Dietary Fat

Mediterranean Diet Benefits

Fight Heart Disease with Food

With new research out further backing the Mediterranean style of eating, maintaining a diet chock full of vegetables, fish and plant-based proteins, and healthy oils can and will help you to fight heart disease.  This lifestyle doesn't just focus on these healthy items, but it is also limited in processed foods, red meats and dairy products, and sugary food items. 

The Mediterranean diet principles are as follows: 

  • High intake of olive oil (4+ tbsp/day), fruit (3+ servings/day), nuts (3+ servings/week), vegetables (2+sevings/day), and cereals
    • Some everyday strategies: sautee vegetables, include beans and legumes in dishes as healthy protein options, make your own salad dressings
  • Moderate intake of fish (3+ times/week) and poultry (to replace red meats)
  • Low intake of dairy products, red meat, processed meats, and sweets
    • Remove all visible fat prior to cooking
  • Wine in moderation, consumed with meals, for habitual drinkers

 All About the Study

Researchers split a cohort of over 7,400 adults aged 55-80 with a risk of heart disease (diagnosed high blood pressure, high cholesterol, or diabetes) into three diet groups: Mediterranean with supplemental extra-virgin olive oil, Mediterranean with supplemental mixed nuts, and a control diet in which fruits, vegetables, grains, and low fat dairy were emphasized.  Participants in the Mediterranean groups had access to group classes run by a dietitian at the beginning of the study to learn about the diet and quarterly thereafter.  The control group on the other hand was mailed information on following a low-fat diet annually.

Monitoring included an annual medical questionnaire, validated food-frequency questionnaire, and validated physical activity questionnaire.  Height, weight, waist circumference, and biomarkers were measured at years 1, 3, and 5.

They saw a 28-30% reduction in incidence of cardiac events (heart attack, stroke) in participants that followed the Mediterranean diet with supplemental fats over the control group.  These statistics are consistent with epidemiologic findings previously published. 

While there are some limitations of the study, I am pleased to see a randomized, prospective research study in a high risk population with such statistically significant findings.  [I'm sure my fellow RDs are happy to see this in a study about nutrition - we're often the red-headed stepchild of the research world!]  To read more on the study directly from the New England Journal of Medicine, check it out here.

Does Dietary Fat Impact Blood Sugars?

Carb Counting and Exchanges

The American Diabetes Association currently promotes the teaching and utilization of carbohydrate counting (formerly exchange lists) as an effective means of managing diabetes.  [Of course it is important to remember that diet works in conjunction with medication for diabetes management.]  For those with type I diabetes who are not producing any insulin, the carbohydrate content of that meal is used to calculate the amount of insulin to be given exogenously.

Carb counting oversimplified: When the body breaks down a meal, the amount of carbohydrate within that meal drives blood sugar levels.  Managing the amount of carbohydrate consumed (ex. eating 60 grams vs 95 grams) leads to better blood glucose management.  

While the overarching principle is true, carb counting does not take into account protein or fat in that given meal, as those two macronutrients do not break down to sugar (directly).  So does fat eaten at that same meal impact blood sugars?  Evidence is starting to show us that free fatty acids circulating in the blood impair insulin sensitivity.

Research Brief

In a new article published in Diabetes Care (November 2012), researchers used a crossover design to follow seven people with Type I Diabetes and had them eat a high fat meal and low fat meal with identical carbohydrate content.  Using an artificial pancreas to monitor BG response over the next 18 hours, the high fat meal required higher insulin infusion than the low fat meal, and despite the higher insulin delivery, led to increased hyperglycemia (high blood sugar).

While this study is hardly enough to draw any sweeping conclusions, it is another step in the direction of understanding the impact of the total diet on diabetes management.  With more research it may lead to changes in dietary recommendations, carb counting, or even insulin algorithms.  

If you want to read the article in more detail please check out the abstract here!