High iron intake is associated with poor cognition among Chinese old adults and varied by weight status—a 15-y longitudinal study in 4852 adults (original) (raw)
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Iron-related dietary pattern increases the risk of poor cognition
Nutrition Journal, 2019
Introduction: High iron intake has been shown to be associated with poor cognition. We aimed to examine the association between iron-related dietary pattern (IDP) and cognitive function in Chinese adults. Method: Longitudinal study data from the China Health and Nutrition Survey (CHNS) during 1991-2006 were used (N = 4852, ≥55 years old). Dietary intake was obtained from a 3-day food record during home visits. Reduced rank regression was used to construct IDP with iron intake as a response variable. Cognitive function was assessed in 1997, 2000, 2004 and 2006. Multivariable mixed linear regression and logistic regression were used in the analyses. Results: IDP was characterised by high intake of fresh vegetable, wheat, legume, beverage, offal, rice and whole grain. High IDP intake was associated with poor cognition. In fully adjusted models, across the quartiles of IDP, the odds ratio (95% CI) for poor cognitive function were: 1.00, 1.06 (0.86-1.30), 1.24 (0.99-1.54), and 1.50 (1.17-1.93), respectively. There was a borderline significant interaction between IDP and meat intake (p interaction 0.085). The association between high IDP and poor cognition was only observed among those with no or low intake of meat. With the adjustment of carbohydrate or iron intake, the IDP and cognition association became non-significant. IDP was positively associated with lead intake. The association between IDP and poor cognition was partly mediated by lead intake. Conclusions: Iron-related dietary pattern is associated with poor cognition in Chinese adults, partly due to high intake of carbohydrate, iron and lead.
Nutrients
Anemia causes hypo-oxygenation in the brain, which could lead to cognitive disorders. We examined dietary iron intake as well as anemia markers (i.e., hemoglobin, hematocrit, mean corpuscular volume) and diabetes coexistence in relation to neuropsychological function and quality of life. In this study, 6117 community-dwelling adults aged 55–75 years (men) and 60–75 years (women) with overweight/obesity and metabolic syndrome were involved. We performed the Mini-Mental State Examination (MMSE), the Trail Making Test parts A and B (TMT-A/B), Semantic Verbal Fluency of animals (VFT-a), Phonological Verbal Fluency of letter P (VFT-p), Digit Span Test (DST), the Clock Drawing Test (CDT), and the Short Form-36 Health Survey (SF36-HRQL test). Dietary iron intake did not influence neuropsychological function or quality of life. However, anemia and lower levels of anemia markers were associated with worse scores in all neurophysiological and SF36-HRQL tests overall, but were especially clear...
A cross-sectional community study of serum iron measures and cognitive status in older adults
2010
The relationship of iron status with cognition and dementia risk in older people is contentious. We have examined the longitudinal relationship between serum ferritin and cognition in 800 community-dwelling Australians 60 years or older. Iron studies (serum iron, transferrin saturation, serum ferritin) were performed in 1994/5 and 2003/4 and clinical and cognitive assessments were conducted in 2003/4 for 800 participants of the Busselton Health Study. All participants completed the Cambridge Cognitive test (CAMCOG). Those with CAMCOG scores < 84 underwent expert clinical review for cognitive disorders, including the Clinical Dementia Rating scale. Mean serum iron (18.3 µmol/l) and transferrin saturation (28.5%) in 2003/4 did not differ significantly from 1994/5 whereas mean serum ferritin decreased from 162 µg/l in 1994/5 to 123 µg/l in 2003/4, possibly reflecting aging or dietary changes. No relationships were observed between serum iron or transferrin saturation and presence or absence of dementia (p > 0.05). In participants without dementia (n = 749), neither serum ferritin in 1994/5 or 2003/4 nor change in serum ferritin between these times was related to total CAMCOG or executive function scores, with or without adjustment for gender, age, National Adult reading test, or stroke history (all p > 0.05). No relationships were observed between ferritin and cognition for participants with possible or probable dementia (n = 51). All participants identified as HFE C282Y homozygous or with serum ferritin > 1,000 ng/ml had normal CAMCOG scores. We conclude abnormal body iron stores (low or high) are unlikely to have clinically significant effects on cognition or dementia risk in community-dwelling older people.
Journal of Nutrition, 2013
The link between iron status and cognition has been established in infants and children, yet evidence in adults is scant and heterogeneous. We examined sex-and menopause-specific cross-time associations of iron status with cognition in the French Supplémentation en Vitamines et Minéraux Antioxydants Study cohort (1539 men, 1431 pre-/perimenopausal women, 962 postmenopausal women). Serum ferritin and hemoglobin data were obtained in 1995. Cognition was assessed after a mean of 13 y through 6 validated instruments, including the RI-48 cued recall test, phonemic and semantic fluency tasks, forward and backward digit span tasks, and a trail-making test. The standardized individual test scores were summed to form a composite cognitive performance measure. Associations between ferritin and hemoglobin and subsequent cognitive performance were examined through multivariable linear regression. Among men, no significant associations were observed. In postmenopausal women, an inverse association was found between ferritin and phonemic fluency (adjusted b: 20.11; 95% CI: 20.21, 20.01). Significant inverse associations between ferritin and both the composite cognitive measure (adjusted b: 20.09; 95% CI: 20.17, 20.00) and the forward digit span scores (adjusted b: 20.13; 95% CI: 20.22, 20.03) were observed only among premenopausal women aged $46 y at baseline. No significant findings with hemoglobin emerged. This study supports an inverse association between midlife iron status and subsequent cognitive performance that is sex-and menopause-dependent. Given the urgent need for prevention research on age-related disorders, future investigations of iron status and cognition are warranted. The study is registered at www.clinicaltrials.gov as NCT00272428.
Dietary Iron is Associated with Memory in Midlife: Longitudinal Cohort Study
Journal of Pharmacy and Nutrition Sciences
This work examined associations between dietary iron and cognitive function in mid-life adults using data from the 1946 British Birth Cohort, a representative population-based sample of men and women born in England, Scotland or Wales. Linear regression was used to determine the association between dietary iron intake or a measure of available iron (calculated by adjusting iron intake for dietary modifiers that are known to inhibit or enhance iron absorption) at ages 36, 43 and 53 years and cognitive measures at ages 43 and 53 years. Cognitive measures included verbal memory, assessed by a three-trial 15-word learning task, and speed and concentration, assessed by a timed letter search task. Examining the data cross-sectionally; dietary iron at ages 43 and 53 years was positively and significantly associated with verbal memory after adjustment for potential confounders. Examining the data longitudinally; earlier dietary iron exposure was significantly associated with later verbal memory. No associations were observed between dietary iron and measures of speed and concentration when examining the data both cross-sectionally and longitudinally. The current study shows that impaired cognition, specifically memory, resulting from inadequate iron intake may extend beyond childhood and also be present in midlife. This finding, coupled with the high prevalence of people reporting iron intakes below the Lower Reference Nutrition Intake in the UK, provide reason for concern.
Nutrients
Several conditions are risk factors for iron deficiency (ID), some of which are highly prevalent in older individuals. Despite the amount of evidence pointing for a role of ID in cognition, mood and physical functional ability, the research addressing these associations in older individuals is still scarce. In the present study, 162 older community-dwelling individuals (29.53% classified as ID) were enrolled in a cross-sectional analysis and characterized regarding cognition, mood, functional ability, general nutritional intake and iron status. Assessment of iron status was performed using several blood biomarkers. Storage and erythropoiesis dimensions were positively associated with memory, along with an interaction (moderator effect) between iron storage and nutritional status. A more depressed mood was negatively associated with (iron) transport, transport saturation and erythropoiesis dimensions, and functional tiredness was positively associated with the erythropoiesis dimensio...
Correlation of Iron Deficiency Anemia with Cognitive Function in Young Adults
IOSR Journals , 2019
Introduction: Iron deficiency anemia is the most common form of anemia. Iron is an essential component of brain growth, myelination, and is required for cell differentiation, protein synthesis, hormone production and fundamental aspects of cellular energy metabolism and functioning. It has also been found that higher hemoglobin levels results in better CNS functions. AIM: To assess the relationship between iron deficiency anemia and cognitive function in young adults. MATERIAL: 100 young adults, 67 female and 33 male in age group of 20-22 yrs. METHODS: For all subjects cognitive assessment scoring was done using MMSE, MoCA cognitive scales and serum samples were sent for determining Hb%, MCH, MCHC, MCV AND S.FERRITIN. Subjects were grouped into anemic and non anemic groups and further anemic group is sub grouped into mild, moderate and severe as per who criteria. RESULTS: In our study prevalence of anemia is 46% .females are more anemic than males. Cognitive scores are lesser in females compared to males. There is significant positive correlation between all parameters of anemia and cognitive scores. MoCA scores are more sensitive than MMSE for cognitive assessment. CONCLUSION: Iron deficiency anemia is significantly correlated with cognition. DISCUSSION: Iron deficiency anemia affects cognition by causing a decrease in the iron concentration in the brain, which causes a reduction in the neurotransmitter levels. This, in turn, causes impaired transmitter functions, leading to hypomyelination and delayed neuromaturation. Anemia affects cognition by its direct neurochemical effect and by its indirect effect on behavior.