Tag Archives: nutrition science

Forging the Future of Personalized Nutrition: My Experience, My Contribution

Introducing the PREDICT 2 Study

I am less than 48 hours away. 48 hours away from beginning my participation in a study that will potentially provide insight into how my body metabolizes food. Not how people my age/gender/race tend to metabolize food, but how my body uniquely metabolizes food.

This study is riding the wave of personalized nutrition that’s been surging through the scientific community for the last decade. Because as scientists learn more and more about nutrition and the digestive system, the clearer it becomes that metabolism is a deeply personal experience.

Imagine this. Instead of following the latest popular diet (i.e. gluten-free, paleo, keto, intermittent fasting), people have the opportunity to take a test to identify their unique responses to different foods. For example, a gluten-free diet may work for some (Celiac disease, gluten intolerance), while for others there might be something else in wheat products that’s causing them discomfort. In theory, this test could identify what “something else” is. 

PREDICT 2

The study is called PREDICT 2, and it involves following a schedule of eating pre-prepared meals and providing blood, saliva, and stool samples for analysis. “PREDICT” stands for “Personalized Responses to Dietary Composition Trial,” and I’ll talk more about the study, its sponsor (a commercial company, Zoe Global Limited), and the collaborators involved (Stanford University, Massachusetts General Hospital, King’s College London, and Tufts University) in more detail later this week. I’ll also be blogging about PREDICT 1, a two-week study that measured physiological responses to specific foods. Researchers showcased preliminary results from PREDICT 1 at the American Society of Nutrition conference early in summer 2019.

12 Days

The study will take place over 12 days: one set-up day, 10 study days, and one follow-up visit to a clinic where I’ll have blood samples taken. I received my study pack in the mail two days ago, and it contained all of the items I’ll need throughout the study, including the standardized meals. 

On some days, I’ll have standardized breakfast and lunch meals that I’ll eat. Depending on the day and the samples I need to provide, I’ll need to wait 2-4 hours after each standardized meal before eating again. I can drink water, coffee, and tea during these times, but they recommend that I drink about the same amount of caffeine that I normally do every day.

I’ll log all of my non-standardized eating and drinking activity in a mobile app I downloaded on my phone. If you’ve ever used My Fitness Pal to track calories and nutrients you’ve consumed through food, the app as very similar to that.

Samples

On the set-up day, I’ll use materials I received in the study pack to collect a stool sample. This sample allows scientists to analyze the diversity of my microbiome, which is key to understanding my body’s unique response to certain nutrients in food. I’ll also collect a saliva sample on the set-up day, which provides the study team with samples of my DNA. The study team describes that DNA samples enable them to “identify certain genetic characteristics that have been previously associated with [my] responses to foods that [they] will measure during the study.” 

On some days, I’ll provide blood samples at specific times before and after meals. From these samples, study scientists can learn about how my blood fat levels change throughout the day and before and after specific meals. The study team describes blood fat levels as a “key metabolic indicator and one of the two main sources of energy in your body,” with blood sugar, or blood glucose, being the other main source of energy.

To measure blood glucose, I’ll be wearing a blood glucose monitor* throughout the study. I activate the monitor myself on the set-up day, about 16 hours before the first study day. The monitor takes this time to calibrate.

*This glucose monitor is FDA-approved for use in the management of diabetes but not for evaluating blood sugar levels in non-diabetic contexts, including this study

In addition to the glucose monitor, I will also be wearing an activity tracker on my nondominant wrist throughout the study to measure my physical activity and sleep levels. This tracker is very similar to FitBit technology.

After the 10 study days, I will visit a Quest Diagnostics Patient Service Center to provide a blood sample. The study team requires that I do this within one week of the tenth study day and before 11:00am so the samples can be shipped and processed at a central lab the following day. 

All of the sample analysis relies on knowing exactly what I consumed to elicit certain physiological responses. Thus, it’s crucial that I follow the food and drink schedule as closely as possible, eating and drinking standardized meals and drinks when scheduled and carefully recording my food and drink consumption at all other times.

Logistics

I am not getting paid to do this study, but I am pretty pumped about getting my results back. The study team is hoping for 1,000 participants, so potentially you could be involved too! A few months after the study, I will be contacted by the study team to discuss my results. If I want them to, they can also share the results with my primary care physician. Essentially, I’m hoping for information on my personal physiological response to components of different foods and how those responses compare to common responses to food. 

While the insights gleaned from this study will likely help build an algorithm for predicting individual responses to food, the informed consent form states: “the predictive value of this research is not yet proven and it is unknown whether you will benefit from the information”

Over the next couple of days, I’ll be posting regular updates about the study as well as providing background information about the people and science involved. I’m really excited (as nerdy as it sounds) to participate in a study that’s doing awesome things for science by learning how different people respond to different foods and what factors account for those differences. I hope people will ask questions about my experiences and be inspired to participate in meaningful studies like this in the future!

Note: While the PREDICT 2 study team encourages participants to share information about the study, the statements made in this blog post and future blog posts are based on my own research and sets of opinions. 

This blog post is the first in a series on my participation in the PREDICT 2 study. Click the links below to read earlier parts of the series:

Algorithm for a Healthy Diet

What can artificial intelligence do for human health? Revolutionize the way we eat, potentially. An opinion article published in the New York Times on Saturday covers the idea of personalized nutrition, made possible by super advanced algorithms and artificial intelligence (A.I.).

The article “The A.I. Diet” is written by cardiologist Eric Topol, and he begins by describing his experience as one of more than a thousand participants in a two-week health study where a sensor and a smartphone app helped track everything he did: eating, sleeping, exercise, and more.

Topol’s data was analyzed by A.I. to ultimately produce a personalized diet algorithm. His results consisted of specific foods receiving a grade, like you would on a test. It seems to me that both his experience and the study design overall highlight the importance of understanding how different foods are good or bad for different people – i.e. blueberries affect me differently than they affect someone else with a different genetic code and lifetime of environmental exposures.

Interestingly, a version of Topol’s study exists as an actual test – commercially available – but analyzes gut microbiome only, not glucose levels or eating habits (here, but it is likely other companies sell something similar).

Topol points out that the main problem is that we often perpetuate the “idea that there is one optimal diet for all people.” More or less, any specific guidance that goes beyond Michael Pollan’s famous quote (and a personal favorite of mine), “Eat food, not too much, mostly plants” is assuming too much about the similarities between individuals, complex and important factors like microbiome status, genetics, and environmental history. Topol: “[This assumption] contradicts the remarkable heterogeneity of human metabolism, microbiome and environment.”

“We know surprisingly little about the science of nutrition.”

Why? Topol cites difficulty with high-quality randomized trials, which are vital for nutrition science (or any type of science for that matter).

“The more understanding we have of foods and nutrition, the more complex food and nutrient interactions become,” explains nutrition scientist Kristine Polley, PhD. “Therefore, controlled and well thought-out study designs are becoming essential to interpret and translate results. High-quality randomized clinical trials provide insight into how nutrients affect human physiology and allow for accurate and critical interpretation of the data collected and the opportunity to apply these outcomes to better overall human health and quality of life.”

Another issue specific to nutrition science studies is that experiments with food habits require strict diet adherence, and there is not always an effective or easy way to ensure study participants are actually following the study’s prescribed diet.

Thirdly, where does the money come from for these types of studies? Unfortunately, often from companies that benefit from the results of the studies, increasing the chances that the results will be swayed one way or the other or misconstrued. In Topol’s words:

“The field [of nutrition science] has been undermined by the food industry, which tries to exert influence over the research it funds.”

The future of individualized/personalized nutrition depends heavily on the success of dependable nutrition studies. This data is vital for building the sophisticated A.I. technology needed to analyze the mass amounts of data to determine each individual’s specific nutritional needs. So the question that remains unanswered is, can nutrition scientists get it together (and find the funding) to obtain the needed results? I think they can.

Do you have an “Appetite for Life?”

The University of North Carolina Nutrition Research Institute (NRI) hosts regular events as a part of a program they call “Appetite for Life.” It’s an initiative to “unlock the promise of personalized nutrition for proactive health management.” In other words, their mission is to show people how to eat for their health, specific to individual genetics and environmental experiences.

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The speaker at the event on September 13 is Steven Zeisel, MD, PhD, and Director of the NRI. Zeisel is world-renowned, a pioneer in the field of personalized nutrition. A nutrient you’ve probably heard of, called choline, is essential for human health, especially concerning pregnant women, and Zeisel is the scientist credited with this discovery.

“I’m not going to tell you what to eat today,” Zeisel says as he begins his talk. Tonight’s event is called “Genetics and Health: Your nutrition needs are as unique as you are,” and the venue, local eatery Restaurant 46, is packed with members of the local community and employees from the neighboring North Carolina Research Campus (NCRC), a 350-acre research center located in Kannapolis, North Carolina.

Zeisel goes on to describe the true meaning of personalized, or precision, medicine and the past, current, and future studies the NRI has in place to make personalized medicine a reality for everyday people concerned with their health.

“Diet can be changed to bypass nutrient deficiencies depicted by the genetic code,” Zeisel goes on. He starts by breaking down the specifics of nutrition science, starting with genetics. He describes single nucleotide polymorphisms (SNPs), common genetic variation that occurs uniquely in all humans, as “spelling errors” in the DNA. Considering that a majority of the audience have a limited understanding of current genetics, Zeisel presents his description of SNPs in an accurate yet simplified manner. After all, what’s the point of talking about bringing personalized medicine to the public if the lay people can’t understand what you’re talking about?

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Zeisel and his colleagues at the NRI are preparing for the future of genetic testing, a technology they predict as being able to sequence an individual’s genetic code to provide a complete record of specific “spelling errors” in the DNA that might make the individual at risk for certain nutrient deficiencies. Being aware of nutrient deficiencies would then allow the individual to change their diet to eat more or less of a certain type of food.

There are companies that exist now, like 23andMe, that can provide genetic information from a DNA sample. However, the product a 23andMe customer gets in return for their money and a cheek swab is just pages and pages of combinations of “AGTC” that’s essentially meaningless unless the customer also happens to be an expert in nutrigenetics with a lot of free time.

Zeisel goes on to talk about choline, folate, and other studies from the NRI and other institutions concerned about health and nutrition. He leaves plenty of time for community members to ask their own questions, many about their health and the health of their loved ones.

The NRI’s story is far from over, but after a while questions subside. For now, people head home with a new perspective on individualized nutrition. The next Appetite for Life event is now something to look forward to, a talk by NRI scientist Stephen Hursting on October 18.

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Images from UNC NRI and Kara Marker