The study showed certain metabolites found in people with type 2 diabetes were linked with metabolites found in people who ate fewer eggs, but were not linked with metabolites found in people who ate more eggs. Metabolites are substances produced during metabolism. Researchers observed these associations among people who ate an average of one egg a day. The study was published in December 2018 in the journal Molecular Nutrition & Food Research. Other research has produced mixed conclusions on the role of eggs in a healthy diet, says Jyrki K Virtanen, PhD, lead author of the new study and adjunct professor of nutritional epidemiology at the Institute of Public Health and Clinical Nutrition at the University of Eastern Finland, in Kuopio. A previous study by Dr. Virtanen and his colleagues, published in May 2015 in The American Journal of Clinical Nutrition, showed that moderate egg consumption — one egg a day — may lower the risk of type 2 diabetes. “The purpose of the current study was to explore, in this same study population, potential mechanisms and pathways that could explain this association,” Virtanen, who is a certified clinical nutritionist, wrote in an email. “For this, we used nontargeted metabolomics analysis, which gives a comprehensive view of the different chemicals in a sample — in this case, blood.” RELATED: 7 Easy Breakfast Ideas for People With Type 2 Diabetes
What’s With All the Flip-Flopping on Eating Eggs?
The 2015 study included 2,332 men ages 42 to 60 who live in eastern Finland. Known as the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD), it is a large, long-term study designed to look at risk factors for heart disease in middle-aged men. The 2015 study findings on egg consumption were intriguing because some healthcare professionals have urged people to limit their egg intake. Moreover, little is known about the effects of eggs on type 2 diabetes risk, according to the 2015 KIHD study. Some research has been conflicting, with a few studies showing no link between egg consumption and the risk of type 2 diabetes, while others have suggested an association. A review of 16 studies published in May 2013 The American Journal of Clinical Nutrition found that eating eggs wasn’t associated with the risk of heart disease and heart-related deaths in the general population. But egg consumption may be associated with an increased incidence of type 2 diabetes among the general population and heart disease among people living with diabetes, that study suggested. “Eggs have traditionally been considered bad because of their high cholesterol content,” Virtanen says. “However, recent research has found that dietary cholesterol intake has just a minor impact on blood cholesterol levels in most people, and dietary cholesterol or egg intake has generally not been associated with increased risk of cardiovascular disease.” He adds that eggs contain several essential nutrients, so judging their health effects based on their cholesterol alone is tricky. According to the Egg Nutrition Center, eggs offer protein, along with vitamins A, E, D, and K. RELATED: Are Eggs Safe for People With Diabetes to Eat?
A Closer Look At the Study on How Eggs May Affect Type 2 Diabetes Risk
In the new research, Virtanen and his colleagues studied 239 people from the KIHD study, analyzing the health of those who consumed an average of one egg per day and those who ate an average of two eggs per week. They examined blood samples and who developed type 2 diabetes over 19 years. The study found that metabolites in blood differed based on participants’ egg eating habits. The metabolites predicting diabetes risk included tyrosine and an unknown hexose-containing compound. “The strengths of the study include detailed information on egg intake that also included eggs used in mixed dishes and recipes,” Virtanen says. “The nontargeted metabolic profiling platform gives a comprehensive view of the metabolites in the blood and creates the possibility of a novel insight of plausible mechanisms.” Nevertheless, one potential limitation is researchers drew the blood samples from an observational study, he says. “We cannot draw conclusions about causality. This would require a clinical trial. But no experimental study so far has used metabolomics analyses to investigate the physiological effects of high egg intake.” The metabolic analysis used in the study provides a newer way to better understand the effects of various foods, says Sandra J. Arevalo, MPH, RDN, a spokesperson for the American Association of Diabetes Educators and director of nutrition and outreach at Montefiore Community Programs in New York City. Arevalo wasn’t involved in the current study. “There is a lot of confusion over eggs,” she says. “I think it comes from the fact that we’ve been concerned about high cholesterol and had the perception that eggs were bad. But new research has come out, and now we know that even though eggs are high in cholesterol, they don’t affect body cholesterol levels as much as we thought.” The new study results are in line with a growing consensus that people managing diabetes or prediabetes don’t need to avoid eggs. “Egg white has a lot of protein. Eggs don’t have carbohydrates,” she says. “When you have diabetes, you have problems with carbohydrates, not with protein.”
How Many Eggs to Eat if You Want to Prevent or Manage Type 2 Diabetes
But, Arevalo says, excessive egg intake, such as two eggs a day, can contribute to heart disease because of the cholesterol and fat content. “What often kills people with diabetes are heart attacks. But you’re not going to get diabetes from eating eggs.” According to the Centers for Disease Control and Prevention (CDC), people with diabetes are 2 times as likely to die of heart disease than people without diabetes. Americans’ egg-eating habits have fluctuated over the past 70 years as studies have been released on their health effects. According to the U.S. Department of Agriculture (USDA), egg consumption per person dropped from 389 eggs per day in 1950 to 236 per year in 1990. But consumption has since risen again, with an average annual consumption of 247 eggs per person in 2008. “For most people, one egg per day seems to be okay, Virtanen said. “However, if you have high blood cholesterol or already have diabetes, it might be better to limit intake to just a couple of eggs per week.”
