Research shows that ultra-processed foods have 32 harmful health effects

Ultra-processed foods (UPF) are directly linked to 32 adverse health consequences, including a higher risk of heart disease, cancer, type 2 diabetes, adverse mental health and premature death, according to the world’s largest review of its kind.

The findings from the first comprehensive, overarching review of evidence stem from rapidly increasing global consumption of UPF, such as breakfast cereals, protein bars, carbonated drinks, convenience foods and fast food.

In Britain and the US, ultra-processed foods now make up more than half of the average diet. For some, especially people who are younger, poorer, or from disadvantaged areas, a diet with as much as 80% UPF is typical.

The findings published in the BMJ suggest that high UPF diets may be detrimental to many elements of health. The results of the study involving nearly 10 million people underscored the need for measures to target and reduce UPF exposure, the researchers said.

The research involved experts from a number of leading institutions, including the Johns Hopkins Bloomberg School of Public Health in the US, the University of Sydney and Sorbonne University in France.

Writing in the BMJ, they concluded: “Overall, direct links were found between exposure to ultra-processed foods and 32 health parameters, including mortality, cancer and mental, respiratory, cardiovascular, gastrointestinal and metabolic health outcomes.”

They added: “Greater exposure to ultra-processed foods was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorders and mortality.

“These findings provide a rationale for developing and evaluating the effectiveness of using population-based and public health interventions to target and reduce dietary exposure to ultra-processed foods for better human health.”

Ultra-processed foods, including packaged baked goods and snacks, carbonated beverages, sugary breakfast cereals, and ready-to-eat or ready-to-eat meals, undergo multiple industrial processes and often contain colorings, emulsifiers, flavorings, and other additives. These products usually also contain a lot of added sugars, fats and/or salt, but few vitamins and fiber.

Previous studies have linked UPF to poor health, but no comprehensive review has yet provided a broad assessment of the evidence in this area.

To bridge this gap, researchers conducted an umbrella review – a high-level summary of the evidence – of 45 different pooled meta-analyses from 14 review articles that linked UPF to adverse health outcomes.

The review articles were all published in the last three years and involved 9.9 million people. None were funded by companies involved in UPF production.

Estimates of ultra-processed food exposure were obtained from a combination of food frequency questionnaires, 24-hour dietary recalls, and diet history, and were measured as higher versus lower consumption, additional servings per day, or a 10% increase.

The researchers rated the evidence as convincing, highly suggestive, suggestive, weak or no evidence. They also rated the quality of the evidence as high, moderate, low or very low.

Overall, the results show that higher UPF exposure was consistently associated with an increased risk of 32 adverse health outcomes, the BMJ reported.

Compelling evidence showed that higher UPF intake was associated with an approximately 50% increased risk of mortality from cardiovascular disease, a 48 to 53% increased risk of anxiety and common mental disorders, and a 12% increased risk on type 2 diabetes.

Highly suggestive evidence also indicated that higher PF intake was associated with a 21% greater risk of death from any cause, a 40 to 66% increased risk of cardiovascular disease-related death, obesity, type 2 diabetes and sleep problems, and a 22% increased risk of death from heart disease, obesity, type 2 diabetes and sleep problems. risk of depression.

There was also evidence of associations between UPF and asthma, gastrointestinal health, some cancers and cardiometabolic risk factors, such as high blood fats and low levels of ‘good’ cholesterol, although the researchers cautioned that evidence for these links remains limited.

The researchers acknowledged several limitations of the overarching review, including that they could not rule out the possibility that other unmeasured factors and variations in the assessment of UPF intake may have influenced their results.

Some experts not involved in the study also emphasized that much of the research in the umbrella review was weak and also warned that the findings do not prove cause and effect.

Dr. However, Chris van Tulleken, an associate professor at University College London and one of the world’s leading UPF experts, said the findings were “completely consistent” with a now “huge number of independent studies that clearly link a diet high in UPF and multiple conditions. adverse health effects, including premature mortality”.

“We have a good understanding of the mechanisms by which these foods cause harm,” he added. “Partly this is due to their poor nutritional profile – they are often high in saturated fat, salt and free sugar.

But the way they are processed is also important – they are developed and marketed in a way that encourages excessive consumption – for example, they are typically gentle and energy-dense and are aggressively marketed, usually to underserved communities.”

In a linked editorialAcademics from Brazil said UPFs are “often chemically engineered cheap ingredients” and are “made tasty and attractive by using combinations of flavors, colors, emulsifiers, thickeners and other additives.”

They added: “Now is the time for UN agencies to work with Member States to develop and implement a framework treaty on ultra-processed foods, analogous to the framework on tobacco.”

Meanwhile, a separate study published in the Lancet Public Health suggested that more than 9,000 heart disease-related deaths could be prevented in England over the next 20 years if all restaurants, fast food outlets, cafes, pubs and takeaways put calories on their menus.