Do long-chain omega-3 fatty acids protect from atopic dermatitis?

Beneficial Outcomes of Omega-6 and Omega-3 Polyunsaturated Fatty Acids on Human Health: An Update for 2021

Oxidative stress and inflammation have been recognized as important contributors to the risk of chronic non-communicable diseases. Polyunsaturated fatty acids (PUFAs) may regulate the antioxidant signaling pathway and modulate inflammatory processes. They also influence hepatic lipid metabolism and physiological responses of other organs, including the heart. Longitudinal prospective cohort studies demonstrate that there is an association between moderate intake of the omega-6 PUFA linoleic acid and lower risk of cardiovascular diseases (CVDs), most likely as a result of lower blood cholesterol concentration. Current evidence suggests that increasing intake of arachidonic acid (up to 1500 mg/day) has no adverse effect on platelet aggregation and blood clotting, immune function and markers of inflammation, but may benefit muscle and cognitive performance. Many studies show that higher intakes of omega-3 PUFAs, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with a lower incidence of chronic diseases characterized by elevated inflammation, including CVDs. This is because of the multiple molecular and cellular actions of EPA and DHA. Intervention trials using EPA + DHA indicate benefit on CVD mortality and a significant inverse linear dose-response relationship has been found between EPA + DHA intake and CVD outcomes. In addition to their antioxidant and anti-inflammatory roles, omega-3 fatty acids are considered to regulate platelet homeostasis and lower risk of thrombosis, which together indicate their potential use in COVID-19 therapy.

The Influence of Dietary Fatty Acids on Immune Responses

Diet-derived fatty acids (FAs) are essential sources of energy and fundamental structural components of cells. They also play important roles in the modulation of immune responses in health and disease. Saturated and unsaturated FAs influence the effector and regulatory functions of innate and adaptive immune cells by changing membrane composition and fluidity and by acting through specific receptors. Impaired balance of saturated/unsaturated FAs, as well as n-6/n-3 polyunsaturated FAs has significant consequences on immune system homeostasis, contributing to the development of many allergic, autoimmune, and metabolic diseases. In this paper, we discuss up-to-date knowledge and the clinical relevance of the influence of dietary FAs on the biology, homeostasis, and functions of epithelial cells, macrophages, dendritic cells, neutrophils, innate lymphoid cells, T cells and B cells. Additionally, we review the effects of dietary FAs on the pathogenesis of many diseases, including asthma, allergic rhinitis, food allergy, atopic dermatitis, rheumatoid arthritis, multiple sclerosis as well as type 1 and 2 diabetes.

Nationwide Online Survey to Complement the Current Voluntary Reporting System for Adverse Events Associated with Dietary Supplements: Application to the Case of Skin Manifestations

The current adverse event reporting system for dietary supplements lacks the ability to collect and analyze ongoing case reports in sufficient numbers to detect health issues. We conducted an online survey to collect data on skin manifestations due to supplement use in consumers and to identify the suspected products and ingredients. An online survey was conducted among 63,737 dietary supplement users in 2016. Those who self-reported experiences of skin anthema or itching caused by supplement use and recognized a causal relationship as almost certain (0.8%) were invited to provide further details of symptoms and products. Most of the users experienced mild symptoms with "itching and/or rash of body part." After the onset of skin manifestations, 69.3% ceased supplement use, while 26.6% continued supplement use, including those who reduced the amount or frequency of use. Respondents who visited the hospital in response to symptoms accounted for 26.0%, while 53.3% did not seek treatment. The products used were identified in 155 of 300 eligible respondents. Although those products were composed of multiple ingredients, the accumulated data suggested that cutaneous symptoms were related to the following constituents: "Peptides or animal by-products" (31.0%), "Herbal/Botanical" (23.2%) and "Fats and lipid" (13.5%). Conducting an online survey to elicit information directly from consumers identified components of supplements that are involved in skin manifestations that could lead to serious damage, and may fill a void in the current adverse event reporting system.