A cross-sectional study has shown that alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein with zeaxanthin, and total carotenoid intake may be inversely associated with the risk of depressive symptoms in U.S. adults.

Depression can be classified as a mood disorder and can bring about long-lasting symptoms such as overwhelming sadness, low energy, loss of appetite and a lack of interest in things that used to bring pleasure. According to the World Health Organization, more than 264 million people worldwide are affected with depression. Depressive episodes can be classified as mild, moderate or severe, depending on the number and severity of the symptoms.

In this study, 17,401 adults from aged 18 – 80 years old who participated in the National Health Examination Survey 2009-2016 were chosen. Depressive symptoms of the participants were assessed using a nine-item depressive symptoms screening instrument-Patient’s Health Questionnaire-9 (PHQ-9). PHQ-9 is a self-administered, screening tool for assessment of the severity of depressive symptoms. Participants were considered to have depressive symptoms if their PHQ-9 scores were ≥10. The dietary carotenoid intake of the participants was obtained through 24-hour dietary recall interviews. The first dietary recall interview was collected at the Mobile Examination Center (MEC), and the second interview was conducted by telephone 3–10 days later. 

The analysis found that the prevalence of depressive symptoms was higher in females, smokers, and those with hypertension and diabetes. At the same time, alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein with zeaxanthin, total carotenoid, and energy intake in participants with depressive symptoms were significantly lower than those without depressive symptoms. 

The result of this association study is similar to the past association study that found higher intakes of alpha-carotene and beta-carotene were associated with a decreased risk of depressive symptoms among the U.S. midlife female. Another report also showed that dietary beta-carotene intake was negatively associated with depressive symptoms in Korean students. It was inferred that there are several possible mechanisms by which carotenoids may play a protective role in depressive symptoms. The first mechanism is the reduction of inflammatory cytokines by carotenoids. Another mechanism is the antioxidant activity of carotenoids, which can effectively remove reactive oxygen species and other free radicals hence protecting the brain from oxidative damage. 

To the researchers’ knowledge, this is the first study to comprehensively examine the associations between dietary carotenoid intakes and depressive symptoms. These findings from association study need to be confirmed by prospective studies.

“The prevalence of depressive symptoms among adults worldwide is increasing. With the current worldwide COVID-19 pandemic, there is considerably increase in adverse mental health condition as reported by CDC. Besides getting carotenoids from diet, one may also opt to get their dietary carotenoid from supplement or fortified food. Natural plant-derived carotenoids ingredients are available in the market. For example, Kemin’s FloraGlo (marigold lutein/ zeaxanthin), LycoRed’s LycoMato (tomato lycopene) and ExcelVite’s branded ingredient – EVTene (palm alpha- and beta-carotene) that can be used in dietary supplement or functional food formulas. This would help one to attain enough carotenoid in their daily intake,” says Bryan See, Business Development Manager of ExcelVite.