Nutrition & Food Science
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Item EVALUATING THE EFFECTS OF MODIFIABLE LIFESTYLE AND CARDIOVASCULAR HEALTH FACTORS ON DIABETES LIFE EXPECTANCY IN NHANES AND BRAIN AGING IN UK BIOBANK(2024) Feng, Li; Lei, David K.Y. DL; Ma, Tianzhou TM; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation explored the impact of lifestyle and cardiovascular health factors on aging, particularly focusing on individuals with diabetes, the effects of blood pressure on brain aging, and the influence of cardiovascular health and genetic predispositions on brain white matter aging.The first study examined the trends in lifestyle quality among US adults with type 2 diabetes from 1999 to 2018 using NHANES data, involving 7,410 participants. A healthy lifestyle score encompassing smoking, drinking, physical activity, and diet showed a slight increased over the years. Notably, disparities remained significant by socioeconomic groups. The study found that adherence to low-risk lifestyle factors was associated with a 55%-57% lower risk of all-cause mortality, emphasizing the importance of lifestyle modification in diabetes management, and it was independent of cardiovascular risk control. The second study investigated the causal effect of elevated blood pressure on white matter brain aging in a cohort of 228,473 European ancestries aged 40-69 from the UK Biobank by using two-sample Mendelian randomization. Our result revealed that high blood pressure, particularly diastolic, accelerated the machine-learning-derived white matter brain age gap, based on white matter microstructure integrity measured by fractional anisotropy derived from diffusion tensor imaging data, with a causal effect evidence found in late middle-aged women. This underscores the importance of blood pressure control in preventing brain aging, especially in post-menopausal women. Lastly, the impact of Life's Essential 8 (LE8), a comprehensive measure of cardiovascular health (lifestyle part: diet, smoke, physical activity, sleep; health part: BMI, blood sugar, blood pressure, blood lipid), on white matter brain aging was assessed, with a particular focus on how the APOE4 genotype modifies the relationship. Analyzing data from 18,817 European ancestries aged 40-60 from the UK Biobank, the study revealed that higher LE8 scores correlated with a younger brain age. Interestingly, the effect varied significantly with APOE4 status, highlighting the need for personalized health strategies based on genetic profiles. In conclusion, these studies collectively highlight the crucial role of modifiable lifestyle and health factors in managing chronic diseases, controlling blood pressure, and maintaining brain health, with an emphasis on the integration of genetic profiles for personalized healthcare.Item VALIDATING THE EXPANDED FOOD SECURITY SCREENER AND HOME-DELIVERED MEAL PRIORITIZATION TOOL FOR ELIGIBLE INDIVIDUALS(2022) Mendez, Izabelle; Sahyoun, Nadine; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The Expanded Food Security Screener (FSS-Exp) is a screening tool for determining food insecurity risk based on individuals’ physical, economic, and social access to food. The FSS-Exp is the only tool that provides a simple and quick method for identifying which home-delivered meal (HDM) applicants are most vulnerable. However, further testing is required to determine the tool’s validity when compared with health and food-related measures associated with food security. Therefore, this study aimed to validate the FSS-Exp and HDM prioritization tool using concurrent and construct validity methods. To evaluate the concurrent validity, we examined the correlations between the FSS-Exp and other health and food-related tools such as SF-36, MOS-SSS, SWFL, SNAQ, and DST, which were associated with economic food insecurity and physical limitation To determine construct validity using the known-groups approach, we compared those health and food-related scores among participants grouped by different access barriers to food (priority levels). The results showed that the FSS-Exp correlated moderately (r=0.20 to 0.33) with other “gold standard” measures: SF-36, MOS-SSS, and SWFL. Furthermore, our results showed that individuals categorized as priority level A and B had significantly lower mean scores than priority level E for the SF-36 (HRQL) summary measures (p<0.05), SWFL (p<0.05), and the tangible social support ( p<0.01). Thus, the FSS-Exp was shown to be a valid measure in identifying and prioritizing older adults with physical and/or economic access to food, which is especially important for HDM programs with limited resources experiencing increased demand for services. For HDM programs which exist to serve vulnerable older adults, using the validated FSS-Exp tool can help identify those who are most vulnerable and in need of immediate service.Item Food Insecurity, Service Awareness, Social Factors, and Quality of Life in Community-Dwelling Older Adults(2021) Vaudin, Anna Margaret; Sahyoun, Nadine R; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Older adults are at risk for food insecurity due to financial constraints, physical difficulties, social isolation, and the resulting limitations on food access. Social isolation has two components – objective, such as social contacts, and subjective, such as loneliness – and each may have a unique relationship with food insecurity. Unmet needs exist for services that aim to improve food access in older adults, and research is limited on how those who do use the services find out about them. Additionally, these services aim to improve quality of life (QOL), and yet this impact cannot be quantified because current tools do not capture the ways food affect QOL beyond nutritional status. This dissertation uses qualitative methods to understand (1) how food and eating impact QOL in community-dwelling older adults, (2) how individuals become aware of the services they use to address barriers to food and eating, and (3) the interaction between food security, loneliness, and QOL. In-depth interviews were conducted with 25 urban- and suburban-dwelling older adults. Interview scripts were transcribed and themes identified in the data using grounded theory methods. The first study showed that health and vitality, independence, mental and emotional well-being, socialization and support, and activities, both inside and outside the home, affected participants’ QOL. Food and eating affected QOL through access and choice, health and vitality, enjoyment of food, and food preparation. The second study showed that participants primarily found out about the resources they use through encounters in their daily lives, rather than service outreach. The final study showed that, compared with those who were food secure, those who were food insecure were more likely to report a negative effect of loneliness on their QOL, primarily experienced as depressive symptoms. This dissertation shows that food and eating affect older adults through not only the physiological effects of good nutrition, but also through social, psychological, and sensory effects on QOL. Additionally, the results point to the importance of social factors for both service awareness and mental health in those who face barriers to food and eating. Future studies and new tools are needed to quantify these impacts.Item The Relationship between Dietary intake and Biomarkers of carotenoids and Physical Functioning among U.S. Older Adults(2015) Sheikomar, Olfat Bakur; Sahyoun, Nadine; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Decline of physical function [PF] in old age might be related to oxidative damage caused by free radicals, and antioxidants may play a role in reducing the risk of physical functional limitations [PFL]. Yet little is known about the role of carotenoids in PFL. The purpose of this study was to assess the association of total and daily dietary intakes of carotenoids, fruit and vegetables [FV] and their biomarkers with PF among U.S. older adults. Data were from 2,905 men and women [≥ 60 years] in the National Health and Nutrition Examination Survey [NHANES] 2003-2006. Using logistic regression, we found that serum concentration of carotenoids was associated with limitations in PF. In the fully adjusted model, the ORs [95% CI] of having limitation in activities of daily living [ADLs], instrumental activities of daily living [IADLs] and movement difficulties [MD] were 2.03 [1.16 - 3.53], 2.34 [1.61 - 3.42], and 2.15 [1.46 - 3.18], respectively, comparing the lowest quintile of serum carotenoids to the highest. Total intake and dietary intake of carotenoids were found to be associated with limitations in IADL. However, low FV consumptions were not significantly associated with PF domains. In conclusion, elevated levels of serum carotenoids are significantly associated with better physical functional performance and may play an important role in delaying the onset of physical decline.Item Unmet Need for Nutrition-Related Services in Recently Hospital-Discharged Older Adults(2015) Vaudin, Anna Margaret; Sahyoun, Nadine R; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Older adults returning home from the hospital may have disabilities that prevent them from obtaining or preparing adequate nutritious food. Additionally, they may have difficulty identifying their need for or accessing services that could provide support. We aimed to identify the level of unmet need for services that may affect nutritional health in community-dwelling older adults. We also compared the prevalence of perceived need for services with objectively assessed need. We explored the need for home health care, transportation, mental health, oral health, vision, grocery delivery, and physical therapy services in 566 community-dwelling, recently hospital-discharged older adults. Almost half (45.6%) of the sample reported unmet need for at least one service. For each service, there was discrepancy between perceived need and assessed need. By improving the screening of hospital-discharged older adults' needs for nutrition-related services, the healthcare community can improve targeting of services to those with the most nutritional risk.Item Nutritional roles of selenium in cellular and mouse aging(2013) Wu, Tsung-Yu; Cheng, Wen-Hsing; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Oxidative stress and persistent DNA damage response can lead to cellular senescence and aging. The ATM kinase and p53 protein play critical roles in the DNA damage response to reactive oxygen species and other DNA-damaging agents. Although the majority of selenoproteins carry antioxidant activities, little is known about the nutritional role of selenium (Se) in aging. Previous studies indicated that selenoprotein H (SelH) is very sensitive to dietary Se deficiency. Moreover, SelH is a nuclear selenoprotein that is proposed to carry redox domains and to transactivate redox genes including one for glutathione biosynthesis. To determine the role of SelH in genome maintenance, SelH and scrambled shRNA knockdown were stably established in MRC-5 human diploid fibroblast or immortalized cancer cells. SelH shRNA MRC-5 cells showed more pronounced induction of β-galactosidase expression, autofluorescence, growth inhibition, and ATM pathway activation (γH2AX and phospho-ATM Ser-1981) as compared to scrambled shRNA cells. Interestingly, the slow proliferation in SelH shRNA MRC-5 cells was alleviated in the presence of ATM kinase inhibitors KU 55933 and KU 60019, by p53 shRNA knockdown, or by maintaining the cells in 3% O2 incubator (vs. ambient O2). Phospho-ATM Ser-1981 and γH2AX induction by H2O2 treatment (20 M) was temporally exacerbated in SelH shRNA but reversed in the scrambled shRNA MRC-5 cells 1-5 days after recovery. GFP-SelH did not relocalize to sites of oxidative DNA damage. Results from cologenic assays indicated that SelH shRNA HeLa cells were hypersensitive to paraquat and H2O2 but not to other clastogens including hydroxyurea, neocarzinostatin or camptothecin. The H2O2-induced cell death was attenuated in the presence of N-acetyl cysteine (NAC), a glutathione analogue, in SelH but not in scrambled shRNA HeLa cells. In conclusion, SelH protects against cellular senescence specifically to oxidative stress through a genome maintenance pathway involving ATM and p53. While recent research has demonstrated that mice unable to express selenoproteins in epidermal cells or in osteo-chondroprogenitor cells showed an apparently aging phenotype characterized by alopecia or bone abnormality, respectively. Thus, a role of selenium, particularly at nutritional levels of intake, in aging is largely unknown. What is lacking is an appropriate aging model of dietary Se deprivation displaying many features of normal aging. Telomere attrition provokes DNA damage response and, subsequently, replicative senescence. Because the chromosomes of mice carry longer telomeres than those of humans, the proposed hypothesis is that lengthy telomeres preclude mice deprived of Se to display aging phenotypes and age-related disorders. To test this hypothesis, weanling late generation Terc-/- mice were fed a Se-deficient diet or the diet supplemented with selenate (0.15 ppm) throughout their life. The objectives are to elucidate the role of Se in reducing age-related loss of function and begin to identify the key molecular mediators and selenoproteins during the aging process. As evidenced by changes in metabolic markers (body weight, glucose intolerance, insulin resistance and bone structure) and aging phenotypes (gray hair, alopecia, wound healing and telomere attrition), these data strongly indicate health span deterioration by dietary Se deficiency in the short telomere mice. MicroRNAs (miRNAs) are regulators of messenger RNA stability and translation and have been proposed as biomarkers for a variety of diseases and physiological conditions, including aging. A high-throughput platform, TaqMan low density array, was used to profile more than 800 miRNAs in plasma whose expression were validated by using individual quantitative PCR. The expression of a couple of miRNAs were induced both by dietary Se deprivation and aging. Altogether, a very interesting model of aging is established in this project by deprivation of Se that displays many hallmarks of human aging and can reveal the roles of Se at nutritional levels, in contrast with previous approaches, in which these essential roles in delaying health span deterioration may have been masked by lengthy telomeres.