Lean and fatty fish diet may slow progression of multiple sclerosis, research suggests

New research supports that a high dietary intake of lean and oily fish may slow the progression of disability in people with multiple sclerosis (MS). The study finds anti-inflammatory and neuroprotective properties of nutrients found in fish may play an important role, underscoring the potential importance of diet in managing the disease. 

The comparative population-based study was published online in the Journal of Neurology Neurosurgery & Psychiatry.

This is an observational study, and as such, no firm conclusions can be drawn about cause and effect, explain the authors. Further research to validate the findings and investigate the underlying biological mechanisms is required.

But they suggest: “While omega-3 fatty acids, predominantly found in oily fish, may contribute to reduced disability progression, the beneficial effects observed from lean fish consumption suggest that other factors may also play a significant role. One such factor is taurine, an amino acid found in significant amounts in fish and seafood.”

“Taurine is the most abundant free amino acid in the brain and, although there are endogenous mechanisms for its production, an exogenous supply is necessary to meet physiological needs.”

The authors explain that taurine has diverse cellular functions, “including cytoprotective actions through antioxidative and anti-inflammatory effects, making it a potential therapeutic agent for neurological disorders.”

Dietary disease interventions

The study authors say emerging evidence indicates that diet may have a role in the development of inflammatory diseases, including MS.

While previously published research has linked fish consumption with lower levels of disability among those with MS, few studies have looked at whether it might slow or lessen the progression of disability, they point out.

To explore this further, they drew on data from 2,719 newly diagnosed participants (average age 38) in the Epidemiologic Investigation of Multiple Sclerosis (EIMS) study, a Swedish nationwide population-based case-control study, all of whom were recruited between April 2005 and June 2015.

On entry to EIMS, all participants provided information on environmental exposures and lifestyle habits, including their consumption of lean and oily fish. This was categorized as never or seldom, one to three times a month, and weekly, and scores ranged from two to six, depending on whether they ate lean or oily fish, or both.

Their disease progression, measured using the Expanded Disability Status Scale (EDSS), was tracked for up to 15 years through the Swedish MS Registry.

Confirmed disability worsening was defined as an increase in the EDSS score of at least one point from baseline, sustained between two further check-ups, at least six months apart.

The highest fish consumption at diagnosis was associated with a 44% lower risk of confirmed disability worsening, a 45% lower risk of progressing to EDSS 3, and a 43% lower risk of progressing to EDSS 4 compared with those who ate none or very little.

Trends analysis indicated that the more lean and oily fish that was consumed, the lower was the risk of confirmed disability worsening and progression to EDSS 3 and 4.

Building on previous research

In 2021, 1,719 participants completed an online follow-up questionnaire that assessed changes in fish intake over time. Of those, 412 (24%) had altered their fish consumption: 288 had increased it; 124 had decreased it.

Those who increased their score from two or three to a score of five or six within five years after diagnosis (133) had a 20% lower risk of confirmed disability worsening, compared with those who continued to eat little or no fish (400).

Only 16 participants increased their fish consumption from a baseline score of two to a score of five to six, but they had a 59% lower risk of confirmed disability worsening, compared with those who remained at the lowest level of consumption (101).

The findings held true even when the potentially influential factors of physical activity, weight, smoking, alcohol intake, and sun exposure were accounted for. They also remained similar when further adjustments were made for vitamin D levels.

The authors conclude: “The results underscore the potential role of diet, particularly fish consumption, as a modifiable factor that could complement existing therapeutic strategies for MS.”

In other dietary intervention research, scientists found that reducing calorie intake may alleviate fatigue in people battling MS. The findings add additional weight to previous research underscoring the importance of reducing fat intake to improve fatigue among people with the condition.

Last September, UK researchers were granted £4.8 million (US$6.3 million) in an eight-year program to examine the link between nutrition, health inequality, and the development of multiple long-term conditions using AI.