Science Update

New study investigates the impact of low vitamin B12 and high homocysteine levels in Parkinson’s disease

B vitamins are essential nutrients involved in numerous metabolic processes and play a significant role in cognitive health. Due to the lack of new drugs to treat neurological disorders, researchers are looking more and more at nutrients to delay or prevent these conditions.

According to a study published last week in Cell Research, researchers identified that vitamin B12 can play a modulatory role in Parkinson’s disease and provide neuroprotection.

Parkinson’s disease is the most common chronic neurodegenerative movement disorder, affecting approximately 1% of individuals over the age of sixty. There is currently no cure and treatments target only the symptoms and not the progression.

Mutations in Leucine-Rich Repeat Kinase 2 (LRRK2) has been identified as a cause in the majority of familial and some sporadic forms of Parkinson’s disease. It has been considered a promising drug target; however, these have demonstrated unwanted side effects and no clear clinical outcome. Vitamin B12 has been shown to inhibit LRRK2 but is more subtle in its actions. This is similar to botanicals modulating inflammatory pathways instead of having a hard lock out on an enzyme system that drugs have with negative side effects. Vitamin B12 appears to help prevent neurotoxicity and dopamine deficits.

Vitamin B12 can cross the blood brain barrier and it plays an essential role in regulating homocysteine levels as well as in the synthesis of fatty acids. Vitamin B12 deficiency is known to contribute to a variety of neurological conditions and low vitamin B12 levels are common in Parkinson’s disease. In addition, there is evidence that L-3,4-Dihydroxyphenylalanine (L-dopa) intake decreases plasma vitamin B12 levels.

According to a study published a year ago in Movement Disorders, researchers demonstrated that low vitamin B12 status was associated with poorer mobility and high homocysteine levels were associated with greater cognitive impairment in Parkinson’s disease.

In addition, three years ago I shared an interesting study published in the Journal of Alzheimer’s Disease. In this study, the research team found there was a link between omega-3 levels, homocysteine, and brain atrophy rates. This study demonstrated that B vitamins had no effect on cognitive decline when omega-3 levels are low. However, when omega-3 levels are in an upper normal range, B vitamins slow cognitive decline and brain atrophy. These findings suggest that a combination of fish oil supplements and B vitamins may help to improve cognition and reduce age-related memory decline.

Monotherapeutics have been a failure in neurodegenerative diseases. There is not a one size fits all approach and one cannot just look at B vitamin status as demonstrated in the last study. All chronic conditions are multifactorial in nature. Each person's biochemical individuality exerts a major influence on his or her health. The level of nutrient intake, lifestyle choices and environmental exposures filtered through genetic predisposition are major factors in the expression of disease, and a successful treatment approach must investigate these factors.

By Michael Jurgelewicz, DC, DACBN, DCBCN, CNS

Source: Schaffner A, Li X, et al. Vitamin B12 modulates Parkinson’s disease LPPK2 kinase activity through allosteric regulation and confers neuroprotection. Cell Res. 2019 Apr; 29(4):313-329.