This two-part series on heart disease is growing into a three-part series. Today in Part II, let’s have a look at how endothelial cells get damaged. Tomorrow in the final part of the series, I will tell you how to protect and heal endothelial cells.
Our endothelial cells get damaged by foods that we eat, specifically, fatty foods (including animal foods, with saturated fat), fast foods, all oils, and caffeine.
Dr. Robert A. Vogel of the University of Maryland School of Medicine demonstrated the direct and immediate impact of fatty food on our endothelial cells in 1999(1) using the Brachial Artery Tourniquet Test (BART), a noninvasive technique that uses ultrasound to measure the diameter of the brachial artery before and after consuming various foods. The test is used to determine how long it takes the brachial artery to spring back to its normal, pre-meal diameter, a measure of how much nitric oxide (a powerful vasodilator) is being produced by the endothelial cells to dilate the artery.
Dr. Vogel used a group of students to show that even one fatty meal could damage the endothelial cells lining the brachial artery wall. He started by using Brachial Artery Tourniquet Test to get a baseline measurement of how long it took the students’ artery walls to spring back to normal.
The students were divided into two groups: one group was fed a fast food breakfast with 900 calories and 50 grams of fat; the other group was fed a breakfast of 900 calories with no fat. Dr. Vogel repeated the Brachial Artery Tourniquet Test after the students ate and found some impressive results: for the “no fat” group, the arteries bounced back to normal as they had when first measured before the meal; for the “high fat” group, the arteries took significantly longer to return to normal. This shows the impact that a single meal can have on our endothelial cells.
Processed vegetable oils, dairy products, and meat (including chicken & fish) injure endothelial cells, and in doing so, reduce the number of functioning endothelial cells that can produce protective nitric oxide. Without enough nitric oxide, plaque blockages build up and grow, and eventually cause heart disease and strokes. And according to Caldwell B. Esselstyn Jr., MD, what BART really tells us is that with every single Western meal we eat, whether it’s meat, dairy, or olive oil, we injure our endothelium.(3) So just imagine what happens after eating one or more high-fat meals every single day, as so many Americans do!
By injuring our endothelial cells and reducing the amount of endothelial cells left to produce nitric oxide, our Standard American Diet also makes our blood “sticky”, so the mess of cholesterol, cells, and debris can cause a whole cascade of events that lead to inflammation, heart disease, plaque formation, and heart attacks.
In a follow-up study the next year, Dr. Vogel used the same Brachial Artery Tourniquet Test technique to investigate the fatty components of the Mediterranean diet to determine the impact of the “healthy” fats on the function of endothelial cells.(4)
In this study, 10 healthy subjects were fed meals with 900 calories and 50 grams of fat. The meals consisted of either olive oil, canola oil, or salmon (fish oil) with bread. In addition, two of the olive oil meals were supplemented with antioxidant vitamins (C and E) or with foods (balsamic vinegar and salad).
Vogel found that after the meals, olive oil constricted blood flow by 31%, three times as much as canola oil (10%) and 15 times as much as fish oil (2%)! So even olive oil is compromising our endothelial cells!
The study concluded that “the beneficial components of the Mediterranean and Lyon Diet Heart Study diets appear to be antioxidant-rich foods, including vegetables, fruits, and their derivatives such as vinegar, and omega-3-rich fish and canola oils” (not olive oil).(4) Canola oil may share some of the unique vasoprotective properties of other omega-3-rich oils, such as fish oil.
Dietary fruits, vegetables, and their products appear to provide some protection against the direct impairment in endothelial function produced by high-fat foods, including olive oil”.
So now we know that fats and oils, even “healthy” olive oil, injure our endothelial cells, reducing the number of endothelial cells that can produce nitric oxide, which we need to protect our arteries from plaque. Tomorrow in the final part of the series, we will look at how to keep our endothelial cells healthy to prevent or reverse heart disease.