Global Initiative Seeks to Preserve Heritage Diets Before They Disappear

A vast body of human knowledge about food, food processing and their effects on health is disappearing and could be lost forever.

Researchers have launched a global initiative to study heritage diets around the world as they come under increasing pressure from the globalization of the food system.

It’s more than just dishes. It also includes the social and ecological context of the diet.– Quirijn de Mast, researcher

In a Comment recently published in Nature Medicine, scientists from a dozen countries introduced the World Diet Initiative, a long-term effort combining the preservation of traditional dietary knowledge with rigorous biomedical research.

The researchers warn that locally rooted food systems are being displaced at an unprecedented rate by increasingly homogeneous diets rich in industrially processed foods, refined carbohydrates, sugar and saturated fats.

Once these dietary systems disappear from everyday life, scientists may be able to reconstruct their recipes. However, they cannot recreate the biological effects of consuming them throughout a lifetime or across generations.

“I was in Pompeii last week, and there I saw people explaining how they could still retrieve the ancient recipes, what people in Pompeii were eating,” Quirijn de Mast, first author of the Comment and one of the researchers behind the initiative, told Olive Oil Times.

“So you can reconstruct later what people used to eat at the time,” he added. “But even in such a case, what is very difficult to reconstruct is the biological exposure.”

De Mast is an associate professor of global health and travel medicine at Radboud University Medical Center in the Netherlands.

He explained that when a community stops habitually consuming a traditional diet, researchers lose the opportunity to study people who have been exposed to that food system since childhood.

Original ingredients, local crop varieties, fermentation microorganisms and knowledge about preparing specific foods may also disappear.

“This is what we commonly hear from the elderly,” de Mast said, referring to communities in Africa where the researchers work. “The young, they just lose the knowledge.”

The World Diet Initiative defines a heritage diet as a historically rooted dietary system maintained across generations and recognized by a community as part of its food culture.

The definition extends well beyond characteristic dishes or recipes. It encompasses what communities grow, gather, buy or exchange, along with seasonal variations and cooking and processing techniques such as fermentation.

“It’s more than just dishes,” de Mast said. “It also includes the social and ecological context of the diet.”

However, he cautioned against romanticizing traditional food systems.

“We don’t want to say that in the past everything was better,” he said, adding that heritage diets should not be regarded as “a frozen museum object.”

Migration, trade, climate and cultural exchanges have always transformed them. The researchers also warn that heritage diets should not automatically be assumed to be healthier.

Instead, their value lies partly in the largely unexplored biological diversity they represent.

The initiative was partly inspired by research that de Mast and his colleagues conducted in the Kilimanjaro region of northern Tanzania.

In a randomized controlled trial published in Nature Medicine in 2025, the researchers recruited 77 healthy young men and examined what happened when participants accustomed to a largely plant-based, fiber-rich Kilimanjaro heritage diet switched to a Western-style diet for two weeks.

Another group made the reverse switch. A third continued eating its usual Western-style diet but added mbege, a traditional fermented banana-and-millet beverage, for one week.

The transition from the heritage diet to the Western-style diet promoted pro-inflammatory changes and altered metabolic pathways associated with noncommunicable diseases.

Switching from the Western-style diet to the heritage diet had largely anti-inflammatory effects, as did the consumption of mbege.

Some of the changes persisted four weeks after the intervention ended.

“Already within two weeks, we saw clear changes in the function of the immune system,” de Mast said.

The findings were particularly significant because most scientific research into the biological effects of dietary patterns has focused on a small number of extensively studied diets, particularly those of the Mediterranean region and Japan.

“It made us realize that, in terms of diets, we only consider and only have scientific data on very few diets, especially the Mediterranean diet,” de Mast said.

The new Nature Medicine paper notes that most research into the biological effects of diet has focused on European and East Asian populations, particularly the Mediterranean diet and Japanese diet.

By contrast, dietary systems in Africa, Latin America, South and Southeast Asia and the Pacific remain comparatively understudied, even as obesity and diet-related noncommunicable diseases rise in many of those regions.

“See how much we learned only from the Mediterranean diet,” de Mast said.

The World Diet Initiative plans to broaden the evidence base through two complementary components.

The World Diet Atlas will document heritage food systems in a standardized, openly accessible resource. It will record ingredients, sourcing, processing and preparation methods, along with behaviors including meal timing, snacking, fasting and commensality, or eating with others.

The World Diet Project will investigate selected diets using standardized biological research protocols, allowing scientists to compare their effects on immunity, metabolism and the microbiome across different populations.

De Mast said a common methodology is essential because existing research is often scattered, with investigators using different technologies and study designs that make direct comparisons difficult.

“What if we bring people together and we don’t start doing everything in a different way, but we try to use kind of a blueprint?” he said.

The initiative also aims eventually to establish a federated multi-omics biobank linking dietary exposure with immune, metabolic and microbiome characteristics.

As more researchers join the initiative, potential projects are extending from Tanzania and Ethiopia to India, Indonesia, Brazil, Canada and Europe.

“India is a laboratory,” de Mast said. “Talking about food diversity, India is, of course, a very good example.”

Africa offers numerous other examples of traditional food systems that remain poorly studied, including Ethiopia, with its ancient grains and fermentation practices.

“They have an ancient grain called teff, which is fermented,” de Mast said. “It is daily food, one of their main staples. In other areas, there is a lot of millet being eaten and sorghum.”

“Take teff,” he added. “It doesn’t contain any gluten. It doesn’t cause those kinds of glucose peaks we see elsewhere.”

“The Ethiopian heritage diets are different from everything else,” de Mast said.

According to de Mast, the goal is not to persuade everyone to adopt a particular traditional diet.

“There is a lot that we can also gain from these insights,” he said. “I’m not saying that we should all start eating like people eat in Ethiopia. Not at all.”

Instead, researchers may identify particular foods, techniques or combinations that could broaden the range of scientifically supported dietary practices.

“If you already see how our diet changed in recent years, at least in the Netherlands, there is a lot of Asian cuisine that is now being consumed,” de Mast said. “Why not also have components from heritage diets?”

De Mast described the World Diet Initiative as a bottom-up effort rather than a conventional research project with a defined endpoint.

The researchers hope it will expand over the coming decades, bringing more institutions, communities and funders into a coordinated international effort to develop the Atlas and support comparable biological studies across countries.

“The website is there,” de Mast said. “We are ready to start now.”

Beyond Tanzania and Ethiopia, the initiative brings together researchers with interests and ongoing work in countries including India, Indonesia and Brazil.

“We really hope that we can grow as an initiative,” de Mast said.

“I think it is important to broaden our view, because there is so much more to learn from everything that is around in the world,” he concluded.