Kegemukan meningkatkan risiko kanker

Kegemukan yang diukur dengan peningkatan indeks massa tubuh (IMT) berhubungan dengan risiko terjadinya penyakit kanker pada usia dewasa. Peneliti dari UK dan Swiss mendapatkan bahwa risiko kanker berhubungan dengan peningkatan IMT sebesar 5 kg/m2.

 

Hasil penelitian menunjukkan pada laki2 peningkatan IMT berhubungan signifikan dengan adenokarsinoma esophagus (RR 1.52) dan tiroid (1.33), usus besar (1.24) dan kanker ginjal (1.24). Pada wanita peningkatan IMT berhubungan signifikan dengan adenokarsinoma endometrium (1.59), kantung empedu (1.59), esophagus (1.51) dan ginjal (1.34). Selain itu juga didapatkan hubungan (RR <1.20) pada laki2 untuk kanker rectal, melanoma maligna, sedangkan pada wanita kanker payudara, pancreas, tiroid dan kolon; serta untuk laki dan perempuan leukemia, multiple pyeloma dan limfoma non-Hodgkin. Temuan ini berlaku untuk populasi di Amerika, Eropa, Australia dan Asia-Pasifik.

 

Kesimpulan peningkatan IMT berhubungan dengan peningkatan risiko penyakit keganasan.

 

The Lancet 22 February 2008 Vol 371 Issue 9612 Pp 569-578 (doi:10.1016/S0140-6736(08)60269-X) © 2008 Elsevier Ltd.
Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies, Dr Andrew G Renehan PhD, Margaret Tyson PhD, Matthias Egger MD, Richard F Heller MD and Marcel Zwahlen PhD.

 

Background

Excess bodyweight, expressed as increased body-mass index (BMI), is associated with the risk of some common adult cancers. We did a systematic review and meta-analysis to assess the strength of associations between BMI and different sites of cancer and to investigate differences in these associations between sex and ethnic groups.

 

Methods

We did electronic searches on Medline and Embase (1966 to November 2007), and searched reports to identify prospective studies of incident cases of 20 cancer types. We did random-effects meta-analyses and meta-regressions of study-specific incremental estimates to determine the risk of cancer associated with a 5 kg/m² increase in BMI.

 

Findings

We analysed 221 datasets (141 articles), including 282 137 incident cases. In men, a 5 kg/m² increase in BMI was strongly associated with oesophageal adenocarcinoma (RR 1·52, p<0·0001) and with thyroid (1·33, p=0·02), colon (1·24, p<0·0001), and renal (1·24, p <0·0001) cancers. In women, we recorded strong associations between a 5 kg/m² increase in BMI and endometrial (1·59, p<0·0001), gallbladder (1·59, p=0.04), oesophageal adenocarcinoma (1·51, p<0·0001), and renal (1·34, p<0·0001) cancers. We noted weaker positive associations (RR <1·20) between increased BMI and rectal cancer and malignant melanoma in men; postmenopausal breast, pancreatic, thyroid, and colon cancers in women; and leukaemia, multiple myeloma, and non-Hodgkin lymphoma in both sexes. Associations were stronger in men than in women for colon (p<0·0001) cancer. Associations were generally similar in studies from North America, Europe and Australia, and the Asia–Pacific region, but we recorded stronger associations in Asia–Pacific populations between increased BMI and premenopausal (p=0·009) and postmenopausal (p=0·06) breast cancers.

 

Interpretation

Increased BMI is associated with increased risk of common and less common malignancies. For some cancer types, associations differ between sexes and populations of different ethnic origins. These epidemiological observations should inform the exploration of biological mechanisms that link obesity with cancer.  

Serat serealia mengurangi risiko diabetes tipe 2

Kejadian diabetes tipe 2 dalam masyarakat AS berkulit hitam telah mencapai tingkat yang memprihatinkan. Pola diet berkait erat dengan budaya masyarakat setempat. Namun dalam penelitian2 terdahulu hubungan asupan karbohidrat dan risiko diabetes tipe 2 belum dapat dijelaskan.

 

Penelitian kohort ini hendak menilai hubungan antara indeks glikemik, glycemic load, dan serat serealia terhadap risiko terjadinya diabetes tipe 2. Penelitian melibatkan 59 ribu wanita kulit hitam di AS mulai tahun 1995 dan diikuti selama 8 tahun.

 

Hasil penelitian menunjukkan bahwa indeks glikemik berasosiasi positif terhadap risiko diabetes. Serat serealia berhubungan terbalik dengan risiko diabetes tipe 2.

 

Sehingga disimpulkan bahwa peningkatan kadar serat serealia dalam makanan merupakan cara efektif untuk menurunkan risiko diabetes tipe 2.

 

 

Arch Intern Med 26 November 2007;167(20):2304-2309. © 2007 American Medical

Glycemic Index, Glycemic Load, and Cereal Fiber Intake and Risk of Type 2 Diabetes in US Black Women,

Supriya Krishnan, Lynn Rosenberg, Martha Singer, Frank B. Hu, Luc Djoussé, L. Adrienne Cupples, Julie R. Palmer.

Background  Previous studies of carbohydrate quality and risk of type 2 diabetes mellitus have yielded inconsistent findings. Because diet is in part culturally determined, a study of dietary factors in US black women is of interest.

Methods  We used data from the Black Women's Health Study, a prospective cohort study of 59 000 US black women, to examine the association of glycemic load, glycemic index, and cereal fiber with risk of type 2 diabetes. Diet was assessed at baseline in 1995 with a modified version of the National Cancer Institute–Block food frequency questionnaire.

Results  During 8 years of follow-up, there were 1938 incident cases of diabetes. Cox proportional hazards models were used to estimate incidence rate ratios (IRRs) for quintiles of dietary factors, while controlling for lifestyle and dietary factors. Glycemic index was positively associated with the risk of diabetes: the IRR for the highest quintile relative to the lowest was 1.23 (95% confidence interval [CI], 1.05-1.44). Cereal fiber intake was inversely associated with risk of diabetes, with an IRR of 0.82 (95% CI, 0.70-0.96) for the highest vs lowest quintiles of intake. Stronger associations were seen among women with a body mass index (calculated as weight in kilograms divided by height in meters squared) lower than 25: IRRs for the highest vs lowest quintile were 1.91 (95% CI, 1.16-3.16) for glycemic index (P value for interaction, .12) and 0.41 (95% CI, 0.24-0.72) for cereal fiber intake (P value for interaction, .05).

Conclusion  Increasing cereal fiber in the diet may be an effective means of reducing the risk of type 2 diabetes, a disease that has reached epidemic proportions in black women.

Dark chocolate dilates the coronaries

Penelitian acak tersamar berganda ini bertujuan untuk menilai efek antioksidan -yang banyak terkandung dalam dark chocolate (kandungan cocoa 70%)- terhadap pembuluh darah koroner dan agregasi trombosit.

 

Hasil penelitian menunjukkan pelebaran diameter arteri koronaria 2 jam setelah pemberian dark chocolate, dan penurunan agregasi trombosit.

 

Disimpulkan bahwa dark chocolate dapat men-dilatasi arteri koronaria, memperbaiki vaskularisasi koroner, dan menurunkan agregasi trombosit 2 jam pasca konsumsi. Efek ini sejalan dengan penurunan stres oksidatif dan berkorelasi positif dengan kadar epicatechin.

 

Circulation. 2007;116:2376-2382. 20 November 2007 © 2007 American Heart Association, Inc.
Dark Chocolate Improves Coronary Vasomotion and Reduces Platelet Reactivity. Andreas J. Flammer, MD; Frank Hermann, MD; Isabella Sudano, MD, PhD; Lukas Spieker, MD; Matthias Hermann, MD; Karen A. Cooper, MSc, PhD; Mauro Serafini, PhD; Thomas F. Lüscher, MD; Frank Ruschitzka, MD; Georg Noll, MD; Roberto Corti, MD 

Background— Dark chocolate has potent antioxidant properties. Coronary atherosclerosis is promoted by impaired endothelial function and increased platelet activation. Traditional risk factors, high oxidative stress, and reduced antioxidant defenses play a crucial role in the pathogenesis of atherosclerosis, particularly in transplanted hearts. Thus, flavonoid-rich dark chocolate holds the potential to have a beneficial impact on graft atherosclerosis.

Methods and Results— We assessed the effect of flavonoid-rich dark chocolate compared with cocoa-free control chocolate on coronary vascular and platelet function in 22 heart transplant recipients in a double-blind, randomized study. Coronary vasomotion was assessed with quantitative coronary angiography and cold pressor testing before and 2 hours after ingestion of 40 g of dark (70% cocoa) chocolate or control chocolate, respectively. Two hours after ingestion of flavonoid-rich dark chocolate, coronary artery diameter was increased significantly (from 2.36±0.51 to 2.51±0.59 mm, P<0.01), whereas it remained unchanged after control chocolate. Endothelium-dependent coronary vasomotion improved significantly after dark chocolate (4.5±11.4% versus –4.3±11.7% in the placebo group, P=0.01). Platelet adhesion decreased from 4.9±1.1% to 3.8±0.8% (P=0.04) in the dark chocolate group but remained unchanged in the control group.

Conclusions— Dark chocolate induces coronary vasodilation, improves coronary vascular function, and decreases platelet adhesion 2 hours after consumption. These immediate beneficial effects were paralleled by a significant reduction of serum oxidative stress and were positively correlated with changes in serum epicatechin concentration.