Moment of Doubt

Doubts About Dietary Options for Heart Health

AHA Heart-Check LogoCould it be that chasing dietary options for heart health is pointless? Commenting on a new study in Annals of Internal Medicine, Amitabh Pandey and Eric Topol express doubts:

Diets and supplements are 2 of the most intense areas of public interest but are among the most lacking in adequate data.

Unfortunately, the current study leaves us with the same foggy conditions that we started with. Until these conditions clear, it would be reasonable to hold off on any supplement or diet modification in all guidelines and recommendations.

Will this put a dent into to the business of selling the AHA Heart-Check seal to help people spot heart healthy foods? How will the California Walnut Board sell so many walnuts if it turns out that they can’t help with heart disease?

Nutrition Science Bites Back

This study was an umbrella review of RCTs and meta-analysis of RCTs for supplements and dietary modifications for their effects on heart disease outcomes. Safi Khan and colleagues looked at data from 277 trials, 24 interventions, and nearly a million human subjects. The quality and certainty of the evidence, they said, was less than optimal.

They found that few diets or supplements had any compelling effect. They even cast doubts on the vaunted Mediterranean diet. Cutting salt, consuming enough omega-3 fatty acids, and folate supplements might have a benefit. Supplements with calcium and vitamin D might actually be harmful because of an increased risk of stroke.

Food marketers will survive, though. They’ve been riding the waves of uncertain dietary science for centuries. Another wave is coming right behind this one to erase those pesky doubts. But it is quite remarkable to see research in a prestigious journal call the foundation of so much commerce into question.

Cranking Out New Guidelines in the Midst of Doubts

Tomorrow the expert advisory committee for the 2020 Dietary Guidelines will hold a public hearing. We doubt they will be daunted by this news. Nope. They will listen intently as members of the public present passionate testimony about their favorite nutritional hobby horse.

You can bet that plant-based diets will get plenty of raves from everyone except the Cattlemen’s Association. Fruits and veggies will be long-suffering heroes, even though they are less profitable than packaged, shelf-stable foods.

What you won’t see is anyone backing off from the presumption that there’s a right way to eat and it looks a lot like the dietary pattern of whomever has the floor. Or at least what that person claims they eat.

Pandey and Topol beg to differ:

The use of any specific diet or supplement is likely to have markedly heterogeneous effects. Testing any diet or supplement in a broad population without acknowledging interindividual variability seems like a recipe for failure

In other words, when it comes to diet and health, one size will never fit all. Duh.

Click here for the study, here for the editorial, and here for more from the New York Times.

Moment of Doubt, photograph © Max Sat / flickr

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July 9, 2019

One Response to “Doubts About Dietary Options for Heart Health”

  1. July 09, 2019 at 11:10 am, Allen Browne said:

    Or as Lee Kaplan has said many times “obesity is a heterogenous disease”