PUFAs and eosinophilic esophagitis
Submitted as a Letter to the Editor of the Medical Post on 2004-10-25:
The article “MDs see more pediatric eosinophilic esophagitis” in the
2004-10-19 edition (p50) suggests that the recent dramatic increase in
the incidence of this little-known condition parallels the increase in
asthma and allergies in general. The reason for the increase has not
been determined.
One possibility that bears investigation may be the changing nature of
western diets. With increased use of vegetable oils, there has been
both an absolute as well as a relative (to omega-6 fatty acids)
decrease in omega-3 fatty acid consumption (Calder, 2003). Increasing
the amount of long-chain omega-3s in the diet appears to decrease
inflammatory cytokine responses such as IL-5 and IL-13 (Dunstan et al,
2003), the same cytokines that are implicated in eosinophilic
esophagitis (Mishra & Rothenberg, 2003).
When I was a child, my mother insisted that I take a daily dose of cod
liver oil, known to be a rich source of omega-3s. Today’s children are
unlikely to be given this foul-tasting substance, and may also reject
oily fish such as salmon or tuna. This, together with a decrease in
intake of saturated fat in favour of omega-6 rich vegetable oils, may
be contributing to the current epidemic of childhood allergic
conditions, including eosinophic esophagitis.
references:
Calder PC. Polyunsaturated fatty acids and cytokine profiles: a clue to the
changing prevalence of atopy? Clin Exp Allergy. 2003 Apr;33(4):412-5.
Mishra A, Rothenberg ME. Intratracheal IL-13 induces eosinophilic esophagitis by an IL-5, eotaxin-1, and STAT6-dependent mechanism.
Gastroenterology. 2003 Nov;125(5):1419-27
Dunstan JA, Mori TA, Barden A, Beilin LJ, Taylor AL, Holt PG, Prescott
SL. Fish oil supplementation in pregnancy modifies neonatal
allergen-specific immune responses and clinical outcomes in infants at high risk of atopy: a randomized, controlled trial. J Allergy Clin Immunol. 2003 Dec;112(6):1178-84