Higher ultra-processed food intake tied to increased MS risk, says study

Higher consumption of ultra-processed foods, such as soft drinks, packaged snacks, and ready-to-eat meals, may be associated with an increased risk of developing multiple sclerosis (MS).

That’s according to a large study involving nearly 186,000 middle-aged adults in the UK, which found that each 10% increase in ultra-processed food intake – measured as a share of total food intake – was linked to about a 9% higher risk of MS.

‘This study found a weak yet significant association between higher [ultra-processed food] consumption and increased risk of MS in middle-aged and older adults,’ researchers wrote. ‘Research to confirm these findings in other population groups and contexts is needed.’

Ultra-processed foods have become a major part of modern diets worldwide. Designed to be convenient, affordable, and highly palatable, these industrially made products now account for a substantial portion of daily food intake in many countries. In the UK, they make up about 57% of total calorie intake in adults.

Beyond being linked to more than 30 health conditions, including type 2 diabetes and diseases of the heart and blood vessels, growing evidence suggests ultra-processed foods may also play a role in neurodegenerative diseases, such as dementia and Alzheimer’s disease.

Although evidence remains limited for MS, diets high in ultra-processed foods have been shown to promote inflammation and oxidative stress – two processes known to play a role in MS development and progression. As they replace healthier foods, they may also reduce the intake of beneficial nutrients that help protect against inflammation.

To explore the link between ultra-processed food consumption and MS onset, researchers in the UK analysed data from 185,788 individuals. This large, population-based study tracks people’s health and lifestyle information over time. No participant had MS at the start of the study.

Dietary habits were assessed using the Oxford WebQ, a web-based questionnaire in which participants report what they ate and drank in the previous 24 hours.

This survey, covering more than 200 common foods and beverages, was completed at up to five time points between 2009 and 2012.

Participants had a mean age of 56 and were mostly white (96%). On average, ultra-processed foods made up about 19.1% of the total grams of food people ate and nearly half (47.5%) of their total calorie intake.

The most commonly consumed ultra-processed foods included soft drinks (3.7% of total grams), ready-to-eat/heat meals (3.5%), packaged breads (2.7%), dairy-based drinks (2.4%), and baked goods such as cakes, buns, and pastries (2.2%).

Over a mean follow-up of nearly nine years, 384 participants developed MS. Those who developed MS were more likely to be women (72.1%) and to have a history of smoking (53.4%). They also tended to be younger and have a lower total calorie intake than those who did not develop MS.

Statistical analyses showed that higher consumption of ultra-processed foods was associated with an increased risk of developing MS. Specifically, for every 10% increase in intake, the risk rose by about 9%. Similar results were observed when intake was measured by calories rather than the total amount of food consumed.

‘Our findings contribute to the limited, but growing, literature on [ultra-processed food] consumption and risk of neurodegenerative diseases, including MS,’ the researchers wrote, adding that the results suggest that reducing ultra-processed food ‘consumption may be important to reduce MS risk in the general population.’

The researchers emphasised that these findings should be interpreted with caution, given the modest effect size and the lack of consistent statistical significance across all analyses. They also noted that, because participants in this study had a mean age of 56, more data will be needed to understand whether these results may also apply to younger adults.

Read more about MS and your diet with our helpful Choices booklet