Evidence connecting ultraprocessed foods to a wide range of health concerns continues to accumulate.Brandon Bell/Getty Images
An enormous body of evidence has found a diet high in ultraprocessed foods is associated with a greater risk of many chronic diseases including heart disease, obesity, hypertension, Type 2 diabetes and fatty liver disease.
Findings from a 2024 review of 45 meta-analyses went as far as to suggest that eating plenty of ultraprocessed foods (UPFs) may be “harmful to most – and perhaps all – body systems”.
Evidence connecting UPFs to a wide range of health concerns continues to accumulate.
In August, researchers reviewed evidence on how a diet reliant on UPFs may work against healthy brain aging over time.
In late September, a large U.K. study again tied a higher intake of UPFs to an increased risk of Type 2 diabetes.
Also in September, study findings suggested that reducing UPF intake can benefit mental health.
Here’s a breakdown of the recent research.
Reducing UPFs + physical activity powerful combo for diabetes prevention
According to new research, cutting back on UPFs and getting regular exercise can substantially lower the risk of developing Type 2 diabetes, even in people at high genetic risk for the condition.
The findings were presented at the annual meeting of the European Association for the Study of Diabetes which took place Sept. 28 through Oct. 2.
The researchers examined data on 56,964 adults in the U.K. Biobank study, a long-term biomedical study that tracks the health, lifestyle and genetic data of half a million people living in the United Kingdom.
During almost eight years of follow-up, 926 participants developed Type 2 diabetes.
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As expected, a higher intake of UPFs was associated with an increased risk of diabetes. And getting at least 150 minutes of moderate to vigorous physical activity (MVPA) each week, the World Health Organization (WHO) recommendation, was tied to a lower risk.
Examples of MVPA include brisk walking, cycling, doubles tennis, running, singles tennis and swimming laps.
The combination of a lower UPF intake and MVPA, however, partially offset diabetes risk among those with a high genetic susceptibility. Doing both was tied to a 49 per cent reduced risk in people whose genes made them highly susceptible to Type 2 diabetes.
The findings also revealed that exercise reduced the impact of UPFs on diabetes risk.
In people with a high intake of UPFs, regular MVPA was associated with a 33 per cent lower risk of diabetes in those at high genetic risk.
Reducing UPFs may help improve mood
Findings from a small preliminary study, published Sept. 23 in the journal JAMA Psychiatry, suggest that reducing intake of UPFs may be a useful complement to the treatment of depression.
The study, conducted in 20 adults with major depressive disorder, found that following a low-UPF diet for four weeks led to significant improvements in depression and anxiety symptoms compared to the four-week period they ate their usual diet.
Participants received individualized dietary counselling to reduce UPFs by replacing them with less processed alternatives.
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Despite the study’s limitations, including a small sample size and short duration, the findings align with observational studies linking high intakes of UFPs with a greater risk of developing depression.
They’re also consistent with earlier Mediterranean diet randomized controlled trials showing that improving diet quality led to significant reductions in depressive symptoms.
Higher UPF intakes may harm the aging brain
A high intake of UPFs is increasingly associated with poorer brain health as we age, including worse cognitive performance and a greater risk of dementia.
For an article published in the August issue of Annual Review of Nutrition, researchers explored emerging evidence to determine what is currently known about how high-UPF diets may harm brain health.
They identified a number of different ways, including inflammation, oxidative stress, impaired blood vessel function, insulin resistance and disruption of the gut microbiome. What’s more, several of these processes may be occurring at the same time.
The researchers emphasized that we still don’t know how much of the risk associated with UPFs is due to the processing itself, additives or processing by-products or the fact that UPFs tend to be lower in fibre and protective phytochemicals and higher in added sugar, sodium and fats.
Takeaways
In the meantime, focus on reduction, not perfection.
The goal doesn’t need to be eliminating UPFs altogether, which is difficult to do. Instead, replace them with whole foods or minimally processed foods when you can.
Instead of packaged snacks like granola bars, pretzels and flavoured crackers, for example, choose fruit, nuts or plain or lightly seasoned popcorn.
At breakfast, swap mass-produced muffins or sugary, refined cereal, for oatmeal, overnight oats or cottage cheese with berries.
Instead of processed meats, choose tuna, salmon, egg salad or leftover cooked chicken or turkey breast.
Most of the time, build meals around whole and minimally processed foods.
Keep in mind, too, not all UPFs are nutritionally equivalent.
While still considered UPFs, flavoured yogurts, 100 per cent whole grain packaged breads and fortified whole grain ready-to-eat cereals can still provide valuable nutrients, such as calcium, protein, fibre, B vitamins and iron.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan.