AD is a common inflammatory disease affecting up to a fifth of people around the world that is associated with financial and psychosocial stress. Some evidence suggests that AD is primarily a skin barrier defect and may be a causative factor in the development of food allergies and other atopic diseases, including asthma and allergic rhinitis. In the industrialized and developing countries their prevalence has increased considerably in the last few decades.
The authors examined a number of factors related to maternal nutrition during pregnancy, infant nutrition, and breastfeeding to find associations between nutritional factors and the development of AD. There was no consistent evidence linking nutritional factors to AD.
However, vitamin D, probiotics, and prebiotics appeared to be the most promising, the authors said. In a Norwegian study, researchers randomly selected 30 children ages 4 to 13 with severe AD to settle in a tropical zone for 4 weeks – where the intake of vitamin D through sunlight would be increased – and 26 children to live in Norway to stay. Significant improvements were seen in the children living in the tropical zone.
A double-blind randomized control study (RCT) that randomly selected 60 patients with AD 14 years of age and older to receive 1,600 IU / day of vitamin D or placebo found a significant improvement for the group taking the vitamin. Still, according to the authors, there is conflicting data on vitamin D; Further RCTs are needed to determine the optimal dose, desired levels, duration of treatment, and the effect of vitamin D supplementation on the prevention and treatment of AD.
The theory behind probiotics and prebiotics with a relationship is based on activation of the interleukin 4 (IL-4) / IL-13 axis in AD, which promotes the breakdown of the skin barrier and its association with changes in the gut microbiota. A recent double-blind RCT of 50 children aged 4 to 17 years reported that a mixture of Bifidobacterium strains was effective in reducing AD severity. In a 2-year follow-up RCT that included 132 infants at risk of AtopyThe authors found that the cumulative incidence of AD was lower in the group fed a formula containing a mixture of prebiotic oligosaccharides (13.6%) compared to the placebo group (27.9%).
The authors said that certain probiotic strains might prove beneficial but need further study, finding that the strain-specific effects of probiotics make it difficult to make recommendations.
Meanwhile, the evidence about breastfeeding and the risk of allergies is contradicting itself, although international scientific studies recommend exclusive breastfeeding for 4 to 6 months to prevent allergic diseases.
“[T]The impact of breastfeeding on the risk of AD remains controversial, possibly due to different study populations and designs, and requires more randomized controlled trials, ”the authors wrote.
Conflicting evidence has also been found regarding maternal diet during pregnancy, vitamin D intake during pregnancy, hydrolyzed formula feeding, vitamin D intake after childbirth, and the long chain omega-3 polyunsaturated fatty acids. There is some evidence that delaying the introduction of solids does not reduce the risk of allergic sensitization and atopic disease, the authors say.
“Long-term follow-up studies are essential to determine the true usefulness of prenatal and early dietary and nutritional interventions as the primary prevention strategy for AD,” they concluded.
Trikamjee T., Comberiati P., D’Auria E., Peroni D., Zuccotti GV. Nutritional factors in the prevention of atopic dermatitis in children. Anterior Pediatr. Published on January 12, 2021. doi: 10.3389 / fped.2020.577413