AI and you: Is the promise of personalized nutrition apps worth the hype?
As a type 2 diabetic, Michael Snyder has long been interested in how blood sugar levels vary from one person to another in response to the same food, and whether a more personalized approach to nutrition could help tackle the rapidly cascading levels of diabetes and obesity in much of the western world.
Eight years ago, Snyder, who directs the Center for Genomics and Personalized Medicine at Stanford University, decided to put his theories to the test. In the 2000s continuous glucose monitoring, or CGM, had begun to revolutionize the lives of diabetics, both type 1 and type 2. Using spherical sensors which sit on the upper arm or abdomen – with tiny wires that pierce the skin – the technology allowed patients to gain real-time updates on their blood sugar levels, transmitted directly to their phone.
It gave Snyder an idea for his research at Stanford. Applying the same technology to a group of apparently healthy people, and looking for ‘spikes’ or sudden surges in blood sugar known as hyperglycemia, could provide a means of observing how their bodies reacted to an array of foods.
“We discovered that different foods spike people differently,” he says. “Some people spike to pasta, others to bread, others to bananas, and so on. It’s very personalized and our feeling was that building programs around these devices could be extremely powerful for better managing people’s glucose.”
Unbeknown to Snyder at the time, thousands of miles away, a group of Israeli scientists at the Weizmann Institute of Science were doing exactly the same experiments. In 2015, they published a landmark paper which used CGM to track the blood sugar levels of 800 people over several days, showing that the biological response to identical foods can vary wildly. Like Snyder, they theorized that giving people a greater understanding of their own glucose responses, so they spend more time in the normal range, may reduce the prevalence of type 2 diabetes.
The commercial potential of such apps is clear, but the underlying science continues to generate intriguing findings.
“At the moment 33 percent of the U.S. population is pre-diabetic, and 70 percent of those pre-diabetics will become diabetic,” says Snyder. “Those numbers are going up, so it’s pretty clear we need to do something about it.”
Fast forward to 2022,and both teams have converted their ideas into subscription-based dietary apps which use artificial intelligence to offer data-informed nutritional and lifestyle recommendations. Snyder’s spinoff, January AI, combines CGM information with heart rate, sleep, and activity data to advise on foods to avoid and the best times to exercise. DayTwo–a start-up which utilizes the findings of Weizmann Institute of Science–obtains microbiome information by sequencing stool samples, and combines this with blood glucose data to rate ‘good’ and ‘bad’ foods for a particular person.
“CGMs can be used to devise personalized diets,” says Eran Elinav, an immunology professor and microbiota researcher at the Weizmann Institute of Science in addition to serving as a scientific consultant for DayTwo. “However, this process can be cumbersome. Therefore, in our lab we created an algorithm, based on data acquired from a big cohort of people, which can accurately predict post-meal glucose responses on a personal basis.”
The commercial potential of such apps is clear. DayTwo, who market their product to corporate employers and health insurers rather than individual consumers, recently raised $37 million in funding. But the underlying science continues to generate intriguing findings.
Last year, Elinav and colleagues published a study on 225 individuals with pre-diabetes which found that they achieved better blood sugar control when they followed a personalized diet based on DayTwo’s recommendations, compared to a Mediterranean diet. The journal Cell just released a new paper from Snyder’s group which shows that different types of fibre benefit people in different ways.
“The idea is you hear different fibres are good for you,” says Snyder. “But if you look at fibres they’re all over the map—it’s like saying all animals are the same. The responses are very individual. For a lot of people [a type of fibre called] arabinoxylan clearly reduced cholesterol while the fibre inulin had no effect. But in some people, it was the complete opposite.”
Eight years ago, Stanford's Michael Snyder began studying how continuous glucose monitors could be used by patients to gain real-time updates on their blood sugar levels, transmitted directly to their phone.
The Snyder Lab, Stanford Medicine
Because of studies like these, interest in precision nutrition approaches has exploded in recent years. In January, the National Institutes of Health announced that they are spending $170 million on a five year, multi-center initiative which aims to develop algorithms based on a whole range of data sources from blood sugar to sleep, exercise, stress, microbiome and even genomic information which can help predict which diets are most suitable for a particular individual.
“There's so many different factors which influence what you put into your mouth but also what happens to different types of nutrients and how that ultimately affects your health, which means you can’t have a one-size-fits-all set of nutritional guidelines for everyone,” says Bruce Y. Lee, professor of health policy and management at the City University of New York Graduate School of Public Health.
With the falling costs of genomic sequencing, other precision nutrition clinical trials are choosing to look at whether our genomes alone can yield key information about what our diets should look like, an emerging field of research known as nutrigenomics.
The ASPIRE-DNA clinical trial at Imperial College London is aiming to see whether particular genetic variants can be used to classify individuals into two groups, those who are more glucose sensitive to fat and those who are more sensitive to carbohydrates. By following a tailored diet based on these sensitivities, the trial aims to see whether it can prevent people with pre-diabetes from developing the disease.
But while much hope is riding on these trials, even precision nutrition advocates caution that the field remains in the very earliest of stages. Lars-Oliver Klotz, professor of nutrigenomics at Friedrich-Schiller-University in Jena, Germany, says that while the overall goal is to identify means of avoiding nutrition-related diseases, genomic data alone is unlikely to be sufficient to prevent obesity and type 2 diabetes.
“Genome data is rather simple to acquire these days as sequencing techniques have dramatically advanced in recent years,” he says. “However, the predictive value of just genome sequencing is too low in the case of obesity and prediabetes.”
Others say that while genomic data can yield useful information in terms of how different people metabolize different types of fat and specific nutrients such as B vitamins, there is a need for more research before it can be utilized in an algorithm for making dietary recommendations.
“I think it’s a little early,” says Eileen Gibney, a professor at University College Dublin. “We’ve identified a limited number of gene-nutrient interactions so far, but we need more randomized control trials of people with different genetic profiles on the same diet, to see whether they respond differently, and if that can be explained by their genetic differences.”
Some start-ups have already come unstuck for promising too much, or pushing recommendations which are not based on scientifically rigorous trials. The world of precision nutrition apps was dubbed a ‘Wild West’ by some commentators after the founders of uBiome – a start-up which offered nutritional recommendations based on information obtained from sequencing stool samples –were charged with fraud last year. The weight-loss app Noom, which was valued at $3.7 billion in May 2021, has been criticized on Twitter by a number of users who claimed that its recommendations have led to them developed eating disorders.
With precision nutrition apps marketing their technology at healthy individuals, question marks have also been raised about the value which can be gained through non-diabetics monitoring their blood sugar through CGM. While some small studies have found that wearing a CGM can make overweight or obese individuals more motivated to exercise, there is still a lack of conclusive evidence showing that this translates to improved health.
However, independent researchers remain intrigued by the technology, and say that the wealth of data generated through such apps could be used to help further stratify the different types of people who become at risk of developing type 2 diabetes.
“CGM not only enables a longer sampling time for capturing glucose levels, but will also capture lifestyle factors,” says Robert Wagner, a diabetes researcher at University Hospital Düsseldorf. “It is probable that it can be used to identify many clusters of prediabetic metabolism and predict the risk of diabetes and its complications, but maybe also specific cardiometabolic risk constellations. However, we still don’t know which forms of diabetes can be prevented by such approaches and how feasible and long-lasting such self-feedback dietary modifications are.”
Snyder himself has now been wearing a CGM for eight years, and he credits the insights it provides with helping him to manage his own diabetes. “My CGM still gives me novel insights into what foods and behaviors affect my glucose levels,” he says.
He is now looking to run clinical trials with his group at Stanford to see whether following a precision nutrition approach based on CGM and microbiome data, combined with other health information, can be used to reverse signs of pre-diabetes. If it proves successful, January AI may look to incorporate microbiome data in future.
“Ultimately, what I want to do is be able take people’s poop samples, maybe a blood draw, and say, ‘Alright, based on these parameters, this is what I think is going to spike you,’ and then have a CGM to test that out,” he says. “Getting very predictive about this, so right from the get go, you can have people better manage their health and then use the glucose monitor to help follow that.”
Forcing Vaccination on Every Child Undermines Civil Liberties
[Editor's Note: This opinion essay is in response to our current Big Question, which we posed to experts with different viewpoints: "Where should society draw the line between requiring vaccinations for children and allowing parental freedom of choice?"]
Our children are the future. The survival of humanity is advanced by the biological imperative that mothers and fathers want and need to protect their children and other children from being harmed for any reason.
Science is not perfect, doctors are not infallible, and medical interventions come with risks.
In the 21st century, consensus science considers vaccination to be one of the greatest inventions in the history of medicine and the greatest achievement of public health programs. The national vaccination rate for U.S. kindergarten children is 94 percent and most children today receive 69 doses of 16 federally recommended vaccines. However, public health is not simply measured by high vaccination rates and absence of infectious disease, which is evidenced by the chronic inflammatory disease and disability epidemic threatening to bankrupt the U.S. health care system.
Science is not perfect, doctors are not infallible, and medical interventions come with risks, which is why parents have the power to exercise informed consent to medical risk taking on behalf of their minor children.
As a young mother, I learned that vaccine risks are 100 percent for some children because, while we are all born equal under the law, we are not born all the same. Each one of us enters this world with different genes, a unique microbiome and epigenetic influences that affect how we respond to the environments in which we live. We do not all respond the same way to infectious diseases or to pharmaceutical products like vaccines.
Few parents were aware of vaccine side effects in 1980, when my bright, healthy two-and-a-half year-old son, Chris, suffered a convulsion, collapse, and state of unconsciousness (encephalopathy) within hours of his fourth DPT shot, and then regressed physically, mentally and emotionally and became a totally different child. Chris was eventually diagnosed with multiple learning disabilities and confined to a special education classroom throughout his public school education, but he and I both know his vaccine reaction could have been much worse. Today, Chris is an independent adult but many survivors of brain injury are not.
Barbara Loe Fisher and her son, Chris, in December 1981 after his fourth DPT shot.
(Courtesy Fisher)
The public conversation about several hundred cases of measles reported in the U.S. this year is focused on whether every parent has a social obligation to vaccinate every child to maintain "community immunity," but vaccine failures are rarely discussed. Emerging science reveals that there are differences in naturally and vaccine acquired immunity, and both vaccinated and unvaccinated children and adults transmit infections, sometimes with few or no symptoms.
Nearly 40 percent of cases reported in the 2015 U.S. measles outbreak occurred in recently vaccinated individuals who developed vaccine reactions that appeared indistinguishable from measles. Outbreaks of pertussis (whooping cough) in highly vaccinated child populations have been traced to waning immunity and evolution of the B. pertussis microbe to evade the vaccines. Influenza vaccine effectiveness was less than 50 percent in 11 of the past 15 flu seasons.
Vaccine policymakers recognize that children with severe combined immune deficiency or those undergoing chemotherapy or organ transplants are at increased risk for complications of infectious diseases and vaccines. However, there is no recognition of the risks to healthy infants and children with unidentified susceptibility to vaccine reactions, including children whose health suddenly deteriorates without explanation after vaccination. Medical care is being denied to children and adults in the U.S. if even one government recommended vaccination is declined, regardless of health or vaccine reaction history.
When parents question the risks and failures of a commercial pharmaceutical product being mandated for every child, the answer is not more force but better science and respect for the informed consent ethic.
The social contract we have with each other when we live in communities, whether we belong to the majority or a minority, is to care about and protect every individual living in the community. One-size-fits-all vaccine policies and laws, which fail to respect biodiversity and force everyone to be treated the same, place an unequal risk burden on a minority of unidentified individuals unable to survive vaccination without being harmed.
A law that requires certain minorities to bear a greater risk of injury or sacrifice their lives in service to the majority is not just or moral.
Between 1991 and 2013, the Institute of Medicine (IOM) published reports documenting that vaccines can cause brain inflammation and other serious reactions, injuries and death. A 2012 IOM report acknowledged that there are genetic, biological, and environmental risk factors that make some individuals more susceptible to adverse responses to vaccines but often doctors cannot identify who they are because of gaps in vaccine science. Congress acknowledged this fact a quarter century earlier in the 1986 National Childhood Vaccine Injury Act, which created a federal vaccine injury compensation program alternative to a lawsuit that has awarded more than $4 billion to vaccine-injured children and adults.
We give up the human right to autonomy and informed consent at our peril, no matter where or in what century we live.
Vaccine manufacturers and administrators have liability protection, yet today almost no health condition qualifies for a medical vaccine exemption under government guidelines. Now, there is a global call by consensus science advocates for elimination of all personal belief vaccine exemptions and censorship of books and public conversations that criticize vaccine safety or government vaccine policy. Some are calling for quarantine of all who refuse vaccinations and criminal prosecution, fines and imprisonment of parents with unvaccinated children, as well as punishment of doctors who depart from government policy.
There is no civil liberty more fundamentally a natural, inalienable right than exercising freedom of thought and conscience when deciding when and for what reason we are willing to risk our life or our child's life. That is why voluntary, informed consent to medical risk-taking has been defined as a human right governing the ethical practice of modern medicine.
In his first Presidential inaugural address, Thomas Jefferson warned:
"All, too, will bear in mind this sacred principle, that though the will of the majority is in all cases to prevail, that will to be rightful must be reasonable; that the minority posses their equal rights, which equal law must protect, and to violate would be oppression."
The seminal 1905 U.S. Supreme Court decision, Jacobson v. Massachusetts, affirmed the constitutional authority of states to enact mandatory smallpox vaccination laws. However, the justices made it clear that implementation of a vaccination law should not become "cruel and inhuman to the last degree." They warned, "All laws, this court has said, should receive a sensible construction. General terms should be so limited in their application as not to lead to injustice, oppression, or an absurd consequence. It will always, therefore, be presumed that the legislature intended exceptions to its language, which would avoid results of this character."
Mothers and fathers, who know and love their children better than anyone else, depend upon sound science and compassionate public health policies to help them protect their own and other children from harm. If individuals susceptible to vaccine injury cannot be reliably identified, the accuracy of vaccine benefit and risk calculations must be reexamined. Yet, consensus science and medicine around vaccination discourages research into the biological mechanisms of vaccine injury and death and identification of individual risk factors to better inform public health policy.
A critic of consensus science, physician and author Michael Crichton said, "Let's be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Period."
Condoning elimination of civil liberties, including freedom of speech and the right to dissent guaranteed under the First Amendment of the U.S. Constitution, to enforce vaccination creates a slippery slope. Coercion, punishment and censorship will destroy, not instill, public trust in the integrity of medical practice and public health laws.
There are more than a dozen new vaccines being fast tracked to market by industry and governments. Who in society should be given the power to force all children to use every one of them without parental consent regardless of how small or great the risk?
We give up the human right to autonomy and informed consent at our peril, no matter where or in what century we live. Just and compassionate public health laws that protect parental and human rights will include flexible medical, religious and conscientious belief vaccine exemptions to affirm the informed consent ethic and prevent discrimination against vulnerable minorities.
[Editor's Note: Read the opposite viewpoint here.]
Not Vaccinating Your Kids Endangers Public Health
[Editor's Note: This opinion essay is in response to our current Big Question, which we posed to experts with different viewpoints: "Where should society draw the line between requiring vaccinations for children and allowing parental freedom of choice?"]
Society has a right and at times an obligation to require children to be vaccinated. Vaccines are one of the most effective medical and public health interventions. They save lives and prevent suffering. The vast majority of parents in the United States fully vaccinate their children according to the recommended immunization schedule. These parents are making decisions so that the interests of their children and the interest of society are the same. There are no ethical tensions.
"Measles is only a plane ride away from American children."
A strong scientific basis supports the recommended immunization schedule. The benefits of recommended vaccines are much bigger than the risks. However, a very small proportion of parents are ideologically opposed to vaccines. A slightly larger minority of parents do not believe that all of the recommended vaccines are in their child's best interests.
Forgoing vaccinations creates risk to the child of contracting diseases. It also creates risk to communities and vulnerable groups of people who cannot be vaccinated because of their age or health status.
For example, many vaccines are not able to be given to newborns, such as the measles vaccine which is recommended at 12-15 months of age, leaving young children vulnerable. Many diseases are particularly dangerous for young children. There are also some children who can't be vaccinated, such as pediatric cancer patients who are undergoing chemotherapy or radiation treatment. These children are at increased risk of serous complication or death.
Then there are people who are vaccinated but remain susceptible to disease because no vaccine is 100% effective. In the case of measles, two doses of vaccines protect 97% of people, leaving 3% still susceptible even after being fully vaccinated. All of these groups of people – too young, not eligible, and vaccinated but still susceptible – are dependent on almost everyone else to get vaccinated in order for them to be protected.
Sadly, even though measles has been largely controlled because most people get the very safe and very effective vaccine, we are now seeing dangerous new outbreaks because some parents are refusing vaccines for their children, especially in Europe. Children have died. Measles is only a plane ride away from American children.
There have been repeated measles outbreaks in the United States – such as the Disneyland outbreak and six outbreaks already this year - because of communities where too many parents refuse the vaccine and measles is brought over, often from Europe.
The public health benefits cannot be emphasized enough: Vaccines are not just about protecting your child. Vaccines protect other children and the entire community. Vaccine-preventable diseases (with the exception of tetanus) are spread from person to person. The decision of a parent to not vaccinate their child can endanger other children and vulnerable people.
As a vaccine safety researcher for 20 years, I believe that the community benefit of vaccination can provide justification to limit parental autonomy.
Given these tensions between parental autonomy and the protective value of vaccines, the fundamental question remains: Should society require all children to submit to vaccinations? As a vaccine safety researcher for 20 years, I believe that the community benefit of vaccination can provide justification to limit parental autonomy.
In the United States, we see this balancing act though state requirements for vaccinations to enter school and the varying availability of non-medical exemptions to these laws. Mandatory vaccination in the United States are all state laws. All states require children entering school to receive vaccines and permit medical exemptions. There are a lot of differences between states regarding which vaccines are required, target populations (daycare, school entry, middle school, college), and existence and types of non-medical (religious or philosophical) exemptions that are permitted.
Amid recent measles outbreaks, for instance, California eliminated all non-medical exemptions, making it one of three states that only permit medical exemptions. The existence and enforcement of these school laws reflect broad public support for vaccines to protect the community from disease outbreaks.
I worry about how many kids must suffer, and even die, from diseases like measles until enough is enough. Such tragedies have no place in the modern era. All parents want to do right by their children. All parents deserve autonomy when it comes to decision-making. But when their choices confer serious risks to others, the buck should stop. Our nation would be better off—both medically and ethically—if we did not turn our backs on our most vulnerable individuals.
[Editor's Note: Read the opposite viewpoint here.]