Association between dietary carotenoid intakes and hypertension in adults

: National Health and Nutrition Examination Survey 2007–2014 Objective: Few epidemiological studies concentrated on dietary carotenoids and hypertension since new hypertension guideline released in 2017. Thus, this study was aimed to evaluate their association. Methods: Data from National Health and Nutrition Examination Survey (NHANES) 2007–2014 were used in this cross-sectional study. Dietary carotenoids data were obtained from 24-h dietary recall interviews. Hypertension was defined as SBP at least 130 mmHg or DBP at least 80 mmHg, taking antihypertensive medicine or self-report. Logistic regression models and restricted cubic spline models were applied to explore the associations between α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin, and total carotenoids from diet and supplements and hypertension. Total carotenoids showed significant reductive risk of hypertension at 100 μg/kg per day and over. Results: A total of 17 398 adults aged 20 years and over were identified. High dose of β-carotene, lycopene, lutein with zeaxanthin, and total carotenoids were significantly associated with decreased risk of hypertension in crude results. After multivariate-adjustment in model 2, the odds ratios (OR) with 95% confidence intervals (CI) of β-cryptoxanthin, lycopene, lutein with zeaxanthin and total carotenoids for hypertension were 0.79 (0.67–0.93), 0.85 (0.73–0.98), 0.69 (0.58–0.83), 0.73 (0.62–0.86) for the highest versus lowest quartile intakes, respectively. Dose–response analyses showed that all of the carotenoids were inversely associated with hypertension in a linear manner. Total carotenoids showed significant effect of lower risk of hypertension at 100 μg/kg per day. Conclusion: Intakes of α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin, and total carotenoids were inversely associated with hypertension in US adults. The intake of total carotenoids was suggested at least 100 μg/kg per day for general adult population. Correspondence to Dongfeng Zhang, Department of Epidemiology and health Statistics, The College of Public Health of Qingdao University, No. 38 Dengzhou Road, Qingdao 266021, China. Tel: +86 53282991712; fax: +86 53283801449; e-mail: zhangdf1961@126.com,zhangdf1962@aliyun.com Received 17 May, 2019 Revised 3 July, 2019 Accepted 3 July, 2019 Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved. Foods Beta-carotene, found in pumpkins, sweet potato, carrots and winter squash, is responsible for their orange-yellow colors.[1]Dried carrots have the highest amount of carotene of any food per 100 gram serving, measured in retinol activity equivalents (provitamin A equivalents).[17] Vietnamese gac fruit contains the highest known concentration of the carotenoid lycopene.[18]Although green, kale, spinach, collard greens, and turnip greens contain substantial amounts of beta-carotene.[1] The diet of flamingos is rich in carotenoids, imparting the orange-colored feathers of these birds.[19] Physiological effects Reviews of epidemiological studies seeking correlations between carotenoid consumption in food and clinical outcomes have come to various conclusions: A 2016 review looking at correlations between diets rich in fruit and vegetables (some of which are high in carotenoids) and lung cancer found a protective effect up to 400 g/day.[20] A 2015 review found that foods high in carotenoids appear to be protective against head and neck cancers.[21] Another 2015 review looking at whether caretenoids can prevent prostate cancer found that while several studies found correlations between diets rich in carotenoids appeared to have a protective effect, evidence is lacking to determine whether this is due to carotenoids per se.[22] A 2014 review found no correlation between consumption of foods high in carotenoids and vitamin A and the risk of getting Parkinson's disease.[23] Another 2014 review found no conflicting results in studies of dietary consumption of carotenoids and the risk of getting breast cancer.[24] Carotenoids are also important components of the dark brown pigment melanin, which is found in hair, skin, and eyes. Melanin absorbs high-energy light and protects these organs from intracellular damage. Several studies have observed positive effects of high-carotenoid diets on the texture, clarity, color, strength, and elasticity of skin.[25][26][27] A 1994 study noted that high carotenoid diets helped reduce symptoms of eyestrain (dry eye, headaches, and blurred vision) and improve night vision.[28][29] Humans and other animals are mostly incapable of synthesizing carotenoids, and must obtain them through their diet. Carotenoids are a common and often ornamental feature in animals. For example, the pink color of salmon, and the red coloring of cooked lobsters and scales of the yellow morph of common wall lizardsare due to carotenoids.[30][citation needed] It has been proposed that carotenoids are used in ornamental traits (for extreme examples see puffin birds) because, given their physiological and chemical properties, they can be used as visible indicators of individual health, and hence are used by animals when selecting potential mates.[31]