RGBstock photo-Gesinek
When it comes to the link between affairs of the heart and nutritious eats, the goal is most often maintaining healthy arteries. But the endothelium is an important aspect that’s usually left out of the discussion – and it’s definitely one you should know more about.
The endothelium is the lining of your blood vessel walls and when it’s not in good shape, trouble is likely brewing. It’s what used to be referred to as hardening of the arteries. These days, in scientific terms, it’s called endothelial dysfunction. And when you’re diagnosed with it, you could be line for a heart attack or stroke.
More and more research, though, is pointing to ways to keep your endothelium healthy and even reverse some of the damage.
Eating a high fat meal – a huge rack of ribs or an oversized burger loaded up with cheese and bacon – can affect the endothelial function even in healthy individuals. When you suddenly load your bloodstream with certain types of fat, saturated fat in particular, the blood flow in your arteries can be impacted. If your arteries are relaxed, so to speak, they are supposed to dilate or open up to let the blood flow through. But not all foods are created equal in their effect.
British research published in the American Journal of Clinical Nutrition evaluated the effects of a high saturated fat meal compared to one which combined the saturated fat with omega-3 fats in healthy subjects. The omega-3 fats used are those found in cold water fish such as salmon, sardines and mackerel.
When the subjects – all non-smoking, under 30 years of age and at healthy weights – consumed the high saturated fat meal, there was evidence of changes in the endothelial function but when the meals included the omega-3s, the arteries acted in a normal fashion.
Over time, the saturated fat laden meals could ultimately lead to endothelial dysfunction – unless the food is accompanied by a fish oil chaser. And how often is that going to happen?
When you think of taking care of your heart, consider the endothelium as being the gatekeeper to your arteries. A healthy one defends against assaults by assorted harmful agents – cigarette smoking, elevated blood cholesterol readings and high blood pressure are just a few. Conditions which can cause inflammation to occur such as obesity and diabetes can also lead to damage.
But if you’ve got a healthy endothelial function, it’s armed to fight back against these various assaults. When confronted by these offenders, a healthy endothelium can release compounds which can counter inflammation. Other weapons released include substances that can decrease the stickiness of blood cells which could lead to deposits and plaque buildup in arteries or the formation of blood clots.
In addition, the endothelium influences the rate of blood flowing through the arteries, allowing them to dilate or relax when necessary. For example, during stress or exercise when there can be a greater rush of blood, a healthy endothelium is akin to a flexible tube and allows for the blood to flow. With endothelial dysfunction, the arteries are more like a rigid pipe and less likely to widen or dilate to allow for the blood flow.
The good news, even for those who already show endothelial dysfunction, is that there are certain foods that not only keep the lining of the arteries in good shape but that some can actually restore healthier function.
Next up: Smart choices for healthy endothelial functioning
Have you heard of this concept before? Please share in the comment section below.
Enlightened Eater 
Hi Rosie – thanks for bringing up the important topic of the endothelium’s role in heart health. Endothelial dysfunction is also implicated in my own diagnosis of Coronary Microvascular Disease. We know that regular exercise, not smoking and other lifestyle choices can contribute to good endothelial health.
The actual role of omega 3 fats in cardiac outcomes is less clear, despite the findings of the AJCN study. Are you familiar with this recent report published in the March 18th Annals of Internal Medicine (Chowdhury et al): “Omega-3 or omega-6 fatty acids have no or little impact on reducing cardiovascular disease outcomes. Looking at the 17 randomized clinical trials that we combined, the majority of the trials — especially the more recent and large-scale ones — showed consistently little significant effect on reducing coronary heart disease events.” http://www.nlm.nih.gov/medlineplus/news/fullstory_145156.html This was a surprise to those of us heart patients who have been routinely ordered to take omega 3s by our cardiologists.
What’s your take on this?
Hi Carolyn, thanks for your comments. I didn’t point to this study as I have seen quite a bit of criticism about how the review was done. I do agree that it’s key to include cold-water fish on the menu but as for the study findings, here is what some highly respected scientists say about the review (http://www.medscape.com/viewarticle/822092):
Dr Eric B Rimm (Harvard School of Public Health, Boston, MA) said, “My colleagues were quite surprised at the findings. We uncovered a serious mistake in their review of PUFA that likely will change the results substantially.” And the parts of the meta-analysis focusing on PUFA didn’t summarize the relevant studies correctly, according to Rimm, who added that “the results are in serious question.”
Dr Alice H Lichtenstein (Tufts University, Boston, MA) replied by email, “The majority of the evidence suggests that replacing saturated fat with polyunsaturated fat reduces heart disease risk, whereas replacing saturated fat with carbohydrate does not. This new study only assessed one factor, an indicator of dietary fat, and not the whole picture, making the conclusions questionable.”
The focus of the study seemed to be more on what happens when you replace saturated fat with carbohydrates – refined, in particular. It also seems to go against what many other studies have shown. The key to remember is that while one study or even meta-analysis may go against the grain, it’s important to wait for a consensus of studies.
At this point, I think it’s still on the side of omega-3s.
I’m still taking my fish oil capsules and eating plenty of fish on our weekly menus – while waiting for researchers to come up with some level of agreement on this!
It is indeed confusing, Carolyn! I think your strategy is smart- listen to the discussions and keep your eyes on the research!