Michael Joyce is a writer-producer with HealthNewsReview.org and tweets as @mlmjoyce
But in the case of these headlines — generated by a Harvard study of ‘Seafood Intake, Sexual Activity, and Time to Pregnancy‘ — you’ll also run the risk of giving couples trying to get pregnant both misinformation and false hope:
Is Fish the Food of Love, and Babies? (New York Times)
Seafood-lovers Have More Sex and Take Less Time to Get Pregnant (New Scientist)
And these bullet points are mostly what the dozens of articles covering this prospective observational study highlighted. Not the limitations or a key consideration related to a potential harm.
And it’s not a stretch to imagine couples who have struggled getting pregnant making a beeline for their local seafood store. But that would be ill-conceived and possibly ill-fated.
First, and foremost, this is an observational study which can’t prove a cause-and-effect relationship between eating more seafood and increased fertility. Yet the Times’s lead sentence — “Trying to have a baby? Eating fish might help” — clearly invites a cause-and-effect conclusion. The Times also downplays the likelihood that other factors — such as a 22% higher rate of sexual activity in the frequent fish eaters — could have played a role. But statistical adjustments to account for these kinds of differences are never foolproof.
Third, self-reported food intake — even when done daily as with this study — is prone to error. Furthermore, the subjects only logged sex activity and seafood intake. Other foods — which could potentially affect fertility or overall health — were not logged.
In short, the findings could easily be coincidental. Are couples who eat more seafood more likely to be healthier overall? Are couples who stay in to cook fish, or go out for sushi, more likely to be sexually active? These are variables that could affect the findings, but this sort of study can’t account for their potential influence.
It’s important to note that very few reporters mentioned the first limitation. None of the articles I read brought up the second and third limitations.
It’s human nature — especially for those of us eager for a good outcome (like a healthy pregnancy) — to adopt this sort of ‘logic’:
“Well, if 2 servings of seafood a week got 92% of couples pregnant, then 3, 4, or more servings should increase the chances of pregnancy even more.”
But what about mercury and other toxins that are found in fish?
In the very superficial news release associated with the Harvard study they make a point that the EPA-FDA say that “90 percent of the fish eaten in the United States is low in mercury and safe to eat.”
But which fish? And what about in other countries? And what about the 2017 EPA-FDA guidelines recommending that “women who are pregnant or may become pregnant” limit their seafood consumption to less than 3 servings of low-mercury fish per week?
The reason? Excessive mercury exposure can cause neurologic damage in fetuses and adults.
But remember, almost all the coverage I came across reported that 92% of the couples who ate “2 servings OR MORE” were pregnant at the end of one year … how much “more” walks a fine line between very questionable benefits and very real harms.
Kudos to WebMD who did raise this and other important concerns. But none of the other articles I read did so, and that oversight could hurt people.
For other examples of questionable reporting on fertility that we’ve covered in the past, click HERE.