Appetite for Life Review
Speed Dating with the NRI: 3-Minute Nutrition Theories

These 3-minute theory presentations are designed to effectively explain complex scientific research in down-to-earth language for a non-scientific audience. 

Precision Nutrition 101

My name is Walter Friday, and I am a research specialist in the lab of Dr. Isis Trujillo-Gonzales. I have worked as a lab technician at the Nutrition Research Institute for the last 12 years.

The UNC NRI was founded around 15 years ago as part of the North Carolina Research Campus in Kannapolis. The NRI has continued to grow in size and research during that time. We have a diverse group of faculty and staff working on a variety of research goals with an overall emphasis on precision nutrition.

That leads to the question, “What exactly is Precision Nutrition?”

Most of the information we have on nutrition is very generalized. I grew up with the USDA’s food pyramid and more recently the food plate has been developed to provide nutritional advice. These provide good information as a general rule. The problem is that a one-size-fits-all approach isn’t always a good fit for everyone. This general approach treats us like we are all the same and looking around the room…clearly, we are not all the same.

For instance, you may have noticed that I am a Caucasian male. I’m in my fifties and was born and raised in North Carolina. My dietary needs may be different than a 30-something African American woman living in California or a 70-year-old Hispanic male living in New York. General nutrition advice, such as the food pyramid, doesn’t take these differences into account.

When precision nutrition comes up at my home, my wife, Renee, has often told me she would like to be able to give a DNA sample then wait for some science to happen and get a definitive result saying, “Renee, broccoli is good but for you no carrots or perhaps pasta with marinara is great, but you can’t have the alfredo.”

This is not what precision nutrition is about, (at least not yet).

Dr. Steve Zeisel, the founding director of the NRI, says that precision nutrition is not about developing unique diet plans for individual people but rather about organizing people into subgroups of the population based on how we are different in such areas as genetics, microbiome, lifestyle, and environmental exposure. With this information we can better provide dietary recommendations and interventions that may lead to better health outcomes by watching what we eat.

At the NRI, we seek to understand better how nutrients are metabolized in the body and how this is related to human development and disease. Our goal increasingly is to replace general dietary guidance with more customized nutrition recommendations, encouraging us all to eat uniquely.

Walter Friday

Walter Friday

Research Specialist, Trujillo Lab

Walter has been a research technician and specialist at the NRI for 12 years, serving first in the Zeisel Lab and currently in the Trujillo Lab where the focus is on understanding the links between choline metabolism and brain development. Broadly, Walter’s work has centered on the foundations of precision nutrition. 

Boosting Energy Expenditure... with fat?!

The Voruganti lab has many research focuses centered on nutrition and human health but our work is aimed primarily at understanding obesity with an emphasis on purine metabolism as well as nutrigenetics and nutrigenomics work, which is how DNA is influenced by nutrition and how nutrition influences DNA.  For the ones wondering what purines are; purines occur within the body and are some of the building blocks of DNA. If you have heard of ATP – which is how cells make energy – you have heard of purines. ATP stands for adenosine triphosphate and adenosine is a purine. Interestingly, adenine was at one point named vitamin B4 but this title did not stick as it is not considered an essential nutrient since our body can make it and we don’t need it in our diets like some other nutrients. Another purine metabolite you may be familiar with is uric acid, of which high levels are indicated in gout and kidney stones. Purines are high in foods like brewer’s yeast, fish, and meat, particularly organ meats like liver.

My current research question is related to inosine, which is a purine, and how consumption of this purine may increase energy expenditure in the body. Now you might be wondering how that is possible. 

In the body there are different types of fat cells – most of the fat on the body is white fat.  But there is another type of fat as well and it’s called brown fat. So why is it called brown fat? Well, have you ever heard that mitochondria are the powerhouse of the cell? Brown fat cells are fat cells with extra mitochondria, making them look brown instead of white. These extra mitochondria mean these cells burn more energy than other fat cells. These cells make a protein called uncoupling protein or UCP-1 which increases the amount of energy that the cells give off as heat.  

In mice studies, inosine supplementation has increased the amount of brown fat and the number of calories that the mice burn. So I am planning to conduct a study looking to see if this inosine supplementation may increase energy expenditure and improve metabolism in humans, as it has been shown to do in mice. First, I am going to look at the differences in inosine treatment on mice cells compared to human cells in cell culture. After that, I will be supplementing research participants with inosine and measuring changes to their metabolic rate by using a room that measures the amount of energy people burn called a metabolic chamber. 

The benefits of this increase in brown fat in humans have been linked with less body fat and improvements in obesity-related diseases such as heart disease, fatty liver, and type 2 diabetes. 

Lydia Dooley

Lydia Dooley

Doctoral Student, Voruganti Lab

A certified Registered Dietitian, Lydia is studying for her PhD in the Voruganti Lab, which focuses on uncovering new connections between genetics, nutrition and epidemiology that can lead to more accurate determination of disease risk and new treatment options for metabolic diseases.

Effects of Drug-induced Weight Loss on Cancer

Obesity affects a lot of people – the latest estimate is that 1/3 of adults in the US are obese, and another 1/3 are overweight. Having obesity can lead to negative health outcomes – like increased risk of cardiovascular disease, diabetes, and several types of cancer – which is my particular area of expertise. Because of this increased risk, reversal of obesity, also known as weight loss, is a major goal with the potential to reduce the odds of developing subsequent chronic diseases. Losing weight can help to improve overall health and quality of life, but the problem is that anyone who’s tried to lose weight through dieting alone knows that it’s really hard! And the alternative approach, bariatric surgery, is effective but it’s an invasive procedure that can be somewhat risky.

A newly developed alternative to these methods of weight loss is a class of drugs known as antiobesity medications, or drugs that are designed to help people lose weight. The pharmaceutical company Eli Lilly recently developed a diabetes drug called tirzepatide, or, as they’re marketing it, Mounjaro. In clinical trials, people taking the drug saw weight loss of around 20% of their body weight after using the drug for almost 1.5 years. While this trial showed that weight loss is achievable with tirzepatide, the researchers doing this study didn’t assess the effects of tirzepatide on cancer outcomes. This is because cancer takes several years to develop in humans, so a trial assessing the effects of tirzepatide on weight loss and cancer development would take decades and millions of dollars to complete. This is where we come in.

In the Hursting lab, where I work, research in mice has already shown that weight loss through either calorie restriction or through bariatric surgery does decrease cancer outcomes like tumor size. The goal of my research is to determine if using tirzepatide to achieve weight loss in mice will have similar effects to what we’ve seen before, where weight loss before breast cancer initiation slows down tumor growth and progression. I’ve already done preliminary work confirming that mice can lose up to 20% of their body weight in as little as 2-3 weeks of tirzepatide use, and I’ll be completing studies in the coming months to determine if tirzepatide treatment before development of breast cancer in obese mice slows down tumor growth. We’re also interested in exploring whether tirzepatide has any effects on tumor growth that occurs separately from weight loss, so these might include direct effects of tirzepatide on tumor cells. We are hypothesizing that weight loss from tirzepatide will slow down breast tumor growth in mice. If our hypothesis is correct, this may mean that weight loss with tirzepatide in humans could prevent or delay cancer development, meaning we could have fewer cases of cancer, and more time to live good and healthy lives with our loved ones.

Violet Kiesel

Violet Kiesel

Postdoctoral Research Associate, Hursting Lab

Violet’s postdoctoral work in the Hursting Lab looks at the molecular and metabolic associations between nutrition, obesity, and cancer. Violet’s focus is on disturbances in metabolism that arise in cancer cells and how these disturbances change as metastasis progresses, particularly in the context of weight loss.

Heart Health Starts in the Mouth

Have you ever wondered how important healthy gums are for heart and blood vessels?  We at the UNC Nutrition Research Institute want to find out for sure with the Baseline Oral Health Study. This is an ongoing study and we are still recruiting participants to put the benefit of treating common gum disease to the test.

There are many reasons for wanting to keep teeth and gums healthy. We focus on the arteries because animal experiments and previous smaller studies showed that less inflammation means healthier arteries in the heart and elsewhere. It is known that inflamed gums send harmful signals to the entire body. We also know that inflammation makes it harder for the arteries to do their active work and get blood to all parts of the body. It is important to know that arteries are not just passive tubes but actively help to get the job done with each heartbeat. This extra push of the blood flow becomes even more important when oxygen transport is slowing because of heart disease.

But how can we measure and show that there is an actual benefit with the gum treatment?

We use an ultrasound instrument that gets detailed images of the large artery in the upper arm. This painless method shows us how well the artery works. We test in detail how the artery widens when it needs to let more oxygen through, for instance to power muscles. We also want to know whether it tightens up properly when we rest. The images show very precisely how the width of the artery changes and how much blood flows under different conditions.

In our study we make these measurements before the first thorough tooth cleaning treatment and then again after 6 and 12 months of constantly promoting and improving gum health. We hope that all that work for healthier gums will make the arteries function better and that we can see the effect with our ultrasound method.

I welcome questions about participation from anybody with heart disease and bleeding or inflamed gums if we have at least 16 healthy teeth to work with. We will be recruiting for a few more months.

This investigation promises to tell us how well an intense program of dental care really supports the health of hearts and blood vessels.

Martin Kohlmeier

Martin Kohlmeier

Professor of Nutrition

Martin joined the NRI in 2010, bringing decades of expertise in nutritional genetics to anchor the NRI’s mission of advancing knowledge of precision nutrition. He is the author of several textbooks on the topic and, as principal investigator, currently leads the Project Baseline Oral Health Study with study sites both at the NRI and on the UNC Chapel Hill campus. This major study bridges our institute with the UNC Adams School of Dentistry, one of many significant collaborations.

When Mom Drinks, Baby Drinks

It is a hidden truth that 1 in 7 pregnant people in United States reports drinking alcohol in the past 30 days. And about 1 in 20 pregnant people reports binge drinking—defined as 4 or more alcoholic beverages on one occasion—in the past 30 days. We all know how drinking alcohol affects the body: it affects organs, and metabolism—suppressing appetite, causing blood sugar to drop—among many other affects. But, what happens when a mother drinks alcohol?

When mothers drink during pregnancy, the alcohol reaches the unborn baby. Because baby has no way to dispose of that alcohol, it keeps floating in the amniotic fluid and causes various degrees of birth defects, stunted growth and memory and cognitive delays. Studies have now shown that, even if there is no visible birth defect or developmental delay in the child, they are still at a risk of having metabolic disorders such as insulin resistance, diabetes, obesity, heart diseases, etc., at the later stages of life.

Various researchers find ways to mitigate these developmental defects after the baby is born. But I want to reduce these effects in the womb only. No doubt, the best way to protect the child is to cut back on alcohol at any time during pregnancy and minimize some of the adverse outcomes. But some pregnant people continue to do so due to multiple reasons.

We all know a balanced nutritious diet increases the chances of a healthy pregnancy. But what alcohol does is, it prevents the absorption of some of the important nutrients in the mother’s body.

Through my research, I want to understand how alcohol interacts with these nutrients in the mother and causes harmful effects in the baby. In the womb, one of the main sources of energy for baby’s growth is glucose that comes from the mother. Glucose is the simplest form of sugar and is used for growth, organ development and even storing fat, which is used by the baby after birth.

My ongoing research finds that when you give alcohol to a pregnant mouse, this transfer of glucose from mother to the fetus is reduced. When limited glucose is available, fetus is forced to decide if it needs to survive or have optimal growth. This is one of the many ways in which alcohol affects the growing baby. In my future research, I want to target mother’s nutrition and improve this transfer of glucose to the fetus so that some these adverse effects can be minimized.

Nipun Saini

Nipun Saini

Postdoctoral Research Associate, Smith Lab

Nipun has worked in the Smith Lab for six years, helping the team advance understanding of the mechanisms by which dietary components affect prenatal development, particularly how alcohol damages the embryo and fetus, and the environmental and genetic factors that heighten alcohol’s toxicity.

Feeding the Brain with Choline

One of the important aspects of eating is the quality of the food. We usually think about how much to eat but we should ask ourselves about the quality of what we decide to eat, I mean the benefits of the food to support our healthy body. 

In terms of nutrition, choline is an essential nutrient for the human body. Choline is able to supports our muscles, makes the liver work well through fat transportation and maintains a healthy heart and brain. It is an essential nutrient to keep us alive and healthy, and that’s the reason for in our research team is evaluating the current status of choline in different scenarios: health and disease. 

One of these includes those related to autism spectrum disorder, particularly Rett syndrome, a disease where girls are apparently healthy, born normally, but eventually develop alterations with repetitive movements, for example clapping, decreased concentration, behavior issues and, finally, loss of motor skills. 

This happens because, when the brain is developing during pregnancy, neurons need to mature and grow, but they remain in a premature state, as in stand-by status without being able to differentiate. Well, choline has been shown to have beneficial effects on these neurons. Using preclinical models of Rett syndrome, choline supplementation ameliorates the challenges of the disease. This potentially translates into a better quality of life for girls living with Rett syndrome. 

How much choline to take? We can include choline in our diets, eaten in fish, eggs, spinach, and low-fat meats. If I include these foods during the week, I can preserve the benefits that choline provides me. 

Remember: Choline keeps our brain healthy; and a healthy brain translates into a happy life! 

Jorge Silva

Jorge Silva

Postdoctoral Research Associate, Trujillo Lab

Jorge joined the NRI from the University of Guadalajara where he studied molecular biology and human nutrition, focusing on chronic inflammatory processes for cancer development and the impact of unbalanced dietary patterns on fatty acids. In the Trujillo Lab at the NRI, he investigates the effects of choline on disorders that impair the growth and development of the brain and central nervous system.

Jump in the Pool

Hello! I’m Julie Stegall. I have worked at the NRI since 2009 on studies with people ages 3 months to 79 years. I have participated in studies myself on the research campus, as have my children, my parents, and other family and friends. In my time at the NRI, I’ve had many people say, “Hey, That was fun! Can you let me know about other studies I could do?” As a result, we developed a “participant pool.”

So I’m here to invite you to jump into our participant pool at the NRI!

The participant pool is a secure database where we store basic contact information of people who are interested in learning about possible research opportunities. When we have a new study come along, we reach out to the people in the pool to share the information. Often they may be the first to learn of a new study opportunity.

I want to highlight some key points about the participant pool:

1. If you sign up it does NOT mean you must participate in any study. Being in the pool only lets us notify you ABOUT a study. We give you the information then it’s up to YOU to follow up with the researcher directly IF you decide you want to learn more. 

2. You are only required to give one method of contact and your birth month and year (not day). Optional information you provide includes other contact methods, sex, race, ethnicity, height, and weight.

3. There are no geographic limitations. Back when the research campus first started, there was one study that had strict limits so people thought if they lived outside a certain area they could not participate in any study. This is not true. Most studies do not have any kind of geographic limitation on them—you decide if it’s a reasonable distance for you.

4. There are no age limitations for the participant pool. While some studies have age limits, there is one coming up soon that nearly every person over 18 can join. No one is too old.

5.  Studies almost always provide some payment in recognition of the time and effort the study requires.

6. Why is study participation important? For us to learn more about individualized nutrition—we need individuals—simple as that. All of us are unique and we need to see ourselves represented in the research. 

Everyone in our area will have a chance to be represented in research in the next few months! We are currently in the process of setting up as an enrollment site for All of Us which is a national research program with a goal of building one of the most diverse health databases in history by enrolling 1 million people. We will also be starting a new nutrition study that goes along with All of Us. We invite you to jump in our participant pool and follow us on social media so you are aware of all the great ways you can help us learn more.

Julie Stegall

Julie Stegall

Research Services Coordinator

Julie joined the NRI in 2009, helping launch some of the first studies with human participants on the campus. She has been study coordinator with three labs on major studies, recruiting babies, kids of all ages, and adults. Currently, she’s working to launch a study at the NRI, part of a nationwide effort funded by the National Institutes of Health that will include 1 million people.