Diet Can Slow Onset of Autoimmune Disease

This study finds a common amino acid can that can dampen the immune response.

SUMMARY 

• Significantly reducing dietary levels of the amino acid methionine could slow onset and progression of inflammatory and autoimmune disorders 
• The research was published in the journal Cell Metabolism. 
• Researchers found that mice eating less methionine had a slower onset and progression of disease in the diets of mouse models of multiple sclerosis.

“These findings provide further basis for dietary interventions as future treatments for these disorders.” said Russell Jones, Ph.D., the study’s senior author and program leader of Van Andel Institute’s Metabolic and Nutritional Programming group. 

 MORE DETAIL

•  Methionine restriction limits the expansion of inflammatory Th17 cells.
• Many cell types in the body produce methionine, but the T cells responsible for responding to threats like pathogens do not. 
• The methionine that fuels these T cells, must be eaten.
• Methionine is found in most foods, but animal products such as meat and eggs contain particularly high levels.
• Methionine is critical for a healthy immune system. 
• These results suggest, for people predisposed to inflammatory and autoimmune disorders, reducing methionine intake can actually dampen the immune cells that cause disease.
• During an immune response, T cells flood the affected area to help the body fend off pathogens. 
• Methionine fuels this process by helping “reprogram” T cells to respond to the threat by more quickly replicating and differentiating into specialized subtypes. 
• Some of these reprogrammed T cells cause inflammation, which is a normal part of an immune response but can cause damage if it lingers, such as the nerve damage that occurs in multiple sclerosis.
• Researchers found that significantly reducing methionine in the diets of mouse models of multiple sclerosis altered the reprogramming of T cells, limiting their ability to cause inflammation in the brain and spinal cord. The result was a delay in the disease’s onset and slowed progression.

“By restricting methionine in the diet, you’re essentially removing the fuel for this over-active inflammatory response without compromising the rest of the immune system,” Russell Jones said.

He cautions that the findings must be verified in humans before dietary guidelines can be developed. 

The team also plans to investigate whether new medications can be designed that target methionine metabolism.

Amounts listed above are estimates of methionine content.
(SOURCE: USDA Nutrient Database Release 28)

MORE DETAILED METHIONINE FOOD LIST

SOURCE:
Methionine Metabolism Shapes T Helper Cell Responses through Regulation of Epigenetic Reprogramming

FURTHER READING:

The low-methionine content of vegan diets may make methionine restriction feasible as a life extension strategy