Kanwar, R. K., A. K. Macgibbon, et al. (2007). "Bovine milk
fat enriched in conjugated linoleic and vaccenic acids attenuates
allergic airway disease in mice." Clin Exp Allergy.
BACKGROUND:
It has been argued that a reduction in the Western diet of anti-inflammatory
unsaturated lipids, such as n-3 polyunsaturated fatty acids, has
contributed to the increase in the frequency and severity of allergic
diseases. Objective We investigated whether feeding milk fat enriched
in conjugated linoleic acid and vaccenic acids (VAs) ('enriched'
milk fat), produced by supplementing the diet of pasture-fed cows
with fish and sunflower oil, will prevent development of allergic
airway responses. Methods C57BL/6 mice were fed a control diet containing
soybean oil and diets supplemented with milk lipids. They were sensitized
by intraperitoneal injection of ovalbumin (OVA) on days 14 and 28,
and challenged intranasally with OVA on day 42. Bronchoalveolar lavage
fluid, lung tissues and serum samples were collected 6 days after
the intranasal challenge. Results Feeding of enriched milk fat led
to marked suppression of airway inflammation as evidenced by reductions
in eosinophilia and lymphocytosis in the airways, compared with feeding
of normal milk fat and control diet. Enriched milk fat significantly
reduced circulating allergen-specific IgE and IgG1 levels, together
with reductions in bronchoalveolar lavage fluid of IL-5 and CCL11.
Treatment significantly inhibited changes in the airway including
airway epithelial cell hypertrophy, goblet cell metaplasia and mucus
hypersecretion. The two major components of enriched milk fat, cis-9,
trans-11 conjugated linoleic acid and VA, inhibited airway inflammation
when fed together to mice, whereas alone they were not effective.
Conclusion Milk fat enriched in conjugated linoleic and VAs suppresses
inflammation and changes to the airways in an animal model of allergic
airway disease.
