Low-carbohydrate diets, dietary approaches to stop hypertension-style diets, and the risk of postmenopausal breast cancer

The authors prospectively examined the association between the Dietary Approaches to Stop Hypertension diet score, overall, animal-based, and vegetable-based low-carbohydrate-diet scores, and major plant food groups and the risk of postmenopausal breast cancer in 86,621 women in the Nurses' Health Study. Diet scores were calculated by using data from up to 7 food frequency questionnaires, with follow-up from 1980 to 2006. The authors ascertained 5,522 incident cases of breast cancer, including 3,314 estrogen receptor-positive (ER+) cancers and 826 estrogen receptor-negative (ER-) cancers. After adjustment for potential confounders, the Dietary Approaches to Stop Hypertension diet score was associated with a lower risk of ER- cancer (relative risk comparing extreme quintiles = 0.80, 95% confidence interval: 0.64, 1.01; P trend = 0.02). However, this was largely explained by higher intakes of fruits and vegetables. The authors also observed an inverse association between risk of ER- cancer and the vegetable-based, low-carbohydrate-diet score (corresponding relative risk = 0.81, 95% confidence interval: 0.65, 1.01; P trend = 0.03). High total fruit and low-protein vegetable intakes were associated with a lower risk of ER- cancer (relative risk comparing extreme quintiles = 0.71, 95% confidence interval: 0.55, 0.90; P trend = 0.005). No association was found between ER+ tumors and fruit and vegetable intakes. A diet high in fruits and vegetables, such as one represented by the Dietary Approaches to Stop Hypertension diet score, was associated with a lower risk of ER- breast cancer. In addition, a diet high in plant protein and fat and moderate in carbohydrate content was associated with a lower risk of ER- cancer.     

Fruit and vegetable intake and risk of cardiovascular disease: the Women's Health Study

BACKGROUND: Prospective data relating fruit and vegetable intake to cardiovascular disease (CVD) risk are sparse, particularly for women. OBJECTIVE: In a large, prospective cohort of women, we examined the hypothesis that higher fruit and vegetable intake reduces CVD risk. DESIGN: In 1993 we assessed fruit and vegetable intake among 39876 female health professionals with no previous history of CVD or cancer by use of a detailed food-frequency questionnaire. We subsequently followed these women for an average of 5 y for incidence of nonfatal myocardial infarction (MI), stroke, percutaneous transluminal coronary angioplasty, coronary artery bypass graft, or death due to CVD. RESULTS: During 195647 person-years of follow-up, we documented 418 incident cases of CVD including 126 MIs. After adjustment for age, randomized treatment status, and smoking, we observed a significant inverse association between fruit and vegetable intake and CVD risk. For increasing quintiles of total fruit and vegetable intake (median servings/d: 2. 6, 4.1, 5.5, 7.1, and 10.2), the corresponding relative risks (RRs) were 1.0 (reference), 0.78, 0.72, 0.68, and 0.68 (95% CI comparing the 2 extreme quintiles: 0.51, 0.92; P: for trend = 0.01). An inverse, though not statistically significant, trend remained after additional adjustment for other known CVD risk factors, with RRs of 1.0, 0.75, 0.83, 0.80, and 0.85 (95% CI for extreme quintiles: 0.61, 1.17). After excluding participants with a self-reported history of diabetes, hypertension, or high cholesterol at baseline, the multivariate-adjusted RR was 0.45 when extreme quintiles were compared (95% CI: 0.22, 0.91; P: for trend = 0.09). Higher fruit and vegetable intake was also associated with a lower risk of MI, with an adjusted RR of 0.62 for extreme quintiles (95% CI: 0.37, 1.04; P: for trend = 0.07). CONCLUSION: These data suggest that higher intake of fruit and vegetables may be protective against CVD and support current dietary guidelines to increase fruit and vegetable intake.     

Potato and french fry consumption and risk of type 2 diabetes in women

BACKGROUND: Potatoes, a high glycemic form of carbohydrate, are hypothesized to increase insulin resistance and risk of type 2 diabetes. OBJECTIVE: The objective was to examine prospectively the relation between potato consumption and the risk of type 2 diabetes. DESIGN: We conducted a prospective study of 84,555 women in the Nurses' Health Study. At baseline, the women were aged 34-59 y, had no history of chronic disease, and completed a validated food-frequency questionnaire. The participants were followed for 20 y with repeated assessment of diet. RESULTS: We documented 4496 new cases of type 2 diabetes. Potato and french fry consumption were both positively associated with risk of type 2 diabetes after adjustment for age and dietary and nondietary factors. The multivariate relative risk (RR) in a comparison between the highest and the lowest quintile of potato intake was 1.14 (95% CI: 1.02, 1.26; P for trend = 0.009). The multivariate RR in a comparison between the highest and the lowest quintile of french fry intake was 1.21 (95% CI: 1.09, 1.33; P for trend < 0.0001). The RR of type 2 diabetes was 1.18 (95% CI: 1.03, 1.35) for 1 daily serving of potatoes and 1.16 (95% CI: 1.05, 1.29) for 2 weekly servings of french fries. The RR of type 2 diabetes for substituting 1 serving potatoes/d for 1 serving whole grains/d was 1.30 (95% CI: 1.08, 1.57). The association between potato consumption and risk of type 2 diabetes was more pronounced in obese women. CONCLUSIONS: Our findings suggest a modest positive association between the consumption of potatoes and the risk of type 2 diabetes in women. This association was more pronounced when potatoes were substituted for whole grains.     

Associations of dietary protein with disease and mortality in a prospective study of postmenopausal women

Some weight loss diets promote protein intake; however, the association of protein with disease is unclear. In 1986, 29,017 postmenopausal Iowa women without cancer, coronary heart disease (CHD), or diabetes were followed prospectively for 15 years for cancer incidence and mortality from CHD, cancer, and all causes. Mailed questionnaires assessed dietary, lifestyle, and medical information. Nutrient density models estimated risk ratios from a simulated substitution of total and type of dietary protein for carbohydrate and of vegetable for animal protein. The authors identified 4,843 new cancers, 739 CHD deaths, 1,676 cancer deaths, and 3,978 total deaths. Among women in the highest intake quintile, CHD mortality decreased by 30% from an isoenergetic substitution of vegetable protein for carbohydrate (95% confidence interval (CI): 0.49, 0.99) and of vegetable for animal protein (95% CI: 0.51, 0.98), following multivariable adjustment. Although no association was observed with any outcome when animal protein was substituted for carbohydrate, CHD mortality was associated with red meats (risk ratio = 1.44, 95% CI: 1.06, 1.94) and dairy products (risk ratio = 1.41, 95% CI: 1.07, 1.86) when substituted for servings per 1,000 kcal (4.2 MJ) of carbohydrate foods. Long-term adherence to high-protein diets, without discrimination toward protein source, may have potentially adverse health consequences.     

Carbohydrate intake and incidence of type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study

It remains unclear what long-term effects of substituting carbohydrates at the expense of protein or fat may have with regard to diabetes risk. Our objective was to evaluate carbohydrate intake in predicting type 2 diabetes using substitution models for fat and protein. We conducted a prospective cohort study of 9,702 men and 15,365 women aged 35-65 years and free of diabetes at baseline (1994-8) who were followed for incident type 2 diabetes until 2005. Dietary intake of macronutrients was estimated with a validated FFQ. We estimated the relative risk (RR) using Cox proportional hazards analysis. During 176,117 person-years of follow-up we observed 844 incident cases of physician-confirmed type 2 diabetes. After adjustment for age, BMI, waist circumference, potential lifestyle and dietary confounders, substituting 5 % of energy intake from total, saturated, or monounsaturated fat with carbohydrates was not associated with diabetes risk. In contrast, substituting carbohydrates for protein or PUFA was inversely related to diabetes risk (RR for 5 % energy substitution of protein 0.77 (95 % CI 0.64, 0.91); RR for PUFA 0.83 (95 % CI 0.70, 0.98)). These associations appeared to be similar for men and women, but gained statistical significance only among men for protein (RR 0.78 (95 % CI 0.61, 0.99)). Restricted cubic spline regression did not indicate non-linearity of these associations (P for non-linearity in full cohort was 0.353 and 0.349). In conclusion, a higher carbohydrate intake at the expense of protein and PUFA might be associated with decreased diabetes risk.     

Diet and bladder cancer: a meta-analysis of six dietary variables

In 1996, more than 300,000 new cases of bladder cancer were diagnosed worldwide. Besides tobacco smoking, occupation, and other factors, diet may play a role in causation of this illness. The authors performed a meta-analytical review of epidemiologic studies linking six dietary factors to bladder cancer. These factors include retinol, beta-carotene, fruits, vegetables, meat, and fat. Increased risks of bladder cancer were associated with diets low in fruit intake (relative risk (RR) = 1.40, 95% confidence interval (CI): 1.08, 1.83), and slightly increased risks were associated with diets low in vegetable intake (RR = 1.16, 95% CI: 1.01, 1.34). Elevated risks were identified for diets high in fat intake (RR = 1.37, 95% CI: 1.16, 1.62) but not for diets high in meat intake (RR = 1.08, 95% CI: 0.82, 1.42). No increased risks were found for diets low in retinol (RR = 1.01, 95% CI: 0.83, 1.23) or beta-carotene (RR = 1.10, 95% CI: 0.93, 1.30) intake. These results suggest that a diet high in fruits and vegetables and low in fat intake may help prevent bladder cancer, but the individual dietary constituents that reduce the risks remain unknown.     

Diet and basal cell carcinoma of the skin in a prospective cohort of men

BACKGROUND: Low intake of fat and high intake of specific vitamins have been hypothesized to reduce risk of basal cell carcinoma of the skin (BCC). OBJECTIVE: Our objective was to examine intakes of fat, antioxidant nutrients, retinol, folate, and vitamin D in relation to risk of BCC. DESIGN: In 1986, diet was assessed by a validated food-frequency questionnaire in 43217 male participants of the Health Professionals Follow-up Study who were 40-75 y of age and free of cancer. During 8 y of follow-up, we ascertained 3190 newly diagnosed cases of BCC. RESULTS: Total fat consumption was associated with a lower risk of BCC [relative risk (RR): 0.81; 95% CI: 0.72, 0.90 for the highest compared with the lowest quintile of intake; P for trend < 0.001). Simultaneous modeling of specific fatty acids suggested that this inverse association was limited to monounsaturated fat (RR: 0.79; 95% CI: 0.65, 0.96; P for trend = 0. 02); saturated and polyunsaturated fat were not associated with BCC risk. Folate intake was associated with a slightly higher risk of BCC (RR: 1.19; 95% CI: 1.01, 1.40; P for trend = 0.11), whereas alpha-carotene was associated with a slightly lower risk (RR: 0.88; 95% CI: 0.79, 0.99; P for trend = 0.01). Intakes of long-chain n-3 fatty acids, retinol, vitamin C, vitamin D, or vitamin E were not materially related to BCC risk. CONCLUSIONS: These findings do not support the hypothesis that diets low in fat or high in specific vitamins lower risk of BCC.     

Dietary saturated fats and their food sources in relation to the risk of coronary heart disease in women

BACKGROUND: Metabolic studies suggest that saturated fatty acids differ in their effects on blood lipids. OBJECTIVE: The objective was to examine the associations between intakes of individual saturated fatty acids and their food sources in relation to the risk of coronary heart disease (CHD). DESIGN: This was a prospective cohort study of 80082 women in the Nurses' Health Study aged 34-59 y. Subjects had no known cardiovascular disease, cancer, hypercholesterolemia, or diabetes, and completed validated food-frequency questionnaires in 1980. RESULTS: During 14 y of follow-up, we documented 939 incident cases of major CHD events. In multivariate analyses in which age, smoking, and other covariates were controlled for, intakes of short- to medium-chain saturated fatty acids (4:0-10:0) were not significantly associated with the risk of CHD. In contrast, intakes of longer-chain saturated fatty acids (12:0-18:0) were each separately associated with a small increase in risk. The multivariate RR for a 1% energy increase from stearic acid was 1.19 (95% CI: 1.02, 1.37). The ratio of polyunsaturated to saturated fat was strongly and inversely associated with CHD risk (multivariate RR for a comparison of the highest with the lowest deciles: 0.58; 95% CI: 0.41, 0.83; P for trend < 0.0001). Conversely, higher ratios of red meat to poultry and fish consumption and of high-fat to low-fat dairy consumption were associated with significantly greater risk. CONCLUSION: A distinction between stearic acid and other saturated fats does not appear to be important in dietary advice to reduce CHD risk, in part because of the high correlation between stearic acid and other saturated fatty acids in typical diets.     

Macronutrient Intakes and Development of Type 2 Diabetes: A Systematic Review and Meta-Analysis of Cohort Studies

Objective: To synthesize the best available evidence on the association between macronutrient intake and type 2 diabetes risk.

Data Sources: MEDLINE, EMBASE, CINAHL, Cochrane Library, ProQuest, Mednar, and the JBI Library of Systematic Reviews were searched up to July 2012 to identify published and unpublished studies. The review was restricted to human participants only but was not restricted by date or by language.

Study Eligibility: Studies were included in the review if they were a cohort study examining the relationship between dietary macronutrient intake and type 2 diabetes risk, included healthy participants with no history of type 2 diabetes at the baseline assessment, and reported risk estimates (odds ratios, hazards ratios, or relative risks [RRs]) and corresponding 95% confidence intervals for type 2 diabetes risk by comparison of the highest with the lowest level of macronutrient consumption.

Methods: Data extraction and risk of bias assessments were performed in duplicate by 2 reviewers. Random-effects meta-analyses were performed to pool RR estimates from individual studies to assess the relationship between dietary macronutrient (carbohydrate, fat, protein, and macronutrient subtypes) intake and type 2 diabetes risk. Statistical heterogeneity was assessed using the I² statistic. Sensitivity analyses were performed to assess robustness of results, and publication bias was evaluated by the visual inspection of funnel plots and was formally assessed using Egger's test.

Results: Twenty-two relevant cohort studies were eligible for inclusion in this review. High intake of total dietary carbohydrate was associated with an increased type 2 diabetes risk (relative risk [RR] = 1.11, 95% confidence interval [CI]: 1.01 to 1.22, p = 0.035); however, this effect was not observed in an analysis stratified by gender. High vegetable fat intake was associated with a reduced type 2 diabetes risk in females (RR = 0.76, 95% CI: 0.68 to 0.85, p < 0.001). Other macronutrients were not significantly associated with type 2 diabetes risk.

Conclusions and Implications: The results of this systematic review and meta-analysis indicate that total carbohydrate is associated with an increased risk of type 2 diabetes; however, this effect was not observed in an analysis stratified by gender. High vegetable fat intake may decrease type 2 diabetes risk in females. There is a need for further well-designed prospective cohort studies to examine the potential association between macronutrient intake and type 2 diabetes risk.     

The association of glycemic load and carbohydrate intake with colorectal cancer risk in the Multiethnic Cohort Study

BACKGROUND: High-glycemic-load diets may increase colorectal cancer risk through hyperinsulinemic effects. OBJECTIVE: We analyzed data for 191,004 participants in the Multiethnic Cohort Study to determine the risk of colorectal cancer associated with glycemic load (GL), carbohydrate, and sucrose and to ascertain whether this risk was modified by sex and ethnicity. DESIGN: During 8 y of follow-up, 2379 incident cases of colorectal adenocarcinoma occurred. We used baseline quantitative food-frequency questionnaire data to assess usual dietary intake over the preceding year. Using Cox regression, we calculated adjusted relative risks (RRs) and 95% CIs for colorectal cancer associated with quintiles of GL, carbohydrate, and sucrose. RESULTS: For both men and women in this cohort, white rice was the major contributor to GL. In multivariate models, RRs for colorectal cancer decreased significantly with increasing GL in women (RR for the highest quintile versus the lowest: 0.75; 95% CI: 0.57, 0.97; P for trend = 0.02) but not in men (RR: 1.15; 95% CI: 0.89, 1.48; P for trend = 0.19). Results for carbohydrate and sucrose were similar. The inverse association with GL was found in women of all ethnic groups (P for interaction = 0.58). In men, an interaction was found between ethnicity and GL (P < 0.01): white men had a positive association with increasing GL (RR: 1.69; 95% CI: 0.98, 2.92; P for trend < 0.01), but men of other ethnic groups did not. CONCLUSION: GL and carbohydrate intake appear to protect against colorectal cancer in women in the Multiethnic Cohort, perhaps because a major source of GL is white rice.     

Dietary fat intake and risk of coronary heart disease in women: 20 years of follow-up of the nurses' health study

The authors examined the associations of dietary fat and specific types of fat with risk of coronary heart disease (CHD) among 78,778 US women initially free of cardiovascular disease and diabetes in 1980. They documented 1,766 incident CHD cases (including 1,241 nonfatal myocardial infarctions and 525 CHD deaths) during 20 years of follow-up. Polyunsaturated fat intake was inversely associated with CHD risk (multivariate relative risk (RR) for the highest vs. the lowest quintile = 0.75, 95% confidence interval (CI): 0.60, 0.92; p(trend) = 0.004), whereas trans-fat intake was associated with an elevated risk of CHD (RR = 1.33, 95% CI: 1.07, 1.66; p(trend) = 0.01). The associations between intakes of polyunsaturated fat and trans-fat with CHD risk were most evident among women younger than age 65 years (for polyunsaturated fat, RR = 0.66, 95% CI: 0.50, 0.85; p(trend) = 0.002 and for trans-fat, RR = 1.50, 95% CI: 1.13, 2.00; p(trend) = 0.01). The inverse association between polyunsaturated fat intake and CHD risk was strongest among women whose body mass index was >or=25 kg/m(2). Findings continue to support an inverse relation between polyunsaturated fat intake and CHD risk, particularly among younger or overweight women. In addition, trans-fat intake was associated with increased risk of CHD, particularly for younger women.     

Dietary patterns as identified by factor analysis and colorectal cancer among middle-aged Americans

BACKGROUND: Although diet has long been suspected as an etiological factor for colorectal cancer, studies of single foods and nutrients have provided inconsistent results. OBJECTIVE: We used factor analysis methods to study associations between dietary patterns and colorectal cancer in middle-aged Americans. DESIGN: Diet was assessed among 293,615 men and 198,767 women in the National Institutes of Health-AARP Diet and Health Study. Principal components factor analysis identified 3 primary dietary patterns: a fruit and vegetables, a diet foods, and a red meat and potatoes pattern. State cancer registries identified 2151 incident cases of colorectal cancer in men and 959 in women between 1995 and 2000. RESULTS: Men with high scores on the fruit and vegetable pattern were at decreased risk [relative risk (RR) for quintile (Q) 5 versus Q1: 0.81; 95% CI: 0.70, 0.93; P for trend = 0.004]. Both men and women had a similar risk reduction with high scores on the diet food factor: men (RR: 0.82; 95% CI: 0.72, 0.94; P for trend = 0.001) and women (RR: 0.87; 95% CI: 0.71, 1.07; P for trend = 0.06). High scores on the red meat factor were associated with increased risk: men (RR: 1.17; 95% CI: 1.02, 1.35; P for trend = 0.14) and women (RR: 1.48; 95% CI: 1.20, 1.83; P for trend = 0.0002). CONCLUSIONS: These results suggest that dietary patterns characterized by a low frequency of meat and potato consumption and frequent consumption of fruit and vegetables and fat-reduced foods are consistent with a decreased risk of colorectal cancer.     

Prospective study of dietary fat and the risk of age-related macular degeneration

BACKGROUND: The relation between intakes of total fat and specific types of fat and age-related macular degeneration (AMD) remains unclear. OBJECTIVE: Our objective was to examine prospectively the association between fat intake and AMD. DESIGN: We conducted a prospective follow-up study of participants in the Nurses' Health Study and the Health Professionals Follow-up Study. At baseline (1984 for women and 1986 for men), the study included 42743 women and 29746 men aged > or = 50 y with no diagnosis of AMD who were followed until 1996. Fat intake was assessed with a food-frequency questionnaire. RESULTS: We accrued 567 patients with AMD with a visual loss of 20/30 or worse. The pooled multivariate relative risk (RR) for the highest compared with the lowest quintile of total fat intake was 1.54 (95% CI: 1.17, 2.01; P for trend = 0.008). Linolenic acid was positively associated with risk of AMD (top versus bottom quintile of RR: 1.49; 95% CI: 1.15, 1.94; P for trend = 0.0009). Docosahexaenoic acid had a modest inverse relation with AMD (top versus bottom quintile of RR: 0.70; 95% CI: 0.52, 0.93; P for trend = 0.05), and >4 servings of fish/wk was associated with a 35% lower risk of AMD compared with < or = 3 servings/mo (RR: 0.65; 95% CI: 0.46, 0.91; P for trend = 0.009). CONCLUSIONS: Total fat intake was positively associated with risk of AMD, which may have been due to intakes of individual fatty acids, such as linolenic acid, rather than to total fat intakes per se. A high intake of fish may reduce the risk of AMD.     

Dietary intakes of fat and risk of Parkinson's disease

Previous epidemiologic studies have generated inconsistent results regarding the associations between fat intakes and risk of Parkinson's disease. The authors investigated these associations in two large, prospective US cohorts. They documented 191 incident cases of Parkinson's disease in men (1986-1998) and 168 in women (1980-1998) during the follow-up. Overall, intakes of total fat or major types of fat were not significantly associated with the risk. The relative risks comparing the highest quintile of animal fat intake with the lowest were 1.42 for men (95% confidence interval (CI): 0.91, 2.20; p for trend = 0.1) and 0.65 for women (95% CI: 0.36, 1.16; p for trend = 0.3). For men, but not women, replacement of polyunsaturated fat with saturated fat was associated with a significantly increased risk (5% of energy intake, relative risk (RR) = 1.83, 95% CI: 1.10, 3.03). Of the individual polyunsaturated fatty acids, arachidonic acid tended to be inversely associated with the risk (pooled RR between extreme quintiles = 0.65, 95% CI: 0.46, 0.91; p for trend = 0.05). Results do not support an important role of overall fat intake in the pathogenesis of Parkinson's disease, but a possible adverse effect of saturated fat for men could not be excluded.     

Dietary pattern in association with squamous cell carcinoma of the skin: a prospective study

BACKGROUND: The role of diet in the development of skin cancer is inconclusive, and the effect of the combined consumption of foods has never been reported. OBJECTIVE: We prospectively investigated the association between dietary patterns and cutaneous basal cell (BCC) and squamous cell (SCC) carcinoma. DESIGN: Principal components analysis of 38 food groups was used to identify dietary patterns in 1360 adults aged 25-75 y who participated in a community-based skin cancer study in Nambour, Australia, between 1992 and 2002. We obtained baseline information about diet, skin color, and sun exposure factors. Multivariate-adjusted relative risks (RRs) for BCC and SCC tumors were estimated by using negative binomial regression modeling. RESULTS: Two major dietary patterns were identified: a meat and fat pattern and a vegetable and fruit pattern. The meat and fat pattern was positively associated with development of SCC tumors (RR=1.83; 95% CI: 1.00, 3.37; P for trend=0.05) after adjustment for confounders and even more strongly associated in participants with a skin cancer history (RR=3.77; 95% CI: 1.65, 8.63; P for trend = 0.002) when the third and first tertiles were compared. A higher consumption of the vegetable and fruit dietary pattern appeared to decrease SCC tumor risk by 54% (P for trend = 0.02), but this protective effect was mostly explained by the association with green leafy vegetables. There was no association between the dietary patterns and BCC tumors. CONCLUSION: A dietary pattern characterized by high meat and fat intakes increases SCC tumor risk, particularly in persons with a skin cancer history.     

Dietary fat intake and risk of type 2 diabetes in women

BACKGROUND: The long-term relations between specific types of dietary fat and risk of type 2 diabetes remain unclear. OBJECTIVE: Our objective was to examine the relations between dietary fat intakes and the risk of type 2 diabetes. DESIGN: We prospectively followed 84204 women aged 34-59 y with no diabetes, cardiovascular disease, or cancer in 1980. Detailed dietary information was assessed at baseline and updated in 1984, 1986, and 1990 by using validated questionnaires. Relative risks of type 2 diabetes were obtained from pooled logistic models adjusted for nondietary and dietary covariates. RESULTS: During 14 y of follow-up, 2507 incident cases of type 2 diabetes were documented. Total fat intake, compared with equivalent energy intake from carbohydrates, was not associated with risk of type 2 diabetes; for a 5% increase in total energy from fat, the relative risk (RR) was 0.98 (95% CI: 0.94, 1.02). Intakes of saturated or monounsaturated fatty acids were also not significantly associated with the risk of diabetes. However, for a 5% increase in energy from polyunsaturated fat, the RR was 0.63 (0.53, 0.76; P < 0.0001) and for a 2% increase in energy from trans fatty acids the RR was 1.39 (1.15, 1.67; P = 0.0006). We estimated that replacing 2% of energy from trans fatty acids isoenergetically with polyunsaturated fat would lead to a 40% lower risk (RR: 0.60; 95% CI: 0.48, 0.75). CONCLUSIONS: These data suggest that total fat and saturated and monounsaturated fatty acid intakes are not associated with risk of type 2 diabetes in women, but that trans fatty acids increase and polyunsaturated fatty acids reduce risk. Substituting nonhydrogenated polyunsaturated fatty acids for trans fatty acids would likely reduce the risk of type 2 diabetes substantially.     

Dietary Fat Consumption and Non-Hodgkin's Lymphoma Risk: A Meta-analysis

Objective: Many studies suggest that high-fat diets are linked to the etiology of non-Hodgkin's lymphoma (NHL). However, the findings are inconsistent and therefore the association between fat and non-Hodgkin's lymphoma remains unclear. In this study, we aim to quantitatively assess the association between fat consumption and the risk for NHL. Methods: We reviewed 221 published cohort and case-control studies that reported relative risk (RRs) and corresponding 95% confidence intervals (CIs) of NHL and fat intake using PubMed, Cochrane, EMBASE, and Google Scholar databases. A random-effects model computed summary risk estimates. Results: Based on our literature search, 10 of 221 studies (two cohort and eight case-control studies) were relevant to this meta-analysis. There was a significant association between total fat consumption and increased risk of NHL (RR = 1.26; 95% CI: 1.12–1.42); in addition, subgroup analysis showed a significant correlation with diffuse large B-cell lymphoma (RR = 1.41; 95% CI: 1.08–1.84) but not with follicular lymphoma (RR = 1.21; 95% CI: 0.97–1.52), small lymphocytic lymphoma/chronic lymphocytic leukemia (RR = 0.91; 95% CI: 0.68–1.23), nor with T cell lymphoma (RR = 1.12; 95% CI: 0.60–2.09). The funnel plot revealed no evidence for publication bias. Conclusion: Total fat consumption, particularly animal fat, increases the risk for NHL.     

山西省不同性别人群膳食模式与高血压关系

  目的   按性别分层探讨膳食模式与高血压的关系。   方法   采用多阶段分层随机整群抽样的方法,对山西省2 667名男性和2 982名女性开展膳食营养调查,通过包含64个食物组的食物频率调查问卷（food frequency questionnaire,FFQ）评估各食物的摄入量,并用因子分析法提取并命名膳食模式。在不同性别人群中,采用Logistic回归分析模型分析高血压与膳食模式的关系。   结果   男性提取出4个膳食模式,分别是高蛋白模式、高脂甜食模式、谷薯腌菜模式、蔬菜水果模式;女性提取出5个膳食模式,分别是低碳水化合物模式、谷物蔬菜模式、高蛋白模式、高脂甜食模式、薯类腌菜模式。其中,有3个相似的膳食模式,分别为高蛋白模式、高脂甜食模式、谷薯腌菜模式。Logistic回归分析模型分析结果显示,男性高脂甜食模式OR=1.361（95% CI:1.069~1.732,P=0.012）,女性低碳水化合物模式OR=1.357（95% CI:1.064~1.731,P=0.014）。   结论   不同性别人群膳食模式与高血压关系存在一定差异。其中,男性的高脂甜食模式和女性的低碳水化合物模式可能会增加高血压的患病风险。     

Low-carbohydrate-high-protein diet and long-term survival in a general population cohort

OBJECTIVE: We have evaluated the effects on mortality of habitual low carbohydrate-high-protein diets that are thought to contribute to weight control. DESIGN: Cohort investigation. SETTING: Adult Greek population. SUBJECTS METHODS: Follow-up was performed from 1993 to 2003 in the context of the Greek component of the European Prospective Investigation into Cancer and nutrition. Participants were 22 944 healthy adults, whose diet was assessed through a validated questionnaire. Participants were distributed by increasing deciles according to protein intake or carbohydrate intake, as well as by an additive score generated by increasing decile intake of protein and decreasing decile intake of carbohydrates. Proportional hazards regression was used to assess the relation between high protein, high carbohydrate and the low carbohydrate-high protein score on the one hand and mortality on the other. RESULTS: During 113 230 persons years of follow-up, there were 455 deaths. In models with energy adjustment, higher intake of carbohydrates was associated with significant reduction of total mortality, whereas higher intake of protein was associated with nonsignificant increase of total mortality (per decile, mortality ratios 0.94 with 95% CI 0.89 -0.99, and 1.02 with 95% CI 0.98 -1.07 respectively). Even more predictive of higher mortality were high values of the additive low carbohydrate-high protein score (per 5 units, mortality ratio 1.22 with 95% CI 1.09 -to 1.36). Positive associations of this score were noted with respect to both cardiovascular and cancer mortality. CONCLUSION: Prolonged consumption of diets low in carbohydrates and high in protein is associated with an increase in total mortality.     

Dietary glycemic index, glycemic load, and the risk of breast cancer in an Italian prospective cohort study

BACKGROUND: Interest in the roles of glycemic index (GI) and glycemic load (GL) in breast cancer etiology has been stimulated by indications that disease risk is linked to insulinemia, sex hormone bioavailability, and insulin-like growth factor 1. OBJECTIVE: We aimed to determine whether GI and GL were associated with the risk of breast cancer in a cohort of Italian women volunteers from Northern Italy, who enrolled between 1987-1992 in the Hormones and Diet in the Etiology of Breast Tumors Study (ORDET Study). DESIGN: Volunteers completed a semiquantitative food-frequency questionnaire, and anthropometric and lifestyle data were collected. Dietary GI and GL in relation to breast cancer risk were examined in 8926 cohort women, including 289 with breast cancer identified after a mean follow-up of 11.5 y. RESULTS: The relative risk (RR) of breast cancer in the highest (versus lowest) quintiles of GI and GL was 1.57 (95% CI: 1.04, 2.36; P for trend = 0.040) and 2.53 (95% CI: 1.54, 4.16; P for trend = 0.001), respectively. Total carbohydrate intake was not associated with greater breast cancer risk, but high carbohydrate from high-GI foods was. When women were categorized by baseline menopausal status and body mass index (BMI; in kg/m(2)), the increased risk of dietary GL was confined to those who were premenopausal (RR = 3.89; 95% CI: 1.81, 8.34) and who had normal BMI (ie, <25) (RR = 5.79; 95% CI: 2.60, 12.90) (P for trend = 0.001 for both). CONCLUSIONS: A high-GL diet may increase the risk of breast cancer in Italian women. The effect is particularly evident in premenopausal women and those with BMI < 25.