A study published in the current issue of the American Journal of Clinical Nutrition finds that eating a meal at McDonalds -- even a "healthy" one -- results in the same degree of endothelial dysfunction as 30 minutes of exposure to secondhand smoke. This finding casts into serious doubt the widespread claims of anti-smoking groups that 30 minutes of secondhand smoke exposure causes hardening of the arteries, atherosclerosis, heart disease, decreased coronary artery blood flow, strokes, heart attacks, and death (see: Rudolph TK, Ruempler K, Schwedhelm E, et al. Acute effects of various fast-food meals on vascular function and cardiovascular disease risk markers: the Hamburg Burger Trial. American Journal of Clinical Nutrition 2007; 86:334-340).
In the study, flow-mediated endothelium-dependent flow-mediated dilatation (widening) of the brachial artery was measured after three different McDonalds meals: a hamburger with fries and soda; a veggie burger with fries and soda; and a veggie burger with salad, fruit, yogurt, and orange juice.
All three meals resulted in signficant endothelial dysfunction, as documented by a significant reduction in flow-mediated endothelium-dependent dilatation. Interestingly, the reduction in brachial artery flow after the highest-fat meal (meal #1) was 22.7%, identical to the reduction in coronary flow velocity reserve due to 30 minutes of secondhand smoke exposure in the Otsuka et al. study.
In a surprise to the authors, the supposed "healthy" option (meal #3) resulted in the same amount of reduction in flow-mediated endothelium-dependent dilatation as the highest-fat meal.
The authors concluded that there was "a decline in FMD [flow-mediated endothelium-dependent dilatation] after all 3 investigated fast-food meals... ."
The Rest of the Story
Begging the question of why someone would go to McDonalds to order a salad, fruit, yogurt, and orange juice in the first place, this study has very important implications for the widespread claims that anti-smoking groups are making about the acute cardiovascular effects of secondhand smoke.
The study casts into serious doubt the widespread claims of anti-smoking groups that 30 minutes of secondhand smoke exposure causes hardening of the arteries, atherosclerosis, heart disease, decreased coronary artery blood flow, strokes, heart attacks, and death. These claims are based largely on the Otsuka et al. study, which showed that brief secondhand smoke exposure causes endothelial dysfunction - as measured by a reduction in coronary endothelial-dependent flow-mediated dilatation - in healthy nonsmokers.
Here, however, we see that simply eating a single high-fat meal - even a seemingly healthy one - also causes endothelial dysfunction and to same extent as a brief exposure to secondhand smoke. Since it would be absurd to claim that eating a single high-fat meal causes hardening of the arteries, atherosclerosis, heart disease, decreased coronary artery blood flow, strokes, heart attacks, and death, it is equally absurd to make the same claims for a single, brief secondhand smoke exposure.
What these studies - both of them - demonstrate is that there is a plausible mechanism by which chronic exposure to high fat meals and secondhand smoke can lead to the development of atherosclerosis and eventually - to heart disease. But clearly, the process does not occur immediately.
Moreover, while it may be technically true that a brief exposure to secondhand smoke could hypothetically trigger a heart attack in someone with severe existing coronary artery disease due to its acute effects on endothelial dysfunction, the same can be said with respect to eating a high-fat meal. But you don't hear health groups going around warning people that eating a high-fat meal can trigger a fatal heart attack.
The point is this: if someone has such severe coronary artery disease that a heart attack can be triggered by an acute impairment of endothelial dysfunction due to a brief secondhand smoke exposure, then such a cardiac event can also be triggered by eating a high-fat meal. We are talking about a very specific situation, so the generalized claims being made by anti-smoking groups that 30 minutes of secondhand smoke triggers heart attacks are simply not supported by the science.
The rest of the story is that the "30 minute claims" being made by anti-smoking groups represent the most shoddy science and they have no place in the tobacco control movement if the movement wishes to maintain any sense of scientific integrity.
Of course, if the movement doesn't care about scientific integrity any more, then retaining these 30-minute claims is a great idea, because it makes for a more sensational communication and will falsely appeal to the public's emotions.
In other words, in making these 30-minute claims, anti-smoking groups are essentially borrowing a classic tobacco industry technique.
While there are over 100 groups making these claims (I have documented this extensively in previous posts), there are three websites in particular that I think need to be fixed immediately beacuse they represent - I believe - the source of the fallacious claims being made by many other groups and these groups are leading sources of health information on secondhand smoke for the tobacco control movement. If these three groups issue retractions or corrections of their public claims, then it will instruct other groups nationwide to do the same. The groups are:
1. American Cancer Society
The American Cancer Society secondhand smoke strategy guide falsely claims that brief secondhand smoke exposure causes atherosclerosis and reduces coronary artery blood flow:
In an internal strategy document entitled "Building Public Awareness About Passive Smoking Hazards," the American Cancer Society and International Union Against Cancer offer suggestions to anti-smoking advocates about how to increase the emotional appeal of secondhand smoke health hazard claims. The guide was designed "to help advocates develop practical strategies to overcome specific barriers to effective tobacco control policies."
One strategy put forward to help advocates overcome barriers to the adoption of smoking bans is to convey to the public that some of the effects of secondhand smoke are "virtually instant" because "these messages convey the issue's urgency." Specifically, the strategy urges advocates to emphasize the following two messages:
1. "Immediate effects of secondhand smoke include cardiovascular problems such as damage to cell walls in the circulatory system, thickening of the blood and arteries, and arteriosclerosis (hardening of the arteries) or heart disease, increasing the chance of heart attack or stroke."
2. "Short-term exposure to tobacco smoke has a measurable effect on the heart in nonsmokers. Just 30 minutes of exposure is enough to reduce blood flow to the heart."
As the Rudolph et al. study demonstrates, claiming that the immediate effects of secondhand smoke includes arteriosclerosis (hardening of the arteries) and heart disease and increased risk of heart attack or stroke is as absurd as claiming that eating a single healthy meal at McDonalds immediately causes atherosclerosis and heart disease and increases the risk of heart attack and stroke.
Based on the Otsuka et al. study, the TobaccoScam website claims that 30 minutes of secondhand smoke exposure is equivalent to clogged coronary arteries:
The specific claims are as follows:
"30 minutes exposure = smoker's arteries"
"Thirty minutes of secondhand smoke compromises a non-smoker's coronary arteries to the same extent as in smokers."
"30 minutes exposure = stiffened, clogged arteries"
"All of these effects not only increase the long term risks of developing heart disease, but also increase the immediate risk of heart attack."
Stating that 30 minutes exposure is equivalent to smoker's arteries or to clogged arteries, based on the Otsuka et al. study is as absurd as claiming that eating a McDonalds meal is equivalent to smoker's arteries or to clogged arteries, based on the Rudolph et al. study.
3. Americans for Nonsmokers' Rights (ANR)
ANR continues to claim in its "fact" sheet titled "Secondhand Smoke: The Science," that just 30 minutes of secondhand smoke exposure causes as much heart damage as is observed in active smokers. In light of the Rudolph et al. study, this claim is obviously very deceptive. One could just as easily state that someone who eats a veggie burger has heart damage similar to that of active smokers.
The specific claim is: "Just thirty minutes of exposure to secondhand smoke can cause heart damage similar to that of habitual smokers. Nonsmokers’ heart arteries showed a reduced ability to dilate, diminishing the ability of the heart to get life-giving blood."
I think that this is the moment of truth for the tobacco control movement. After this study, it should be very clear to tobacco control practitioners that the claims their groups are making are scientifically shoddy. I don't think the groups are going to be able to get away with this kind of shoddy science so easily. Now we will see the extent to which the movement is able to respond to this scientific crisis and restore its scientific integrity. Failure could mean the end of any semblance of scientific integrity and eventually, to the loss of the movement's scientific reputation.
Of course, another possibility is that the movement doesn't actually care about its scientific integrity, but only cares about the emotional impact of its public claims.
I think we'll find out this week. Just keep checking here and here and here. I'll summarize any response to this post, any defense of the claims, and any web site changes on Friday.
(Thanks to JustTheFacts for the tip. Jacob Sullum's take on this new article can be found here.)