Unexpected villain in plant-based diets
By RYAN O'HARE, IMPERIAL COLLEGE
LONDON
The research, led by the University of São
Paulo and involving Imperial College London, used data from
more than 118,000 people. It suggests that while plant-based diets are linked
with reduced disease risk, overall, UPFs were linked with worse health
outcomes.
They find that eating plant-based UPFs was
linked with a 7% increase in the risk of cardiovascular diseases, compared with
eating unprocessed plant-based foods. They also found that the all consumption
of UPFs (animal-based and plant-based) was linked with a higher risk of
cardiovascular diseases and dying from these diseases.
Marketing Versus Reality of Plant-Based UPFs
According to the researchers, their findings
– published in the journal Lancet Regional Health – indicate that while
plant-based UPFs may be marketed as healthy alternatives, they may be linked to
worse health outcomes. They add that dietary guidelines should be updated to
encourage people to reduce their consumption of UPFs as well as to promote
plant-based diets.
Dr. Eszter Vamos, co-author of the study,
from the School of Public Health at Imperial College London, said: “Fresh
plant-based foods such as fruits and vegetables, wholegrains and legumes are
known to have important health and environmental benefits. While
ultra-processed foods are often marketed as healthy foods, this large study
shows that plant-based ultra-processed foods do not seem to have protective
health effects and are linked to poor health outcomes.”
Defining UPFs and Their Impact on Health
Plant-based diets are linked with a reduced
risk of cardiovascular diseases, such as heart attacks and strokes. But many
plant-based foods, including meat-free alternatives such as some sausages,
burgers, and nuggets, can be classified as ultra-processed foods (UPFs),
despite often being marketed as healthy options.
UPFs are generally higher in salt, fat,
sugar, and contain artificial additives. Previous research has linked UPFs with
a range of poor health outcomes, including obesity, type 2 diabetes, cardiovascular disease, and cancer.
Study Methodology and Detailed Findings
In the latest study, researchers from the
University of São Paulo in Brazil (USP), Imperial College London, and the
International Agency for Research on Cancer (IARC), investigated the potential
impacts of plant-based UPFs on health.
Using data from the UK Biobank study, they
looked at data for more than 118,000 people England, Scotland, and Wales aged
40 to 69 years who had their diets assessed over at least two days. These data
were linked to hospital and mortality records to obtain information on
cardiovascular diseases.
Health Outcomes Associated With UPF Consumption
The team looked at the contribution of food
items to diet, and classified food items as UPFs, as defined by the Nova
classification, and non-UPFs – unprocessed or minimally processed foods,
processed culinary ingredients, and processed foods. These groups were further
divided into ‘plant-based’ or ‘animal-based’. Plant-based foods composed
exclusively or primarily of plant origin (e.g. fruits, vegetables, grains,
bread, cakes and sweets, sweetened beverages). Animal-based foods included all
meats (fish, poultry, red meats, etc.), dairy and eggs.
The consumption of all plant-based foods
together showed no association with any of the related diseases. Eating more
plant-based non-UPFs was linked to better health outcomes, and replacing
plant-based UPFs with plant-based non-UPFs was linked with a 7% lower risk of
developing cardiovascular diseases and a 15% lower risk of mortality associated
with these conditions. However, consumption of plant-based UPFs was associated
with an increased risk of both outcomes.
Analysis showed that increasing the dietary
contribution of plant-based non-UPFs by 10% was also associated with a 13%
reduction in mortality from all cardiovascular diseases, with a 20% reduction
in mortality caused by coronary heart disease.
Recommendations for Dietary Guidelines
Dr. Fernanda Rauber, a researcher at USP and
first author of the study said: “Despite being plant-based, these foods can
contribute to risk factors such as dyslipidaemia and hypertension due to their
composition and processing methods. Food additives and industrial contaminants
present in these foods can cause oxidative stress and inflammation, further
aggravating the risks. Therefore, our results support the shift towards
plant-based food choices that consider the degree of processing to improve
cardiovascular health outcomes.”
Conclusion and Future Implications
The researchers say that, based on the
available evidence, nutritional guidelines promoting plant-based diets should
focus not only on reducing the amount of meat and other animal-products people
eat, but also on the importance of the level of processing involved in the
food, and avoiding UPFs.
Dr. Renata Levy, a professor at USP, said:
“The study aimed to fill the gap in the evidence regarding the consumption of
ultra-processed plant-based foods and their impacts, especially when it comes
to cardiovascular diseases. Research like this is essential for guiding public
policies. In this case, we have yet another strong argument to encourage the
reduction of ultra-processed food consumption, regardless of whether it is of
animal or plant origin.”
Reference: “Implications of food
ultra-processing on cardiovascular risk considering plant origin foods: an
analysis of the UK Biobank cohort” by Fernanda Rauber, Maria Laura da Costa
Louzada, Kiara Chang, Inge Huybrechts, Marc J. Gunter, Carlos Augusto Monteiro,
Eszter P. Vamos and Renata Bertazzi Levy, 10 June 2024, The Lancet Regional Health – Europe.
DOI:
10.1016/j.lanepe.2024.100948