Study addresses iron inadequacies in EAT-Lancet’s nutritionally controversial planetary health diet

23 Mar 2023 --- A recent study published in The Lancet Planetary Health found vitamin and mineral shortfalls in the EAT-Lancet planetary health diet, due to the low amounts of animal-based foods. They are addressing concerns that the suggested diets are inadequate in iron, have nutritional gaps in four essential micronutrients and contain low amounts of nutritious animal-based foods.

“The EAT-Lancet team is in the process of developing their 2.0 version, so I expect it will address our concerns,” Dr. Ty Beal, research advisor on the knowledge leadership team at GAIN and co-author of Estimated micronutrient shortfalls of the EAT-Lancet planetary health diet, reveals to NutritionInsight.

Beal explains that they shared a draft manuscript with Walter Willette, co-chair of the EAT-Lancet Commission, and incorporated his feedback in the published paper, showing collaboration among the scientists.

The most significant shortcoming in the initial version of the diet is that it only provides for 55% of iron intake recommendations for women of reproductive age.

Beal underscores that “animal-based foods are rich in bioavailable essential nutrients commonly lacking globally."However, not everyone in the scientific community agrees that the EAT-Lancet planetary is nutritionally insufficient, Dr. Anna Herby, nutrition education program manager for the US Physicians Committee for Responsible Medicine, tells us that “the conclusion that the EAT-Lancet diet is nutritionally deficient is inaccurate.”

Animal foods at the center of the debate
Beal explains that there is disagreement about optimal diets and recommended intakes of animal-based foods among the scientific community. He believes the disagreement is both a science-based and an ideological one, as “scientists debate how much animal source foods, and which ones, should be a part of healthy and sustainable diets” due to environmental concerns.

“A lot of scientists are hesitant to promote or encourage animal sourced foods in some contexts,” Ty Beal said last year for the Performance Nutrition Podcast. 

“In our view, we chose the recommended intakes and bioavailability estimates with the most support behind them,” he notes.

Beal underscores that “animal-based foods are rich in bioavailable essential nutrients commonly lacking globally, including iron, zinc, calcium, vitamins B12 and D, choline, EPA, DHA, and EAAs. ASFs and PSFs have complementary nutrient profiles, and diets containing both ASFs and PSFs reduce the risk of nutrient deficiencies.” 

“Animal-based foods also contain beneficial compounds unavailable in plant-based foods, including creatine, anserine, taurine, cysteamine, 4-hydroxyproline, carnosine, conjugated linoleic acid, certain bioactive peptides, and many others,” he continues.

Herby defends that the EAT-Lancet planetary health diet is nutritionally sound.

“We have large scale and long-term studies showing that those following a mostly plant-based diet live longer, healthier lives, and do not have higher rates of micronutrient deficiencies,” she says.

“I do not think that there’s a bias in favor of complete elimination of meats in diets. The science reflects that meat reduction is necessary to make an impact on the climate crisis we are facing, and our food choices play a huge role in that,” Herby continues. The initial version of the EAT-Lancet diet only provided for 55% of iron intake recommendations for women of reproductive age.

Iron inadequacies
Herby addresses the iron shortfalls found in Beal’s study, saying that “vegetarians have no lower rates of iron-deficiency anemia than omnivores” and that “well-planned vegan and vegetarian diets are adequate for all stages of life.”

“The study recalculated iron adequacy of the EAT-Lancet planetary health diet based on 10% bioavailability, which is based on limited data. More comprehensive research shows that iron from plant-based sources can vary greatly depending on the overall diet composition and a person’s iron status,” notes Herby.

“The absorption can vary from 1% all the way up to 23%. Eating iron-rich foods combined with vitamin C-rich foods (like tomatoes, bell peppers, and fresh fruit) will enhance absorption, and people who are low on iron will actually be able to absorb even more from plant sources than people who have sufficient iron stores,” she continues.  

“The example of the EAT-Lancet planetary health diet can be useful for advocacy, but future efforts should consider context-specific guidelines using local data when possible to inform relevant policy making and program planning,” explains the study (Estimated micronutrient shortfalls of the EAT-Lancet planetary health diet) in its conclusions.

“Rather than a planetary health diet, it might be better to suggest locally appropriate diets that meet nutrient needs and local dietary guidelines within different types of cultural contexts and environmental conditions.”Herby underscores that "for most developed countries, a shift toward a more plant-based diet would provide both health and environmental benefits."

This week the IPCC recommended that all countries adopt “balanced diets” to combat climate change. Some advocacy groups like ProVeg noted that the IPCC didn’t go far enough and called it a “missed opportunity” to raise even more awareness about the effects of diets on climate.

Nonetheless, not all countries have access to broad supplementation, and animal foods are the only way to achieve balanced diets.

“It could be that meeting micronutrient requirements through intrinsically nutrient-dense foods alone is not feasible while minimizing the risk of NCDs (noncommunicable diseases) or risk of environmental harm. If this were to be the case, the trade-offs to consider would change,” asks the study.

“First, should intrinsically nutrient-dense foods be prioritized at the expense of the environment? Second, should fortification and supplementation be prioritized at the expense of a diet containing primarily intrinsically nutrient-dense foods? Third, is environmental preservation prioritized at the expense of nutrient adequacy? Finally, is minimizing NCD risk prioritized at the expense of optimizing nutrient adequacy, or vice versa?”

Herby highlights that meat reduction is necessary.

“There are some parts of the world where food insecurity and malnutrition are a major concern, and the EAT-Lancet report acknowledges that local and regional realities need to be considered in these situations. But for most developed countries, a shift toward a more plant-based diet would provide both health and environmental benefits,” Herby concludes. 

By Marc Cervera