Martha Clare Morris

Cognitive activity and incident AD in a population-based sample of older persons

Background: Participation in cognitively stimulating activities is hypothesized to be associated with risk of AD, but knowledge about this association is limited. Methods: A biracial community in Chicago was censused, persons aged 65 years and older were asked to participate in an interview, and 6,158 of 7,826 (79%) eligible persons did so. As part of the interview, persons rated current frequency of participation in seven cognitive activities (e.g., reading a newspaper) and nine physical activities (e.g., walking for exercise) from which composite measures of cognitive and physical activity frequency were derived. Four years later, 1,249 of those judged free of AD were sampled for a detailed clinical evaluation of incident disease and 842 (74% of those eligible) participated. Results: The composite measure of cognitive activity ranged from 1.28 to 4.71 (mean 3.30; SD 0.59), with higher scores indicating more frequent activity. A total of 139 persons met National Institute of Neurological and Communicative Disorders and Stroke–Alzheimer’s Disease and Related Disorders Association criteria for AD on clinical evaluation. In a logistic regression model adjusted for age, education, sex, race, and possession of the APOE ε4 allele, a one-point increase in cognitive activity score was associated with a 64% reduction in risk of incident AD (OR 0.36; 95% CI 0.20 to 0.65). By contrast, weekly hours of physical activity (mean 3.5; SD 5.1) was not related to disease risk (OR 1.04; 95% CI 0.98 to 1.10). Education was associated with risk of AD and a similar trend was present for occupation, but these effects were substantially reduced when cognitive activity was added to the model. Conclusion: Frequency of participation in cognitively stimulating activities appears to be associated with risk of AD and may partially explain the association of educational and occupational attainment with disease risk.

Towards Establishing Dietary Reference Intakes for Eicosapentaenoic and Docosahexaenoic Acids

There is considerable interest in the impact of (n-3) long-chain PUFA in mitigating the morbidity and mortality caused by chronic diseases. In 2002, the Institute of Medicine concluded that insufficient data were available to define Dietary Reference Intakes (DRI) for eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), noting only that EPA and DHA could contribute up to 10% toward meeting the Adequate Intake for alpha-linolenic acid. Since then, substantial new evidence has emerged supporting the need to reassess this recommendation. Therefore, the Technical Committee on Dietary Lipids of the International Life Sciences Institute North America sponsored a workshop on 4-5 June 2008 to consider whether the body of evidence specific to the major chronic diseases in the United States--coronary heart disease (CHD), cancer, and cognitive decline--had evolved sufficiently to justify reconsideration of DRI for EPA+DHA. The workshop participants arrived at these conclusions: 1) consistent evidence from multiple research paradigms demonstrates a clear, inverse relation between EPA+DHA intake and risk of fatal (and possibly nonfatal) CHD, providing evidence that supports a nutritionally achievable DRI for EPA+DHA between 250 and 500 mg/d; 2) because of the demonstrated low conversion from dietary ALA, protective tissue levels of EPA+DHA can be achieved only through direct consumption of these fatty acids; 3) evidence of beneficial effects of EPA+DHA on cognitive decline are emerging but are not yet sufficient to support an intake level different from that needed to achieve CHD risk reduction; 4) EPA+DHA do not appear to reduce risk for cancer; and 5) there is no evidence that intakes of EPA+DHA in these recommended ranges are harmful.

Vitamin E and vitamin C supplement use and risk of incident Alzheimer disease.

Oxidative stress may play a role in neurologic disease. The present study examined the relation between use of vitamin E and vitamin C and incident Alzheimer disease in a prospective study of 633 persons 65 years and older. A stratified random sample was selected from a disease-free population. At baseline, all vitamin supplements taken in the previous 2 weeks were identified by direct inspection. After an average follow-up period of 4.3 years, 91 of the sample participants with vitamin information met accepted criteria for the clinical diagnosis of Alzheimer disease. None of the 27 vitamin E supplement users had Alzheimer disease compared with 3.9 predicted based on the crude observed incidence among nonusers (p = 0.04) and 2.5 predicted based on age, sex, years of education, and length of follow-up interval (p = 0.23). None of the 23 vitamin C supplement users had Alzheimer disease compared with 3.3 predicted based on the crude observed incidence among nonusers (p = 0.10) and 3.2 predicted adjusted for age, sex, education, and follow-up interval (p = 0.04). There was no relation between Alzheimer disease and use of multivitamins. These data suggest that use of the higher-dose vitamin E and vitamin C supplements may lower the risk of Alzheimer disease.

Associations of vegetable and fruit consumption with age-related cognitive change.

Objective: To examine the association between rates of cognitive change and dietary consumption of fruits and vegetables among older persons. Methods: The authors conducted a prospective cohort study of 3,718 participants, aged 65 years and older of the Chicago Health and Aging Project. Participants completed a food frequency questionnaire and were administered at least two of three cognitive assessments at baseline, 3-year, and 6-year follow-ups. Cognitive function was measured using the average z-score of four tests: the East Boston Tests of immediate memory and delayed recall, the Mini-Mental State Examination, and the Symbol Digit Modalities Test. Results: The mean cognitive score at baseline for the analyzed cohort was 0.18 (range: –3.5 to 1.6), and the overall mean change in score per year was a decline of 0.04 standardized units. In mixed effects models adjusted for age, sex, race, and education, compared with the rate of cognitive decline among persons in the lowest quintile of vegetable intake (median of 0.9 servings/day), the rate for persons in the fourth quintile (median, 2.8 servings/day) was slower by 0.019 standardized units per year (p = 0.01), a 40% decrease, and by 0.018 standardized units per year (p = 0.02) for the fifth quintile (median, 4.1 servings/day), or a 38% decrease in rates. The association remained significant (p for linear trend = 0.02) with further control of cardiovascular-related conditions and risk factors. Fruit consumption was not associated with cognitive change. Conclusion: High vegetable but not fruit consumption may be associated with slower rate of cognitive decline with older age.

Adherence to a Mediterranean-type dietary pattern and cognitive decline in a community population–

BACKGROUND Many of the foods abundant in the traditional Mediterranean diet, such as vegetables and fish, have been associated with slower cognitive decline. OBJECTIVE We investigated whether adherence to a Mediterranean dietary pattern or to the Healthy Eating Index-2005 (HEI-2005) is associated with cognitive change in older adults. DESIGN This article is based on analyses of data from an ongoing longitudinal study in adults aged ≥65 y known as the Chicago Health and Aging Project (CHAP). CHAP participants (2280 blacks and 1510 whites) with ≥2 cognitive assessments were evaluated for adherence to 1) the Mediterranean dietary pattern (MedDiet; maximum score: 55) and 2) the HEI-2005 (maximum score: 100). For both scoring systems, higher scores connote greater adherence. Cognitive function was assessed at 3-y intervals on the basis of a composite measure of global cognition. Linear mixed models were used to examine the association of dietary scores to change in cognitive function. Mean follow-up time was 7.6 y. RESULTS Mean (±SD) scores for participants were 28.2 ± 0.1 for the MedDiet and 61.2 ± 9.6 for the HEI-2005. White participants had higher energy-adjusted MedDiet scores but lower HEI-2005 scores than did black participants. Higher MedDiet scores were associated with slower rates of cognitive decline (β = +0.0014 per 1-point increase, SEE = 0.0004, P = 0.0004) after adjustment for age, sex, race, education, participation in cognitive activities, and energy. No such associations were observed for HEI-2005 scores. CONCLUSION The Mediterranean dietary pattern as captured by the MedDiet scoring system may reduce the rate of cognitive decline with older age.

CD33 Alzheimer's disease locus: altered monocyte function and amyloid biology

In our functional dissection of the CD33 Alzheimers disease susceptibility locus, we found that the rs3865444C risk allele was associated with greater cell surface expression of CD33 in the monocytes (t50 = 10.06, Pjoint = 1.3 × 10−13) of young and older individuals. It was also associated with diminished internalization of amyloid-β 42 peptide, accumulation of neuritic amyloid pathology and fibrillar amyloid on in vivo imaging, and increased numbers of activated human microglia.

Dietary fat intake and 6-year cognitive change in an older biracial community population

Objective: To examine whether consumption of different types of fat is associated with age-related change in cognition. Methods: The authors related fat consumption to 6-year change in cognitive function among 2,560 participants of the Chicago Health and Aging Project, ages 65 and older, with no history of heart attack, stroke, or diabetes at baseline. Fat intake was measured by food frequency questionnaire. Cognitive function was measured at baseline and 3-year and 6-year follow-ups, using the average z score of four cognitive tests: the East Boston Tests of Immediate and Delayed Recall, the Mini-Mental State Examination, and the Symbol Digit Modalities Test. Results: In separate mixed models adjusted for demographic and cardiovascular risk factors and intakes of antioxidant nutrients and other dietary fats, higher intakes of saturated fat (p for trend = 0.04) and trans-unsaturated fat (p for trend = 0.07) were linearly associated with greater decline in cognitive score over 6 years. These associations became stronger in analyses that eliminated persons whose fat intake changed in recent years or whose baseline cognitive scores were in the lowest 15%. Inverse associations with cognitive decline were observed in these latter restricted analyses for high intake of monounsaturated fat and a high ratio of polyunsaturated to saturated fat intake. Intakes of total fat, vegetable and animal fats, and cholesterol were not associated with cognitive change. Conclusion: A diet high in saturated or trans-unsaturated fat or low in nonhydrogenated unsaturated fats may be associated with cognitive decline among older persons.

Prevalence and Functional Correlates of Low Back Pain in the Elderly: The Iowa 65+ Rural Health Study

As part of an interview survey of a defined population of 3,097 rural persons 65 years and older (the Iowa 65+ Rural Health Study), the prevalence and functional correlates of specifically defined low back pain were studied. Low back pain was reported by 23.6 per cent of the women and 18.4 per cent of the men in the year prior to the survey, with prevalence rates declining with age. Forty per cent of those with low back pain noted its presence at the time of the interview. Over half had used analgesics. Use of medical and chiropractic services for this symptom was nearly 75 per cent; 25 per cent had at least one hospitalization directly related to low back pain and over 5 per cent had low back surgery. Limitation of walking, sitting, bending over, and performing household chores was reported by 15 to 40 per cent, and 21 per cent attributed sleep disturbance to the low back pain. Nearly 75 per cent of subjects with low back pain reported first onset of the problem prior to age 65, which has important implications for pathogenesis and prevention. The functional and clinical burdens of low back pain in this population of rural elderly were substantial and require further evaluation of risk factors and impact on health status. J Am Geriatr Soc 33:23, 1985

Cognitive activity and cognitive decline in a biracial community population

Background: Frequent participation in cognitively stimulating activities has been associated with reduced risk of AD in several prospective studies. However, the association of cognitive activity with cognitive decline, the principal manifestation of AD, is not well understood. Methods: More than 4,000 older residents of a geographically defined biracial community of Chicago were interviewed at approximately 3-year intervals for an average of 5.3 years. Each interview included administration of four cognitive function tests from which a previously established global measure was derived. At baseline, each person rated frequency of participation in cognitively stimulating activities (e.g., reading a magazine) from which a previously established composite measure of cognitive activity was derived. Results: Cognitive activity scores ranged from 1 to 5 (mean = 3.14, SD = 0.66), with higher scores indicating more frequent participation. More frequent cognitive activity was associated with reduced cognitive decline during follow-up. In a model that controlled for baseline level of cognition, age, sex, race, and education, a 1-point increase in cognitive activity score was associated with an approximately 19% decrease in annual rate of cognitive decline (p < 0.001). This effect remained when we controlled for depressive symptoms and chronic medical conditions (p < 0.001), and when we excluded persons with evidence of memory impairment at baseline (p < 0.001). Conclusion: Frequent participation in cognitively stimulating activities is associated with reduced cognitive decline in older persons.

Dietary and lifestyle guidelines for the prevention of Alzheimer's disease.

Risk of developing Alzheimers disease is increased by older age, genetic factors, and several medical risk factors. Studies have also suggested that dietary and lifestyle factors may influence risk, raising the possibility that preventive strategies may be effective. This body of research is incomplete. However, because the most scientifically supported lifestyle factors for Alzheimers disease are known factors for cardiovascular diseases and diabetes, it is reasonable to provide preliminary guidance to help individuals who wish to reduce their risk. At the International Conference on Nutrition and the Brain, Washington, DC, July 19-20, 2013, speakers were asked to comment on possible guidelines for Alzheimers disease prevention, with an aim of developing a set of practical, albeit preliminary, steps to be recommended to members of the public. From this discussion, 7 guidelines emerged related to healthful diet and exercise habits.