When it comes to heart health, eggs may be at par with cigarettes, but doctors say it's not a fair comparison, reveals recent study.
For the study, researchers at Western University in Canada surveyed 1,200 patients about their egg and cigarette consumption and used ultrasound to measure the plaque in their arteries.
They then concluded that people who ate more eggs over time had more plaque in their arteries, and equated eating eggs to smoking cigarettes.
The study's lead researcher, Dr. David Spence, said in a press release that his study has shown that yolks make plaque build up more quickly in the arteries, "about two-thirds as much as smoking," adding, "in the long haul, egg yolks are not okay for most Canadians."
But cardiologists say the study shouldn't be taken so seriously because the research is flawed.
"This is very poor quality research that should not influence patient's dietary choices," ABC News quoted Dr. Steven Nissen, who chairs the department of Cardiovascular Medicine at the Cleveland Clinic Foundation, as writing in an email.
"It is extremely important to understand the differences between 'association' and 'causation'," he wrote.
Nissen said the researchers relied on patients to recall how many eggs they consumed, but asked them once and assumed it remained constant, which isn't reliable.
He said the way researchers measured patients' plaque has come under "considerable criticism," and that researchers failed to adjust for other dietary factors.
Dr. David Frid, a cardiologist at the Cleveland Clinic, said he doesn't think smoking should be equated with eating eggs because eggs have an indirect rather than direct impact on heart disease.
The eggs have to first increase cholesterol to create plaque build-up. The impact of smoking on heart disease is direct because smoking causes arteries to become inflamed, which prompts the body to respond with plaque.
According to him, the study fails to take exercise or other dietary habits into account. Study participants could have consumed more salt, or they could have been on cholesterol-reducing drugs, too.
"It may be that people who consume a lot of eggs also consume a lot of other fatty foods," Frid said.
He also said that how the egg is prepared should also be taken into account.
Tom Linden, a medical journalism professor at the University of North Carolina, said journalists should exercise caution when writing about studies like this. He said they should put the studies into context by explaining the caveats and consulting experts.
"The danger here is headline writers who aren't necessarily science writers may go way overboard in headlining the story," Linden said.
According to Linden, the bottom line is that journalists and readers should be cautious when they interpret study results. Studies need to be put in context beyond the snappy headline or lead.
The study has been published in the journal Atherosclerosis.