Tuesday, July 14, 2009

Eating Corn Flakes Found to Cause Endothelial Dysfunction; Would Anti-Smoking Researches Assert that Corn Flakes Increases Heart Attack Risk?

By the reasoning of anti-smoking researchers - who have warned the public that a 30-minute exposure to secondhand smoke causes heart attacks by virtue of the finding that short exposures to tobacco smoke impair endothelial function - the same warning should be made to the public about Corn Flakes.

A new study published in the June 19 issue of the Journal of the American College of Cardiology found that the hyperglycemic state associated with eating Corn Flakes results in measurable decrements in endothelial dysfunction, as assessed by endothelium-dependent flow-mediated dilation, among obese and overweight non-diabetic adults (see: Lavi T, et al. The acute effect of various glycemic index dietary carbohydrates on endothelial fucntion in nondiabetic overweight and obese subjects. Journal of the American College of Cardiology 2009; 53:2283-2287).

The study found that: "Baseline %FMD, not significantly different in the 3 carbohydrate-based meals, was reduced 2 h post-prandially in all groups, showing statistical significance in only high-glycemic index meals: glucose (15 ± 9% vs. 10 ± 8%, p < 0.01), cornflakes (13 ± 7% vs. 9 ± 7%, p < 0.01).

The Rest of the Story

Based on the same type of information in this study regarding Corn Flakes, anti-smoking researchers and organizations - including the CDC - have concluded that 30 minutes of exposure to secondhand smoke causes heart attacks. The CDC went so far as to publish an article claiming that eating a meal in a restaurant with tobacco smoke is sufficient to trigger a heart attack. The CDC's and other anti-smoking researchers' claims that 30 minutes of tobacco smoke causes heart attacks is based on evidence that brief exposure to secondhand smoke impairs endothelial dysfunction, as measured by endothelium-dependent flow-mediated dilation.

The difference between these cardiovascular disease researchers and the anti-smoking researchers, of course, is not in the science or the methodology, but in the nature of the conclusions.

For the cardiovascular disease researchers who conducted this study, the conclusion is that we now have a biologic mechanism by which a hyperglycemic diet could contribute to cardiovascular disease risk. Over a long period of time, sustained damage to the endothelium is a risk factor for the development of atherosclerosis and cardiovascular disease.

For the anti-smoking researchers, however, the same science led to very different conclusions: 30 minutes of secondhand smoke exposure is enough to cause a heart attack and this proves that even transient exposure to secondhand smoke has potentially fatal cardiovascular consequences.

Of note, you don't see the cardiovascular disease researchers jumping to this startling and sensational conclusion. You don't see any warning in their article that eating Corn Flakes might trigger a heart attack, or that we need to ban Corn Flakes in order to prevent heart attacks. You don't see any assertions that if we could only prevent Corn Flake consumption, we would reduce the number of heart attacks being triggered by acute Corn Flake consumption.

The point is this: the research demonstrates an adverse physiologic effect of hyperglycemic food on the endothelium, which if sustained over many years, could eventually result in atherosclerosis and heart disease. The same is true for secondhand smoke. But these results - in both cases - do not support a conclusion that people are going to drop dead from a transient exposure to either secondhand smoke or Corn Flakes.

Unless, of course, you eat your Corn Flakes in a smoky restaurant, in which case I guess you are just asking for a heart attack.

It is of some consolation to me that Vienna Fingers have yet to be implicated as a cause of endothelial dysfunction.

(Thanks to Michael J. McFadden for the tip.)

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