News & Events
Lester M. Crawford, D.V.M., Ph.D. - Univ. of Massachusetts
This text contains Dr. Crawfords prepared remarks. It should be used with the understanding that some material may have been added or deleted during actual delivery.
15th Endersen Lecture
Food Science Dept., U. of Massachusetts
"Trends, opportunities and hazards of future food research"
Lester M. Crawford, D.V.M., Ph.D.
Acting Commissioner of the FDA
March 3, 2004
My topic today is the future of food science, a subject that has never inspired more imagination and creativity, or held greater promise of benefits to humanity -- as well as professional fulfillment -- than it does at present. And yet, as a scientist, and a public health official I cannot start discussing the challenges and opportunities of food research without raising one of the most sobering medical issues of the present time.
I am referring to the epidemic of overweight and obesity, which affects 64 percent of adult Americans, and 15 percent of our children and teenagers. The emergence of this phenomenon in the last two to three decades is one of ironies of modern food technology: on the one hand, it has made possible a horn of plenty beyond the wildest dreams of our ancestors. On the other, combined with insufficient exercise, this affordable abundance has put millions of Americans at a greater risk for diabetes, coronary disease and a host of other serious and life-threatening diseases.
The resulting U.S. healthcare costs are estimated at $117 billion a year. And the problem is not limited to the United States, although we seem to be at the top of the global body mass statistics. According to a recent report by the World Health Organization, 300 million people worldwide are obese and 750 million are overweight, including 22 million children under the age of 5.
Except for the potential threat of bioterrorism, our agency, the Food and Drug Administration, is confronting no public health hazard more urgent than this epidemic. And since the search for answers to this serious problem is a challenge for all of us engaged in food science, it might be useful if I outlined some of the key questions that we at the FDA are convinced need to be addressed if this epidemic is to be brought under control.
You may recall that the World Health Organization report placed the causes of obesity pretty much at the doors of the food and advertising industries. At the FDA, where we are currently considering a variety of measures for confronting obesity, we don't quite see it that way. While both industries have a role to play, we believe that the key factor is individual dietary decisions, and that one of our needs is for a research that would guide our agency in taking effective measures that would encourage consumers to eat healthier meals.
We need to know, for example, what are consumer attitudes toward weight management, and toward food labeling on packages and in restaurants. Would consumers respond to a food label that would inform them about the caloric content in bold print, and on the front of the package? What would be the consumer reaction to similar information on the menu of restaurants? One of the many intriguing questions that call for well-researched answers is whether our agency should consider weight gain as an adverse side effect when evaluating the safety and effectiveness of regulated drugs, foods and dietary supplements. In other words, is weight gain an outcome suggesting that the product is not safe?
We also need to conduct a thorough evaluation of long-term health effects of weight gain, and consider if and how the results should be incorporated in our assessment of food safety. To give you one example: there is some evidence that certain infant formulas may adversely affect a child's ability to maintain healthy weight while growing up and as an adult. We need to develop and validate animal models measuring the effects of different formula compositions on the growth pattern of infants, and the potential for these growth patterns to affect long-term weight management.
A related issue requiring exploration is the so-called developmental imprinting hypothesis, which suggests that childhood obesity is, in part, the result of the mother's diet. According to this theory, the mother's poor nutrition or exposure to some toxic agent during the perinatal period can create in the fetus and neonate a dysfunctional metabolic pathway that, in the child's later years, can contribute to overweight or obesity.
There is also a great deal of work to be done in translating basic scientific research into information we can use in developing policies and programs for confronting obesity. For example, how can we use emerging genomics, proteomics and metabolomics technologies to identify whether, and how, FDA-regulated products can modify risk factors and susceptibilities for weight gain, obesity, and co-morbidities?
These are just a few examples of the research needs and opportunities that I hope your and other great universities will find of interest and worthy of exploration. But despite the great current need for obesity-associated research, it is my conviction that in the long run, food-associated scientific inquiry will not deal with questions on how to make consumers eat less, but how to help them eat better, and still more affordably than today. And there is no doubt that the main tool of this search will be the manipulation of plant and animal rDNA, a revolutionary technology that is my principal topic today, and is already changing the ways food has been grown for millenia.
In our country, this trend has been evident since the 1980s, when industrial and academic scientists began using biotechnology to create crops that increase the yield and reduce the need for pesticides and herbicides. This research, which has been mainly focused on corn, cotton and soybeans -- but also included potatoes, squash, and papaya -- has so far resulted in the introduction of more than 50 biotech food products that have been reviewed by the FDA for safety. In United States, these products have been readily accepted by the agricultural industry and the public.
In 2003, for example, 81% of U.S.-grown soybeans, 73% of cotton, and 40% of corn were bioengineered, primarily to ward off pests or tolerate weed-killing herbicides. The Grocery Manufacturers of America estimates that 70%-75% of all processed foods in our supermarkets -- including breads, cereal, frozen pizzas, hot dogs and sodas -- are likely to contain soybean or cottonseed oil, corn syrup, and other ingredients from genetically engineered plants.
And many more bioengineered, food-producing plants are in the R&D pipelines. Most of these innovations are designed to improve agricultural profits and productivity. For example, there are intensive efforts to develop herbicide-tolerant wheat, the last major U.S. crop that is yet to be genetically modified. There is research under way to produce a variety of coffee beans that would ripen simultaneously, so that the the entire harvest could be collected much more efficiently than now, when the beans ripen at different times, and have to be picked over the course of several weeks.
Another advanced project is the development of a new type of tomato that could be grown in salty soils and irrigated with brakish water. The bioengineered plants now in testing store the salt in their leaves, and the fruit's taste is not affected. Also in field trials is a transgenic sunflower resistant to white mold, which is serious problem in some areas. And as you may know, researchers at the University of Florida have already patented a method for producing grape vines that carry a silkworm gene to provide protection from Pierce's disease, a fatal bacterial disease that affects grapes and several other plants.
The latest trend in biotech food research, however, is the development of products that will bring benefits to consumers, because they will be healthier or better tasting than the conventional varieties. For example, there are several varieties of tomatoes under investigation that have very high levels of Lycopene, a Vitamin A-related cartenoid with strong anti-oxidant properties.
Another new product with high nutritional properties has been created by Swiss researchers who have inserted two genes from daffodil and one gene from a bacterial species into a rice plant. The resulting rice, which is primarily intended for cultivation in such countries as India and Pakistan, synthesizes beta-carotene, the precursor of Vitamin A. This substance help provide protection from vision impairment, diarrhea, respiratory diseases, and measles, which affect the populations of many underdeveloped countries. Field tests of these plants are expected within a year.
Transgenic research has focused also on improving the nutritional quality of canola, a major oilseed crop, by enhancing its Vitamin E content and modifying the balance of fatty acids. Coffee, which is a $40 billion business a year and, next to oil, the world's second largest-traded commodity, is also the subject of much research. For example, since scientists in Hawaii and Scotland identified the genes in coffee beans and tea leaves that trigger the production of caffeine, there has been research going on how to turn off these genes.
The goal is to grow coffee and tea that are naturally decaffeinated, and therefore better tasting than the existing varieties, which are produced with organic solvents. A similar technology has already succeeded in developing a tobacco plant that does not synthesize nicotine in the leaf. This variety is currently in field trials in Pennsylvania, and is expected to be used to manufacture nicotine-free cigarettes.
So far, I've talked about the benefits that genetically engineered plants can bring to food producers and consumers. But what about the risks? They have been of great concern to the FDA ever since the technology was in its infancy. The FDA is mandated to make sure that 80 percent of our food supply -- and that includes practically everything we eat, except for meat, poultry and some egg products -- is safe, wholesome, and truthfully labeled. Biotechnology-produced foodstuffs and animal feed are no exception -- they are held to the same standards of safety and nutritional value that apply to conventional foods.
And yet the Food, Drug and Cosmetic Act does not give FDA the authority to require the review and approval of food products, because in 1938, when this basic law was passed, genetic engineering did not exist, and the vast majority of conventional foods had been in use for centuries, and were generally recognized as safe.
The FDA can only take legal action if a food product does not meet the lawful standards. I should add at this point that this rule does not apply to genetically modified animals and plants that have been engineered to produce pharmaceutical materials. Under the law, these two transgenic types of products are regulated by the FDA as drugs, which means that the agency oversees their clinical trials; the sponsors have to show evidence that the products are safe and effective; and this evidence must be formally reviewed and approved by our agency. One such plant, which is already being evaluated, is a transgenic banana that contains inactivated viruses intended for use as vaccines against cholera, hepatitis B, and diarrhea.
Getting back to the plants bioengineered to produce food and feed: when industry began developing them in the late 1980s and early 1990s, the FDA addressed the technology in a scientific guidance, and established a process by which developers could consult with FDA's specialists on problems of safety testing. In 1992, FDA published a policy that strongly encouraged firms to submit to FDA, before a bioengineered product is marketed, evidence showing that it is as safe and nutritious as its conventional counterpart. The biotech industry, which wants to win public acceptance for the new foodstuffs, has readily complied.
Why does the FDA want to review these products? In the first place, to make sure that the new products do not present a risk to human health. The prime focus of interest has been to ensure that the bioengineered food is not an allergen, and that it can be digested like conventional food substances.
In general, bioengineered foods reviewed by FDA so far have been found to be no more likely to cause allergic reactions than conventional foods. Tests of several dozen bioengineered products have uncovered only one soybean variety that was allergenic, and it was never marketed.
Another question explored by the FDA's review is whether the consumption of the new products could generate antibiotic resistance. At several stages of the laboratory process, developers of transgenic crops use DNA that codes for resistance to certain antibiotics, and in some cases, this DNA becomes a permanent feature of the final product. This has triggered concerns that a transfer of a resistance gene from the transgenic food to micro-organisms in human stomach and intestines, or to bacteria that's ingested with food, could increase the number of pathogenic microorganisms that are resistant to antibiotics.
The spread of such microorganisms in clinical settings where antibiotics are used has been a serious concern to FDA ever since its review of the first marketed transgenic product -- Calgene's FlavrSavr tomato -- which had been developed using an antibiotic-resistant gene as a select marker. The FDA had to make sure that the ingestion of the raw tomato would not leave in the stomach small amounts of an enzyme product of the DNA that could inactivate an oral dose of an antibiotic. Tests ran at that time showed that this would not occur, but firms since then have taken steps to phase out the use of the antibiotic-resistant genes in transgenic plants.
Anther central question considered by FDA when reviewing a new transgenic plant is whether it contains important vitamins, minerals, nutrients, and other beneficial components of conventional crops. Damage to the environment is another perceived hazard of genetic manipulation of plants, and FDA recognizes its importance, but this is an aspect of the technology that's overseen by the Environmental Protection Agency and the U.S. Department of Agriculture, and therefore I will only say that there is no evidence so far to support the charges that biotechnology wreaks chaos in the environment.
This issue was most prominently raised four years ago, when it was charged that the pollen from an insect-resistant biotech corn kills the larvae of the Monarch butterflies. Laboratory tests then showed that the caterpillars were indeed susceptible to poisons used in certain bioengineered corn varieties to kill the European corn borer. There was a huge outcry by the international environmental-protection community, but on close examination it turned out that the involved toxic protein was being used -- and less and less so -- in fewer than 2% of the corn acreage in North America, and that the most common varieties of transgenic corn do not produce pollen that affects the caterpillars or the butterflies.
Another environmental hazard, the possibility that hybridization of transgenic crops with nearby weeds may transfer to the weeds such undesirable qualities as resistance to herbicides, is also not serious, at least in the case of corn and soybeans. These two most widely grown transgenic crops have in the United States no wild relatives with which to hybridize. But there are other environmental issues that need careful scrutiny. There is a wild relative of corn in Mexico, there are wild varieties of soybeans in China, and there are some concerns that transgenic proteins might leak from the plant into the soil, and adversely affecting nearby communities of beneficial micro-organisms.
Before I leave the subject of transgenic plants, I want to address two frequently asked questions. One of them is how well have worked the various protections that our government has put in place to avoid potential harm that could be caused by the introduction of transgenic plants.
As I've already mentioned, the FDA has evaluated more than 50 varieties of bioengineered crops, none of which has presented any public health risks. There has been only one incident that raised a very remote possibility of such a hazard. It was the accidental commingling in Nebraska of some stalks of transgenic corn with conventional soybeans. That corn was one of the new bioengineered plants that produce not food, but pharmaceutical material, and as such are regulated by the FDA as drugs, which means that the agency oversees their clinical trials and eventually reviews them for safety and effectiveness.
When the incident was reported, our agency, the U.S. Department of Agriculture, and the State of Nebraska very quickly made sure that none of the soybeans entered the food supply, and FDA subsequently strengthened the controls on any transgenic plants grown in clinical trials.
The second question that's frequently asked is whether the transgenic foods will ever find widespread acceptance abroad, particularly in Europe. Here, the answer is more complicated. The scientific community in Europe generally recognizes that the five year-old unofficial ban of the European Union on imports of biotech food is a measure based more on trade and emotional grounds than on public health concerns and science. European newspapers are widely speculating that the ban will be soon lifted, and in January, the EU executive took a step in that direction by supporting a proposal to allow the imports of transgenic sweet corn.
Also in January, the Economic Journal magazine in the United Kingdom published a survey in which 42% of the participants said that they would buy genetically modified food products if the price was right, and 23% said they had no qualms about eating such products, regardless of the price. But since then, a poll in France has indicated that 66% of French farmers would not sow transgenic seeds even if they were authorized to do so by the government, which they are not. Twenty-three percent of the respondents said they were not sure about the risks involved in biotech agriculture, 15% said they see no reason for using such seeds, 14% believed the technology is still in an experimental stage, and 14% felt they did not have enough information about biotechnology to have an opinion.
Although genetic modification of plants is by far the most advanced and most widely utilized tool of food biotechnology, there is also great interest in developing transgenic animals, and research in this area, which in many ways represents the cutting edge of rDNA manipulation, is advancing rapidly.
There are essentially three kinds of so-called biotech animals: clones, which are produced by transferring cell nuclei from one animal into enucleated oocytes of another to generate the donor's genomic copies; transgenic animals, which contain stably integrated genes from another animal or species; and animals that had been infused with non-heritable DNA constructs.
Many of these animals are being developed to produce pharmaceutical materials and even materials for devices, but I will limit my overview to the trends, opportunities and risks of animal biotechnology as they apply to the food arena. Some 300 prized bulls have been already cloned and are being sold in the U.S. to ranchers who want to improve the quality of their breeding stock. Owners of these animals have agreed to keep their meat and milk, and the meat and the milk of their offsprings, from the market until our agency determines whether these products are safe for human consumption.
As in the case of transgenic plants, much of the research involving transgenic animals is focused on improving food production. Probably the best-known example is the farm-bred salmon that has been infused with an added gene of a growth hormone. As a result, the fish reaches the market weight of 7-9 pounds in about half the time it takes to the salmons in the ocean. The transgenic salmon is not yet on the market, but it has already received a lot of publicity. Less well known is that catfish and tilapia have been also genetically modified to grow faster and more efficiently than their non-transgenic counterparts. Rainbow trout has been engineered to increase its contents of omega 3 fatty acids, and shellfish is being modified to reduce its allergenicity and make it grow faster.
Cows can be bioengineered to produce several varieties of milk: milk with a lower level of a protein that's allergenic to some infants; milk that is more easily digested by people who are lactose intolerant; milk that has more naturally occurring antimicrobial enzyme, and therefore has longer shelf life; and milk that makes better cheese because it has altered distribution of caseins or less fat.
A great deal of scientific work is also being done to improve the health of food animals by using the tools of biotechnology. For example, lysostaphin, a bacteriocidal enzyme, has been introduced into cows to decrease their susceptibility to mastitis, and various beneficial proteins have been introduced into sows' milk to increase the post-natal survival of their piglets. But the most exciting research in this arena is focused on the development of cows that would be resistant to BSE, the so-called Mad Cow's disease, which is a specter haunting the cattle industry everywhere.
There are several scientific teams working on this project, and they use essentially two strategies: they're either trying to alter the animal's prion protein so that it is less likely to assume the form that induces the spongiform encephalopathy; or they aim at completely eliminating this protein, so that even if the animal is exposed to prions, they will have no proteins to alter. One of these teams, in South Korea, claims to have developed BSE-resistant cows using the first approach. In addition, there are three groups in the U.S. pursuing the same aim by using both approaches. If this research succeeds in protecting the cattle industry from the wasting disease, it will be worth a fortune.
Although the opportunities of animal engineering are great and many, they're not without hazards. Because the technology is so new, and because it is applied to highly complex organisms, it can cause many kinds of adverse outcomes. For example, if the gene is accidentally inserted into a chromosonal region that encodes products necessary for normal cell function, or that regulates cell growth, the result can be a mutagenesis with highly damaging consequences for the animal. Another type of deleterious effect occurs when the vector activates genes that should not be expressed. And the capacity of some of the viral-based vectors to become incorporated in other organisms, including humans, poses risks for the scientists and others who handle the experimental animals.
We are also concerned about the impact of animal biotechnology on the environment because of the capacity of some of the transgenic animals to escape from their confinement, and by interbreeding spread traits that could be dangerous to their species and even the ecosystem. This is a serious issue for the FDA, which -- as I've mentioned -- regulates transgenic animals under the same rules as drugs, and therefore is co-responsible for making sure that the technology does not endanger the environment.
For example, in the case of the bioengineered salmon, the strategy is to produce in inland hatcheries reproductively sterile, all-female offsprings that would be transferred to ocean net pens only to mature and be harvested for food. Genetically engineered pigs, which are relatively easy to confine, present another environmental problem -- because of their size they can expensive to dispose of in a way that would prevent their inadvertent introduction into human or animal food. Resolving this problem is yet another challenge posed by biotechnology.
I started my remarks by raising some urgent questions that need to be answered if we are to overcome the epidemic of obesity, which is in part an unintended consequence of the great success of science and agriculture. But I don't want to conclude without noting that this hazard appears as almost frivolous when compared with the scourge of hunger that had ravaged humanity for millennia -- until, that is, it developed a body of priceless knowledge that enabled food producers to feed not only themselves and their families, but also others.
As Charles Darwin pointed out in The Descent of Man, this was the foundation of all modern progress. The "body of well-instructed men, who have not to labor for their daily bread," Darwin wrote, "is important to a degree which cannot be overestimated; as all high intellectual work is carried out by them, and on such work material progress of all kinds mainly depends."
That was in 1871, and there are still great regions in our world where men and women labor for their daily bread, and where material progress is beyond reach. For these millions, biotechnology holds the greatest promise for lifting the bane of malnutrition and hunger, and releasing new creative energies.
Let us not lose sight of that. As food scientists, and as members of Darwin's "body of well-instructed men" and women, we have not only a professional, but also a moral obligation to continue advancing this indispensable knowledge, and bring it to its full potential of providing adequate nutrition for all of us on this planet.