At the Market Stall

Not All Plant-Based Diets Are Created Equal

Philippa Sandall and Alan BarclayWhile many guidelines recommend plant-based diets to reduce the risk of heart disease, some are associated with a higher risk of heart disease. So says a recent study in the Journal of the American College of Cardiology.

Comparing Three Variations

The Harvard researchers created three versions of a plant-based diet: an overall plant-based diet which emphasized the consumption of all plant foods and reduced (but did not eliminate) animal food intake; a healthful plant-based diet that emphasized the intake of healthy plant foods such as whole grains, fruits, and vegetables; and a less healthy plant-based diet which emphasized consumption of refined grain products, fries, white bread, sugar-sweetened beverages etc.

“When we examined the associations of the three food categories with heart disease risk, we found that healthy plant foods were associated with lower risk, whereas less healthy plant foods and animal foods were associated with higher risk,” said Ambika Satija, the study’s lead author. “It’s apparent that there is a wide variation in the nutritional quality of plant foods, making it crucial to take into consideration the quality of foods in a plant-based diet.”

Limitations & Quibbles

The authors note limitations on their study. It’s observational and based on self-reported diet assessments. While it’s very important to remind people that not all plant-based diets are equally healthful, we do have a couple of quibbles about their lists.

They did not look at the overall GI/GL of diets. Their selection of “less healthy” foods includes the usual suspects, but leaves out alcohol – they say they adjusted for it. That selection of “less healthy” items also adds in foods and beverages that current dietary guidelines recommend as good choices in moderation as part of a healthy eating pattern. In particular:

  • Traditional staples (regular durum wheat pasta and white rice). These often go with significant portions of vegetables. Millions of people worldwide eat them in healthy meals as part of their cuisine
  • 100% fruit juices – ½ cup or 125mL is counts as equivalent to one serving of fruit in Dietary Guidelines

No wonder the punters feel confusion about what to eat – nutrition gurus aren’t consistent with dietary guidelines they help formulate.

This article, by Philippa Sandall and Alan Barclay was originally published in the GI News. With thanks to the authors, we urge you to check out the GI News and subscribe here. For further perspective, you might enjoy this article on flexitarian diets from Professor Clare Collins.

At the Market Stall, painting by Louise Moillon / WikiArt

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December 5, 2018