Preventing Type 2 Diabetes
The age old saying prevention is better than cure is all too true for type 2 diabetes. We often focus so much on managing diabetes that we take our eye off the fact that it is a preventable disease! There is some interesting literature about preventing type 2 diabetes. Professor Renée Blaauw took the time to sift through the latest literature and presented her findings in a most interesting seminar. In this article I am summarizing the main findings.
Although not a new finding, it is important to mention that obesity (BMI > 30) is strongly related to diabetes. This is because obesity is connected with inflammation, and this disrupts the insulin action, contributing to insulin resistance. The key is to stay in a healthy weight range by not eating an excess of calories.
High protein diets have shown positive effects on weight loss and glucose control in the short term. However, what is now showing in studies is that if protein is eaten in high quantities, especially if it is eaten instead of carbohydrates or fats, it actually results in an increased risk for type 2 diabetes. Interestingly, in a study by Ericson et al the difference in protein intake between the lowest and highest intakes was 7% (14g for women and 18g for men), and this led to a 63% increased risk in type 2 diabetes. A large egg contains 7g of protein.
Grains and Fibre
It is well known that refined grains are not good for our health. The protective effect of whole grains was quantified as a 32% decrease in type 2 diabetes from 3 servings of whole grains per day in a meta-analysis by Aune et al. Is it the whole grains per se or the fibre content? A meta-analysis of the relationship between dietary fibre and risk for type 2 diabetes by Yao et al demonstrated that there is a 19% reduced risk for type 2 diabetes. Two points of interest from the study were 1) that there were different results for the different fibre components (the risk reduction was far greater for insoluble fibre and cereal fibre – 25 and 23% respectively – than for fruit fibre – 6%) and 2) that there was a dose-response effect (15g of fibre resulted in a 2% risk reduction; 25g an 11% reduction; and 35g a 34% reduction). From this we can see that it is important to eat your fibre and to eat a variety of foods for best benefit.
Red and Processed Meat
The picture is not so pretty for red meat. The total intake of red meat is linked with an increased rate of type 2 diabetes. A review done by Feskens et al found that there is a 15% increased risk with the intake of unprocessed red meat and a 32% increase risk with the intake of processed red meat. Substituting one serving of red meat with one serving of nuts, low-fat dairy or whole grains per day has been shown to lower the risk of type 2 diabetes by 16-35%.
Quite contrary to meat, dairy has been shown to have a protective effect. Studies have shown that there is a 10% lowered risk for every serving of dairy per day. And the fat content of the diary products produced different results. Studies using the low-fat dairy and yoghurt (as opposed to the high-fat diary ad whole milk) had the greatest percentage decreased risk for type 2 diabetes.
Fish (Omega 3 Fatty Acids)
We would assume that eating fish and especially fatty fish would protect us from diabetes. However, the literature is very neutral! There is no significant relationship between fish consumption and type 2 diabetes. So there is no harm, but also no benefit. The only noteworthy point is that there is a distinct difference between the data from North America and Europe versus Asia. There is an increase in the risk of type 2 diabetes correlated with fish consumption from the North America and Europe data and a small decrease in the incidence of diabetes from the Asia data. This could be due to type of fish consumed, method of preparation of the fish as well as pollution of the waters.
In the real world we don’t focus on individual nutrients, but rather on the overall diet or diet pattern. There are often interactions between nutrients and accumulative benefits that cannot be seen in single nutrient studies. Studies on dietary patterns are showing us that there are certain dietary patterns that can help prevent type 2 diabetes. What is key is that even without weight loss, they are helping to prevent diabetes. These eating patterns include the Mediterranean, DASH, prudent and low-carb (with plant fat) diets.
There is no substitute to having a healthy diet. Focus on eating real, whole foods, incorporating variety. Before you dismiss carbs in their entirety cut out the refined ones, sugar as well as the junk food and fast food. The quality of your food is the most important factor in any diet!