Kopi, diabetes dan berat badan

Beberapa penelitian epidemiologi menyimpulkan bahwa kopi (baik caffeinated maupun decaffeinated) dapat mengurangi risiko diabetes. Ini mungkin berhubungan dengan penurunan berat badan. Penurunan berat badan diduga berhubungan dengan kandungan kafein dan zat2 lain dalam kopi (chlorogenic acid dan quinides). Namun kopi dapat menyebabkan kenaikan tekanan darah akut sehingga ditakutkan akan meningkatkan risiko penyakit kardiovaskuler. Satu penelitian singkat menyimpulkan bahwa kopi decaffeinated tidak menaikan tekanan darah. Dengan demikian konsumsi kopi decaffeinated lebih aman dan tetap dapat mengurangi risiko diabetes.

Abstract

American Journal of Clinical Nutrition, Vol. 84, No. 4, 682-693, October 2006 © 2006 American Society for Nutrition. Coffee, diabetes, and weight control. James A Greenberg, Carol N Boozer and Allan Geliebter. From the Department of Health and Nutrition Sciences, Brooklyn College, City University of New York, New York NY (JAB), and the Department of Medicine, Columbia University and New York Obesity Research Center, St Luke's-Roosevelt Hospital Center, New York, NY (NB and AG) Several prospective epidemiologic studies over the past 4 y concluded that ingestion of caffeinated and decaffeinated coffee can reduce the risk of diabetes. This finding is at odds with the results of trials in humans showing that glucose tolerance is reduced shortly after ingestion of caffeine or caffeinated coffee and suggesting that coffee consumption could increase the risk of diabetes. This review discusses epidemiologic and laboratory studies of the effects of coffee and its constituents, with a focus on diabetes risk. Weight loss may be an explanatory factor, because one prospective epidemiologic study found that consumption of coffee was followed by lower diabetes risk but only in participants who had lost weight. A second such study found that both caffeine and coffee intakes were modestly and inversely associated with weight gain. It is possible that caffeine and other constituents of coffee, such as chlorogenic acid and quinides, are involved in causing weight loss. Caffeine and caffeinated coffee have been shown to acutely increase blood pressure and thereby to pose a health threat to persons with cardiovascular disease risk. One short-term study found that ground decaffeinated coffee did not increase blood pressure. Decaffeinated coffee, therefore, may be the type of coffee that can safely help persons decrease diabetes risk. However, the ability of decaffeinated coffee to achieve these effects is based on a limited number of studies, and the underlying biological mechanisms have yet to be elucidated.

Are vegetables better food for brain?

Untuk meneliti hubungan antara perubahan fungsi kognitif dengan konsumsi buah dan sayuran di kalangan manula, para ahli melakukan penelitian kohort prospektif dengan 3.718 subyek berusia >65 tahun.

Rerata skor kognitif pada awal penelitian adalah 0,18 dan terjadi penurunan sebesar 0,04 standard unit pertahun. Kelompok yang paling sedikit makan sayur ternyata mengalami penurunan fungsi kognitif lebih cepat dibanding kelompok yang paling banyak makan sayur. Mereka yang makan sayur 3-4 porsi perhari mengalami penurunan skor kognitif 40% lebih lambat dibanding mereka yang makan sayur kurang dari 1 porsi perhari. Sedangkan tingkat konsumsi buah tidak berhubungan dengan perubahan kognitif.

Kesimpulan banyak konsumsi sayuran dapat menghambat penurunan fungsi kognitif pada manula.

Abstract

Neurology 2006;67:1370-1376 October 24 2006 © 2006 American Academy of Neurology. Associations of vegetable and fruit consumption with age-related cognitive change M. C. Morris, ScD, D. A. Evans, MD, C. C. Tangney, PhD, J. L. Bienias, ScD and R. S. Wilson, PhD

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.

From Rush Institute for Healthy Aging (M.C.M., D.A.E., J.L.B.), Department of Preventive Medicine (M.C.M., J.L.B.), Department of Internal Medicine (M.C.M., D.A.E.), Department of Clinical Nutrition (C.C.T.), Rush Alzheimer's Disease Center (R.S.W.), Department of Neurological Sciences (R.S.W.), and Department of Psychology (R.S.W.), Rush University Medical Center, Chicago, IL.

Makronutrien sebagai Prediktor Perubahan Lingkar Pinggang

Sering kali kita bertanya-tanya apakah bahan makanan atau minuman tertentu menyebabkan perut menjadi buncit? Temuan penelitian berikut ini sangat menarik.

Para ahli dari Denmark mencari hubungan antara asupan energi/kalori, asupan makronutrien tertentu dan subgrup-nya terhadap perubahan lingkar pinggang 5 tahun kemudian, dengan melakukan studi kohort atas lebih dari 40 ribu pria dan wanita berusia 50-64 tahun.

Ternyata protein menunjukkan asosiasi terbalik dengan perubahan lingkar pinggang. Artinya semakin besar konsumsi protein, semakin kecil perubahan lingkar pinggang. Demikian juga untuk buah dan sayuran. Pada wanita terdapat asosiasi positif antara asupan karbohidrat refined, kentang dan gula. Lemak nabati dan alkohol juga ber-asosiasi positif. Artinya semakin besar konsumsi bahan makanan tersebut semakin besar pula perubahan lingkar pinggang dalam waktu 5 tahun.

American Journal of Clinical Nutrition, Vol. 84, No. 4, 789-797, October 2006 © 2006

Intake of macronutrients as predictors of 5-y changes in waist circumference

Jytte Halkjær, Anne Tjønneland, Birthe L Thomsen, Kim Overvad and Thorkild IA Sørensen From the Danish Epidemiology Science Centre, Institute of Preventive Medicine, Copenhagen University Hospital, Copenhagen, Denmark (JH and TIAS); The Danish Cancer Society, Institute of Cancer Epidemiology, Copenhagen, Denmark (JH, AT, and BLT); and the Department of Clinical Epidemiology, Aalborg Hospital, Aarhus University Hospital, Aalborg, Denmark (KO)

Background:The diet may influence the development of abdominal obesity, but the few studies that have prospectively examined the relations between diet and changes in waist circumference (WC) have given inconsistent results. Objective:Associations between total energy intake, energy intake from macronutrients, and energy intake from macronutrient subgroups based on different food sources and 5-y differences in WC (DWC) were investigated. Design:A Danish cohort of 22.570 women and 20.126 men aged 50-64 y with baseline data on WC, diet, BMI, and potential confounders reported their WC 5 y later. Associations of baseline diet with DWC were assessed by multiple linear regression analysis. Results:Neither total energy intake nor energy intake from each of the macronutrients was associated with DWC, except for an inverse association with protein, especially animal protein. In women, positive associations with DWC were seen for carbohydrate from refined grains and potatoes and from foods with simple sugars, whereas carbohydrate from fruit and vegetables was inversely associated and significantly different from any other carbohydrate subgroup. The results for men resembled those for women, although none were significant. Vegetable fat was positively associated with DWC for both men and women in a combined analysis. A U-shaped association between alcohol from wine and DWC was present for both sexes, and alcohol from spirits was positively associated with DWC in women. Conclusions:Although no significant associations with total energy or energy from fat, carbohydrate, or alcohol were observed, protein intake was inversely related to DWC, and some macronutrient subgroups were significantly associated with DWC.