The 21st century food system is awash in ethical issues. To name just a handful: There's the environmental impacts of farming, the human health effects of diets based on animal products and processed foods, the growing clamor around food waste, and the longstanding concerns about agricultural labor. The last decade has seen the emergence of "ethical consumption," as people have been encouraged to avoid products that are associated with animal cruelty or unfair to farmers.
Misguided concerns about GMOs are missing the point altogether and distracting from a far more substantive ethical problem.
But consumers have never been so ignorant about where food comes from, and they are vulnerable to oversimplifications and faulty messaging. Many would include the first generation of crops from agricultural applications of recombinant DNA methods for genetic improvement—so called GMOs—among the foods they should avoid for ethical reasons. Unfortunately, these misguided concerns are missing the point altogether and distracting from a far more substantive ethical problem.
As we stand on the precipice of a new era in food and biotechnology – crops and animals with genomes altered through gene editing – it is more important than ever to let go of unnecessary fears and to pay attention to the real hazards of agricultural innovation.
But first, as a bioethicist with almost 40 years of experience working on issues in the food system, let me stress the overall context and rationale for trying to make changes in plant and animal genetics. Doing so, whether through conventional breeding or biotechnology, allows producers to meet the challenges of seasonal climate differences and increase yields.
And just because a food was created through ordinary plant breeding vs. genetic modification does not automatically make it safe. Things can and do go wrong in ordinary plant breeding, such as with potatoes and tomatoes. These both produce toxins in the green parts of the plant, and breeders exercise caution to ensure that toxins aren't transferred to edible parts.
Despite real risks, there is no regulatory oversight that protects us from these known hazards. We rely on the professional ethics of agricultural scientists. And GMOs are, in comparison, much more carefully tested and regulated. The claim that they are "unregulated" is just false.
We should not ignore the role that all gene technologies have played in displacing small farmers, depleting rural communities, and shifting economic control.
I do want to shift the public's attention away from the anti-GMO debate to more substantive questions about contemporary agriculture that really have little to do with where the genes in their food came from, or how they got there.
No matter how important genetic improvements might be in terms of total global food production, we should not ignore the role that all gene technologies—including breeding—have played in displacing small farmers, depleting rural communities and shifting economic control of agriculture into a small circle of powerful actors. Globally, these changes have had disproportionately harmful effects on women and people of color.
Combined with mechanization and chemicals, gene technologies have freed planters from their dependence on impoverished and poorly educated field hands, but they did nothing to help the fieldworkers transition to a new line of work. These are the real problems that deserve the public's and the science community's attention, not the overly narrow worries about eating GMOs.
But these problems are viewed as "not ours" by agricultural insiders, and they continue to be ignored by scientists whose focus is solely on biology. Many of the concerns that are today viewed as "urban problems" or "social issues" have origins in agriculture. For example, in California tomatoes, the development of mechanical harvesting led to a rapid concentration of ownership and the displacement of thousands of field hands. In the South, similar technologies displaced black farmers working land owned by whites, causing migration to urban centers and unskilled jobs. I must fault the science community for a lack of willingness to even take the thrust of these more socially oriented critiques seriously.
The new suite of tools for genetic modification that go under the name "gene editing" promise greater precision. They should allow scientists to target the locus for new genes in a plant or animal genome, and minimize the chance for causing unwanted impacts on gene functioning. This added precision is reducing some of the uncertainties in the mind of technology developers, and they have been expressing hope that their own confidence will be shared by regulators and by the public at large. In fact, the U.S. government recently issued a statement that gene-edited crops do not require additional regulation because they're just as safe as crops produced through conventional breeding.
It is indeed possible that the public doubts about genetically modified food will be assuaged by this argument. We can only wait and see. Whether or not gene editing will lead to more reflection about agriculture's complicity in problems of economic inequality or structural racism depends much more on the culture of the science community than it does on the technology itself.
The Friday Five covers five stories in health research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Listen to the Episode
Covered in this week's Friday Five:
- A new blood test for cancer
- Patches of bacteria can use your sweat to power electronic devices
- Researchers revive organs of dead pigs
- Phone apps detects cancer-causing chemicals in foods
- Stem cells generate "synthetic placentas" in mice
Plus, an honorable mention for early research involving vitamin K and Alzheimer's
The doctor will sniff you now? Well, not on his or her own, but with a device that functions like a superhuman nose. You’ll exhale into a breathalyzer, or a sensor will collect “scent data” from a quick pass over your urine or blood sample. Then, AI software combs through an olfactory database to find patterns in the volatile organic compounds (VOCs) you secreted that match those associated with thousands of VOC disease biomarkers that have been identified and cataloged.
No further biopsy, imaging test or procedures necessary for the diagnosis. According to some scientists, this is how diseases will be detected in the coming years.
All diseases alter the organic compounds found in the body and their odors. Volatolomics is an emerging branch of chemistry that uses the smell of gases emitted by breath, urine, blood, stool, tears or sweat to diagnose disease. When someone is sick, the normal biochemical process is disrupted, and this alters the makeup of the gas, including a change in odor.
“These metabolites show a snapshot of what’s going on with the body,” says Cristina Davis, a biomedical engineer and associate vice chancellor of Interdisciplinary Research and Strategic Initiatives at the University of California, Davis. This opens the door to diagnosing conditions even before symptoms are present. It’s possible to detect a sweet, fruity smell in the breath of someone with diabetes, for example.
Hippocrates may have been the first to note that people with certain diseases give off an odor but dogs provided the proof of concept. Scientists have published countless studies in which dogs or other high-performing smellers like rodents have identified people with cancer, lung disease or other conditions by smell alone. The brain region that analyzes smells is proportionally about 40 times greater in dogs than in people. The noses of rodents are even more powerful.
Take prostate cancer, which is notoriously difficult to detect accurately with standard medical testing. After sniffing a tiny urine sample, trained dogs were able to pick out prostate cancer in study subjects more than 96 percent of the time, and earlier than a physician could in some cases.
But using dogs as bio-detectors is not practical. It is labor-intensive, complicated and expensive to train dogs to bark or lie down when they smell a certain VOC, explains Bruce Kimball, a chemical ecologist at the Monell Chemical Senses Center in Philadelphia. Kimball has trained ferrets to scratch a box when they smell a specific VOC so he knows. The lab animal must be taught to distinguish the VOC from background odors and trained anew for each disease scent.
In the lab of chemical ecologist Bruce Kimball, ferrets were trained to scratch a box when they identified avian flu in mallard ducks.
Glen J. Golden
There are some human super-smellers among us. In 2019, Joy Milne of Scotland proved she could unerringly identify people with Parkinson’s disease from a musky scent emitted from their skin. Clinical testing showed that she could distinguish the odor of Parkinson’s on a worn t-shirt before clinical symptoms even appeared.
Hossam Haick, a professor at Technion-Israel Institute of Technology, maintains that volatolomics is the future of medicine. Misdiagnosis and late detection are huge problems in health care, he says. “A precise and early diagnosis is the starting point of all clinical activities.” Further, this science has the potential to eliminate costly invasive testing or imaging studies and improve outcomes through earlier treatment.
The Nose Knows a Lot
“Volatolomics is not a fringe theory. There is science behind it,” Davis stresses. Every VOC has its own fingerprint, and a method called gas chromatography-mass spectrometry (GCMS) uses highly sensitive instruments to separate the molecules of these VOCs to determine their structures. But GCMS can’t discern the telltale patterns of particular diseases, and other technologies to analyze biomarkers have been limited.
We have technology that can see, hear and sense touch but scientists don’t have a handle yet on how smell works. The ability goes beyond picking out a single scent in someone’s breath or blood sample. It’s the totality of the smell—not the smell of a single chemical— which defines a disease. The dog’s brain is able to infer something when they smell a VOC that eludes human analysis so far.
Odor is a complex ecosystem and analyzing a VOC is compounded by other scents in the environment, says Kimball. A person’s diet and use of tobacco or alcohol also will affect the breath. Even fluctuations in humidity and temperature can contaminate a sample.
If successful, a sophisticated AI network can imitate how the dog brain recognizes patterns in smells. Early versions of robot noses have already been developed.
With today’s advances in data mining, AI and machine learning, scientists are trying to create mechanical devices that can draw on algorithms based on GCMS readings and data about diseases that dogs have sniffed out. If successful, a sophisticated AI network can imitate how the dog brain recognizes patterns in smells.
In March, Nano Research published a comprehensive review of volatolomics in health care authored by Haick and seven colleagues. The intent was to bridge gaps in the field for scientists trying to connect the biomarkers and sensor technology needed to develop a robot nose. This paper serves as a reference manual for the field that lists which VOCs are associated with what disease and the biomarkers in skin, saliva, breath, and urine.
Weiwei Wu, one of the co-authors and a professor at Xidian University in China, explains that creating a robotic nose requires the expertise of chemists, computer scientists, electrical engineers, material scientists, and clinicians. These researchers use different terms and methodologies and most have not collaborated before with the other disciplines. “The electrical engineers know the device but they don’t know as much about the biomarkers they need to detect,” Wu offers as an example.
This review is significant, Wu continues, because it can facilitate progress in the field by providing experts in all the disciplines with the basic knowledge needed to create an effective robot nose for diagnostic use. The paper also includes a systematic summary of the research methodology of volatolomics.
Once scientists build a stronger database of VOCs, they can program a device to identify critical patterns of specified diseases on a reliable basis. On a machine learning model, the algorithms automatically get better at diagnosing with each use. Wu envisions further tweaks in the next few years to make the devices smaller and consume less power.
A Whiff of the Future
Early versions of robot noses have already been developed. Some of them use chemical sensors to pick up smells in the breath or other body emission molecules. That data is sent through an electrical signal to a computer network for interpretation and possible linkage to a disease.
This electronic nose, or e-nose, has been successful in small pilot studies at labs around the world. At Ben-Gurion University in Israel, researchers detected breast cancer with electronic gas sensors with 95% accuracy, a higher sensitivity than mammograms. Other robot noses, called p-noses, use photons instead of electrical signals.
The mechanical noses being developed tap different methodologies and analytic techniques which makes it hard to compare them. Plus, the devices are intended for varying uses. One team, for example, is working on an e-nose that can be waved over a plate to screen for the presence of a particular allergen when you’re dining out.
A robot nose could be used as a real-time diagnostic tool in clinical practice. Kimball is working on one such tool that can distinguish between a viral and bacterial infection. This would enable physicians to determine whether an antibiotic prescription is appropriate without waiting for a lab result.
Davis is refining a hand-held device that identifies COVID-19 through a simple breath test. She sees the tool being used at crowded airports, sports stadiums and concert venues where PCR or rapid antigen testing is impractical. Background air samples are collected from the space so that those signals can be removed from the human breath measurement. “[The sensor tool] has the same accuracy as the rapid antigen test kits but exhaled breath is easier to collect,” she notes.
The NaNose, also known as the SniffPhone, uses tiny sensors boosted by AI to distinguish Alzheimer's, Crohn's disease, the early stages of several cancers, and other diseases with 84 to 98 percent accuracy.
Haick named his team’s robot nose, “NaNose,” since it is based on nanotechnology; the prototype is called the SniffPhone. Using tiny sensors boosted by AI, it can distinguish 23 diseases in human subjects with 84 to 98 percent accuracy. This includes early stages of several cancers, Alzheimer’s, tuberculosis and Crohn’s disease. His team has been raising the accuracy level by combining biomarker signals from both breath and skin, for example. The goal is to achieve 99.9 percent accuracy consistently so no other diagnostic tests would be needed before treating the patient. Plus, it will be affordable, he says.
Kimball predicts we’ll be seeing these diagnostic tools in the next decade. “The physician would narrow down what [the diagnosis] might be and then get the correct tool,” he says. Others are envisioning one device that can screen for multiple diseases by programming the software, which would be updated regularly with new findings.
Larger volatolomics studies must be conducted before these e-noses are ready for clinical use, however. Experts also need to learn how to establish normal reference ranges for e-nose readings to support clinicians using the tool.
“Taking successful prototypes from the lab to industry is the challenge,” says Haick, ticking off issues like reproducibility, mass production and regulation. But volatolomics researchers are unanimous in believing the future of health care is so close they can smell it.