“We were encouraged to see that patients who increased their fish intake after diagnosis still benefited, indicating that dietary changes may have a meaningful impact on MS progression, even later in the disease course,” says study author Anna Hedström, MD, PhD, a senior research specialist with the department of clinical neuroscience at the Karolinska Institute in Stockholm.
“While more research is needed, fish consumption as part of a balanced, anti-inflammatory diet could be a simple and practical strategy for MS management,” Dr. Hedström says.
People With MS Saw Benefits From Both Oily and Lean Fish
Drawing on dietary and health data from more than 2,700 adults newly diagnosed with MS, researchers observed that eating more fish was associated with slowing of disability progression. Participants were 38 years old on average, and were followed for up to 15 years after diagnosis.
One of the most interesting findings, Hedström says, was that both lean and oily fish were tied to a lower risk of disability progression.
She and her collaborators expected to see positive effects from oily fish, such as salmon, mackerel, sardines, and herring, as these are rich in vitamin D and omega-3 fatty acids, nutrients known for their anti-inflammatory and neuroprotective properties.
The study authors, however, were somewhat surprised to also find positive health outcomes associated with lean fish such as cod, haddock, and pollock. Hedström and her team speculate that specific bioactive compounds in these types of fish, such as taurine and selenium, may play a role, as their antioxidant effects and positive influence on the body’s immune response may help protect nerve cells.
“While there are no specific MS guidelines, our findings suggest that consuming fish at least once a week — and ideally a mix of both lean and oily fish — may be associated with better long-term outcomes in MS,” says Hedström.
She warns, however, that excessive intake of certain fish can lead to exposure to mercury and other environmental contaminants. Large predatory fish, in particular — such as shark, swordfish, and king mackerel — may have higher mercury levels and should be eaten in moderation, advises Hedström.
How Eating Fish Affects MS Disability Progression
For the study, 2,719 MS patients provided information regarding their consumption of lean and oily fish, with frequency categorized as: never or seldom, one to three times a month, and weekly.
The results showed that eating fish weekly at the time of diagnosis was associated with a 34 percent lower risk of confirmed disability worsening, compared with monthly or never.
Trends analysis found that the more lean and oily fish consumed, the lower was the risk of confirmed disability worsening and progression to higher scores of 3 and 4 on the EDSS scale.
A subset of about 1,700 participants completed an online follow-up questionnaire that assessed changes in their fish intake over time.
In this group, those who increased their fish consumption within five years post diagnosis had a significantly lower risk of confirmed disability worsening — as much as 59 percent lower — compared with those who maintained a low intake of fish.
The researchers further noted that the results held true even after accounting for potentially influential factors of physical activity, body mass index (BMI), smoking, alcohol intake, and sun exposure.
The Role of Diet in Easing MS Symptoms
For Kalina Sanders, MD, a neurologist and director of the Comprehensive MS Clinic at Baptist Health in Jacksonville Beach, Florida, the study reinforces how important dietary habits are for MS management.
“Having a balanced diet that is rich in polyunsaturated fatty acids found in fish is a way to minimize inflammation and enhance neuroprotection,” says Dr. Sanders. “This may ultimately impact how some patient’s disease activity and disability changes over time.”
She stresses that the research has limitations, in that fish consumption details were self reported, so there may be inaccuracies with recall. The study also lacked information on fish preparation methods, which could influence the nutritional content and health effects.
Additionally, she emphasizes that this is an observational study, so it cannot establish a causal relationship between fish consumption and reduced MS disability progression.
