In the news: Omega-3s in Pregnancy May Help Kids Breathe Easier; Nutrition & Asthma Tips

Omega-3s in Pregnancy Lower Childhood Asthma

Asthma has been steadily increasing over the past few decades, with nearly 9% of US children suffering from the condition. Researchers have long suspected a connection between these rising rates and the low intake of anti-inflammatory omega-3 fatty acids in many Western countries typically eating a “meat-sweet” diet. The results of a study published in the New England Journal of Medicine (1) seem to confirm that idea.

In the trial, Danish researchers randomly assigned 736 women who were 6 months pregnant to receive either 2.4 grams of fish oil (55% EPA and 37% DHA in triglyceride form) or placebo. Blood levels of EPA and DHA were measured in the expectant moms at 24 weeks and 1 week after delivery.

The children were followed for 5 years. For the first 3 years, neither the investigators nor the parents knew who received fish oil. For the 2 years after that, the investigators were still blinded to treatment assignments. Most children who have asthma develop their first symptoms earlier than age 5, but an actual diagnosis is usually only clinically established at 5 years of age.

The research team found a 31% lower risk of persistent wheezing or asthma in the offspring of women who received the fish oil supplement. The risk of lower respiratory tract infections was also reduced in these children.

The effect of maternal omega-3 supplementation was strongest in children whose moms had the lowest blood levels of EPA and DHA at the study’s start or had a gene variant that reduced their ability to produce EPA and DHA from a precursor omega-3 fatty acid. For these children, the risk of developing asthma was reduced by 54%.

One of the researchers noted that women with low blood levels of EPA and DHA are even more common in the US than in Denmark where the study was conducted. Pregnant women are cautioned to avoid over consuming fish – particularly large, predatory fish – which can contain high levels of mercury that can be harmful to the developing fetus. Though the level of omega-3s tested in this study was safely used, future studies should examine whether lower doses in expectant moms might be just as effective (2).

Nutrition Tips for Those with Asthma

Evidence suggests that diet and nutrition may also help those who already have asthma in controlling their symptoms and managing the disease.

Being overweight, for example, can worsen asthma while reducing weight can improve symptoms, which results in less use of asthma medications as well as an improved asthma-related quality of life (3).

Sulfites, used as preservatives in wine and foods such as dried fruits, can trigger asthma symptoms in some people with moderate to severe asthma, so avoiding sulfite-containing foods and beverages might help.

Paying particular attention to several nutrients may also pay dividends:

• Vitamin D – Low levels have been seen in those with more severe disease, and restoring those level may improve asthma (Dec, 2014 and Oct, 2016 Staying Healthy).

• Vitamins C and E – Oxidative stress (an over-production of cell-damaging free radicals) – fosters inflammation leading to lung swelling and irritation. Getting sufficient amounts of these two antioxidant vitamins is important, so a fruit and vegetable-rich diet is the way to go. Some research also supports the use of extra vitamin C, especially in reducing the symptoms of exercise-induced asthma or respiratory symptoms caused by exercise (4).
  

References

1. Bisgaard, H, et al. Fish oil–derived fatty acids in pregnancy and wheeze and asthma in offspring. NEJM 375:2530-39, Dec. 29, 2016.
2. Ramsden CE. Editorial: Breathing easier with fish oil -A new approach to preventing asthma? NEJM 375:2596-98, 2016.
3. Asthma and obesity: is weight reduction the key to achieve asthma control? Curr Opin Pulm Med. 22:69-73, 2016.
4. Hemilia H. The effect of vitamin C on bronchoconstriction and respiratory symptoms caused by exercise: a review and statistical analysis. Allergy Asthma Clin Immunol.10:58, 2014.