The subject of the news release is a newly published, randomized, controlled study comparing the effects of a Mediterranean diet and a lacto-ovo vegetarian diet (which excludes meat and fish but allows eggs and dairy) on total body weight, BMI, fat mass, and cholesterol levels.
The release clearly outlines the differences in the two diets and makes it clear this is the first head-to-head comparison of these two diets within groups of meat consumers.
But the news release falls short in not including many of the study’s limitations, as well as making it clear to readers that the study outcomes are based on surrogate markers that cannot draw direct conclusions about “preventing heart disease” or stroke as implied.
According to the CDC, heart disease is the leading cause of death in the U.S., with more than 600,000 deaths per year. Dietary patterns are known to affect our risk for heart disease, and represent an opportunity for each of us to modify that risk.
What concerns most of us is having the duration or quality of our life affected by a heart attack, stroke, or other cardiovascular disease. So studies which actually look at hard outcomes like that — rather than surrogate markers such as cholesterol levels measured over just a few months — are more relevant to more people.
Furthermore, studies which look at the effect of diet on major diseases like cancer, heart disease, diabetes, and stroke aren’t just widespread, but often lead to wide-ranging and wide-reaching news coverage. Such studies usually have significant limitations, debatable outcomes, and are prone to unjustified or hyperbolic language. This places a premium on journalists covering such studies to look for independent viewpoints, and a premium on readers for staying skeptical.
At first glance it might seem appropriate that costs are not mentioned. However, the comparative costs of these two diets could vary considerably depending on what part of the world you live in (ie. in some locations, a Mediterranean diet is either not feasible or prohibitively expensive).
Also, the subjects in this study received both nutritional counseling and diet plans which, may not only have influenced the outcomes of this study, but also would carry a price tag in the real world.
Both the lacto-ovo vegetarian diet (Vd) and the Mediterranean diet (Md) were effective in reducing body weight, body fat, and body mass index with no significant differences between them. The release presents these benefits in absolute numbers. However, the Md led to greater reductions in triglyceride levels, while the Vd led to greater reductions in low-density lipoproteins (so called “bad” cholesterol). These were well covered in the news release.
But the latter benefits are changes in surrogate markers measured over just 3 months in people at a low risk for cardiovascular disease. Whether these results translate into meaningful, sustained, and clinically relevant outcomes that actually affect people’s risk for developing heart or vascular disease can not be answered by this small randomized, controlled study.
Both diets used in the study are generally safe for most people. Food intolerances aside, the only potential harm we could see in the diets used in the study is that the calorie quota (about 2100 calories per day) may not be appropriate for all people.
Although the news release does mention one study limitation (“the fact that participants were at ‘relatively low’ risk of cardiovascular disease”) it did not mention two other important limitations; mainly, a relatively small study size (in a ‘low-risk country for cardiovascular disease’ as the authors mention) and a short study duration of just 3 months.
It’s also not mentioned that the subjects received nutritional counseling and menu plans which — as with the limitations mentioned above — limits how relevant these findings may be to people trying to incorporate either of these diets into their lives.
Finally, this study shows very short-term outcomes with surrogate markers (such as weight, BMI, body fat). It did not look at hard outcomes of cardiovascular disease — like heart attacks, strokes, or death — as the headlines suggest.
No disease mongering but the news release walks a very fine line of equating surrogate markers with actual cardiovascular disease.
The release noted “this research received no specific grant from any funding agency, commercial, or not-for-profit sectors.” No conflicts of interest are identified in the published study.
This study was designed to strictly compare just two types of diets. So not bringing up other dietary options seems appropriate.
The release didn’t specifically address availability. We do acknowledge that while different fruits and vegetables are limited in different parts of the world, it is feasible to adopt a Mediterranean style or vegetarian style diet almost anywhere by substituting some vegetables and protein sources for others.
The news release clearly establishes the novelty of this study (which is also mentioned in the published study):
Previous separate studies have shown that the Mediterranean diet reduces certain risk factors for cardiovascular disease, as does a vegetarian diet; however, this was the first study to compare effects of the two distinct eating patterns.
The headline of this news release is not justified because the study did not investigate the impact of these diets on preventing heart disease.
Also, stating that these two diets are “likely equally effective in reducing the risk of heart disease and stroke” is not supported by the study, which looked at surrogate markers, not disease incidence or prevalence.
Systematic, Criteria-Driven
Do you write news releases?
And want help?
We offer free pre-publication review of releases. SEE MORE →
We will not display your name or e-mail address on the site, nor will we share your e-mail address with any third parties.
Thank you for joining the HealthNewsReview.org mailing list. It’s a good way for you to stay up-to-date on what we’ve published, even if you forget to come to our website every day or every week.
-Gary Schwitzer, Publisher, HealthNewsReview.org
By submitting this form, you are granting: HealthNewsReview.org, University of Minnesota , Minneapolis, MN, 55455, United States, https://www.healthnewsreview.org permission to email you. You may unsubscribe via the link found at the bottom of every email. Emails are serviced by Mailchimp. (See their Email Privacy Policy for details.)
I liked a @YouTube video https://t.co/UK2YPzEodd Steve's Deep Brain
Comments
We Welcome Comments. But please note: We will delete comments left by anyone who doesn’t leave an actual first and last name and an actual email address.
We will delete comments that include personal attacks, unfounded allegations, unverified facts, product pitches, or profanity. We will also end any thread of repetitive comments. Comments should primarily discuss the quality (or lack thereof) in journalism or other media messages about health and medicine. This is not intended to be a forum for definitive discussions about medicine or science. Nor is it a forum to share your personal story about a disease or treatment -- your comment must relate to media messages about health care. If your comment doesn't adhere to these policies, we won't post it. Questions? Please see more on our comments policy.
Our Comments Policy
But before leaving a comment, please review these notes about our policy.
You are responsible for any comments you leave on this site.
This site is primarily a forum for discussion about the quality (or lack thereof) in journalism or other media messages (advertising, marketing, public relations, medical journals, etc.) It is not intended to be a forum for definitive discussions about medicine or science.
We will delete comments that include personal attacks, unfounded allegations, unverified claims, product pitches, profanity or any from anyone who does not list a full name and a functioning email address. We will also end any thread of repetitive comments. We don”t give medical advice so we won”t respond to questions asking for it.
We don”t have sufficient staffing to contact each commenter who left such a message. If you have a question about why your comment was edited or removed, you can email us at feedback@healthnewsreview.org.
There has been a recent burst of attention to troubles with many comments left on science and science news/communication websites. Read “Online science comments: trolls, trash and treasure.”
The authors of the Retraction Watch comments policy urge commenters:
We”re also concerned about anonymous comments. We ask that all commenters leave their full name and provide an actual email address in case we feel we need to contact them. We may delete any comment left by someone who does not leave their name and a legitimate email address.
And, as noted, product pitches of any sort – pushing treatments, tests, products, procedures, physicians, medical centers, books, websites – are likely to be deleted. We don”t accept advertising on this site and are not going to give it away free.
The ability to leave comments expires after a certain period of time. So you may find that you’re unable to leave a comment on an article that is more than a few months old.
You might also like