Personalized nutrition apps could provide valuable data to people trying to eat healthier, though more research must be done to show effectiveness.
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.”
A wired baby in a neonatal intensive care unit.
I'll never forget the experience of having a child in the neonatal intensive care unit (NICU).
Now more than ever, we're working to remove the barriers between new parents and their infants.
It was another layer of uncertainty that filtered into my experience of being a first-time parent. There was so much I didn't know, and the wires attached to my son's small body for the first week of his life were a reminder of that.
I wanted to be the best mother possible. I deeply desired to bring my son home to start our lives. More than anything, I longed for a wireless baby whom I could hold and love freely without limitations.
The wires suggested my baby was fragile and it left me feeling severely unprepared, anxious, and depressed.
In recent years, research has documented the ways that NICU experiences take a toll on parents' mental health. But thankfully, medical technology is rapidly being developed to help reduce the emotional fallout of the NICU. Now more than ever, we're working to remove the barriers between new parents and their infants. The latest example is the first ever wireless monitoring system that was recently developed by a team at Northwestern University.
After listening to the needs of parents and medical staff, Debra Weese-Mayer, M.D., a professor of pediatric autonomic medicine at Feinberg School of Medicine, along with a team of materials scientists, engineers, dermatologists and pediatricians, set out to develop this potentially life-changing technology. Weese-Mayer believes wireless monitoring will have a significant impact for people on all sides of the NICU experience.
"With elimination of the cumbersome wires," she says, "the parents will find their infant more approachable/less intimidating and have improved access to their long-awaited but delivered-too-early infant, allowing them to begin skin-to-skin contact and holding with reduced concern for dislodging wires."
So how does the new system work?
Very thin "skin like" patches made of silicon rubber are placed on the surface of the skin to monitor vitals like heart rate, respiration rate, and body temperature. One patch is placed on the chest or back and the other is placed on the foot.
These patches are safer on the skin than previously used adhesives, reducing the cuts and infections associated with past methods. Finally, an antenna continuously delivers power, often from under the mattress.
The data collected from the patches stream from the body to a tablet or computer.
New wireless sensor technology is being studied to replace wired monitoring in NICUs in the coming years.
(Northwestern University)
Weese-Mayer hopes that wireless systems will be standard soon, but first they must undergo more thorough testing. "I would hope that in the next five years, wireless monitoring will be the standard in NICUs, but there are many essential validation steps before this technology will be embraced nationally," she says.
Until the new systems are ready, parents will be left struggling with the obstacles that wired monitoring presents.
Physical intimacy, for example, appears to have pain-reducing qualities -- something that is particularly important for babies who are battling serious illness. But wires make those cuddles more challenging.
There's also been minimal discussion about how wired monitoring can be particularly limiting for parents with disabilities and mobility aids, or even C-sections.
"When he was first born and I was recovering from my c-section, I couldn't deal with keeping the wires untangled while trying to sit down without hurting myself," says Rhiannon Giles, a writer from North Carolina, who delivered her son at just over 31 weeks after suffering from severe preeclampsia.
"The wires were awful," she remembers. "They fell off constantly when I shifted positions or he kicked a leg, which meant the monitors would alarm. It felt like an intrusion into the quiet little world I was trying to mentally create for us."
Over the last few years, researchers have begun to dive deeper into the literal and metaphorical challenges of wired monitoring.
For many parents, the wires prompt anxiety that worsens an already tense and vulnerable time.
I'll never forget the first time I got to hold my son without wires. It was the first time that motherhood felt manageable.
"Seeing my five-pound-babies covered in wires from head to toe rendered me completely overwhelmed," recalls Caila Smith, a mom of five from Indiana, whose NICU experience began when her twins were born pre-term. "The nurses seemed to handle them perfectly, but I was scared to touch them while they appeared so medically frail."
During the nine days it took for both twins to come home, the limited access she had to her babies started to impact her mental health. "If we would've had wireless sensors and monitors, it would've given us a much greater sense of freedom and confidence when snuggling our newborns," Smith says.
Besides enabling more natural interactions, wireless monitoring would make basic caregiving tasks much easier, like putting on a onesie.
"One thing I noticed is that many preemie outfits are made with zippers," points out Giles, "which just don't work well when your baby has wires coming off of them, head to toe."
Wired systems can pose issues for medical staff as well as parents.
"The main concern regarding wired systems is that they restrict access to the baby and often get tangled with other equipment, like IV lines," says Lamia Soghier, Medical Director of the Neonatal Intensive Care Unit at Children's National in Washington, D.C , who was also a NICU parent herself. "The nurses have to untangle the wires, which takes time, before handing the baby to the family."
I'll never forget the first time I got to hold my son without wires. It was the first time that motherhood felt manageable, and I couldn't stop myself from crying. Suddenly, anything felt possible and all the limitations from that first week of life seemed to fade away. The rise of wired-free monitoring will make some of the stressors that accompany NICU stays a thing of the past.
