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Cornflakes, White Bread Could Boost Heart Risk

June 17, 2009


That’s the title of an article recently published in the Atlanta Journal Constitution, drawing on information from an Israeli study. In the study, researchers asked 56 healthy but overweight adults to fast overnight, then eat a different breakfast for each of four mornings, starting with high-glycemic index foods and moving to lower-glycemic index foods. The first morning, they were served pure glucose – straight blood sugar, no digestion needed to turn it into fuel for the body. On subsequent days, breakfast was cornflakes, then high-fiber cereal, then water.

The goal was to see how meals of varying glycemic index would affect the function of participants’ blood vessels. It’s well accepted that high-glycemic foods like cornflakes and white bread raise blood sugar more quickly than low-glycemic foods like pasta, beans, and vegetables. But can they affect our actual blood vessels as well as our blood?

Here’s where it gets interesting. Before and after each breakfast, researchers measured the functioning of participants’ endothelium, the layer of cells that line the inside of the entire circulatory system, from the smallest capillary to the heart. Healthy, elastic endothelial cells control blood pressure, help our blood clot properly, and perform many other important functions. If they become stiff and rigid, hardening of the arteries impairs all of these many functions.

The Israeli study found immediate loss of function of the endothelium with high-glycemic foods.  “High-glycemic index carbs are dangerous since they reduce or inhibit endothelial function, which is ‘the risk of the risk factors,’  leading to atherosclerosis and potentially leading to heart disease,” said Dr. Michael Schechter, senior cardiologist at Tel Aviv University.

We get the idea that our food choices take years to catch up with us, so the idea that measurable changes take place within minutes of eating certain foods certainly gives pause. I’m writing this after enjoying a big low-glycemic index breakfast of steel-cut oats with pears and blueberries, and I can almost feel my blood vessels thanking me with each breath.

– Cindy

P.S. If this blog entry has piqued your interest in understanding your blood vessels and endothelium, I highly recommend The Cardiovascular Cure by John Cooke, MD, PhD, and Judith Zimmer. It’s a clear and compelling owner’s guide for your 100,000 miles of blood vessels – for both heart patients and those who would like to avoid heart disease.

One Comment leave one →
  1. June 17, 2009 9:34 pm

    It’s amazing to know the researchers could find such immediate effects on blood vessels. This study confirms why some researchers (Frank Hu comes to mind) think we should put more focus on glycemic index to prevent cardiovascular disease.

    High-glycemic index eating raises the risk of coronary heart disease by up to 25%, according to a comprehensive study published last year in the American Journal of Clinical Nutrition.

    Other associated illnesses were type 2 diabetes and gallbladder disease.

    For anyone interested in the boring details, I blogged about them here:


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