Dietary fiber intakes and insulin requirements in pregnant women with type 1 diabetes

OBJECTIVE: To determine whether higher dietary fiber intake (water soluble and insoluble) is associated with lower insulin requirements and better glycemic control in pregnant women with type 1 diabetes consuming a self-selected diet. DESIGN: A longitudinal, observational study. SUBJECTS: Pregnant women (n=141) with type 1 diabetes participating in an interdisciplinary program examining the effects of glycemic control on pregnancy outcome (Diabetes and Pregnancy Program, University of Cincinnati Medical Center). MEASUREMENTS: We determined total, water soluble and insoluble fiber intakes from 3-day food records kept each trimester during pregnancy. Outcome measures were insulin dose, pre-meal blood glucose, and glycated hemoglobin concentrations. STATISTICAL ANALYSES: Correlation coefficients, multiple regression, mixed-model analysis of variance. RESULTS: Mean intakes (g/day) of total, water soluble fiber, and insoluble fiber were 14.0 (range, 1.8-33.1), 4.8 (range, 0.6-10.5) and 9.0 (range, 1.1-24.0), respectively. In the second and third trimesters of pregnancy, insulin requirements were inversely associated with total, water soluble, and insoluble fiber intakes; the correlation coefficients ranged from -0.22 to -0.17 (P=.02 to .08). Insulin requirements associated with a higher fiber intake (20.5 g/day) were 16% to 18% lower than for a lower fiber intake (8.1 g/day). These relations remained after adjustment for body weight, disease severity and duration, insulin type, and study year in the second (P=.03 to .10) but not in the third trimester. Pre-meal blood glucose and glycated hemoglobin concentrations were not associated with fiber intake. CONCLUSIONS: Among pregnant women with type 1 diabetes, higher fiber intake is associated with lower daily insulin requirements. Dietary fiber intake should be considered when counseling patients about the management of blood glucose concentrations.     

Dietary Fibre Intake in Type 2 and New-Onset Prediabetes/Diabetes after Acute Pancreatitis: A Nested Cross-Sectional Study

The association between intake of dietary fibre and glucose metabolism has been extensively investigated in numerous metabolic disorders. However, little is known about this association in individuals after an attack of acute pancreatitis (AP). The aim was to investigate the associations between intake of dietary fibre and markers of glucose metabolism in individuals with new-onset prediabetes or diabetes after acute pancreatitis (NODAP), pre-exiting type 2 prediabetes or diabetes, and normoglycaemia after acute pancreatitis. This cross-sectional study was nested within the parent prospective longitudinal cohort study. The studied markers of glucose metabolism were fasting plasma glucose and glycated haemoglobin. Habitual intake of dietary fibre was determined using the EPIC-Norfolk food frequency questionnaire. Multivariable linear regression analyses were conducted. The study included a total of 108 individuals after AP. In the NODAP group, increased intakes of total fibre (β = −0.154, p = 0.006), insoluble fibre (β = −0.133, p = 0.01), and soluble fibre (β = −0.13, p = 0.02) were significantly associated with a reduction in fasting plasma glucose. Increased intakes of vegetables (β = −0.069, p = 0.004) and nuts (β = −0.039, p = 0.038) were significantly associated with a reduction in fasting plasma glucose. Increased intake of nuts (β = −0.054, p = 0.001) was also significantly associated with a reduction in glycated haemoglobin. None of the above associations were significant in the other study groups. Habitual intake of dietary fibre was inversely associated with fasting plasma glucose in individuals with NODAP. Individuals after an attack of AP may benefit from increasing their intake of dietary fibre (specifically, vegetables and nuts) with a view to preventing NODAP.     

Day-to-day consistency in amount and source of carbohydrate intake associated with improved blood glucose control in type 1 diabetes.

OBJECTIVE: To determine if a relationship exists between blood glucose control and variability in nutrient intake from day-to-day in subjects with type 1 diabetes. METHODS: Two three-day diet records and one measurement of glycated hemoglobin (HbA1c) were obtained from 272 subjects with type 1 diabetes treated with a mixture of regular and NPH insulins before breakfast and supper and using a standardized algorithm to adjust insulin dose according to the results of self-monitoring of blood glucose two to four times daily. Day-to-day variation in nutrient intake was expressed as the coefficient of variation (CV = SDx100/mean). RESULTS: Nutrient intakes in the study population (mean +/- SD) were energy 8.35+/-2.43 MJ, fat 81+/-30 g, protein 94+/-28 g, carbohydrate 227+/-68 g, starch 126+/-38 g and dietary fiber 20+/-6 g with diet glycemic index being 84.2+/-7.4. Neither energy, nutrient intakes nor insulin dose was significantly related to HbA1c. Day-to-day variation of carbohydrate (p = 0.0097) and starch (p = 0.0016) intakes and diet glycemic index (p = 0.033) was positively related to HbA1c, and the associations remained significant when adjusted for age, sex, duration of diabetes and BMI. Day-to-day variation in energy, protein or fat intakes was not related to HbA1c. CONCLUSIONS: Consistency in the amount and source of carbohydrate intake from day-to-day is associated with improved blood glucose control in people with type 1 diabetes, a result which supports continued educational efforts to achieve adherence to a diabetes diet plan. This conclusion may not apply to people on intensified insulin therapy who adjust their insulin dose based on their actual carbohydrate intake at each meal.     

Glycemic index,glycemic load,and risk of type 2 diabetes

The possibility that high, long-term intake of carbohydrates that are rapidly absorbed as glucose may increase the risk of type 2 diabetes has been a long-standing controversy. Two main mechanisms have been hypothesized, one mediated by increases in insulin resistance and the other by pancreatic exhaustion as a result of the increased demand for insulin. During the past decade, several lines of evidence have collectively provided strong support for a relation between such diets and diabetes incidence. In animals and in short-term human studies, a high intake of carbohydrates with a high glycemic index (a relative measure of the incremental glucose response per gram of carbohydrate) produced greater insulin resistance than did the intake of low-glycemic-index carbohydrates. In large prospective epidemiologic studies, both the glycemic index and the glycemic load (the glycemic index multiplied by the amount of carbohydrate) of the overall diet have been associated with a greater risk of type 2 diabetes in both men and women. Conversely, a higher intake of cereal fiber has been consistently associated with lower diabetes risk. In diabetic patients, evidence from medium-term studies suggests that replacing high-glycemic-index carbohydrates with a low-glycemic-index forms will improve glycemic control and, among persons treated with insulin, will reduce hypoglycemic episodes. These dietary changes, which can be made by replacing products made with white flour and potatoes with whole-grain, minimally refined cereal products, have also been associated with a lower risk of cardiovascular disease and can be an appropriate component of recommendations for an overall healthy diet.     

Hyperglycemia and Carotenoid Intake Are Associated with Serum Carotenoids in Youth with Type 1 Diabetes

BackgroundSerum carotenoids are commonly used as biomarkers of fruit and vegetable (F/V) intake in the general population. Although hyperglycemia induces oxidative stress, it is unknown whether this pathway is associated with lower serum carotenoid concentrations in individuals with type 1 diabetes. Consequently, the utility of serum carotenoids as markers of F/V intake in individuals with type 1 diabetes is unclear.ObjectiveThe study objectives were: 1) to investigate the relationship of glycemic control, oxidative stress, dietary carotenoid and F/V intake with serum carotenoid concentrations in youth with type 1 diabetes and 2) to determine whether glycemic control or oxidative stress moderates the association of carotenoid and F/V intake with serum carotenoids.DesignThe study was a secondary analysis of baseline data from youth with type 1 diabetes. Blood samples were drawn from youth with type 1 diabetes to assess carotenoids and markers of glycemic control (glycated hemoglobin and 1,5-anhydroglucitol); urine samples were used to assess oxidative stress (8-iso-prostaglandin F_2α); and 3-day diet records completed by families were used to determine F/V and carotenoid intake.Participants/settingThe study participants were youth with type 1 diabetes (n=136; age range: 8 to 16.9 years; diabetes duration ≥1 year; glycated hemoglobin: 5.8% to 11.9%) enrolled in a nutrition intervention trial from 2010 to 2013 at a tertiary diabetes center in Boston, MA.Main outcome measuresSerum carotenoids (total carotenoids and α-carotene, β-carotene, lycopene, β-cryptoxanthin, and lutein+zeaxanthin).Statistical analysisRegression analyses were used to estimate the association of glycemic control, oxidative stress, F/V and carotenoid intake with serum carotenoids, as well as the role of glycemic control and oxidative stress in moderating diet-serum carotenoid associations.ResultsGreater F/V intake (β=0.35, P<0.001) and carotenoid intake (β=0.28, P<0.01) were associated with higher total serum carotenoids, and no moderation by glycemic control or oxidative stress was observed. Greater hyperglycemia, as indicated by lower 1,5-anhydroglucitol (β=0.27, P<0.01), was related to lower serum carotenoids; however, glycated hemoglobin was not associated with serum carotenoids. 8-Iso-prostaglandin F2α was not associated with glycemic control or serum carotenoids.ConclusionsFindings support the validity of serum carotenoids as markers of F/V and carotenoid intake in youth with type 1 diabetes.     

Postprandial glucose,insulin, and lipid responses to four meals containing unpurified dietary fiber in non-insulin-dependent diabetes mellitus (NIDDM), hypertriglyceridemic subjects.

To evaluate the effects of two levels of total dietary fiber (10 g vs. 20 g) and two soluble:insoluble fiber ratios (1:4 vs. 2:3) on postprandial glucose and lipid metabolism in hypertriglyceridemic subjects with non-insulin-dependent diabetes mellitus (NIDDM).

Eight NIDDM, mildly hypertriglyceridemic subjects consumed four test breakfasts, each containing variable proportions of the same cereal and fruit fiber sources. Blood samples were obtained during the 4 hours following the test meals and analyzed for glucose, insulin, triglyceride, total cholesterol and high density lipoprotein cholesterol.

The incremental area under the curve for glucose and insulin was lowered after consuming 20 g as compared to 10 g of dietary fiber (p < 0.05), but was not affected by the soluble insoluble fiber ratio. The postprandial lipemia was similar after all test meals.

The proportion of soluble to insoluble fiber in cereal and fruit does not necessarily predict the effect of fiber on the glycemic response, while the overall quantity of fiber does appear to affect postprandial glucose metabolism in NIDDM.     

Carbohydrate intake and biomarkers of glycemic control among US adults: the third National Health and Nutrition Examination Survey (NHANES III)

BACKGROUND: Recommendations for preventing and treating type 2 diabetes include consuming carbohydrates, predominantly from whole grains, fruit, vegetables, and low-fat milk. However, the quantity and type of carbohydrates consumed may contribute to disorders of glycemic control. OBJECTIVE: We evaluated the association between carbohydrate intakes and biomarkers of glycemic control in a nationally representative sample of healthy US adults who participated in a cross-sectional study, the third National Health and Nutrition Examination Survey. DESIGN: The sample (5730 men and 6125 women aged > or = 20 y) was divided into quintiles of carbohydrate intake (as a percentage of energy). Carbohydrate intakes were examined in relation to glycated hemoglobin (Hb A(1c)), plasma glucose, serum C-peptide, and serum insulin concentrations by using logistic regression. RESULTS: Carbohydrate intakes were not associated with Hb A(1c), plasma glucose, or serum insulin concentrations in men or women after adjustment for confounding variables. Carbohydrate intakes were inversely associated with serum C-peptide concentrations in men and women. Odds ratios for elevated serum C-peptide concentrations for increasing quintiles of carbohydrate intake were 1.00, 0.88, 0.57, 0.39, and 0.75 (P for trend = 0.016) in men, and 1.00, 0.69, 0.57, 0.36, and 0.41 (P for trend = 0.007) in women. When carbohydrate intakes were further adjusted for intakes of total and added sugar, the association of serum C-peptide with carbohydrate intakes was strengthened in men. CONCLUSIONS: Carbohydrate intakes were not associated with Hb A(1c), plasma glucose, or serum insulin concentrations but were inversely associated with the risk of elevated serum C-peptide; this supports current recommendations regarding carbohydrate intake in healthy adults.     

Glycemic response and health--a systematic review and meta-analysis: relations between dietary glycemic properties and health outcomes

BACKGROUND: Reduction of dietary glycemic response has been proposed as a means of reducing the risk of diabetes and coronary heart disease. The impact of glycemic response on markers of health remains to be elucidated. OBJECTIVE: We assessed the evidence relating the glycemic impact of foods to measures relevant for health maintenance and management of disease. DESIGN: This was a systematic review and synthesis of interventional evidence from literature reported on glycemic index and markers of health through the use of meta-analyses and meta-regression models. RESULTS: Data from 45 relevant publications were found to January 2005. Lower glycemic index (GI) diets reduced both fasting blood glucose and glycated proteins independently of variance in available and unavailable carbohydrate intakes. Elevated unavailable carbohydrate added to improvements in both blood glucose and glycated protein control. These effects were greater in persons with poor fasting blood glucose control. No effects were seen on fasting insulin<100 pmol/L; above this, study numbers were few but consistent with prevention of hyperinsulinemia in some but not all overweight persons. Insulin sensitivity according to a variety of measurement methods was improved by lower GI, higher unavailable carbohydrate interventions in persons with type 2 diabetes, in overweight and obese persons, and in all studies combined. Fasting triacylglycerol in addition to body weight reduction related more to glycemic load than to GI. Glycemic load reduction by >17 g glucose equivalents/d was associated with reduced body weight. CONCLUSIONS: Consumption of reduced glycemic response diets are followed by favorable changes in the health markers examined. The case for the use of such diets looks compelling. Unavailable carbohydrate intake is equally important.     

Dietary fiber intake and risk of breast cancer by menopausal and estrogen receptor status

Purpose

Evaluate the hypothesis that relation of breast cancer associated with dietary fiber intakes varies by type of fiber, menopausal, and the tumor’s hormone receptor status.

Methods

A case–control study of female breast cancer was conducted in Connecticut. A total of 557 incident breast cancer cases and 536 age frequency-matched controls were included in the analysis. Information on dietary intakes was collected through in-person interviews with a semi-quantitative food frequency questionnaire and was converted into nutrient intakes. Odds ratios and 95% confidence intervals were estimated by unconditional logistic regression.

Results

Among pre-menopausal women, higher intake of soluble fiber (highest versus lowest quartile of intake) was associated with a significantly reduced risk of breast cancer (OR = 0.38, 95% CI, 0.15–0.97, P _trend = 0.08). When further restricted to pre-menopausal women with ER^? tumors, the adjusted OR for the highest quartile of intake was 0.15 (95% CI, 0.03–0.69, P _trend = 0.02) for soluble fiber intake. Among post-menopausal women, no reduced risk of breast cancer was observed for either soluble or insoluble fiber intakes or among ER⁺ or ER^? tumor groups.

Conclusions

The results from this study show that dietary soluble fiber intake is associated with a significantly reduced risk of ER^? breast cancer among pre-menopausal women. Additional studies with larger sample size are needed to confirm these results.     

Phylloquinone intake, insulin sensitivity, and glycemic status in men and women

BACKGROUND: Limited evidence suggests that vitamin K may have a beneficial role in glucose homeostasis. No observational data exist on the associations between vitamin K intake and insulin sensitivity. OBJECTIVE: We aimed to examine associations between vitamin K intake and measures of insulin sensitivity and glycemic status in men and women aged 26-81 y. DESIGN: We assessed the cross-sectional associations of self-reported phylloquinone (vitamin K(1)) intake with insulin sensitivity and glycemic status in the Framingham Offspring Cohort. Dietary and supplemental phylloquinone intakes were assessed by using a food-frequency questionnaire. Insulin sensitivity was measured by fasting and 2-h post-oral-glucose-tolerance test (OGTT) insulin, the homeostasis model assessment of insulin resistance (HOMA-IR), and the insulin sensitivity index (ISI(0,120)). Glycemic status was assessed by fasting and 2-h post-OGTT glucose and glycated hemoglobin (HbA(1c)). RESULTS: Higher phylloquinone intake was associated with greater insulin sensitivity and glycemic status, as measured by 2-h post-OGTT insulin and glucose and ISI(0,120), after adjustment for age, sex, waist circumference, lifestyle characteristics, and diet quality [2-h post-OGTT insulin: lowest and highest quintile, 81.0 and 72.7 microU/mL, respectively (P for trend = 0.003); 2-h post-OGTT glucose: 106.3 and 101.9 mg/dL, respectively (P for trend = 0.009); ISI(0,120): 26.3 and 27.3 mg L(2)/mmol mU min (P for trend = 0.009)]. Phylloquinone intake was not associated with fasting insulin and glucose concentrations, HOMA-IR, or HbA(1c). CONCLUSION: Our findings support a potential beneficial role for phylloquinone in glucose homeostasis in men and women.     

Dietary Fiber Intake and Endogenous Serum Hormone Levels in Naturally Postmenopausal Mexican American Women: The Multiethnic Cohort Study

This study investigated dietary fiber intake in association with serum estrogen levels in naturally postmenopausal Latina women with a wide range of fiber intake. Estrone (E₁), estradiol (E₂), and sex-hormone-binding globulin (SHBG) were measured in 242 women. Associations between estrogen levels and intake of dietary fiber, including insoluble and soluble fractions, quantified from a food frequency questionnaire, were examined. The biomarker enterolactone was also measured. After adjustment for age, weight, and other nondietary factors, dietary fiber intake was inversely associated with E₁ and E₂; there was a 22% and 17% decrease (2P _trend = 0.023 and 0.045) among subjects in the highest quintile of intake compared with the lowest. Fitting dietary fiber together with soluble and insoluble nonstarch polysaccharides (NSP) showed a much greater decrease in E₁ and E₂ (47% and 41%, respectively) while increased soluble NSP intake showed increases in E₁ and E₂ (64% and 69%, respectively). Two foods, avocado and grapefruit, showed significant positive associations with E ₁ (2P _trend = 0.029 and 0.015, respectively). This study suggests that different components of dietary fiber may have very significant different effects on serum estrogen levels. The suggestive findings relating increased estrogen levels to avocado and grapefruit intakes need confirmation.     

Association between dietary fiber and markers of systemic inflammation in the Women's Health Initiative Observational Study

OBJECTIVE: Systemic inflammation may play an important role in the development of atherosclerosis, type 2 diabetes, and some cancers. Few studies have comprehensively assessed the direct relations between dietary fiber and inflammatory cytokines, especially in minority populations. Using baseline data from 1958 postmenopausal women enrolled in the Women's Health Initiative Observational Study, we examined cross-sectional associations between dietary fiber intake and markers of systemic inflammation (including serum high-sensitivity C-reactive protein [hs-CRP], interleukin-6 [IL-6], and tumor necrosis factor-alpha receptor-2 [TNF-alpha-R2]) in addition to differences in these associations by ethnicity. METHODS: Multiple linear regression models were used to assess the relation between fiber intake and makers of systemic inflammation. RESULTS: After adjustment for covariates, intakes of dietary fiber were inversely associated with IL-6 (P values for trend were 0.01 for total fiber, 0.004 for soluble fiber, and 0.001 for insoluble fiber) and TNF-alpha-R2 (P values for trend were 0.002 for total, 0.02 for soluble, and <0.001 for insoluble fibers). Although the samples were small in minority Americans, results were generally consistent with those found among European Americans. We did not observe any significant association between intake of dietary fiber and hs-CRP. CONCLUSION: These findings lend support to the hypothesis that a high-fiber diet is associated with lower plasma levels of IL-6 and TNF-alpha-R2. Contrary to previous reports, however, there was no association between fiber and hs-CRP among postmenopausal women. Future studies on the influence of diet on inflammation should include IL-6 and TNF-alpha-R2 and enroll participants from ethnic minorities.     

53例糖尿病患者膳食中膳食纤维的摄入量调查

目的调查糖尿患者总膳食纤维、可溶及不可溶性膳食纤维的摄入量,为糖尿患者膳食纤维营养状况的研究提供重要基础数据。方法通过不同实验室间的比对研究建立膳食纤维酶重量分析方法。采用称重法和食物计量图片法登记53例糖尿患者连续3d每餐的食物摄入种类和重量,利用酶重量法建立的食物中膳食纤维数据库计算膳食纤维摄入的数量和种类。结果3个实验室测定膳食纤维数据的相对标准偏差在2.63%~9.67%之间。调查对象蔬菜类食物摄入量最多,是膳食纤维的主要来源。调查对象总膳食纤维摄入量为(26.5±9.8)g/d,不可溶性膳食纤维摄入量为(14.6±5.8)g/d,可溶性膳食纤维摄入量为(10.4±4.4)g/d。结论本次调查对象的总膳食纤维日摄入量处于美国糖尿病协会推荐摄入量范围内。     

The dietary glycemic index during pregnancy: influence on infant birth weight, fetal growth, and biomarkers of carbohydrate metabolism

During pregnancy, lower levels of maternal glucose before and during a glucose load have been associated with reduced infant birth weight and an increased risk of small-for-gestational-age births. A lower incremental area under the glucose response curve defines a low glycemic diet. Thus, during pregnancy the maternal diet, as measured by the glycemic index, may influence fetal growth and infant birth weight. A total of 1,082 gravidas who enrolled in the Camden Study between August 1996 and October 2002 were followed prospectively during pregnancy. The dietary glycemic index was computed from three 24-hour recalls in the course of pregnancy. Samples for plasma glucose and for glycosylated hemoglobin were obtained at 24-28 weeks' gestation. The glycemic index was positively and significantly related to maternal glycosylated hemoglobin and plasma glucose. There were as well significant linear trends for dietary fat intake to decrease and for intakes of carbohydrate, sucrose, fiber, and folate to increase as the glycemic index declined. Gravidas with a low dietary glycemic index had reduced infant birth weight and approximately a twofold increased risk of a small-for-gestational-age birth. Consistent with data on maternal plasma glucose, data in this study show that the type of carbohydrate in the diet of urban, low-income women influences fetal growth and infant birth weight.     

Increased sucrose intake is not associated with a change in glucose or insulin sensitivity in people with type 2 diabetes

Background Debate continues over the role of sucrose and sucrose-containing food in the diet for people with type 2 diabetes. Traditionally, dietary recommendations have suggested sucrose be reduced to a minimum level to improve glycaemic control. More recently the American Diabetes Association evidence-based guidelines have suggested a more liberal approach.

Objective To investigate whether a 50 g increase in sucrose given as three slices of cake a day over a period of 24 days (88±7.5 g total sucrose/day) in combination with an increased monounsaturated fat intake (20% E) in line with current American Diabetes Association recommendations has an effect on glycaemic control or insulin sensitivity in people with type 2 diabetes.

Design We re-examined results from a larger study that investigated the type of fat in the diet of people with type 2 diabetes. Nine overweight people with type 2 diabetes received a high-sucrose, high-monounsaturated-fat isocaloric diet for 24 days.

Results Weight and glycaemic control remained stable throughout the study. There was no significant change in HbA1c over the study period. There was no change in insulin sensitivity, measured by the short insulin tolerance test. There was no change in fasting or postprandial incremental area under the curve in response to an identical standard test meal for glucose or insulin.

Conclusions Over the 3-week intervention period, an isocaloric increase in the dietary intakes of sucrose to 13% of total energy per day in people with type 2 diabetes was not associated with a decline in glycaemic control or insulin sensitivity.     

Dietary fiber intake and risk of type 2 diabetes: a dose–response analysis of prospective studies

Observational studies suggest an association between dietary fiber intake and risk of type 2 diabetes, but the results are inconclusive. We conducted a meta-analysis of prospective studies evaluating the associations of dietary fiber intake and risk of type 2 diabetes. Relevant studies were identified by searching EMBASE (from 1974 to April 2013) and PubMed (from 1966 to April 2013). The fixed or random-effect model was selected based on the homogeneity test among studies. In addition, a 2-stage random-effects dose–response meta-analysis was performed. We identified 17 prospective cohort studies of dietary fiber intake and risk of type 2 diabetes involving 19,033 cases and 488,293 participants. The combined RR (95 % CI) of type 2 diabetes for intake of total dietary fiber, cereal fiber, fruit fiber and insoluble fiber was 0.81 (0.73–0.90), 0.77 (0.69–0.85), 0.94 (0.88–0.99) and 0.75 (0.63–0.89), respectively. A nonlinear relationship was found of total dietary fiber intake with risk of type 2 diabetes (P _{for nonlinearity} < 0.01), and the RRs (95 % CI) of type 2 diabetes were 0.98 (0.90–1.06), 0.97 (0.87–1.07), 0.89 (0.80–0.99), 0.76 (0.65–0.88), and 0.66 (0.53–0.82) for 15, 20, 25, 30, and 35 g/day. The departure from nonlinear relationship was not significant (P _{for nonlinearity} = 0.72), and the risk of type 2 diabetes decreased by 6 % (RR 0.94, 95 % CI 0.93–0.96) for 2 g/day increment in cereal fiber intake. Findings from this meta-analysis indicate that the intakes of dietary fiber may be inversely associated with risk of type 2 diabetes.     

Impact of Adopting Lower-Fat Food Choices on Energy and Nutrient Intakes of American Adults

Objective To evaluate the energy and nutrient intake of free-living men and women who choose foods consistent with different fat-reduction strategies.Design For each year of the Continuing Survey of Food Intake by Individuals from 1989 through 1991, food codes were used to sort respondents by type of milk; type of meats; and type of cheese, yogurt, salad dressing, cake, and pudding (ie, full-fat or fat-modified products) consumed.Subjects A nationally representative sample of 3,313 men and 3,763 women who completed 3-day intake records and consumed either a reduced-fat or full-fat food from at least 1 of the 3 fat-reduction strategy categories.Statistical analysis performed Analysis of variance with the Scheffé test was used to analyze differences in energy and nutrient intake between exclusive users, mixed users, and nonusers of each strategy or combined strategies.Results Regardless of fat-reduction strategy, men and women who used them reported significantly lower intakes of total fat (up to 18 g lower), saturated fat (up to 12 g lower), cholesterol (up to 75 ing lower) and energy compared with nonusers. Exclusive users of single strategies met or approached recommendations of the National Cholesterol Education Program for total fat, saturated fat, and cholesterol intake; micronutrient intake varied depending on the strategy used. Skim milk users had the most favorable micronutrient intake, whereas lean meat users reported inadequate intake of zinc (men 6396 and women 59% of the Recommended Dietary Allowances [RDAs]) and female users of fat-modified products reported inadequate intakes of vitamin E (64% of RDA) and zinc (65% of RDA). Multiple-strategy users achieved National Cholesterol Education Program goals and reported adequate micronutrient intakes and significantly lower energy intake. Mixed users of fat-modified products compared with nonusers of any fat-modified products had adequate micronutrient intake and lower intakes of total fat (32% vs 36% of energy for men and 32% vs 35% of energy for women) and saturated fat (11% vs 13% of energy for men and 11% vs 12% of energy for women). In addition, nonusers of any fat-modified strategy had the highest cholesterol and energy intake and the lowest intake of. many micrbnutrients.Applications A variety of fat-reduction strategies can be implemented to reduce energy, total fat, saturated fat, and cholesterol intake. Some of the strategies were associated with an inadequate micronutrient intake, so additional dietary guidance is needed to ensure that all nutrient requirements are met. Furthermore, people who do not use any fat-reduction strategy or those who exclusively use lean meats or fat-modified products would benefit from understanding how to balance their food choices. J Am Diet Assoc. 1999;99:177–183.     

Carbohydrates, dietary fiber, and incident type 2 diabetes in older women

BACKGROUND: Dietary carbohydrates may influence the development of type 2 (non-insulin-dependent) diabetes, for example, through effects on blood glucose and insulin concentrations. OBJECTIVE: We examined the relations of baseline intake of carbohydrates, dietary fiber, dietary magnesium, and carbohydrate-rich foods and the glycemic index with incidence of diabetes. DESIGN: This was a prospective cohort study of 35988 older Iowa women initially free of diabetes. During 6 y of follow-up, 1141 incident cases of diabetes were reported. RESULTS: Total grain, whole-grain, total dietary fiber, cereal fiber, and dietary magnesium intakes showed strong inverse associations with incidence of diabetes after adjustment for potential nondietary confounding variables. Multivariate-adjusted relative risks of diabetes were 1.0, 0.99, 0.98, 0.92, and 0.79 (P for trend: 0.0089) across quintiles of whole-grain intake; 1.0, 1.09, 1.00, 0.94, and 0.78 (P for trend: 0.005) across quintiles of total dietary fiber intake; and 1.0, 0.81, 0.82, 0.81, and 0.67 (P for trend: 0.0003) across quintiles of dietary magnesium intake. Intakes of total carbohydrates, refined grains, fruit and vegetables, and soluble fiber and the glycemic index were unrelated to diabetes risk. CONCLUSION: These data support a protective role for grains (particularly whole grains), cereal fiber, and dietary magnesium in the development of diabetes in older women.     

Association between Dietary Magnesium Intake and Glycemic Markers in Ghanaian Women of Reproductive Age: A Pilot Cross-Sectional Study

Low magnesium intake has been shown to be associated with an increased risk of type 2 diabetes mellitus (T2DM) in several studies conducted in high-income countries. However, very few studies have been performed in Africa, where many countries have a growing rate of T2DM. We conducted a pilot cross-sectional study among 63 women in Ghana to investigate the association between magnesium intake and glycemic markers. We assessed dietary magnesium using a food frequency questionnaire and glycemic markers using fasting blood glucose and glycated hemoglobin A1c (HbA1c). Our findings showed that the mean magnesium intake was 200 ± 116 mg/day. The prevalence of T2DM was 5% by measuring fasting blood glucose and 8% by measuring HbA1c. Unadjusted linear regression models revealed that higher magnesium intake significantly predicted higher fasting blood glucose levels (β = 0.31; 95% CI: 0.07, 0.55; p = 0.01) and HbA1c levels (β = 0.26; 95% CI: 0.01, 0.51; p = 0.04). In adjusted analyses, magnesium intake was no longer significantly associated with either fasting blood glucose levels (β = 0.22; 95% CI: −0.03, 0.46; p = 0.08) or HbA1c levels (β = 0.15; 95% CI: −0.08, 0.39; p = 0.20). In conclusion, our study did not show a significant association between magnesium intake and glycemic markers in women of reproductive age in Ghana. The results of this study need to be further substantiated because this was the first study to examine magnesium intake and glycemic markers in this population in Africa.