient levels in meat and milk from a few dozen cattle and pig clones and hundreds of their progeny, and compared them with values from conventional animals. They measured vitamins A, C, B1, B2, B6 and B12 as well as niacin, pantothenic acid, calcium, iron, phosphorous, zinc, 12 kinds of fatty acids, cholesterol, fat, protein, amino acids and carbohydrates including lactose.
For almost every measure, the values were virtually the same. The few that differed were still within the range considered normal.
Separately, the agency looked at studies in which milk and meat from clones were fed to animals for up to 3 1/2 months. There was no evidence of health effects, allergic reactions or behavioral changes.
In the end, the agency concluded that it did not have enough information to rule on the safety of food from cloned sheep. It also decided that edible products from newborn cattle clones, which often are metabolically unstable, "may pose some very limited human food consumption risk."
But it found no safety hazards for meat from healthy cattle clones more than a few weeks old, milk from cloned cows, or meat from cloned pigs or goats of any age.
"Food from cattle, swine, and goat clones is as safe to eat as that from their more conventionally-bred counterparts," the FDA risk assessment concludes.
Looking ahead, the report says FDA is collaborating with veterinary and scientific organizations, notably the International Embryo Transfer Society, to create a database on the health of new clones, which will help the agency track the field as the industry grows.
Working with the FDA, the International Embryo Transfer Society is also creating the first manual of animal care standards for clones, to be made available to farmers and the public later this year.