1. The Effects of Dietary Intake on Exercise-Induced Asthma (EIA)
Meghan Macdonald
HUN 6930
Dr. Arjmandi

2. Presentation Overview:
Background Information about EIA
Pharmaceutical Methods of Treatment
Suggested Nutritional Methods of Treatment
EIA and n-6 & n-3 PUFAS
Conclusions
Areas for Future Research

3. Asthma:
In million Americans had been diagnosed with asthma by a health care professional at some point in their life
Children ages 5-17 had the highest prevalence with 8.4 million having been diagnosed with asthma in the life time
Females are 9.3% more likely to have ever been diagnosed with asthma
2006 National Health Interview Survey (NHIS)

4. Common Triggers:

5. What is Exercise-Induced Asthma?
EIA is a term used to describe the transient narrowing of the airways that can occur during and following vigorous exercise resulting in post-exercise decrement in lung function (2)
Also known as exercise-induced bronchoconstriction (EIB), or airflow-induced bronchoconstriction (AIB)

6. Clinical Diagnosis of EIA:
Diagnosed by measuring forced expiratory volume (FEV) or peak flow in response to exercise
A fall in lung function of 10% from the baseline indicates EIA

7. Mechanisms of EIA:

8. Pharmaceutical Treatment of EIA:
According to the American Lung Association, in billion dollars were spent on asthma (indirectly and directly)
Of that 19.7 billion, 6.2 billion were spent on prescription medications for the treatment of asthma
Most common medications include: inhaled corticosteroids, and inhaled Beta2-agonist

9. Hypothesized Nutritional Treatments of EIA:
Vitamin C
May help to protect epithelial lining of the respiratory system from oxidant damage (Bodner et al., 1999)
Vitamins E, and A/Beta-carotene
Possible antioxidant capacity to reduce inflammation, and protect against ozone-induced bronchoconstriction (McKeever and Britton, 2004)

10. Hypothesized Nutritional Treatments of EIA cont.
Sodium
Enhancement of dietary salt may worsen bronchiolar smooth muscle reactivity in people with EIA (Gotshall et al., 2000)
Minerals Se, Mg, Cu, and Zn
Possible antioxidant defenses as coenzymes, may be linked to bronchodilation (McKeever and Britton, 2004)
Fatty Acids
Omega-3 PUFA may be beneficial, while omega-6 and trans-fatty acids may be detrimental to asthma (McKeever and Britton, 2004)

11. Focus of This Presentation:
Omega-3, and Omega-6 PUFA’s

12. Omega-3 and Omega-6 PUFA’s and EIA:
Omega-3 PUFA affects characteristics of cellular membranes, and appear to have anti-inflammatory effects (20)
Metabolism of omega-6 PUFA arachidonic acids lead to the generation of proinflammatory four-series leukotrienes and two-series prostanoids (prostaglandin, & thromboxin) (20)
Eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) found in fish oils competitively inhibit omega-6 PUFA (20)

13. Data from Mickleborough et al., 2006.
Figure 1. The percentage change in FEV1 from before to after exercise across the three diets. Reductions in FEV1 > 10% represent a positive diagnosis of EIB. Letters a and b refer to comparisons by diet within respective time period. Different letters designate a significant difference (p < 0.05).

14. Mickleborough et al., 2006.

15. Mickleborough et al., 2006.

16. Mickleborough et al., 2006.

17. Mickleborough et al., 2006.

18. Results from Mickleborough et al., 2006:
The fish oil diet (3.2 g of EPA and 2.0 g of DHA) improved pulmonary function in post exercise FEV, and decreased bronchodilator use by 31%
The fish oil diet reduced airway inflammation in asthmatic patients with EIA

19. Similar Findings from a similar study done by Mickleborough et al
Figure 1. The percent change in FEV1 from pre- to post-exercise in subjects with exercise-induced bronchoconstriction (EIB) and control subjects across the three diets. Reductions in FEV1 in excess of 10% represent abnormal pulmonary function. Letters (a,b) refer to comparisons by diet within respective time period. Different letters designate significant difference (p < 0.017).

21. Dietary Supplementation with fish oil rich in omega-3 PUFA in children with bronchial asthma
Subjects: 29 children (4-17yrs); 15 fish oil group, 14 control group
Fish oil capsule (300 mg) contained 84mg EPA, and 36 mg DHA
Control capsule contained 300mg olive oil
Children weighing kg took 6 capsules/day, took 8 capsules/day, took 10 capsules/day
Acetylcholine inhalation to test airway responsiveness
Nagakura et al., 2000

22. Dietary Supplementation with fish oil rich in omega-3 PUFA in children with bronchial asthma
Results indicate asthma scores were significantly lower than baseline in the fish oil group in the 6th (p=0.005), 7th (p=0.014), 8th (p=0.007), 9th (p=0.032), and 10th (p=0.01) months after the start of administration
Acetylcholine responsiveness decreased significantly in the fish oil group, but not the control group
Nagakura et al., 2000

23. Conclusions:
Omega-3 PUFA supplementation appears to have a beneficial effect on improving the symptoms of asthma
However, since testing was done on small populations, or under extreme dietary controls, further research needs to be completed to solidify results

24. Future Research…
Test omega-3 PUFA supplementation on larger populations
Increase the duration of omega-3 PUFA supplementation studies
Further investigate other nutritional means of attenuating asthma

25. Thankyou!
Question?