Another study came out today reminding us that something you probably assumed wasn’t that healthy probably isn’t that healthy: cured meat. In a word, the study concluded that cured meat and worsening asthma symptoms go hand-in-hand. But like many nutrition studies, this one’s conclusions come with some major caveats, and are already generating controversy.
The researchers looked at 971 subjects who took part in the so-called EGEA study (that’s short for Epidemiological study on the Genetics and Environment of Asthma). This subset of EGEA participants, all of whom experience some degree of asthma, received medical examinations and filled out questionnaires regarding their symptoms. They also received a 118-item food frequency questionnaire, which included items from 46 food groups, and cured meats like “ham”, “dried sausage” and “sausage”. The participants did follow-up surveys on their asthma conditions five to ten years later.
After collecting and analysing the data, the researchers found that the odds of worsening asthma symptoms were 76 percent higher for those who ate the most cured meat (more than four servings a week), compared with those who ate the least cured meat (less than one serving a week). The team published its results in the journal that may have the best name in all of science: Thorax.
The whole cured meat is bad thing should sound familiar. Last year, a World Health Organisation committee announced that processed meats like bacon and hot dogs cause cancer, and other red meats like beef and veal might be carcinogenic.
The most recent Thorax study is an observational study, meaning the scientists didn’t actually tell anyone to eat ham, but merely looked at how a group of people changed over time. Lead study author Zhen Li, a PhD Student at the French National Institute of Health and Medical Research, made sure to point this fact out to me, and how they corrected for other factors that could have worsened the asthma. “We have information about age, sex, education level, or physical activity, and have already taken into account these confounders in our analysis,” she said. “We don’t think that’s a major limitation of this study.”
The team wasn’t sure what caused the worsening symptoms, but one hypothesis is that the nitrites in processed meat could inflame our airways. As far as takeaways from the study, “at the moment, public health strategy [should be] to reduce cured meat intake,” said Li. “Nothing is lost by doing so.”
At least one controversial figure in the nutrition world, Edward Archer, isn’t having it. A former obesity researcher at the University of Alabama, Birmingham and current Chief Science Officer for the health tech startup EnduringFX, Archer believes studies like this one should be thrown out the window, and that the aged practice of food frequency questionnaires should be inadmissible as a research tool. He noted that there are thousands of foods not included in the questionnaire, and essentially anyone who fills it out is doing so based on memory, which is most certainly somewhat wrong.
Archer also took issue with the term “processed” — the French researchers did not use this term, but the press release and past studies have. “What does ‘processed’ mean,” he asked. “Cooking is processing. When your ancestors ripped the skin off the beef, added salt, added spices, it’s all processing.”
I forwarded Archer’s response to Li, who disagreed. “A real scientist would never say that research using FFQ (food frequency questionnaire) data is pseudoscience,” she responded via email. “In FFQs, people are asked to indicate their intakes of some foods (sometimes also food groups) but not with details on commercial brands and or species (e.g. green or red grapes). It would not be possible be include such details in FFQs — people have limited time.”
Li’s paper also points out that nutrition studies have tied many negative health effects to cured meat, including lung problems and chronic obstructive pulmonary disease.
So which side should you take? I’m not 100 percent sure, though I’d be lying if I said I will dump cured meat myself. Here are some generic recommendations anyway:
1. If you have asthma, try dumping cured meat. Maybe you’ll get better, maybe you won’t.
2. If you want to do something good for the world, you should probably give up meat regardless, because climate change.
3. I mean, if you eat lots of twinkies and immediately get stomachaches, stop eating twinkies?
4. Try going for a nice jog, there are many cute dogs outside.
5. Nutrition is based on pretty shaky science. [Thorax]