https://doi.org/10.4082/kjfm.20.0225 • Korean J Fam Med 2021;42:9-16 Review Article eISSN: 2092-6715 Fruit Intake to Prevent and Control Hypertension and Diabetes Hyun Ah Park* Department of Family Medicine, Inje University Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea Fruits are considered healthy because of their high antioxidant, vitamin, mineral, fiber, and phytochemical con- tents. However, their high sugar content is a concern for glucose, lipid, and uric acid metabolism. We reviewed re- lated articles published in the last 10 years and summarized evidence that relates fruit intake to the prevention and control of hypertension and diabetes mellitus. Clinicians should familiarize themselves with appropriate fruit in- take to counsel at-risk patients on hypertension and diabetes. Keywords: Fruit; Blood Pressure; Blood Glucose; Hypertension; Diabetes Mellitus Received: September 11, 2020, Revised: October 4, 2020, Accepted: October 11, 2020 *Corresponding Author: Hyun Ah Park https://orcid.org/0000-0003-2343-8964 Tel: +82-2-2270-0097, Fax: +82-2-2270-0902, E-mail: [email protected] Copyright © 2021 The Korean Academy of Family Medicine This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 10 www.kjfm.or.kr Hyun Ah Park • Fruit, Hypertension and Diabetes INTRODUCTION sugar levels and lower dietary fiber and phytochemical levels. The purpose of this study was to evaluate the relationship between Approximately 80%–90% of fruit mass is composed of water. Along fruit intake, separate from vegetable intake, and type 2 diabetes (T2D) with vegetables, fruits are a fiber-rich food; fruit flesh has large or hypertension by examining previous studies on this subject, in or- amounts of soluble fiber, while fruit skin has large amounts of insolu- der to suggest appropriate fruit intake for the prevention and control of ble fiber. Fruits contain vitamins B, C, and E, beta-carotene, folate, and T2D and hypertension. minerals such as Mg and K. Fruits rarely contain fat, saturated fatty ac- ids, cholesterol, and sodium.1,2) REVIEW METHODS Fruits are considered healthy and are known for having low energy density while being highly satiating due to their fiber and water con- We reviewed longitudinal and experimental studies and their meta- tent. Nutrients such as vitamins C and E, beta-carotene, and phyto- analyses, and meta-analysis of these studies, which assessed the rela- chemicals exert antioxidant effects. In most cases, fruits are consumed tionship between fruit intake and hypertension or T2D in adult partici- raw as a dessert or a snack, and therefore, have the potential to replace pants. The included studies were published in English peer-reviewed energy-dense snacks.2) journals after 2010. We searched PubMed, Embase, and Google Schol- A combination of fruits and vegetables is recommended for a ar using the following terms: fruit AND diabetes, fruit AND blood glu- healthy diet. Nutrients and phytochemicals in fruits and vegetables cose, fruit and hypertension, fruit and blood pressure. Additionally, have been postulated to lower blood pressure by improving endotheli- manual searches were performed. al function, modulating baroreflex sensitivity, causing vasodilation, Studies were excluded if they were on specific fruit extracts (e.g., fla- and increasing anti-inflammatory activity.3,4) However, unlike vegeta- vonoids) or powders, on a specific fruit that is not commonly con- bles, fruits contain high levels of sugars, including fructose, glucose, sumed (e.g., dragon fruit), involving specific fruit biomarkers (e.g., ca- and saccharose (Table 1).5) Furthermore, the sugar content in fruits rotenoids, vitamin C), on the combined effect of fruit and vegetables, may cause a high postprandial insulin level that predisposes individu- in which the effect from fruit could not be distinguished from that of als to diabetes and may increase uric acid production, which is associ- vegetables, on pregnant women or participants with health concerns ated with both elevated blood pressure and insulin resistance.6,7) Fruit (e.g., chronic renal failure), and on any dietary patterns including intake without substitution of other foods leads to increased energy in- fruits. As for controlled trials, we restricted our analysis to studies that take and weight gain, which in turn leads to higher blood pressure and attempted to promote or increase fruit intake without specifying other blood glucose levels. Furthermore, processed fruit juices have nutrient dietary changes to closely replicate the scenario of increasing fruit in- profiles that are slightly different to those of raw fruits, including higher take in freely living human populations. EPIDEMIOLOGY OF FRUIT INTAKE Table 1. Energy and sugar contents of fruits and fruit juice (per 100 g) Fruits and fruit juice Energy (kcal) Sugar (g) In 2018, the mean (±standard error) fruit intake of Korean adults >19 years old was 129.2±5.2 g for males and 160.5±5.1 g for females, while Apple, Fuji 56 11.1 Apple juice 42 10.0 the total mean fruit intake was 144.9±4.1 g for both sexes. Fruit intake Banana 84 14.6 increased with increasing age. In females, the maximum intake de- Blueberry 43 5.8 creased in women in their 50s (228.3±15.2 g) and 60s (188.7±11.8 g) Grape 57 11.9 (Figure 1).8) Grape juice 47 10.9 The mean sugar intake for Koreans aged >19 years was 62.9±1.2 g/d Kiwi, green 66 6.7 Korean melon 47 9.1 for males and 53.0±1.0 g/d for females based on the 2018 Korea Na- Mango 61 13.6 tional Health and Nutrition Examination Survey.9) Fruits were ranked Muskmelon 40 8.3 1st on the list of dietary sugar sources (22.8%), followed by fruit bever- Nectarine 32 4.7 ages and drinks (20.0%), and dairy products (12.9%). Orange 47 9.2 Orange juice 34 6.5 Peach 49 9.5 RECOMMENDATIONS ON FRUIT INTAKE Pear, Oriental 46 9.8 Persimmon, ripe 65 12.3 1. Korea Nutrition Society Pineapple 53 10.3 The 2005 Korea Nutrition Society recommends that people consume Strawberry 34 6.1 1–4 servings of fruit per day, supposing that a single serving is 50 kcal Satsuma 39 8.0 10) Watermelon 31 5.1 (Figure 2). The recommended fruit varies according to the total en- From Ministry of Food and Drug Safety. Korea nutrient database for standard ergy intake, and is balanced with the intake of other foods. For exam- reference. Cheongju: Ministry of Food and Drug Safety; 2020.5) ple, in adults consuming 1,000 kcal/d, 1 serving of fruit (50 kcal) is rec- https://doi.org/10.4082/kjfm.20.0225 Hyun Ah Park • Fruit, Hypertension and Diabetes www.kjfm.or.kr 11 250 Male 228.3 Female 207.8 Total 199.4 198.5 200 188.7 170.7 155.7 151.2 148.0 145.8 (g/d) 150 131.5 128.5 138.5 136.3 e 125.4 118.7 117.7 100.9 100.5 93.5 97.1 intak 100 79.5 73.4 76.2 ruit F 50 Figure 1. Fruit consumption of Koreans by age group and sex. From Ministry of Health and Welfare. Korea health statistics 2018: 0 Korea National Health and Nutrition Examina- 9 10 18 19 29 30 39 40 49 50 59 60 69 >70 tion Survey (KNHANES VII-3). Sejong: Ministry Age group (y) of Health and Welfare; 2019.8) Koreanmelon (150 g) Apple (100 g) Pear, Oriental (100 g) Peach (100 g) Satsuma (100 g) Fruits (50 kcal) Orange (100 g) Banana (100 g) Kiwi, green (100 g) Persimmon (100 g) Grape (100 g) Figure 2. One serving of fruit for Koreans from the Korea Nutrition Society. From Korea Nutrition Society. Dietary reference intakes for Koreans 2015. Seoul: Korea Nutrition Society; Raisin (15 g) Dried jujube (15 g) Fruit juice (100 mL) 2015.10) ommended, while for those consuming 2,800 kcal/d, 4 servings (200 mend a specific intake of fruit. kcal) are recommended. The Standards Medical Care of Diabetes 2020 of the American Dia- betes Association recommends that carbohydrate intake should com- 2. U.S. Department of Agriculture prise nutrient-dense carbohydrate sources that are high in fiber and The U.S. Department of Agriculture used the term “MyPlate” in a pub- are minimally processed.14) Fruits are recommended as a part of a lic nutrition guide to inform how much of each food group should be healthy eating plan together with non-starchy vegetables, minimally consumed.11) “My plate” is a food circle that depicts a plate and glass, added sugars, whole grains, and dairy products. The recommended which recommends the consumption of approximately 10% fruit, 30% fruit intake was not specified. People with diabetes and those at risk grains, 40% vegetables, and 20% protein, accompanied by a smaller are advised to replace sugar-sweetened beverages (including fruit juic- circle representing dairy, such as a glass of milk or a cup of yogurt. es) with water as much as possible. The Korean Society of Hypertension15) and the 2017 American Col- 3. World Health Organization lege of Cardiology/American Heart Association16) advised the Dietary The World Health Organization advises the intake of a minimum of Approaches to Stop Hypertension dietary pattern, a diet rich in fruits, 400 g of fruits and vegetables combined per day for the prevention of vegetables, whole grains, and low-fat dairy products, with reduced sat- chronic diseases such as heart disease, cancer, diabetes, and obesity.12) urated and total fat, to lower blood pressure and normalize lipid me- tabolism.