活発な身体活動によって認知症リスクが低下する可能性がある

Bowen氏は活発な身体活動と認知症リスクとの関係を検討し研究結果を報告しました（Am J Health Promot, 2012 July）。

この研究の主な結果：
・ 認知症リスクと活発な身体活動には顕著な関係が認められた。
・ 最終的には、活発な身体活動を行っていた高齢者では認知症と診断されるリスクが21％低くなると考えられる（p≦0.05）。
・ 活発な身体活動は、認知症リスク低下の独立した危険因子の可能性がある。

http://www.carenet.com/news/risk/carenet/30257

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A prospective examination of the relationship between physical activity and dementia risk in later life.

American journal of health promotion, 2012 Jul;26(6); 333-40

Author: Mary Elizabeth Bowen

Abstract Purpose . To examine the relationship between vigorous physical activity and dementia risk. Design . Prospective study design utilizing physical activity data from the Health and Retirement Study and cognitive outcome data from the Aging, Demographics, and Memory Study. Setting . Community-based. Subjects . Adults age 71 and over (N ?=? 808) with 3 to 7 years of physical activity information prior to dementia/no dementia diagnosis. Measures . Physical activity was measured by participation in vigorous activities such as aerobics, sports, running, bicycling, and heavy housework three or more times per week (yes/no). Dementia diagnosis was based on an expert panel (e.g., neuropsychologists, neurologists, geropsychiatrists) who performed and reviewed a battery of neuropsychological tests. Analysis . Binary logistic regression models were used to account for demographic characteristics, genetic risk factors (one or two apolipoprotein E ε4 alleles), health behaviors (e.g., smoking, drinking alcohol), health indicators (body mass index), and health conditions (e.g., diabetes, heart disease) in a sequential model-building process. Results . The relationship between vigorous physical activity and dementia risk remained robust across models. In the final model, older adults who were physically active were 21% (p ? .05) less likely than their counterparts to be diagnosed with dementia. Conclusion . Vigorous physical activity may reduce the risk for dementia independently of the factors examined here. This study's findings are important given that few preventative strategies for dementia have been explored beyond hormonal therapy and anti-inflammatory drugs.

炭水化物中心の食生活で認知症の発症リスクが増加する可能性がある

食生活は認知症の発症にも関係する可能性があると言われてますが、Roberts氏らは、どのような食生活が認知症リスクを高めるのかを検討し研究結果を報告しました（J Alzheimers Dis, 2012 Jul 17）。その研究で、炭水化物からのカロリー摂取率が高く、脂質およびタンパク質からの摂取率が低い高齢者では、軽度認知障害または認知症の発症リスクが増加する可能性が示唆されました。

http://www.carenet.com/news/30280

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Title: Relative Intake of Macronutrients Impacts Risk of Mild Cognitive Impairment or Dementia.

Journal: Journal of Alzheimer's disease. 2012 Jul 17

Author: Rosebud O Roberts, Lewis A Roberts, Yonas E Geda, Ruth H Cha, V Shane Pankratz, Helen M O'Connor, David S Knopman, Ronald C Petersen

Affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota and Scottsdale, AZ, USA.

Abstract: 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.