Action on Smoking and Health (UK) Tried to Convince Restaurant Workers to Sue Employers Over Secondhand Smoke Exposure But Used False Information

Action on Smoking and Health (ASH-UK) has a web page on its old web site which attempts to recruit employees who have suffered health damage from secondhand smoke at work to sue their employers. The page, prepared in collaboration with the Thompsons Solicitors law firm, advises the public that if an employee believes he has suffered health damage as a result of secondhand smoke exposure at work, he should consider filing a lawsuit against the employer to receive compensation for personal injuries.

One of the key pieces of information provided by ASH-UK to the public is the following: "Exposure [to secondhand smoke] for just 30 minutes has been shown to reduce coronary blood flow, increasing the risk of angina, heart attacks and strokes."

The Rest of the Story

While ASH-UK has every right to provide information to the public about the health effects of secondhand smoke exposure - information which might lead them to take legal action against their employers, I find it appalling that ASH-UK would provide false information to the public in the hopes that this misleadingly startling data might stimulate lawsuits against employers.

When you get into the area of trying to encourage lawsuits, I think you take on a special responsibility to provide accurate information to the public. ASH-UK has shirked that responsibility.

It is false that 30 minutes of secondhand smoke exposure has been shown to reduce coronary artery blood flow. What brief exposure has been shown to do is to reduce coronary flow velocity reserve (CFVR), which is something very different from coronary artery blood flow. I have already provided a detailed explanation of the important difference between these two and discussed how the conflation of these two entities by anti-smoking groups has led to numerous fallacious health claims.

Briefly, coronary flow velocity reserve is a measure of the ability of the coronary arteries to dilate in order to increase blood flow under experimental conditions. What a decline in coronary flow velocity reserve indicates is something called endothelial dysfunction - an impairment of the ability of the coronary arteries to dilate in response to a variety of stimuli. This ability to dilate is mediated by the endothelial cells -- the cells which line the blood vessel.

The endothelial cells respond to certain stimuli by producing nitric oxide and other chemicals which diffuse into the smooth muscle in the artery wall, sending a chemical message that causes the muscle to relax and therefore causing the artery to dilate. There are a number of exposures that impair the ability of the endothelium to accomplish this function; among them are active smoking, secondhand smoke, high cholesterol, consumption of trans-fats, and consumption of a high-fat meal.

When endothelial dysfunction is triggered repeatedly over a long period of time, it has been shown to result, ultimately, in atherosclerosis (narrowing of the coronary arteries). When this occurs, coronary blood flow is reduced.

It is important to note that a reduction in coronary blood flow is not observed acutely when the endothelial dysfunction is being measured from a single experimental exposure (such as in the Otsuka et al. study). The reduction in coronary blood flow does not occur until the process has been sustained long enough that atherosclerosis has progressed and the coronary artery has actually narrowed. It is the narrowing of the artery that causes reduced coronary blood flow.

A single high-fat meal has been documented to cause endothelial dysfunction. If you were to go to Burger King for a Whopper, fries and a milk shake and then go to a laboratory to have your coronary flow reserve velocity tested, you would find that it is reduced. In fact, it will probably be reduced to the same level as in an active smoker.

Would it therefore be accurate for an anti-obesity group to claim that eating a hamburger reduces coronary artery blood flow in healthy young adults?

I would argue that it would not. In fact, I think such a statement would be very misleading and deceptive to the public.

Instead, what the science shows is that eating a hamburger or any high-fat food causes endothelial dysfunction. Therefore, if you chronically eat lots of fatty foods over a long period of time (many years), the evidence indicates that this could cause atherosclerosis and heart disease. If you do develop heart disease, then your coronary blood flow will be decreased and you will be in danger of possibly suffering a heart attack. But there is no danger of death or a heart attack after simply eating one Whopper.

By conflating coronary blood flow with coronary flow velocity reserve, anti-smoking groups have, I think, been able to deceive people into thinking that the effects of acute secondhand smoke exposure are much more severe than they actually are.

The second part of ASH-UK's statement - that 30 minutes of secondhand smoke exposure has been found to increase the risk of angina, heart attacks, and strokes is also false, or at least very misleading. It is blatantly false that 30 minutes of secondhand smoke exposure increases the risk of angina, heart attacks, or strokes in an otherwise healthy nonsmoker. The only situation in which it is even plausible that brief secondhand smoke exposure could cause angina, heart attacks, or strokes is if the individual has pre-existing severe coronary artery or cerebrovascular disease. Since ASH-UK did not qualify its statement in any way, the public may easily interpret it to imply that it applies to them, even if they do not have severe heart disease or cerebrovascular disease.

There is some evidence that brief secondhand smoke exposure can exacerbate angina symptoms in people with angina (i.e., existing heart disease). However, there is no evidence that it can trigger heart attacks or strokes. This is pure speculation. But ASH-UK is presenting this as fact, stating that it has been shown. In that sense, ASH-UK's statement is demonstrably false.

It is bad enough for ASH-UK to be making false health claims, but to do so in the setting of trying to drum up litigation against employers is appalling.


(Thanks to Fredrik Eich for the tip).