Meet the researcher: How researching plant-based foods changed this scientist’s perspective on processed products

As a researcher investigating the barriers stopping people from embracing more plant-based foods, Sarah Nájera Espinosa has plenty of personal experience to draw on. 

15 May 2024.

Plant-based food products
Plant-based meat for sale in a supermarket
Sarah Nájera Espinosa

Name: Sarah Nájera Espinosa

Job title: PhD candidate  

Organisation: London School of Hygiene and Tropical Medicine

Sustainable protein specialism: Nutrition and climate change

As a researcher investigating the barriers stopping people from embracing more plant-based foods, Sarah Nájera Espinosa has plenty of personal experience to draw on. 

Growing up in Ecuador, the national food culture made it hard for her to adopt a plant-based diet. “If you went for a meal with a family member, they would give you a bowl of salad if I asked for no meat,” she said.

Things didn’t get any easier when she moved to study for a Bachelor’s in environmental studies in the United States, where she found few meat-free options in the university cafeteria.

Moving again – this time to study food security at the University of Edinburgh – meant Sarah was exposed to a lot of vegan food, and although she has been following a flexitarian diet ever since, she was still put off plant-based meat due to the perception it was heavily processed. 

This only changed when she began her current role researching a PhD at the London School of Hygiene and Tropical Medicine (LSHTM), assessing whether plant-based and fermentation-made foods can provide a healthy, sustainable and affordable alternative to meat and dairy.

A fresh perspective on food processing

“Once I started researching these foods, my attitude towards them changed a lot,” she said. “I started trying a lot of the products I was exploring and began looking at them through a very different lens.”

An earlier role at the UN’s Food and Agriculture Organisation (FAO) in Rome, where she dealt with areas such as food safety and nutrition, also gave her fresh insights. “I had always believed that processing was bad for you,” she said. “But I saw how additives and additional ingredients were vital to keeping food safe.”

Sarah’s work at LSHTM has so far produced a literature review looking into the nutritional and environmental impact of plant-based foods in high-income countries – finding that, with few exceptions, these products caused less greenhouse gas emissions, and used less water and land than their animal-based equivalents.

While health data was limited, they also scored highly in areas such as supporting weight loss, and improving biomarkers for non-communicable diseases and gut health.

She is now planning further studies, including a survey of more than 400 UK consumers, looking into the main barriers and drivers encouraging people to switch from animal to plant-based products – including factors such as price, taste and health.

Another study will take an average UK weekly shopping basket containing a mixture of healthy foods and snacks, substitute animal-based products with the closest possible plant-based alternatives, and analyse the cost, nutritional value and environmental footprint of each basket. 

“An important aspect of this study is to provide realistic examples of what people can already do,” she said.

Sarah plans to use the findings to inform policymakers about what drives consumer choice and what can be done to influence larger numbers of people to switch to more plant-forward diets.

Unpicking the UPF debate

Her own earlier attitude has given Sarah an insight into the ongoing debate over ultra-processed foods (UPFs).

“Before plant-based alternatives came along there was a lot of evidence showing that we shouldn’t eat very processed products,” she said. “We were all exposed to the idea that we shouldn’t be eating sugary drinks or biscuits – that messaging was so well captured that there are now lots of doubts about products like plant-based meat, which can be healthy.”

She believes the food industry has an important role to play in generating more knowledge and challenging myths – through measures such as information campaigns and clearer categorisation of products.

“It took me years to understand how to read a label,” she said. “People are confused by them, and because the UPF debate has become so big, they get very nervous when they see this long list of ingredients.”

As plant-based foods are still in their infancy, she also thinks academia can do more to provide analytical evidence for the nutritional value of these products, particularly their micronutrient content. “We already know a lot about the composition of beef,” she said. “But some studies are starting to show that mycoprotein – for example – contains zinc and other micronutrients.” 

Sarah also wants to see more opportunities for academics, industry figures and policymakers to come together and discuss the benefits and challenges of plant-based foods.

“We need a food system transformation and plant-based foods – as well as cultivated meat and precision fermentation –  have the potential to really change things. But we need to understand how to use them so the general population take them up.”

For more information about the nutritional quality of plant-based meat, see our report or read a summary here.

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