1 November 2017

PERSPECTIVES WITH DR ALAN BARCLAY

DIABETES. IS AN EGG A DAY OK? 
Boiled eggs
The answer is a qualified yes. Here’s why. Eggs are popular. They are delicious and convenient and easy to cook. There’s also a steady stream of scientific research looking at whether we can enjoy them as part of our daily fare, or whether we should limit them. Two recent systematic reviews help explain the evidence and provide an answer for people with type 2 diabetes and those at risk. It’s worth remembering, eggs are a highly nutritious food. One hard-boiled egg is: 

  • A good source of protein and vitamins – B (B12, pantothenic acid, riboflavin, folate), A, E, and is one of the few food sources of vitamin D 
  • A relatively good source of iodine, iron, zinc and phosphorus 
  • Rich in omega-3 fatty acids and cholesterol, and is a source of saturated, poly-unsaturated, and mono-unsaturated fats, with a saturated : unsaturated fat ratio of 0.48 (the ideal ratio is less than or equal to 0.5 so they squeeze in). 
The systematic review that looked at egg consumption on cardiovascular risk factors for people with diabetes included all randomised controlled trials where people consumed either 6–12 eggs per week compared to a control group that consumed no eggs or few eggs (less than 2 eggs a week), for 12 to 20 weeks. In a total of 6 studies, the authors found that consuming 6 to 12 eggs per week had no impact on total cholesterol, LDL (“bad”) cholesterol, triglycerides, fasting blood glucose (sugar), or insulin and that HDL (“good”) cholesterol increased in 4 of the 6 included studies. While these results are encouraging, the study authors noted that “...the studies varied in diet composition aside from the addition of eggs.” Indeed, most of the studies were reduced energy (kilojoules/calories), and had beneficial ratios of saturated : unsaturated fats.

The second review looked at all of the data from observational studies and the risk of developing type 2 diabetes and found that from a total of ten studies (5 in Europe, 4 in the USA and 1 in Asia), consuming 1 egg a day was associated with a 13% higher risk of developing type 2 diabetes. However, they determined that risk was strongly influenced by where you live, with people in the USA consuming 1 egg a day having a 47% increased risk, and people living in Europe and Asia having no increased risk. The authors noted that “...in the US studies, egg intake is often associated with smoking or lower physical activity or higher intake of red meat, whereas this is generally not observed in studies outside the USA.” and that “Food preparation methods (e.g. boiled or fried eggs, whole eggs or only egg whites) or concurrent consumption of other foods that may increase diabetes risk (e.g. home fries, bacon) may also account for a part of the differences, but such information is not available in these studies.”

So yes, it is ok to eat an egg a day if you are at risk of or have type 2 diabetes – provided you enjoy them as part of a healthy balanced diet, rich in other quality proteins (lean poultry, meats and seafoods), minimally refined low GI carbohydrates, and healthy fats (e.g., Canola, olive, peanut, or sesame oil; nuts and seeds). It’s the overall eating pattern that counts. And poach don’t fry.

Declaration of interest. My family loves eggs. We keep chooks and enjoy meals made with their fresh eggs every week.

Studies 
 Dr Alan Barclay  
Alan Barclay, PhD is a consultant dietitian. He worked for Diabetes Australia (NSW) from 1998–2014 . He is author/co-author of more than 30 scientific publications, and author/co-author of  The good Carbs Cookbook (Murdoch Books), Reversing Diabetes (Murdoch Books), The Low GI Diet: Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment, New York).