In a groundbreaking study, researchers at Sinai Health have challenged the prevailing belief that a surge in insulin levels following meals is detrimental to health. Led by Dr. Ravi Retnakaran, a Clinician-Scientist at the Lunenfeld-Tanenbaum Research Institute, the study offers new insights into the connection between post-meal insulin levels and long-term heart and metabolic health.
Contrary to common assumptions, the research suggests that an increase in insulin levels could actually be an indicator of positive future health outcomes. Published in eClinicalMedicine, the study sought to clarify the impact of insulin levels after meals on cardiometabolic health. Previous research had produced conflicting results, with some suggesting harmful effects, particularly in relation to weight gain and insulin resistance.
Insulin resistance occurs when the body’s cells do not respond effectively to insulin, increasing the risk of type 2 diabetes. Dr. Retnakaran explained that the concern arose from the belief that rapid insulin increases, especially after consuming carbohydrates, may contribute to weight gain and insulin resistance. Some individuals, influenced by online information, adopted the idea that minimizing insulin spikes is crucial for health.Â
The research team aimed to provide a more comprehensive understanding by investigating the long-term cardiometabolic implications of insulin responses. The study focused on new mothers, leveraging the insulin resistance that occurs during pregnancy to assess their future risk of type 2 diabetes. A total of 306 participants were recruited during pregnancy between 2003 and 2014, undergoing comprehensive cardiometabolic testing at one, three, and five years after giving birth.Â
To address the limitations of past studies, the team considered baseline blood sugar levels, recognizing that individual insulin responses vary depending on blood sugar levels. The study utilized the corrected insulin response (CIR), a measurement that accounts for baseline blood glucose levels, providing a more accurate understanding of insulin’s role.Â
Surprising trends emerged from the study. As the corrected insulin response increased, there were observable negative impacts on waist circumference, HDL (good cholesterol) levels, inflammation, and insulin resistance when not considering accompanying factors. However, these seemingly adverse effects were accompanied by improved beta-cell function. Beta cells, responsible for insulin production, play a crucial role in diabetes risk; higher beta cell function is associated with a lower risk of diabetes.Â
Dr. Retnakaran emphasized, “Our findings do not support the carbohydrate-insulin model of obesity.” He clarified that a robust post-challenge insulin secretory response, when adjusted for glucose levels, was associated with beneficial metabolic effects. Contrary to the belief that high post-meal insulin levels are inherently bad, the study indicated that a strong post-challenge insulin secretory response predicts favorable metabolic function in the future.Â
The research challenges the notion held by some practitioners that higher insulin levels are universally negative. Dr. Retnakaran expressed the complexity of the issue, noting that recommendations to limit insulin fluctuations after meals might oversimplify the relationship.Â
In the long run, higher corrected insulin response levels were linked with better beta-cell function, lower glucose levels, and a significantly reduced risk of developing pre-diabetes or diabetes. The study’s findings have the potential to reshape how both medical professionals and the public perceive the role of insulin in metabolism and weight management.Â
Anne-Claude Gingras, Director of LTRI and Vice President of Research at Sinai Health acknowledged the significance of the research in challenging preconceived notions about insulin’s impact on metabolism. Dr. Retnakaran hopes that the study will prompt a reevaluation of current perspectives on insulin and its role in promoting overall health.Â
Journal reference Â
Future Cardiometabolic Implications of Insulin Hypersecretion in Response to Oral Glucose, eClinicalMedicine (2023). www.thelancet.com/journals/ecl … (23)00540-0/fulltextÂ
