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.”
These new products have their own pros and cons. Still, doctors are welcoming new contraceptives following a long drought in innovation. "It's been a long time since we've had something new in the world of contraception," says Heather Irobunda, an obstetrician and gynecologist at NYC Health and Hospitals.
On social media, Irobunda often fields questions about one of these new options, a lubricating gel called Phexxi. San Diego-based Evofem, the company behind Phexxi, has been advertising the product on Hulu and Instagram after the gel was approved by the Food and Drug Administration in May 2020. The company's trendy ads target women who feel like condoms diminish the mood, but who also don't want to mess with an IUD or hormones.
Here's how it works: Phexxi is inserted via a tampon-like device up to an hour before sex. The gel regulates vaginal pH — essentially, the acidity levels — in a range that's inhospitable to sperm. It sounds a lot like spermicide, which is also placed in the vagina prior to sex to prevent pregnancy. But spermicide can damage the vagina's cell walls, which can increase the risk of contracting sexually transmitted diseases.
"Not only is innovation needed, but women want a non-hormonal option."
Phexxi isn't without side effects either. The most common one is vaginal burning, according to a late-stage trial. It's also possible to develop a urinary tract infection while using the product. That same study found that during typical use, Phexxi is about 86 percent effective at preventing pregnancy. The efficacy rate is comparable to condoms but lower than birth control pills (91 percent) and significantly lower than an IUD (99 percent).
Phexxi – which comes in a pack of 12 – represents a tiny but growing part of the birth control market. Pharmacies dispensed more than 14,800 packs from April through June this year, a 65 percent increase over the previous quarter, according to data from Evofem.
"We've been able to demonstrate that not only is innovation needed, but women want a non-hormonal option," says Saundra Pelletier, Evofem's CEO.
Beyond contraception, the company is carrying out late-stage tests to gauge Phexxi's effectiveness at preventing the sexually transmitted infections chlamydia and gonorrhea.
Phexxi is inserted via a tampon-like device up to an hour before sex.
Phexxi
A New Pill
The first birth control pill arrived in 1960, combining the hormones estrogen and progestin to stop sperm from joining with an egg, giving women control over their fertility. Subsequent formulations sought to ease side effects, by way of lower amounts of estrogen. But some women still experience headaches and nausea – or more serious complications like blood clots. On social media, women recently noted that birth control pills are much more likely to cause blood clots than Johnson & Johnson's COVID-19 vaccine that was briefly paused to evaluate the risk of clots in women under age 50. What will it take, they wondered, for safer birth control?
Mithra Pharmaceuticals of Belgium sought to create a gentler pill. In April, the FDA approved Mithra's Nextstellis, which includes a naturally occurring estrogen, the first new estrogen in the U.S. in 50 years. Nextstellis selectively acts on tissues lining the uterus, while other birth control pills have a broader target.
A Phase 3 trial showed a 98 percent efficacy rate. Andrew London, an obstetrician and gynecologist, who practices at several Maryland hospitals, says the results are in line with some other birth control pills. But, he added, early studies indicate that Nextstellis has a lower risk of blood clotting, along with other potential benefits, which additional clinical testing must confirm.
"It's not going to be worse than any other pill. We're hoping it's going to be significantly better," says London.
The estrogen in Nexstellis, called estetrol, was skipped over by the pharmaceutical industry after its discovery in the 1960s. Estetrol circulates between the mother and fetus during pregnancy. Decades later, researchers took a new look, after figuring out how to synthesize estetrol in a lab, as well as produce estetrol from plants.
"That allowed us to really start to investigate the properties and do all this stuff you have to do for any new drug," says Michele Gordon, vice president of marketing in women's health at Mayne Pharma, which licensed Nextstellis.
Bonnie Douglas, who followed the development of Nextstellis as part of a search for better birth control, recently switched to the product. "So far, it's much more tolerable," says Douglas. Previously, the Midwesterner was so desperate to find a contraceptive with fewer side effects that she turned to an online pharmacy to obtain a different birth control pill that had been approved in Canada but not in the U.S.
Contraceptive Access
Even if a contraceptive lands FDA approval, access poses a barrier. Getting insurers to cover new contraceptives can be difficult. For the uninsured, state and federal programs can help, and companies should keep prices in a reasonable range, while offering assistance programs. So says Kelly Blanchard, president of the nonprofit Ibis Reproductive Health. "For innovation to have impact, you want to reach as many folks as possible," she says.
In addition, companies developing new contraceptives have struggled to attract venture capital. That's changing, though.
In 2015, Sabrina Johnson founded DARÉ Bioscience around the idea of women's health. She estimated the company would be fully funded in six months, based on her track record in biotech and the demand for novel products.
But it's been difficult to get male investors interested in backing new contraceptives. It took Johnson two and a half years to raise the needed funds, via a reverse merger that took the company public. "There was so much education that was necessary," Johnson says, adding: "The landscape has changed considerably."
Johnson says she would like to think DARÉ had something to do with the shift, along with companies like Organon, a spinout of pharma company Merck that's focused on reproductive health. In surveying the fertility landscape, DARÉ saw limited non-hormonal options. On-demand options – like condoms – can detract from the moment. Copper IUDs must be inserted by a doctor and removed if a woman wants to return to fertility, and this method can have onerous side effects.
So, DARÉ created Ovaprene, a hormone-free device that's designed to be inserted into the vagina monthly by the user. The mesh product acts as a barrier, while releasing a chemical that immobilizes sperm. In an early study, the company reported that Ovaprene prevented almost all sperm from entering the cervical canal. The results, DARÉ believes, indicate high efficacy.
A late-stage study, slated to kick off next year, will be the true judge. Should Ovaprene eventually win regulatory approval, drug giant Bayer will handle commercializing the device.
Other new forms of birth control in development are further out, and that's assuming they perform well in clinical trials. Among them: a once-a-month birth control pill, along with a male version of the birth control pill. The latter is often brought up among women who say it's high time that men take a more proactive role in birth control.
For Summers, her search for a safe and convenient birth control continues. She tried Phexxi, which caused irritation. Still, she's excited that a non-hormonal option now exists. "I'm sure it will work for others," she says.