Vegetarians, Pescatarians and Flexitarians with Adequate Vitamin B12 Levels Have No Increased Risk of Polyneuropathy

Background: In recent years, an increasing number of people adapt to a vegetarian, pescatarian or flexitarian dietary pattern that reduces the consumption of meat and fish. Although these dietary patterns have a risk for developing vitamin B12 deficiency associated polyneuropathy, it is unknown whether this risk is still increased when vitamin B12 levels are adequate. Objective: To examine whether a vegetarian, pescatarian or flexitarian dietary pattern is associated with an increased risk for idiopathic axonal polyneuropathy. Methods: We conducted a case-control study that included 256 idiopathic axonal polyneuropathy patients with adequate vitamin B12 blood levels and 630 controls. We used questionnaire data to determine the frequency of meat and fish consumption and defined dietary patterns. Results: The vegetarian (no meat or fish consumption) and the pescatarian (fish consumption, no meat consumption) dietary patterns showed no increased risk of axonal polyneuropathy. Frequency-effect analysis and quantity-effect analysis also did not show that a reduction of meat or fish consumption (flexitarian dietary pattern), either small or large, changed the risk of axonal polyneuropathy. Conclusions: We did not find an increased risk for axonal polyneuropathy among people with a vegetarian, pescatarian or flexitarian diet and an adequate vitamin B12 level.