Eating more oily fish, wholegrain bread may help reduce MS risk
Findings add to growing evidence that a healthy diet may prevent the disease
- A new analysis found that eating oily fish and wholegrain bread may significantly reduce a person's risk of developing multiple sclerosis.
- The findings support evidence that diet is a modifiable risk factor for MS.
- Oily fish alone lowered MS risk by 32%, while eating wholegrain bread reduced it by 28%; Combined, the risk dropped by 47%.
Eating more oily fish and wholegrain or wholemeal bread may help reduce a person’s risk of developing multiple sclerosis (MS), according to a new study that used data from a large U.K. database.
The findings contribute to growing evidence showing that diet is “a potentially modifiable factor in MS onset and [also] progression,” the researchers wrote, noting that the data suggest that maintaining a healthy diet may help prevent the disease from developing.
“Our findings revealed that regular intake of oily fish and consumption of whole meal/whole grain bread are associated with a decreased risk of MS,” the researchers wrote, noting that “oily fish” are those with high levels of fat in their soft tissues, “such as sardines, salmon, mackerel, and herring.”
The team also noted that “cereal and grain are essential components of a [healthy] diet.”
Still, the scientists noted that “further research is required to explore the [underlying] mechanisms,” particularly a potential synergistic effect of eating both wholegrain bread and oily fish.
The study, “Diet and the Risk of Multiple Sclerosis: Evidence With UK Biobank Nested Case-Control Study and Mendelian Randomization Analysis,” was published in the journal Molecular Nutrition & Food Research.
MS occurs when the immune system mistakenly attacks the protective myelin sheath covering nerve fibers in the brain and spinal cord. The disease arises from a combination of genetic and environmental risk factors, and diet is believed to be one of the factors that contribute to the development of MS.
Study focused on different foods, not specific diet plans
Diet can influence immune function and brain health, and can also alter the activity of microbes that reside in the digestive tract. While there is no single MS diet, it is generally recommended that patients eat a varied and well-balanced diet similar to what is recommended for the general population.
Most studies, however, have examined specific diets or dietary patterns in people with MS, so it’s not known whether individual foods can alter MS risk or disease outcomes.
To better understand how different foods are linked to the disease, researchers in China analyzed data from 303 adults with MS followed at the UK Biobank and 1,212 adults without the condition, who served as controls. The controls were matched for age and sex to allow a fairer comparison.
Compared with the controls, the individuals with MS were less physically active, had smoked more often, and had lower levels of vitamin D in the blood. Patients also had higher numbers of circulating neutrophils, which are white blood cells involved in the immune response.
Diet also differed between the two groups. Patients were more likely to eat fewer than 10 slices of bread per week, and were less likely to eat oily fish regularly. Oily fish, such as salmon and mackerel, is rich in omega-3 fatty acids and vitamin D.
Statistical analyses revealed that eating oily fish reduced the risk of MS by 32%, while eating more bread reduced it by 28% — an effect driven by wholemeal/wholegrain bread.
“Comparing to increasing the quantity of bread intake, switching diet type to intake wholemeal/wholegrain bread was more beneficial,” the researchers wrote.
Eating both oily fish and wholegrain breads may have synergistic effects
Importantly, according to the researchers, eating both oily fish and wholemeal or wholegrain bread appeared to be synergistic, meaning it was more beneficial than eating each food alone. In fact, people who ate both oily fish and wholemeal or wholegrain bread had a 47% lower risk of MS compared with those who ate neither, the data showed.
The researchers next employed Mendelian randomization, a method that uses genetic differences related to diet to test how foods are linked to MS. Eating more raw vegetables, oily fish, and cereal reduced the risk of MS, that analysis found. Meanwhile, eating more cooked vegetables increased the risk fourfold. Pork increased it ninefold.
The benefits of oily fish were especially strong for certain categories of people: adults ages 45 to 60, women, people with less physical activity, and those with a lower body mass index, or BMI, which is a measure of body fat based on height and weight. For bread, younger adults and those with higher BMI benefited most.
Our study provided evidence that regular consumption of oily fish and wholemeal/wholegrain bread can effectively lower the risk of developing MS, verifying the association between various diets patterns and the onset of MS.
Mediation analyses helped explain why oily fish may be protective, with higher levels of vitamin D and higher numbers of neutrophils each partly explaining the benefit, independent of each other. The benefit of bread appears to come from other mechanisms that are not yet clear, the researchers noted.
“Taken together, these findings suggest that a diet comprising a combination of oily fish and wholemeal/whole grain bread may notably reduce the risk of developing MS,” the team wrote.
The researchers say the results support the idea that eating a healthy diet may be the best plan for helping to prevent MS.
“Our study provided evidence that regular consumption of oily fish and wholemeal/wholegrain bread can effectively lower the risk of developing MS, verifying the association between various diets patterns and the onset of MS,” the researchers concluded.
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