Asthma is a chronic respiratory disease that causes inflammation in the airways of the lungs making it hard to breath. Asthma impacts more than 25 million Americans1 and is the leading chronic disease in children.2
Asthma is conventionally managed by medications that target opening the airway passages to the lungs and reducing inflammation. However, supporting lung health with a healthy diet has also been encouraged to lessen asthma symptoms.3
Orange juice may be helpful in promoting lung health by providing vitamin C and phytonutrients (naturally occurring plant compounds) called flavonoids. While more research needs to be conducted, studies have shown these compounds may be associated with supporting lung function and providing anti-inflammatory benefits.4,5
Several observational studies provide support for potential respiratory benefits with the consumption of citrus fruits, and compounds found in citrus, such as vitamin C and the flavonoids hesperidin and naringenin. Some studies have reported these compounds may be associated with decreased incidence and prevalence of asthma and improved asthma-related respiratory symptoms.6-10
In children, higher fruit juice consumption was associated with lower risk of reported asthma and atopic wheeze,11 and, while not reaching statistical significance, increased frequency of 100% orange juice consumption tended (p=0.065) to reduce asthma risk.12 Recent studies support 100% orange juice consumption to not be associated with risk of asthma in adults.21
Vitamin C may be particularly beneficial in reducing inflammation and providing antioxidant support. Data suggest that vitamin C can support bronchodilation by modulating prostaglandin synthesis.13 Histamine is involved in the asthmatic response of the lungs and the presentation of allergy symptoms, and since vitamin C is required to breakdown histamine,14 vitamin C is thought to have an anti-histamine effect.15 Indeed, a meta-analysis combining several human clinical studies, reported that vitamin C significantly reduced exercise-induced asthma symptoms by 48 percent in asthmatic adults and adolescents.4
Orange juice is an excellent source of vitamin C with an 8-ounce glass providing more than 100% of the Daily Value.* Citrus juices are reported to be a major contributor of vitamin C in the diet.16
Flavonoids are plant compounds linked to many health benefits, and while science isn’t conclusive, a potential link might be made to flavonoid consumption and respiratory health. Clinical studies in humans designed to test the effect of flavonoids in 100% orange juice report positive changes in antioxidant enzymes, altered white blood cell gene expression to anti-inflammatory profiles, and lowered oxidative stress biomarkers that protect against DNA damage and lipid peroxidation.5,17 These compounds may support respiratory health by helping mitigate inflammatory mechanisms associated with respiratory illnesses.
In adults, a 31 to 36 percent decrease in asthma incidence was associated with higher intakes of naringenin and hesperidin.10 Furthermore, a systematic review of flavonoids found that upper respiratory tract infection was decreased by 33 percent,18 suggesting flavonoids play a role in respiratory health.
The flavonoids hesperidin and naringenin are found in abundance in citrus, and hesperidin is rarely found in other foods making citrus a unique source of this bioactive compound.19
There is growing awareness of the probable importance of vitamin D and how this key vitamin plays an important role in respiratory health by reducing inflammation. Studies suggest that low levels of vitamin D in asthmatic children is associated with exacerbated symptoms, reduced lung function, and increased respiratory inflammation, resulting in increased medication usage.20
While orange juice does not naturally contain vitamin D, 8 ounces of fortified orange juice contains 15% of the recommend Daily Value.** Values based on a 2000 calorie diet. Average of USDA SR28 database entries for 09206 and 09209 were used for calculating Daily Values. FDA rounding rules applied when calculating percent DV based upon 2018 rules. Information is not intended for labeling food in packaged form. Nutrient values may vary based on manufacturer, brand, or product types.