Added Sugar Intake and Risk of Falling Among Older People: The Seniors-ENRICA Cohort Study

Special Article - Fall Prevention

Gerontol Geriatr Res. 2021; 7(2): 1056.

Added Sugar Intake and Risk of Falling Among Older People: The Seniors-ENRICA Cohort Study

Ballesteros JM1*, Struijk E1, Machado-Fragua MD1, Ortolá R1, Rodriguez-Artalejo F1,2, Lopez-Garcia E1,2

1Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid-IdiPaz and CIBERESP (CIBER of Epidemiology and Public Health), Madrid, Spain

2IMDEA-Food Institute, CEI UAM+CSIC, Madrid, Spain

*Corresponding author: Ballesteros JM, Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, s/n, 28029 Madrid, Spain

Received: May 11, 2021; Accepted: June 08, 2021; Published: June 15, 2021

Abstract

Background: Added sugar intake is a key contributor to the development of several chronic diseases. We aimed to investigate the prospective association between added sugar intake and the risk of falling among older men and women.

Methods: We analyzed data from 2,154 Spanish adults aged ≥65 years from the Seniors-ENRICA cohort. Baseline food consumption was collected in 2008-2010 with a validated diet history, in which 155 foods were identified to contain added sugar. The occurrence of falls was ascertained up to 2015. Analyses were conducted with Cox models adjusted for potential confounders, including nutritional status, chronic diseases and sleeping medication.

Results: Over 7.2y of follow-up, 605 participants experienced ≥1 fall and 527 suffered injurious falls. The hazard ratios (95% confidence interval) for ≥1 fall across quintiles of added sugar intake were: 1.0, 1.09 (0.83-1.42), 1.07 (0.82-1.40), 1.15 (0.88-1.52), and 1.48 (1.12-1.96); p-trend 0.03. The corresponding figures for injurious falls were: 1.0, 1.17 (0.88-1.56), 1.06 (0.79- 1.41), 1.13 (0.84-1.52), and 1.40 (1.03-1.90); p-trend 0.10. These associations did not vary over strata of age, protein, calcium or vitamin intake, diet quality, physical activity or alcohol consumption. No differences were found when solid and liquid sources of added sugars were examined separately.

Conclusions: Intake of added sugars was associated with a higher risk of falling in older people. This adds to the evidence to support interventions to reduce added sugar intake.

Keywords: Added sugars; Falls; Elderly; Cohort study

Introduction

Added sugar intake is a key contributor to the development of the most prevalent chronic diseases, including cardiovascular disease [1], type 2 diabetes [2], hypertension [3], and obesity [4]. Recent studies have also found an association between sugary drink consumption and risk of cancer [5], and between added sugar intake and frailty risk [6]. Accordingly, the World Health Organization has recommended to reduce the daily intake of free sugars below 10% of the total energy intake, and called for a further reduction below 5% to provide additional health benefits [7]. Moreover, according to the American Heart Association, women should consume <100 kcal/d and men <150kcal/d from added sugars [8]. However, current consumption of added sugars represents an average of 7.3% of the total energy intake per day in Spain [9] and 14.9% in the United States [1].

About one-third of people over 65 years of age fall each year; this percentage increases to 50% among those over 80 years or who live in nursing homes [10,11]. Falls in older people are associated with many adverse health outcomes; specifically, a substantial proportion of falls results in serious injuries (28% of them lead to fractures) and disability [12]. Also the “post-fall syndrome” is of relevance because it produces loss of self-confidence and autonomy, social withdrawal and physical decline that, in turn, increases the risk of subsequent falls [13,14]. The high incidence of falls in older adults and their long-term consequences represent a significant burden for healthcare systems, and compromise the sustainability of social protection systems in many countries [15,16].

Unfortunately, knowledge of the effect of diet on the risk of falling is still very limited. Poor nutritional status has been associated with an increased risk of falling [17] while adherence to a Mediterranean-style diet has been linked to lower likelihood of falls in older people [18]. However, studies that focused on specific nutrients, such as protein [19], calcium and vitamin D [20], or foods like fruit and vegetables [21] had inconclusive results. To the best of our knowledge, there is no information about the role of added sugars in this process. Therefore, we aimed to investigate the association between added sugar intake and the risk of falling in a cohort of community-dwelling older adults in Spain.

Methods

Study population

Data were taken from people participating in the Seniors-ENRICA (Study on Nutrition and Cardiovascular Risk in Spain) cohort study [22]. Baseline information was collected between 2008 and 2010 in three stages: first, a phone interview to obtain data on health status, lifestyle, morbidity, and health services use; second, a home visit to collect blood and urine samples; and finally, a second home visit to perform a physical examination and to record usual diet and prescribed medication. Follow-up data collection was conducted in 2012 and 2015, following the same protocols than in baseline. Participants were followed up to the date of the occurrence of the outcome, death, moment in which they abandoned the study, or the end of the study in 2017, whichever came first. The study was approved by the Clinical Research Ethics Committee of La Paz University Hospital in Madrid, and informed written consent was provided by all the participants.

From the 2,452 participant’s ≥65 years at baseline, we excluded 13 with implausible energy intake (outside the range of 800-5,000 kcal/d for men and 500-4,000 kcal/d for women). We also excluded 285 individuals who were frail, defined as having ≥3 criteria in the FRAIL scale [23], or lacked data on this variable at baseline, because frailty is a strong predictor of falls. Therefore, the analyses were conducted with 2,154 individuals.

Study variables

Food consumption: Baseline food consumption was obtained with a validated computer-assisted face-to-face dietary history, which was developed from that used in the EPIC-cohort study in Spain [24]. Study participants reported their weekly consumption of 861 different foods that were classified according to their nutritional content. We considered as added sugars those that were artificially present in foods (mainly mono- and di-saccharides added due to their sweetening properties), by contrast to those naturally existing in fruits, vegetables, and milk. We selected 155 foods containing added sugars, which were classified in the following food groups: table sugar, honey and syrups, special breads, baked goods and cookies, pastries, breakfast cereals, flavored milk, yogurt and fermented milk, dairy desserts, sweetened cheeses, canned fruits, jam and jelly, candy, chocolate, soft drinks, juice and nectars. Intake of sugar, macronutrients and energy were calculated using standard food composition tables [25-28] and were adjusted for energy intake using the residual method [29]. The validity of the diet history has previously been assessed by comparison against seven 24-hour recalls during one year [30]. Pearson’s correlation coefficients for the main food groups were the following: cereals (r= 0.66), meat (r= 0.66), fish (r= 0.42), vegetables (r= 0.62) and fruits (r= 0.44); and for the main nutrients were: total protein (r= 0.58), fats (r= 0.73), total carbohydrates (r= 0.66), fiber (r= 0.49) and total sugars (r= 0.55). Regarding the reliability of the diet history, the intraclass correlation coefficient between two diet assessments was >0.40 for most foods and nutrients [30].

Falls: Incident falls were obtained in 2012 and 2015 by asking the participants how many times they had fallen since the last interview. The responses were recorded from zero (no falls) to nine or more falls. Due to the small number of participants with recurrent falls, we classified the main outcome of this study into two categories: no falls and ≥1 fall. A secondary outcome was the consequences of falls. People who had fallen also reported if, as a result, they had injuries (including contusion, bruise, wounds, shock, unconsciousness, or fracture) or needed healthcare assistance (including consultation with a doctor or nurse, emergency care or hospital admission).

Potential confounders: Socio-demographic data recorded at baseline included sex, age and education (primary, secondary, and university studies). Tobacco consumption was categorized as never, former, and current smoking. Physical activity during leisure time was assessed with the EPIC-cohort questionnaire validated in Spain [31], and was expressed in tertiles of metabolic equivalent taskshour/ week. Weight and height were measured under standardized conditions; the Body Mass Index (BMI) was calculated as weight (kg) divided by squared height (m) and classified as <25, 25-29.9, and ≥30 kg/m². Alcohol consumption was categorized into never drinking, former drinking, moderate intake, and excessive intake (the threshold between moderate and excessive intake was 24g/day in women and 40g/day in men). Total energy, protein, vegetables, calcium and vitamin D intake were categorized in tertiles. The MEDAS score was used to assess accordance with the Mediterranean diet pattern, an indicator of diet quality [32]. Use of sleeping pills was self-reported and checked against drug packages at home and categorized as regular or occasional. Study participants also reported the following physician-diagnosed diseases: cardiovascular disease (ischemic heart disease, stroke, and heart failure), type 2 diabetes, cancer, hypertension, asthma or chronic bronchitis, osteomuscular disease (osteoarthritis, arthritis and hip fracture), and depression needing drug treatment.

Statistical analyses

Differences in sociodemographic, lifestyle and clinical variables across quintiles of added sugar intake were assessed with the chi-square test for qualitative variables and the ANOVA test for continuous variables. Person-years of follow-up were calculated from the date of the baseline questionnaire (starting in March 2008) until the date of the outcome, death, loss to follow-up, or the end of the study (June 2015), whichever came first. Cox proportional hazard models were used to estimate the Hazard Ratios (HR) and their 95% Confidence Interval (CI) for the association between added sugar intake and the incidence of falls (≥1 fall, injurious falls, and falls requiring healthcare assistance). Three sequential multivariable models were fitted: the first one was adjusted for sex, age, and education; the second was further adjusted for lifestyle (smoking status, BMI, physical activity, energy, protein, calcium and vitamin D intake, and alcohol consumption); and the third model was additionally adjusted for chronic diseases and sleeping medication to understand their impact on the studied association. To investigate the linear dose-response relation, we modeled the quintiles of added sugar intake as a continuous variable.

In sensitivity analysis we replicated the Cox models using as exposure the cumulative average of added sugar intake from questionnaires in years 2008-10 to 2013. We also performed analysis stratified by age (<70 vs. ≥70 years), protein intake (<60.6, which is the minimum protein requirement recommended for elderly people by the WHO, according to their weight [33] vs. ≥60.6g/d), the median of vegetables, calcium and vitamin D intake, MEDAS score, and physical activity, and also by alcohol consumption (drinkers vs. nondrinkers). Due to the limited sample size, these stratified analyses were based on tertiles of added sugar.

In an attempt to understand variations of the effect of added sugars depending on the food source, we analyzed the risk of falling by comparing the lowest against the highest tertile of the intake of sugary food groups more frequently consumed by the participants in the study: table sugar and candy, yogurt and fermented milk, pastries and cookies, soft drinks, juice and nectars. Finally, we also investigated the studied association by gathering together solid and liquid sources of added sugars. Statistical analyses were performed with STATA, version 15.0. This manuscript follows the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations. The authors had full access to the data and take responsibility for its integrity. All authors have read and agreed to the manuscript as written.

Results

In our cohort, mean consumption of added sugars was 19.5 (SD 21) g/d, representing 3.9% of the total energy intake. One-third of the added sugars intake was in the form of table sugar, honey and jam. The remaining two-thirds were sugars added during food processing, mainly in pastries and cookies, yogurt and fermented milk, soft drinks, juice and nectars. Also, 83.9% of participants did not drink soft drinks and 92.8% did not consume commercial juice or nectars.

Baseline characteristics of the study participants across quintiles of daily intake of added sugars are presented in Table 1. Those in the highest versus the lowest quintile of intake were more frequently women, had less physical activity, and a lower frequency of diabetes and excessive alcohol intake. Total energy intake increased across the quintiles of added sugars while the quality of the diet (MEDAS score) decreased. Protein, calcium, and vitamin D intakes were higher among participants in the highest quintile.