Engaging in cognitive activities, aging, and mild cognitive impairment: a population-based study.

The authors investigated whether engaging in cognitive activities is associated with aging and mild cognitive impairment (MCI) in a cross-sectional study derived from an ongoing population-based study of normal cognitive aging and MCI in Olmsted County, MN. A random sample of 1,321 study participants ages 70 to 89 (N=1,124 cognitively normal persons, and N=197 subjects with MCI) were interviewed about the frequency of cognitive activities carried out in late life (within 1 year of the date of interview). Computer activities; craft activities, such as knitting, quilting, etc.; playing games; and reading books were associated with decreased odds of having MCI. Social activities, such as traveling, were marginally significant. Even though the point-estimates for reading magazines, playing music, artistic activities, and group activities were associated with reduced odds of having MCI, none of these reached statistical significance. The equally high prevalence of reading newspapers in both groups yielded no significant between-group difference.

Caloric intake, aging, and mild cognitive impairment: a population-based study.

In a population-based case-control study, we examined whether moderate and high caloric intakes are differentially associated with the odds of having mild cognitive impairment (MCI). The sample was derived from the Mayo Clinic Study of Aging in Olmsted County, Minnesota. Non-demented study participants aged 70-92 years (1,072 cognitively normal persons and 161 subjects with MCI) reported their caloric consumption within 1 year of the date of interview by completing a Food Frequency Questionnaire. An expert consensus panel classified each subject as either cognitively normal or having MCI based on published criteria. We conducted multivariable logistic regression analyses to compute odds ratios (OR) and 95% confidence intervals (95% CI) after adjusting for age, gender, education, depression, medical comorbidity, and body mass index. We also conducted stratified analyses by apolipoprotein E ε4 genotype status. Analyses were conducted in tertiles of caloric intake: 600 to <1,526 kcals per day (reference group); 1,526 to 2,143 kcals per day (moderate caloric intake group); and >2,143 kcals per day (high caloric intake group). In the primary analysis, there was no significant difference between the moderate caloric intake group and the reference group (OR 0.87, 95% CI 0.53-1.42, p = 0.57). However, high caloric intake was associated with a nearly two-fold increased odds of having MCI (OR 1.96, 95% CI 1.26-3.06, p = 0.003) as compared to the reference group. Therefore, high caloric intake was associated with MCI but not moderate caloric intake. This association is not necessarily a cause-effect relationship.

Relative intake of macronutrients impacts risk of mild cognitive impairment or dementia.

High caloric intake has been associated with an increased risk of cognitive impairment. Total caloric intake is determined by the calories derived from macronutrients. The objective of the study was to investigate the association between percent of daily energy (calories) from macronutrients and incident mild cognitive impairment (MCI) or dementia. Participants were a population-based prospective cohort of elderly persons who were followed over a median 3.7 years (interquartile range, 2.5-3.9) of follow-up. At baseline and every 15 months, participants (median age, 79.5 years) were evaluated using the Clinical Dementia Rating scale, a neurological evaluation, and neuropsychological testing for a diagnosis of MCI, normal cognition, or dementia. Participants also completed a 128-item food-frequency questionnaire at baseline; total daily caloric and macronutrient intakes were calculated using an established database. The percent of total daily energy from protein (% protein), carbohydrate (% carbohydrate), and total fat (% fat) was computed. Among 937 subjects who were cognitively normal at baseline, 200 developed incident MCI or dementia. The risk of MCI or dementia (hazard ratio, [95% confidence interval]) was elevated in subjects with high % carbohydrate (upper quartile: 1.89 [1.17-3.06]; p for trend = 0.004), but was reduced in subjects with high % fat (upper quartile: 0.56 [0.34-0.91]; p for trend = 0.03), and high % protein (upper quartile 0.79 [0.52-1.20]; p for trend = 0.03) in the fully adjusted models. A dietary pattern with relatively high caloric intake from carbohydrates and low caloric intake from fat and proteins may increase the risk of MCI or dementia in elderly persons.