Let's count the ways crap food can kill you
By BMJ
Consistent evidence shows that higher exposure to ultra-processed foods is associated with an increased risk of 32 damaging health outcomes including cancer, major heart and lung conditions, mental health disorders, and early death.
The findings, published recently by The BMJ, show that diets high in ultra-processed food
may be harmful to many body systems and underscore the need for urgent measures
that target and aim to reduce dietary exposure to these products and better
understand the mechanisms linking them to poor health.
Ultra-processed foods, including packaged
baked goods and snacks, fizzy drinks, sugary cereals, and ready-to-eat or heat
products, undergo multiple industrial processes and often contain colors,
emulsifiers, flavors, and other additives. These products also tend to be high
in added sugar, fat, and/or salt, but are low in vitamins and fiber.
They can account for up to 58% of total daily
energy intake in some high-income countries, and have rapidly increased in many
low and middle-income nations in recent decades.
Comprehensive Review of the Evidence
Many previous studies and meta-analyses have
linked highly processed food to poor health, but no comprehensive review has
yet provided a broad assessment of the evidence in this area.
To bridge this gap, researchers carried out
an umbrella review (a high-level evidence summary) of 45 distinct pooled
meta-analyses from 14 review articles associating ultra-processed foods with
adverse health outcomes.
The review articles were all published in the
past three years and involved almost 10 million participants. None were funded
by companies involved in the production of ultra-processed foods.
Estimates of exposure to ultra-processed
foods were obtained from a combination of food frequency questionnaires,
24-hour dietary recalls, and dietary history and were measured as higher versus
lower consumption, additional servings per day, or a 10% increment.
The researchers graded the evidence as
convincing, highly suggestive, suggestive, weak, or no evidence. They also
assessed the quality of evidence as high, moderate, low, or very low.
Overall, the results show that higher
exposure to ultra-processed foods was consistently associated with an increased
risk of 32 adverse health outcomes.
Convincing evidence showed that higher
ultra-processed food intake was associated with around a 50% increased risk
of cardiovascular disease-related death, a 48-53% higher risk
of anxiety and common mental disorders, and a 12% greater risk of type 2
diabetes.
Highly suggestive evidence also indicated
that higher ultra-processed food intake was associated with a 21% greater risk
of death from any cause, a 40-66% increased risk of heart disease-related
death, obesity, type 2 diabetes, and sleep problems, and a 22% increased risk
of depression.
Evidence for the associations of
ultra-processed food exposure with asthma, gastrointestinal health, some
cancers, and cardiometabolic risk factors, such as high blood fats and low
levels of ‘good’ cholesterol, remains limited.
Calls for Action and Further Research
The researchers acknowledge that umbrella
reviews can only provide high-level overviews and they can’t rule out the
possibility that other unmeasured factors and variations in assessing
ultra-processed food intake may have influenced their results.
However, their use of rigorous and
prespecified systematic methods to evaluate the credibility and quality of the
analyses suggests that the results withstand scrutiny.
As such, they conclude: “These findings
support urgent mechanistic research and public health actions that seek to
target and minimize ultra-processed food consumption for improved population
health.”
Ultra-processed foods damage health and
shorten life, say researchers in a linked editorial. So what can be done to
control and reduce their production and consumption, which is rising worldwide?
They point out that reformulation does not
eliminate harm, and profitability discourages manufacturers from switching to
make nutritious foods, so public policies and action on ultra-processed foods
are essential.
These include front-of-pack labels,
restricting advertising and prohibiting sales in or near schools and hospitals,
and fiscal and other measures that make unprocessed or minimally processed
foods and freshly prepared meals as accessible and available as, and cheaper
than, ultra-processed foods.
It is now time for United Nations agencies,
with member states, to develop and implement a framework convention on
ultra-processed foods similar to the framework on tobacco, and promote examples
of best practice, they write.
Finally, they say multidisciplinary
investigations “are needed to identify the most effective ways to control and
reduce ultra-processing and to quantify and track the cost-benefits and other
effects of all such policies and actions on human health and welfare, society,
culture, employment, and the environment.”
Reference: “Ultra-processed food exposure and
adverse health outcomes: umbrella review of epidemiological meta-analyses” by
Melissa M Lane, Elizabeth Gamage, Shutong Du, Deborah N Ashtree, Amelia J
McGuinness, Sarah Gauci, Phillip Baker, Mark Lawrence, Casey M Rebholz, Bernard
Srour, Mathilde Touvier, Felice N Jacka, Adrienne O’Neil, Toby Segasby and
Wolfgang Marx, 28 February 2024, BMJ.
DOI:
10.1136/bmj-2023-077310