The greatest review of its sort ever conducted found a direct correlation between ultra-processed food (UPF) and 32 detrimental health outcomes, including an increased risk of heart disease, cancer, type 2 diabetes, poor mental health, and early mortality.
The results of the first thorough overarching analysis of the data are released at a time when the consumption of UPF-containing foods and beverages—such as cereals, protein bars, carbonated drinks, prepared meals, and fast food—is expanding quickly worldwide.
Ultra-processed food currently makes up more than half of the average diet in the US and the UK. For some, particularly those who are younger, less well-off, or from underprivileged backgrounds, a diet that contains up to 80% UPF is normal.
Diets high in UPF may be detrimental to various aspects of health, according to research published in the BMJ. The review’s findings, which included data from nearly 10 million individuals, highlighted the necessity of taking action to limit exposure to ultraviolet light-blocking substances.
Experts from several prestigious universities participated in the review, including the University of Sydney, the Sorbonne University in France, and the Johns Hopkins Bloomberg School of Public Health in the US.
“Overall, direct associations were found between exposure to ultra-processed foods and 32 health parameters spanning mental, respiratory, cardiovascular, gastrointestinal, and metabolic health outcomes,” the authors said in the BMJ.
They continued, saying that “Greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorders and mortality outcomes.
“These findings provide a rationale to develop and evaluate the effectiveness of using population-based and public-health measures to target and reduce dietary exposure to ultra-processed foods for improved human health.”
Ultra-processed foods go through several industrial processes and frequently include colors, emulsifiers, flavors, and other additives. Examples of these foods include packaged baked goods and snacks, carbonated drinks, sugary cereals, and ready-to-eat or ready meals. These goods also frequently have poor vitamin and fiber contents and high added sugar, fat, and/or salt content.
Although prior research has connected UPF to ill health, no thorough analysis has yet offered an extensive evaluation of the available data in this field.
An umbrella review, or high-level evidence summary, encompassing 45 different pooled meta-analyses from 14 review papers linking UPF to worse health outcomes was conducted by researchers in order to close this gap.
9.9 million persons were involved in the review articles, all of which were published within the last three years. Companies interested in UPF manufacture did not fund any of them.
Estimates of exposure to ultra-processed foods were measured as additional servings per day, a 10% increase, or higher versus lower intake. These estimates were derived from a mix of food frequency questionnaires, 24-hour dietary recalls, and dietary history.
The evidence was rated by the researchers as strong, weak, suggestive, compelling, or lacking proof. Additionally, they assigned a good, moderate, low, or extremely low quality rating to the evidence.
According to The BMJ, overall findings indicate that a higher level of UVF exposure was consistently linked to a higher risk of 32 unfavorable health outcomes.
Strong evidence indicated that a higher UPF intake was linked to a 48–53% higher risk of anxiety and common mental disorders, a 12% higher risk of type 2 diabetes, and an almost 50% increased risk of death from cardiovascular disease.
Additionally, there was highly suggestive evidence linking higher PF intake to a 21% increased risk of death from all causes, a 40–66% increased risk of death related to heart disease, obesity, type 2 diabetes, sleep issues, and depression.
The researchers emphasized that the evidence for these correlations is still weak. There was also evidence of links between UPF and asthma, gastrointestinal health, certain malignancies, and cardiometabolic risk factors, such as high blood fats and low levels of “good” cholesterol.
The researchers recognized a number of limitations with the umbrella review, such as the inability to completely rule out the chance that discrepancies in the assessment of UVF consumption and other unmeasured factors could have affected their findings.
In addition to pointing out that a large portion of the research included in the umbrella review was inadequate, some experts who were not engaged in the study issued a warning, pointing out that the findings do not establish cause and effect.
The results, according to one of the world’s foremost authorities on UPF, Dr. Chris van Tulleken, associate professor at University College London, are “entirely consistent” with the “enormous number of independent studies which clearly link a diet high in UPF to multiple damaging health outcomes including early death.”
“We have good understanding of the mechanisms by which these foods drive harm,” he continued. “In part it is because of 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’re engineered and marketed in ways which drive excess consumption – for example they are typically soft and energy dense and aggressively marketed usually to disadvantaged communities.”
Brazilian scholars claimed in a related editorial that UPFs were often chemically manipulated cheap ingredients” and “made palatable and attractive by using combinations of flavours, colours, emulsifiers, thickeners and other additives”.
“It is now time for UN agencies, with member states, to develop and implement a framework convention on ultra-processed foods analogous to the framework on tobacco.” they continued.
In the meantime, a another study that was published in the Lancet Public Health revealed that if calories were listed on the menus of all eateries, fast food chains, cafes, pubs, and takeaways, over 9,000 heart disease-related deaths in England could be avoided over the course of the next 20 years.