Brain Inflammation & Folic Acid

You may have heard recommendations for pregnant women to consume foods high in folic acid, such as orange juice, spinach and fortified breakfast cereals, to help development of the unborn child’s brain. However, folic acid may also help improve the health of the adult brain. High folic acid intake may lower the risk of Alzheimer’s disease and improve recovery from brain or spinal cord injury by reducing brain inflammation.

Function of Folic Acid

Folic acid exists in a variety of forms in the body, which means it can supply carbons to support a variety of metabolic functions within the body. Specifically, it donates a carbon group to a molecule called homocysteine to synthesize the amino acid methionine. However, insufficient levels of folic acid in your body will reduce methionine production and lead to a build-up of homocysteine. Homocysteine is an inflammatory protein closely associated with neurologic inflammation and disease. Additionally, since vitamin B-12 is required to mediate the transfer of the carbon group from folate to form methionine, low levels of vitamin B-12 can lead to homocysteine buildup even if you have sufficient folate.

Brain Development

Folic acid deficiency in pregnant women has been associated with neural defects since the 1960s. Fetal development requires precise timing of cell growth and division. Certain cells also must degenerate at the appropriate time in order for overall development to move forward. The increased homocysteine as a result of folic acid deficiency increases the inflammation and degeneration rate of the cells, which impairs brain development and may lead to lower brain mass.

Alzheimer's Disease

Similarly, the increased inflammation associated with high levels of homocysteine is associated with developing Alzheimer’s disease and dementia. A 2002 article published in “New England Journal of Medicine” showed individuals with high homocysteine levels were twice as likely to develop Alzheimer’s compared to those with normal levels of the protein. Although the mechanisms are not completely clear, homocysteine can have multiple effects on brain cells. Homocysteine may interfere with proper electrical signaling between neurons, increase oxidative stress, damage DNA and cause microvascular problems. Sufficient folic acid normalizes homocysteine levels, reducing its inflammatory effects on the brain.

Brain Injury

Head and spinal cord injuries lead to increased brain tissue inflammation, which is the major contributor to the permanent neural damage that follows such an injury. However, supplementing with folate may enhance the early recovery phase following a head injury. In a 2010 study published in “Developmental Neuroscience,” young piglets who were supplemented with folic acid following brain and spinal cord trauma showed improved motor function and problem-solving ability compared to injured piglets that were not supplemented. However, the mechanism for this is unclear, since supplemented piglets did not have lower homocysteine levels, and scientists have not established whether this treatment would be effective in humans.