Gesa Joslowski

Association between carbohydrate quality and inflammatory markers: systematic review of observational and interventional studies

BACKGROUND Chronic low-grade inflammation is a likely intermediary between quality of carbohydrate and chronic disease risk. OBJECTIVE We conducted a systematic literature search to evaluate the relevance of carbohydrate quality on inflammatory markers in observational and intervention studies. DESIGN MEDLINE, EMBASE, and the Cochrane Library were searched for studies on associations between glycemic index (GI), glycemic load (GL), dietary fiber or fiber supplements or whole grain intake, and high-sensitivity C-reactive protein (hsCRP) or interleukin 6 (IL-6). Included studies had to be conducted on adults (healthy, overweight, with type 2 diabetes or metabolic syndrome features, but without inflammatory disease) with ≥20 participants and a 3-wk duration. RESULTS In total, 22 of the 60 studies that met our inclusion criteria examined GI/GL: 5 of 9 observational studies reported lower concentrations of hsCRP or IL-6 among persons with a lower dietary GI/GL; 3 of 13 intervention studies showed significant antiinflammatory effects of a low-GI/GL diet, and 4 further studies suggested beneficial effects (trends or effects in a subgroup). For fiber intake, 13 of 16 observational studies reported an inverse relation with hsCRP or IL-6, but only 1 of 11 intervention studies showed a significant antiinflammatory effect of fiber intake, and a further trial reported a beneficial trend. For whole-grain intake, 6 of 7 observational studies observed an inverse association with inflammatory markers, but only 1 of 7 intervention studies reported significant antiinflammatory effects, 1 further study was suggestive (in a subgroup) of such, and another study found an adverse effect (trend only). CONCLUSIONS Evidence from intervention studies for antiinflammatory benefits is less consistent for higher-fiber or whole-grain diets than for low-GI/GL diets. Benefits of higher fiber and whole-grain intakes suggested by observational studies may reflect confounding.

Increased Intake of Carbohydrates from Sources with a Higher Glycemic Index and Lower Consumption of Whole Grains during Puberty Are Prospectively Associated with Higher IL-6 Concentrations in Younger Adulthood among Healthy Individuals

Chronic low-grade inflammation represents a likely intermediary in the relation between carbohydrate nutrition and both type 2 diabetes and cardiovascular disease. This study assessed the prospective association between carbohydrate quantity and quality [dietary glycemic index (GI), glycemic load (GL), and added sugar, fiber, and whole-grain intake] during puberty, a potentially critical period for later disease, and low-grade inflammation in younger adulthood. The analysis was based on 205 participants (113 girls and 92 boys) from the DONALD (Dortmund Nutritional and Anthropometric Longitudinally Designed) study with at least 2 3-d weighed dietary records during puberty (girls: 9-14 y, boys: 10-15 y) and blood samples in younger adulthood (18-36 y). Multivariable linear regression models were used to analyze the associations between carbohydrate nutrition and circulating concentrations of pro- and anti-inflammatory immune mediators [high-sensitivity C-reactive protein (hs-CRP), interleukin (IL) 6, IL-18, and adiponectin]. A higher intake of carbohydrates during puberty (P-trend = 0.005), particularly from higher-GI food sources (P-trend = 0.01), was prospectively related to higher concentrations of IL-6 in younger adulthood, independently of baseline BMI and early life, socioeconomic, and other nutritional factors. Furthermore, a higher dietary GL (P-trend = 0.002) and a lower intake of whole grains (P-trend = 0.01) were independently associated with higher IL-6 concentrations in adults. Dietary GI and added sugar and fiber intakes were not independently associated with IL-6 (P-trend ≥ 0.09). Carbohydrate nutrition during puberty was not independently related to hs-CRP, IL-18, and adiponectin concentrations (all P-trend > 0.1). During puberty, a higher intake of carbohydrates from higher-GI food sources and lower whole-grain consumption prospectively predict greater IL-6 concentrations in young adulthood. These data support the hypothesis that diet during puberty influences later inflammation and metabolic dysfunction.

Habitually Higher Dietary Glycemic Index During Puberty Is Prospectively Related to Increased Risk Markers of Type 2 Diabetes in Younger Adulthood

OBJECTIVE Carbohydrate nutrition during periods of physiological insulin resistance such as puberty may affect future risk of type 2 diabetes. This study examined whether the amount or the quality (dietary glycemic index [GI], glycemic load [GL], and added sugar, fiber, and whole-grain intake) of carbohydrates during puberty is associated with risk markers of type 2 diabetes in younger adulthood. RESEARCH DESIGN AND METHODS The analysis was based on 226 participants (121 girls and 105 boys) from the Dortmund Nutritional and Anthropometric Longitudinally Designed Study (DONALD) with an average of five 3-day weighed dietary records (range 2–6) during puberty (girls, age 9–14 years; boys, age 10–15 years) and fasting blood samples in younger adulthood (age 18–36 years) (average duration of follow-up 12.6 years). Multivariable linear regression was used to analyze the associations between carbohydrate nutrition and homeostasis model assessment–insulin resistance (HOMA-IR) as well as the liver enzymes alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT) (n = 214). RESULTS A higher dietary GI was prospectively related to greater values of HOMA-IR (Ptrend = 0.03), ALT (Ptrend = 0.02), and GGT (Ptrend = 0.04). After adjustment for sex, adult age, baseline BMI, and early life and socioeconomic factors as well as protein and fiber intake, predicted mean HOMA-IR values in energy-adjusted tertiles of GI were 2.37 (95% CI 2.16–2.60), 2.47 (2.26–2.71), and 2.59 (2.35–2.85). The amount of carbohydrates, GL, and added sugar, fiber, and whole-grain intake were not related to the analyzed markers. CONCLUSIONS Our data indicate that a habitually higher dietary GI during puberty may adversely affect risk markers of type 2 diabetes in younger adulthood.

Prospective association of protein intake during puberty with body composition in young adulthood

To examine the association of habitual animal and plant protein intake during the potentially critical period of puberty with body composition in young adulthood.

Prospective associations of dietary insulin demand, glycemic index, and glycemic load during puberty with body composition in young adulthood.

Background:Puberty is a so-called critical period for overweight development and is characterized by physiological insulin resistance during mid-puberty. This study addressed the hypothesis that habitual consumption of a diet inducing higher levels of postprandial glycemia or insulinemia during puberty may have an unfavorable effect on the body composition in young adulthood.Methods:Multivariate regression analysis was performed on 262 participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study with at least two 3-day weighed dietary records during puberty (baseline: girls 9–14 years; boys 10–15 years) and anthropometric measurements in young adulthood (18–25 years). A published dietary glycemic index was assigned to each carbohydrate-containing food. Similarly, each food was assigned a food insulin index (insulinemic response to a 1 MJ portion of food relative to 1 MJ of glucose) using 121 values measured at Sydney University.Results:Dietary glycemic index or glycemic load during puberty was not related to body composition in young adulthood. In contrast, a higher dietary insulin index and a higher dietary insulin load during puberty were associated with higher levels of percentage of body fat (%BF) in young adulthood, even after adjustment for early life, socioeconomic and nutritional factors; %BF in energy-adjusted tertiles of dietary insulin index were 22.9 (95% confidence intervals (CI): 21.6, 24.1), 24.5 (23.2, 25.7), 24.7 (23.5, 25.9) %, P for trend=0.01; %BF in energy-adjusted tertiles of dietary insulin load were 22.8 (95% CI: 21.5, 24.0), 24.5 (23.2, 25.7), 24.8 (23.6, 26.0) %, P for trend=0.01. Adjustment for baseline %BF attenuated these relationships (P for trend=0.1 and=0.08, respectively). Dietary insulin demand was not related to body mass index.Conclusion:This study suggests a prospective adverse influence of dietary insulin demand during puberty on %BF in young adulthood. Postprandial increases in insulinemia rather than increases in glycemia appear to be implicated in an unfavorable development of body composition.

Animal Protein Intakes during Early Life and Adolescence Differ in Their Relation to the Growth Hormone-Insulin-Like-Growth-Factor Axis in Young Adulthood

Recent studies provide evidence that insulin-like-growth-factor I (IGF-I) and its binding proteins (IGFBP) IGFBP-2 and IGFBP-3 are related to the risk of several common cancers. It remains to be clarified whether their concentrations can be programmed by protein intake from different sources during growth. This study addressed the hypothesis that animal protein intakes during infancy, mid-childhood, and adolescence differ in their relevance for the growth-hormone (GH)-IGF-I axis in young adulthood. Data from the Dortmund Nutritional and Anthropometric Longitudinally Designed Study participants with at least 2 plausible 3-d weighed dietary records during adolescence (age: girls, 9-14 y; boys, 10-15 y; n = 213), around the adiposity rebound (age 4-6 y; n = 179) or early life (age 0.5-2 y; n = 130), and one blood sample in young adulthood were included in the study. Mean serum concentrations of IGF-I, IGFBP-1, IGFBP-2, and IGFBP-3 were compared between tertiles of habitual animal protein intake using multivariable regression analysis. Habitually higher animal protein intakes in females during puberty were related to higher IGF-I (P-trend = 0.005) and IGFBP-3 (P-trend = 0.01) and lower IGFBP-2 (P-trend = 0.04), but not to IGFBP-1 in young adulthood. In turn, IGF-I concentrations in young adulthood were inversely related to animal protein intakes in early life among males only (P-trend = 0.03), but not to animal protein intake around adiposity rebound (P-trend > 0.5). Our data suggest that, among females, a habitually higher animal protein intake during puberty may precipitate an upregulation of the GH-IGF-I axis, which is still discernible in young adulthood. By contrast, among males, higher animal protein intakes in early life may exert a long-term programming of the GH-IGF-I axis.

Breastfeeding and Its Prospective Association with Components of the GH-IGF-Axis, Insulin Resistance and Body Adiposity Measures in Young Adulthood – Insights from Linear and Quantile Regression Analysis

Background Breastfeeding may lower chronic disease risk by long-term effects on hormonal status and adiposity, but the relations remain uncertain. Objective To prospectively investigate the association of breastfeeding with the growth hormone- (GH) insulin-like growth factor- (IGF) axis, insulin sensitivity, body composition and body fat distribution in younger adulthood (18–37 years). Design Data from 233 (54% female) participants of a German cohort, the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study, with prospective data on infant feeding were analyzed. Multivariable linear as well as quantile regression were performed with full breastfeeding (not: ≤2, short: 3–17, long: >17 weeks) as exposure and adult IGF-I, IGF binding proteins (IGFBP) -1, -2, -3, homeostasis model assessment of insulin resistance (HOMA-IR), fat mass index, fat-free mass index, and waist circumference as outcomes. Results After adjustment for early life and socio-economic factors, women who had been breastfed longer displayed higher adult IGFBP-2 (ptrend = 0.02) and lower values of HOMA-IR (ptrend = 0.004). Furthermore, in women breastfeeding duration was associated with a lower mean fat mass index (ptrend = 0.01), fat-free mass index (ptrend = 0.02) and waist circumference (ptrend = 0.004) in young adulthood. However, there was no relation to IGF-I, IGFBP-1 and IGFBP-3 (all ptrend>0.05). Associations for IGFBP-2 and fat mass index were more pronounced at higher, for waist circumference at very low or high percentiles of the distribution. In men, there was no consistent relation of breastfeeding with any outcome. Conclusions Our data suggest that breastfeeding may have long-term, favorable effects on extremes of adiposity and insulin metabolism in women, but not in men. In both sexes, breastfeeding does not seem to induce programming of the GH-IGF-axis.

Dietary glycemic load, insulin load, and weight loss in obese, insulin resistant adolescents: RESIST study

BACKGROUND & AIMS The optimal dietary approach for weight loss and improving insulin sensitivity in adolescents is unknown. This study aimed to explore the association between the estimated insulin demand of the diet, as measured by glycemic and insulin load, weight loss, percentage body fat and insulin sensitivity index (ISI) in obese adolescents with clinical features of insulin resistance and/or prediabetes after a 3 month lifestyle and metformin intervention. METHODS Secondary data analysis of 91 adolescents (median age 12.7 years (range 10.1-17.4) participating in a randomized controlled trial, known as RESIST; ACTRN12608000416392. Weight change between baseline and 3 months was measured by BMI expressed as percentage of the 95th centile (BMI %95). Body composition was measured by dual energy X-ray absorptiometry and ISI was determined by an oral glucose tolerance test. RESULTS Higher dietary glycemic load and insulin load were associated with less weight loss (BMI %95), adjusted for sex and pubertal stage, β = 0.0466, P = 0.007 and β = 0.0124, P = 0.040, respectively. Inclusion of total energy intake in the model explained observed associations between dietary glycemic load and insulin load and change in BMI %95. Neither dietary glycemic load nor insulin load were associated with changes in percentage body fat or ISI. Dietary glycemic index and macronutrient content (% of total energy) were not associated to changes in BMI %95, percentage body fat or ISI. CONCLUSION Reduced energy diet contributes to weight loss in obese, insulin resistant adolescents. Diets with a lower insulin demand were associated with a lower energy intake and may hence assist with weight loss.

Velocities of weight, height and fat mass gain during potentially critical periods of growth are decisive for adult body composition

Objectives:To examine whether maximal velocities of weight, height and fat mass during potentially critical periods of growth were associated with body composition in young adulthood.Subjects/methods:Analyses were performed on 277 female and 271 male participants of the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study with anthropometric measurements in young adulthood (18–25 years) as well as early life (0–2 years), mid-childhood (3–8 years) or puberty (9–15 years). Maximum growth velocities were calculated using the SuperImposition by Translation And Rotation (SITAR) routine or polynomial functions and related to adult fat mass index (FMI) and fat-free mass index (FFMI).Results:In early life, faster weight gain was associated with a moderately higher FMI and FFMI in young adulthood in women only (Ptrend=0.01). In mid-childhood and puberty, weight and fat mass velocities were related to adult FMI and FFMI in both sexes (Ptrend⩽0.002): relative differences between the highest and lowest tertiles of these growth velocities ranged 33–69% for adult FMI and 6–12% for adult FFMI. A higher mid-childhood height velocity was related to a modestly higher adult FMI in women only (Ptrend=0.0005).Conclusions:Faster gain in weight and body fat during mid-childhood and puberty appear to be particularly relevant for adult fat mass.

Early Diet and Later Cancer Risk: Prospective Associations of Dietary Patterns During Critical Periods of Childhood with the GH-IGF Axis, Insulin Resistance and Body Fatness in Younger Adulthood

Early life, adiposity rebound, and puberty represent critical growth periods when food choices could have long-term relevance for cancer risk. We aimed to relate dietary patterns during these periods to the growth hormone-insulin-like-growth-factor (GH-IGF) axis, insulin resistance, and body fatness in adulthood. Data from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study participants with outcome data at 18–37 years, and ≥2 dietary records during early life (1–2 yr; n = 128), adiposity rebound (4–6 years, n = 179), or puberty (girls 9–14, boys 10–15 yr; n = 213) were used. Dietary patterns at these ages were derived by 1) reduced rank regression (RRR) to explain variation in adult IGF-I, IGF-binding protein-3 (IGFBP-3), homoeostasis model assessment for insulin resistance (HOMA-IR) and fat-mass index; 2) principal component analysis (PCA). Regarding RRR, the patterns “cake/canned fruit/cheese & eggs” (early life), “sweets & dairy” (adiposity rebound) and “high-fat foods” (pubertal boys) were independently associated with higher adult HOMA-IR. Furthermore, the patterns “favorable carbohydrate sources” (early life), “snack & convenience foods” (adiposity rebound), and “traditional & convenience carbohydrates” (pubertal boys) were related to adult IGFBP-3 (P trend < 0.01). PCA identified “healthy” patterns for all periods, but none was associated with the outcomes (P trend > 0.1). In conclusion, dietary patterns during sensitive growth periods may be of long-term relevance for adult insulin resistance and IGFBP-3.