Diet Mediterrania dapat mencegah Alzheimer

Para ahli meneliti hubungan antara diet mediterrania dan penyakit Alzheimer dengan melakukan studi kasus kontrol.

Hasil penelitian mendapatkan bahwa penganut diet mediterrania mempunyai risiko lebih rendah untuk terkena penyakit Alzheimer (odds ratio, 0.76; 95% confidence interval, 0.67-0.87; P<.001). Namun belum jelas mekanisme yang mempengaruhi hal tersebut.

Abstract

Mediterranean Diet, Alzheimer Disease, and Vascular Mediation

Nikolaos Scarmeas, MD; Yaakov Stern, PhD; Richard Mayeux, MD; Jose A. Luchsinger, MD Arch Neurol. 2006;63:(doi:10.1001/archneur.63.12.noc60109).

Objectives To examine the association between the Mediterranean diet (MeDi) and Alzheimer disease (AD) in a different AD population and to investigate possible mediation by vascular pathways. Design, Setting, Patients, and Main Outcome Measures A case-control study nested within a community-based cohort in New York, NY. Adherence to the MeDi (0- to 9-point scale with higher scores indicating higher adherence) was the main predictor of AD status (194 patients with AD vs 1790 nondemented subjects) in logistic regression models that were adjusted for cohort, age, sex, ethnicity, education, apolipoprotein E genotype, caloric intake, smoking, medical comorbidity index, and body mass index (calculated as weight in kilograms divided by height in meters squared). We investigated whether there was attenuation of the association between MeDi and AD when vascular variables (stroke, diabetes mellitus, hypertension, heart disease, lipid levels) were simultaneously introduced in the models (which would constitute evidence of mediation). Results Higher adherence to the MeDi was associated with lower risk for AD (odds ratio, 0.76; 95% confidence interval, 0.67-0.87; P<.001). Compared with subjects in the lowest MeDi tertile, subjects in the middle MeDi tertile had an odds ratio of 0.47 (95% confidence interval, 0.29-0.76) and those at the highest tertile an odds ratio of 0.32 (95% confidence interval, 0.17-0.59) for AD (P for trend <.001). Introduction of the vascular variables in the model did not change the magnitude of the association. Conclusions We note once more that higher adherence to the MeDi is associated with a reduced risk for AD. The association does not seem to be mediated by vascular comorbidity. This could be the result of either other biological mechanisms (oxidative or inflammatory) being implicated or measurement error of the vascular variables. Published online October 9, 2006 (doi:10.1001/archneur.63.12.noc60109). Author Affiliations: Taub Institute for Research on Alzheimer's Disease and the Aging Brain (Drs Scarmeas, Stern, Mayeux, and Luchsinger); Gertrude H. Sergievsky Center (Drs Scarmeas, Stern, and Mayeux); and Departments of Neurology (Drs Scarmeas, Stern, and Mayeux) and Medicine (Dr Luchsinger), Columbia University, New York, NY.

Sterol nabati dalam jus jeruk dapat memperbaiki profil lipid dan menurunkan kadar CRP

Pernah saya menulis tentang sterol nabati yang bisa memperbaiki profil lipid. Sterol nabati biasanya dicampur dalam lemak. Dalam penelitian ini sterol nabati dicampurkan dalam jus jeruk rendah kalori.

Ternyata penambahan sterol nabati dapat menurunkan kadar kolesterol total dan LDL sebesar hampir 10%, sekaligus meningkatkan kadar kolesterol HDL. Selain memperbaiki profil lipid, kadar CRP (penanda proses inflamasi kardiovaskuler) juga dapat diturunkan sampai 12%.

Hasil yang sangat positif dapat mendukung sterol nabati sebagai bahan makanan sehat yang perlu dikonsumsi dalam diet sehari-hari. Namun masih perlu dilakukan penelitian lebih mendalam tentang manfaat sterol nabati. Abstract

American Journal of Clinical Nutrition October 2006, Vol. 84, No. 4, 756-761. Reduced-calorie orange juice beverage with plant sterols lowers C-reactive protein concentrations and improves the lipid profile in human volunteers. Sridevi Devaraj, Bryce C Autret and Ishwarlal Jialal. Background: Dietary plant sterols effectively reduce LDL cholesterol when incorporated into fat matrices. We showed previously that supplementation with orange juice containing plant sterols (2 g/d) significantly reduced LDL cholesterol. Inflammation is pivotal in atherosclerosis. High-sensitivity C-reactive protein (hs-CRP), the prototypic marker of inflammation, is a cardiovascular disease risk marker; however, there is a paucity of data on the effect of plant sterols on CRP concentrations.

Objective: The aim of this study was to examine whether plant sterols affect CRP concentrations and the lipoprotein profile when incorporated into a reduced-calorie (50 calories/240 mL) orange juice beverage.

Design: Seventy-two healthy subjects were randomly assigned to receive a reduced-calorie orange juice beverage either without (Placebo Bev) or with (1 g/240 mL; Sterol Bev) plant sterols twice a day with meals for 8 wk. Fasting blood was obtained at baseline and after 8 wk of Placebo Bev or Sterol Bev supplementation.

Results: Sterol Bev supplementation significantly reduced total cholesterol (5%; P < 0.01) and LDL cholesterol (9.4%; P < 0.001) compared with both baseline and Placebo Bev (P < 0.05). HDL cholesterol increased significantly with Sterol Bev (P < 0.02). No significant changes in triacylglycerol, glucose, or liver function tests were observed with Sterol Bev. Sterol Bev supplementation resulted in no significant change in vitamin E and carotenoid concentrations. Sterol Bev supplementation resulted in a significant reduction of CRP concentrations compared with baseline and Placebo Bev (median reduction: 12%; P < 0.005).

Conclusion: Supplementation with a reduced-calorie orange juice beverage containing plant sterols is effective in reducing CRP and LDL cholesterol and could be incorporated into the dietary portion of therapeutic lifestyle changes.

Multivitamin dan Mineral: Dapatkah Mencegah Kanker dan Penyakit Kronik?

Suplemen multivitamin dan mineral sekarang banyak dikonsumsi masyarakat. Seberapa efektif untuk mencegah kanker dan penyakit kronik? Amankah dikonsumsi? Penelitian di bawah ini membedah 12 artikel studi efikasi dan 8 studi keamanan.

Hasil penelitian di Cina pada masyarakat dengan status gizi buruk, suplementasi ß-carotene, tocopherol, dan selenium, mengurangi angka insiden kanker lambung dan mortalitas kanker lain2 sebesar 13-21%. Hasil penelitian di Perancis, suplementasi vitamin C, vitamin E, ß-carotene, selenium, dan zinc mengurangi kejadian kanker sebesar 31% untuk laki2, tapi tidak bermakna untuk wanita. Suplementasi multivitamin dan mineral tidak bermakna untuk penyakit kardiovaskuler atau katarak. Suplementasi ß-carotene, selenium, -tocopherol, retinol, and zinc mengurangi mortalitas stroke sebesar 29% (penelitian Linxian). Suplementasi zinc dan anti-oksidan dapat memperlambat progresi AMD.

Efek samping pemberian multivitamin dan mineral tidak terbukti.

Berdasarkan bukti2 tersebut efektivitas suplementasi kombinasi multivitamin dan mineral untuk mencegah kanker dan penyakit kronik kurang kuat.

Abstract

The Efficacy and Safety of Multivitamin and Mineral Supplement Use To Prevent Cancer and Chronic Disease in Adults: A Systematic Review for a National Institutes of Health State-of-the-Science Conference

Ann Intern Med 5 September 2006. Volume 145 Issue 5, 372-385. © 2006 American College of Physicians – American Society of Internal Medicine

Han-Yao Huang, PhD, MPH; Benjamin Caballero, MD, PhD; Stephanie Chang, MD; Anthony J. Alberg, PhD, MPH; Richard D. Semba, MD, MPH; Christine R. Schneyer, MD; Renee F. Wilson, MSc; Ting-Yuan Cheng, MSc; Jason Vassy, MPH; Gregory Prokopowicz, MD, MPH; George J. Barnes, II, BA; and Eric B. Bass, MD, MPH.

Background: Multivitamin and mineral supplements are the most commonly used dietary supplements in the United States. Purpose: To synthesize studies on the efficacy and safety of multivitamin/mineral supplement use in primary prevention of cancer and chronic disease in the general population. Data Sources: English-language literature search of the MEDLINE, EMBASE, and Cochrane databases through February 2006 and hand-searching of pertinent journals and articles. Study Selection: Randomized, controlled trials in adults were reviewed to assess efficacy, and randomized, controlled trials and observational studies in adults or children were reviewed to assess safety. Data Extraction: Paired reviewers extracted data and independently assessed study quality. Data Synthesis: 12 articles from 5 randomized, controlled trials that assessed efficacy and 8 articles from 4 randomized, controlled trials and 3 case reports on adverse effects were identified. Study quality was rated fair for the studies on cancer, cardiovascular disease, cataracts, or age-related macular degeneration and poor for the studies on hypertension. In a poorly nourished Chinese population, combined supplementation with ß-carotene, -tocopherol, and selenium reduced the incidence of and mortality rate from gastric cancer and the overall mortality rate from cancer by 13% to 21%. In a French trial, combined supplementation with vitamin C, vitamin E, ß-carotene, selenium, and zinc reduced the rate of cancer by 31% in men but not in women. Multivitamin and mineral supplements had no significant effect on cardiovascular disease or cataracts, except that combined ß-carotene, selenium, -tocopherol, retinol, and zinc supplementation reduced the mortality rate from stroke by 29% in the Linxian study and that a combination of 7 vitamins and minerals stabilized visual acuity loss in a small trial. Combined zinc and antioxidants slowed the progression of advanced age-related macular degeneration in high-risk persons. No consistent adverse effects of multivitamin and mineral supplements were evident. Limitations: Only randomized, controlled trials were considered for efficacy assessment. Special nutritional needs, such as use of folic acid by pregnant women to prevent birth defects, were not addressed. Findings may not apply to use of commercial multivitamin supplements by the general U.S. population. Conclusions: Evidence is insufficient to prove the presence or absence of benefits from use of multivitamin and mineral supplements to prevent cancer and chronic disease.