Dr. Eran Segal—The Value of Personalized Nutrition

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In this episode of Longevity by Design, our hosts, Dr. Gil Blander and Ashley Reaver, MS, RD, CSSD, are joined by Dr. Eran Segal, Faculty Member at The Weizmann Institute of Science in Israel. Tune in as Dr. Eran Segal discusses the value of personalized nutrition, how data contributes to our knowledge of personalized food responses, and the relationship between food and longevity.

Meet Longevity by Design’s podcast guest, Dr. Eran Segal

Dr. Eran Segal is a computational biologist and faculty member in the Department of Computer Science and Applied Mathematics at The Weizmann Institute of Science in Israel. The Segal Lab is multidisciplinary, with research scientists focusing on the microbiome, nutrition, genetics, gene regulation, and more. The Segal Lab’s collective goal is to develop both personalized nutrition and medicine using machine learning, computational biology, and more.

Nutrition is truly personal

Nutrition undoubtedly influences our overall health. Recent research makes a strong case for personalized nutrition. Individuals respond uniquely to food—different people need different foods and nutrients to meet their personal needs. Therefore, personalized nutrition is vital. 

When Dr. Segal’s team began researching personalized nutrition, the first question they needed to resolve was what outcome or endpoint to measure to quantify the impact of personalized nutrition. He explained that other research teams used body weight as an outcome. Yet, the more he contemplated, he decided that body weight has shortcomings, “It takes time to change body weight to change robustly. And when you look at an individual—say at baseline and then a few weeks or months moving forward—body weight changes are affected by many factors.” He further explained that it would be difficult to attribute particular aspects of a person’s nutrition to their body weight: as weight fluctuations are representative of the compounded effect of meals, exercise, sleep patterns, etc. Dr. Segal shifted focus to exploring postprandial glucose response using continuous glucose monitors (CGM). 

Glucose monitoring devices continuously measure the glucose concentration in one's interstitial fluid. The glucose concentration in interstitial fluid is highly correlated with blood glucose concentration, giving insights into how a person's body responds to their meals. Dr. Segal's team put CGM's on 1,000 healthy people and studied glucose responses to 50,000 meals, supplying him with a unique dataset to evaluate variations between people after eating the same meal. "We saw a lot of surprises. Foods that you would expect to cause huge glucose spikes didn't occur in some people, and vice versa. At times, foods that are considered healthy spiked some glucose levels and eventually caused participants to gain weight." 



Taking a data-driven approach to personalized nutrition

Dr. Segal commonly measures large quantities of data with multiple outcomes, including subclinical data. "I truly believe that if you measure enough data for enough time, you'll obtain insights into the underlying factors that account for the variation in people and how different inputs combined with the makeup of an individual lead to specific outcomes. Such data is valuable for deciphering the different questions related to healthspan and longevity." 

Dr. Segal further discusses the three significant findings from his nutrition studies. First, people have very different blood glucose responses to food. "Generally, food affects people differently. While we studied glucose specifically, the variation in a population's response to foods aren't confined to just glucose. When measuring the right data, you can understand what factors correlate with different responses. Then, with enough data, you can develop an algorithm that predicts how a person will respond to a meal."



Personalized nutrition and longevity

Personalized nutrition has the power to affect longevity, but it also contributes to the quality of our current lifespan. Dr. Segal's final takeaway relates to the success he has seen from testing personalized nutrition strategies through clinical trials. Dr. Segals' team has conducted many clinical trials on populations with different health conditions, including pre-diabetes, type two diabetes, and breast cancer. "When you implement this personalized nutrition approach on a sick population, you can improve their health and clinical outcomes. We've seen this many, many times now. Through personalized dietary change, people have come off blood pressure medications, medications for type two diabetes, their weight comes down, and their glucose improves without medication," explains Dr. Segal. People are different, and their nutrition approaches must reflect these differences. 

Because chronic diseases are highly prevalent in the United States, healthcare focuses on disease treatment with medications that alleviate symptoms rather than addressing underlying causes. However, healthcare can focus on disease prevention by approaching this problem with lifestyle interventions. As a result, personalized nutrition has introduced us to an exciting new era of healthspan and longevity.



Advice on living a healthier longer life

Dr. Eran Segal has made a strong case for how each person's health and nutrition are unique. When asked to share one decision he makes every day to improve his health, he responds, "While I don't believe you should take my advice as a rule that would work for everybody, I find that I personally feel best when I confine my window of eating from around lunchtime to evening. This is not a religious practice—you have to find the right balance between healthy living and enjoying life. In general, I eat the foods I have found are right for me. This combination makes me feel energetic and able to do extensive sports in the morning, and then I don't feel hungry until around lunchtime."