Approximately 80% of sea travelers will experience seasickness, an unpleasant experience characterized by nausea and vomiting. Seasickness is usually triggered by elevated levels of histamine in the brain and is associated with vestibular, visual, and somatosensory miscommunication.
Vitamin C can reduce the symptoms of seasickness.
A double-blind placebo-controlled crossover study of 70 volunteers found that 2,000 mg of vitamin C taken 1 hour prior to exposure to three-foot waves significantly decreased seasickness symptoms. Symptom improvement was most notable in women in general, and younger men specifically.
Following wave exposure:
- Serum histamine increased in both groups
- Serum vitamin C increased significantly in the supplement group
- Serum diamine oxidase (DAO) increased significantly in the supplement group
- Severe symptoms were noted in two subjects with elevated baseline serum tryptase (a compound released by mast cells and basophils), despite no significant changes after wave exposure.
- Significantly more individuals in the placebo group left the study raft before the 20-minute test time was reached
Interestingly…
- Histamine increases in most individuals when exposed to wave action
- Most seasickness drugs are antihistamines
- An inverse association exists between vitamin C and histamine
- Individuals with mastocytosis, characterized by elevated histamine, have significantly lower vitamin C levels
- Histamine can be released under stress or spontaneously in individuals with mastocytosis and elevated tryptase
- Samoa island inhabitants consume 1-2 mangoes, a significant source of vitamin C, prior to going to sea
- Some individuals, e.g., Chinese, are genetically prone to seasickness due to a SNP in the alpha 2A-adrenergic receptor
- Even fish can experience seasickness
Optimal Takeaway
A 2,000 milligram (2 gram) dose of vitamin C can reduce symptoms of seasickness without adverse side effects.
References
Jarisch, R et al. “Impact of oral vitamin C on histamine levels and seasickness.” Journal of vestibular research : equilibrium & orientation vol. 24,4 (2014): 281-8. doi:10.3233/VES-140509