Renate De Groot

Prenatal famine exposure and cognition at age 59 years

BACKGROUNDnDespite the perceived importance of early life nutrition for mental development, few studies have related gestational undernutrition to later-life cognitive functioning. We investigated the consequences of gestational exposure to the Dutch famine of 1944-45 for cognitive functioning at the age of 59 years.nnnMETHODSnWe recruited men and women who were (i) born in birth clinics in Amsterdam, Rotterdam and Leiden, between January 1945 and March 1946, whose mothers experienced famine during or immediately preceding pregnancy (n = 354); (ii) born in the same three institutions during 1943 and 1947, whose mothers did not experience famine during this pregnancy (n = 292); or (iii) same-sex siblings of those in the first two categories (n = 311). We assessed cognitive performance at the age of 59 years by means of a comprehensive test battery.nnnRESULTSnAll cognitive functioning test scores were within normal ranges for this age group. There were no differences in cognitive performance at the age of 59 years between individuals exposed to gestational undernutrition and those without this exposure. For the general cognitive index, a summary measure across six functional domains (mean 100, standard deviation (SD) 15 points), famine exposure was associated with a decrease of 0.57 points [95% confidence interval (95% CI) -2.41 to 1.28] points. Individuals exposed to famine in gestational weeks 1-10 had a cognitive functioning index 4.36 (95% CI 8.04-0.67) points lower than those without this exposure. Within-sibling-pair analyses gave consistent results.nnnCONCLUSIONnWe found no overall association between maternal exposure to acute famine in pregnancy and cognitive performance of the offspring at the age of 59 years, but cannot rule out an association specific to early pregnancy exposure.

The effect of caffeine on working memory load-related brain activation in middle-aged males

Caffeine is commonly consumed in an effort to enhance cognitive performance. However, little is known about the usefulness of caffeine with regard to memory enhancement, with previous studies showing inconsistent effects on memory performance. We aimed to determine the effect of caffeine on working memory (WM) load-related activation during encoding, maintenance and retrieval phases of a WM maintenance task using functional magnetic resonance imaging (fMRI). 20 healthy, male, habitual caffeine consumers aged 40-61 years were administered 100 mg of caffeine in a double-blind placebo-controlled crossover design. Participants were scanned in a non-withdrawn state following a workday during which caffeinated products were consumed according to individual normal use (range = 145-595 mg). Acute caffeine administration was associated with increased load-related activation compared to placebo in the left and right dorsolateral prefrontal cortex during WM encoding, but decreased load-related activation in the left thalamus during WM maintenance. These findings are indicative of an effect of caffeine on the fronto-parietal network involved in the top-down cognitive control of WM processes during encoding and an effect on the prefrontal cortico-thalamic loop involved in the interaction between arousal and the top-down control of attention during maintenance. Therefore, the effects of caffeine on WM may be attributed to both a direct effect of caffeine on WM processes, as well as an indirect effect on WM via arousal modulation. Behavioural and fMRI results were more consistent with a detrimental effect of caffeine on WM at higher levels of WM load, than caffeine-related WM enhancement. This article is part of a Special Issue entitled Cognitive Enhancers.

Plasma phospholipid fatty acid status and depressive symptoms: association only present in the clinical range

BACKGROUNDnLong-chain polyunsaturated fatty acids (LCPUFA) have been implicated in depression, but their role in mood variability in the general population is still unclear. We investigated the associations between LCPUFA status or fish consumption on the one hand and depressive symptoms and chronicity of depressed mood on the other in a community-based sample.nnnMETHODSnPlasma phospholipid LCPUFA profiles of 241 participants of the Maastricht Aging Study (MAAS) were determined. Depressive symptoms were measured using the CES-D and SCL-90 questionnaires. Using linear regression analyses, associations between the actual level and longitudinal (12-year) variability in depressive symptoms on the one hand and LCPUFA concentrations or fish consumption on the other were examined.nnnRESULTSnNo linear associations were found in the total sample between depressive symptoms and LCPUFA concentrations or fish consumption. Chronicity of depressed mood was also not related to LCPUFA status or fish consumption. Post-hoc analyses, however, showed a negative correlation between docosahexaenoic acid (DHA, 22:6n-3) concentration and depressed mood in persons with CES-D scores above the clinical threshold. Regression analysis suggested a non-linear association between depressive symptoms and DHA concentration in the total sample.nnnLIMITATIONSnThe cross-sectional nature of the present study did not allow for inferences about causality.nnnCONCLUSIONSnThis study offers a first indication that a suboptimal LCPUFA status might accompany depressive symptoms primarily within the clinical spectrum.

Effects of a comprehensive educational group intervention in older women with cognitive complaints: a randomized controlled trial

Objective: This study presents a new comprehensive educational group intervention that offers psycho-education about cognitive aging and contextual factors (i.e., negative age stereotypes, beliefs, health, and lifestyle), focuses on skills and compensatory behavior, and incorporates group discussion. Its effects were investigated in community-dwelling older women who report normal age-related cognitive complaints. Methods: A randomized controlled trial with an experimental and waiting-list control condition was carried out in a sample of 50 women aged 60–75 years. As the main problem of these individuals were perceived cognitive deficits without actual cognitive decrements, metacognition served as the primary outcome measure. Objective cognitive functioning and psychological well-being were secondary outcome measures. A double baseline and a follow-up assessment were carried out. Results: Participants in the experimental condition reported significantly fewer negative emotional reactions toward cognitive functioning (Uu2009=u2009164.500, pu2009=u20090.004). The reported effect size (δu2009=u2009−0.473) could be interpreted as large. Conclusions: This new comprehensive educational group intervention reduces negative emotional reactions toward cognitive functioning, which seems a prerequisite for improved subjective cognitive functioning and well-being. It can potentially contribute the well-being of an important and large group of older adults.

Consuming Functional Foods Enriched with Plant Sterol or Stanol Esters for 85 Weeks Does Not Affect Neurocognitive Functioning or Mood in Statin-Treated Hypercholesterolemic Individuals

Recent animal and human studies have shown that plant sterols and stanols, which are used as functional food ingredients to lower increased LDL cholesterol concentrations, pass the blood-brain barrier. Whether this affects neurocognitive functioning and mental well-being in humans has, to our knowledge, never been investigated. The aim of the present study was therefore to examine the effects of long-term plant sterol or stanol consumption on neurocognitive functioning and mood in a randomized, double-blind, placebo-controlled dietary intervention trial. To this end, hypercholesterolemic individuals, aged 43-69 y, receiving stable statin treatment were randomly assigned to an 85-wk supplementation with margarines enriched with plant sterol esters (2.5 g/d), plant stanol esters (2.5 g/d), or placebo. At baseline and at the end of the intervention period, all participants underwent a cognitive assessment. In addition, subjective cognitive functioning and mood were assessed by means of questionnaires (Cognitive Failure Questionnaire and depression subscale of the Symptom Checklist 90, respectively). Long-term supplementation with plant sterol or stanol esters did not affect cognitive performance (memory, simple information processing speed, complex information processing speed, Letter-Digit Substitution test performance), subjective cognitive functioning, or mood. In conclusion, the present results indicate that long-term use of plant sterols or stanols at recommended intakes of 2.5 g/d does not affect neurocognitive functioning or mood in hypercholesterolemic individuals receiving statin treatment.

Public Education about Memory and Aging: Objective Findings and Subjective Insights

Public education about memory was evaluated with a controlled intervention trial. Participants in group 1 (n = 273) attended a symposium covering memory-related topics and received a magazine with identical information. Group 2 (n = 141) only received the magazine. Participants were nonprofessionals and professionals aged between 29 and 88. Outcome measures were knowledge about memory and subjective experience. For nonprofessionals, knowledge increment was higher in group 1 than in group 2, indicating that an objective increment in knowledge is present in nonprofessionals after attending the symposium. No knowledge change occurred in professionals. Furthermore, participants were very satisfied after both interventions, even when knowledge transfer was limited.

A New Comprehensive Educational Group Program for Older Adults with Cognitive Complaints: Background, Content, and Process Evaluation.

This paper presents a comprehensive group intervention for older adults with cognitive complaints. It offers psychoeducation about cognitive aging and contextual factors, focuses on skills and compensatory behavior, and incorporates group discussion. The intervention reduced negative emotional reactions towards cognitive functioning in a controlled study in healthy women aged 60 to 75 years. Its background and content are described in detail to enable replication and large-scale implementation. Therefore, a process evaluation was carried out. The results support participants appreciation and point to better self-evaluations after intervention. This intervention may offer a valuable contribution to public health care for older adults.

Level of processing and reaction time in young and middle-aged adults and the effect of education

The first aim was to examine whether differences in reaction time (RT) between younger (25–35 years) and middle-aged (50–60 years) individuals increase with depth of processing. The second aim was to examine whether this increase is less pronounced in higher educated individuals. Processing of words at the perceptual, phonological, and semantic level was induced by a case decision, an “e” detection, and a living/nonliving discrimination task, respectively. RTs increased with age and level of processing. However, there were no interactions between age, task, and education, suggesting that different processing levels are equally sensitive to slowing in midlife and that education was not a moderating factor. Although no overall age by level of processing interaction was found, there were age by stimulus type interactions in the deeper processing tasks. First, age-related differences in RT for words containing the letter “e” were smaller than for words without the letter “e”, suggesting that middle-aged adults were slower than younger adults in performing a terminating search strategy. Second, age-related differences in RT for words referring to living items were smaller than for words referring to nonliving items. This suggests that middle-aged adults compared to younger adults have reduced access to specific semantic categories. Taken together, the results show that vulnerability to age-related cognitive decline already exists in middle age.

Subjective sleepiness and sleep quality in adolescents are related to objective and subjective measures of school performance.

This study investigated the relation between sleep and school performance in a large sample of 561 adolescents aged 11–18u2009years. Three subjective measures of sleep were used: sleepiness, sleep quality, and sleep duration. They were compared to three measures of school performance: objective school grades, self-reported school performance, and parent-reported school performance. Sleepiness – “I feel sleepy during the first hours at school” – appeared to predict both school grades and self-reported school performance. Sleep quality on the other hand – as a measure of (un)interrupted sleep and/or problems falling asleep or waking up – predicted parent-reported school performance. Self- and parent-reported school performance correlated only moderately with school grades. So it turns out that the measures used to measure either sleep or school performance impacts whether or not a relation is found. Further research on sleep and school performance should take this into account. The findings do underscore the notion that sleep in adolescence can be important for learning. They are compatible with the hypothesis that a reduced sleep quality can give rise to sleepiness in the first hours at school which results in lower school performance. This notion could have applied value in counseling adolescents and their parents in changing adolescents’ sleep behavior.

Are Age Differences in Verbal Learning Related to Interstimulus Interval and Education

The present study investigated the effects of a narrow range of interstimulus intervals (ISI; 1, 2, or 3 s) on word-learning performance in relation to age and education. Individuals (N = 338) from four age groups (24 to 76 years) with low or high educational attainment were randomly assigned to one of three ISI conditions. Older age, lower education, and shorter ISI each led to lower performance. However, age differences in performance were not affected by ISI. Furthermore, lower educated individuals needed more time to achieve the same performance level as higher educated individuals.