Relation of dietary glycemic load with ischemic and hemorrhagic stroke: a cohort study in Greece and a meta-analysis

Maternal Dietary Carbohydrate and Pregnancy Outcomes: Quality over Quantity

Dietary nutrition plays a crucial role in determining pregnancy outcomes, with poor diet being a major contributor to pregnancy metabolic syndrome and metabolic disorders in offspring. While carbohydrates are essential for fetal development, the excessive consumption of low-quality carbohydrates can increase the risk of pregnancy complications and have lasting negative effects on offspring development. Recent studies not only highlighted the link between carbohydrate intake during pregnancy, maternal health, and offspring well-being, but also suggested that the quality of carbohydrate foods consumed is more critical. This article reviews the impacts of low-carbohydrate and high-carbohydrate diets on pregnancy complications and offspring health, introduces the varied physiological effects of different types of carbohydrate consumption during pregnancy, and emphasizes the importance of both the quantity and quality of carbohydrates in nutritional interventions during pregnancy. These findings may offer valuable insights for guiding dietary interventions during pregnancy and shaping the future development of carbohydrate-rich foods.

Relative validity of a glycemic index extended food-frequency questionnaire

BACKGROUND AND AIMS

The dietary glycemic index (GI) and glycemic load (GL) are increasingly recognized as important for the prevention and management of diabetes mellitus. To extend the portfolio of assessment methods for large-scale epidemiological studies, we propose a GI-specific addition to an already established FFQ.

METHODS AND RESULTS

The German version of the EPIC-FFQ was extended by GI-specific questions for major carbohydrate sources varying notably in GI (breakfast cereals, bread, pasta, rice, potato etc.). We performed relative validation analyses comparing the GI-extended FFQ to three to four 3-day weighted dietary records (3-d WDR) in 100 middle-aged individuals with diabetes mellitus participating in the German Diabetes Study (GDS). Level of agreement between the two methods was assessed by correlation and cross-classification analyses as well as Bland-Altman-Plots, conducted separately for women and men. Spearman correlation analysis for female participants suggested good agreement between the GI-extended FFQ and 3-d WDRs for energy adjusted dietary GL (r = 0.52, p = 0.0004). For both women and men, agreement with the estimations of dietary GI, GL (for men) and carbohydrates from low and higher-GI food sources from the GI-extended FFQ was acceptable (r: 0.28-0.45). Classification of the dietary GI and GL in the opposite quartile was <10% comparing the GI-extended FFQ and 3-d WDR. Bland-Altman plots suggested a tendency for an overestimation of the dietary GI from the GI-extended FFQ in the lower GI-ranges, particularly for men.

CONCLUSION

Compared to the 3-d WDR, the GI-extended FFQ showed a moderate to good relative validity for parameters of carbohydrate quality.

Associations of Glycemic Index and Glycemic Load with Cardiovascular Disease: Updated Evidence from Meta-analysis and Cohort Studies

PURPOSE OF REVIEW

Diet and lifestyle patterns are considered major contributory factors for cardiovascular disease (CVD) and mortality. In particular, consuming a diet higher in carbohydrates (not inclusive of fruits and vegetables, but more processed carbohydrates) has been associated with metabolic abnormalities that subsequently may increase the risk of CVD and related mortality. Glycemic index (GI) and glycemic load (GL) are values given to foods based on how fast the body converts carbohydrates into glucose also referred to as the glycemic burden of carbohydrates from foods. Conflicting associations of how high GI and GL influence CVDs have been observed even in high-quality meta-analysis studies. We synthesize and report the associations of high GI and GL with various CVDs by sex, obesity, and geographical locations using an updated review of meta-analysis and observational studies.

RECENT FINDINGS

We identified high GI or high GL is associated with an increased risk of CVD events including diabetes (DM), metabolic syndrome (MS), coronary heart disease (CHD), stroke, and stroke mortality in the general population, and the risk of CVD outcomes appears to be stratified by sex, obesity status, and preexisting CVD. Both high GI and GL are associated with DM and CHD in the general population. However, high GI is strongly associated with DM/MS, while high GL is strongly associated with an increased risk of CHD in females. In addition, high GL is also associated with incident stroke, and appears to be associated with CVD mortality in subjects with preexisting CVD or high BMI and all-cause mortality in non-obese DM subjects. However, high GI appears to be associated with CVD or all-cause mortality only in females without CVD. High GI/GL is an important risk factor for CVD outcomes in the general population. High GI seems to be markedly associated with DM/MS, and it may enhance the risk of CVD or all-cause mortality in both sexes and predominately females. Although both high GI and high GL are risk factors for CHD in females, high GL is associated with CVD outcomes in at-risk populations for CVD. These data suggest that while high GI increases the propensity of CVD risk factors and mortality in healthy individuals, high GL contributes to the risk of severe heart diseases including CVD or all-cause mortality, particularly in at-risk populations. These data indicate dietary interventions designed for focusing carbohydrate quality by lowering both GI and GL are recommended for preventing CVD outcomes across all populations.

Fat-restricted low-glycemic index diet controls weight and improves blood lipid profile: A pilot study among overweight and obese adults in Southwest China

Evidence from trials demonstrating the benefits and risks of low-glycemic index and fat-restricted diets in weight loss and blood lipid profile changes is unclear. This study aimed to assess the implemented and effects of a fat-restricted low-glycemic index diet on weight control and blood lipid profile changes in in overweight/obese Southwest Chinese individualst.This prospective pilot study enrolled overweight/obese subjects at the People's Hospital of Sichuan Province between February and July 2019. The daily energy intake was reduced by 300 to 500 kcal according to the participant's weight and activity level, with low-glycemic index carbohydrate- and fat-energy ratios < 45% and 25% to 30%, respectively. Participants received guidance for 3 months by telephone follow-up, internet interaction, or WeChat. Changes in weight, body composition, and blood profile were measured.A total of 254 patients were finally analyzed, including 101 males and 153 females. After adjusting for potential confounders, weight (P < .001), body mass index (P < .001), waist circumference (P < .001), waist-hip ratio (P < .001), body fat percentage (P < .001), visceral fat area (P < .001), basal metabolism (P = .002), cholesterol (P < .001), and triglycerides (P < .001) were significantly reduced after the 3-month intervention. The above indexes showed no significant differences between men and women.Regardless of gender, fat-restricted low-glycemic index diet might be helpful for controlling weight and lowering blood cholesterol and triglycerides in overweight/obese individuals in Southwest China.

Dietary glycemic index, glycemic load, and chronic disease: an umbrella review of meta-analyses of prospective cohort studies

We aimed to present a comprehensive review of the association of dietary glycemic index (GI) and load (GL) with the risk of chronic disease. Published meta-analyses of prospective observational studies evaluating the association of dietary GI and GL with risk of chronic disease were identified by a search in PubMed and Scopus to November, 2020. Summary relative risks (SRRs) were recalculated using random-effects models. The certainty of evidence was rated by the GRADE approach. Eighteen meta-analyses of prospective cohort studies, reporting 19 SRRs for dietary GI and 17 SRRs for dietary GL were identified. There was a positive association between dietary GI and the risk of type 2 diabetes, coronary heart disease, and colorectal, breast, and bladder cancers, as well as between dietary GL and the risk of coronary heart disease, type 2 diabetes, and stroke. With regard to cancers at other sites, there was no significant association. The certainty of evidence ranged from very low to low. Although by GRADE classification no associations were rated stronger than low, they were classified as one grade higher when the NutriGrade system was used. Further research is needed to add evidence for the relation of dietary GI and GL with cancer risk.

Carbohydrate quality, glycemic index, glycemic load and cardiometabolic risks in the US, Europe and Asia: A dose-response meta-analysis

BACKGROUND AND AIMS

Despite the proven evidence of high glycemic index (GI) and glycemic load (GL) diets to increase cardiometabolic risks, knowledge about the meta-evidence for carbohydrate quality within world geographic regions is limited. We conducted a meta-analysis to synthesize the evidence of GI/GL studies and carbohydrate quality, gathering additional exposures for carbohydrate, high glycemic carbohydrate, total dietary fiber, and cereal fiber and risks for type 2 diabetes (T2DM), coronary heart disease (CHD), stroke, and mortality, grouped into the US, Europe, and Asia. Secondary aims examined cardiometabolic risks in overweight/obese individuals, by sex, and dose-response dietary variable trends.

METHODS AND RESULTS

40-prospective observational studies from 4-Medline bibliographical databases (Ovid, PubMed, EBSCOhost, CINAHL) were search up to November 2019. Random-effects hazard ratios (HR) and 95% confidence intervals (CI) for highest vs. lowest categories and continuous form combined were reported. Heterogeneity (I²>50%) was frequent in US GI/GL studies due to differing study characteristics. Increased risks ((HR_GI,T2DM,US=1.14;CI:1.06,1.21), HR_GL,T2DM,US=1.02 (1.01, 1.03)), HR_GI,T2DM,Asia=1.25;1.02,1.53), and HR_GL,T2DM,Asia=1.37 (1.17, 1.60)) were associated with cardiometabolic diseases. GI/GL in overweight/obese females had the strongest magnitude of risks in US-and Asian studies. Total dietary fiber (HR_T2DM,US = 0.92;0.88,0.96) and cereal fiber (HR_T2DM,US = 0.83;0.77,0.90) decreased risk of developing T2DM. Among females, we found protective dose-response risks for total dietary fiber (HR_{5g-total-dietary-fiber,T2DM,US} = 0.94;0.92,0.97)_, but cereal fiber showed better ability to lower T2DM risk (HR_{5g-cereal-fiber},_T2DM,US = 0.67;0.60,0.74). Total dietary-and cereal fibers' dose-response effects were nullified by GL, but not so for cereal fiber with GI.

CONCLUSIONS

Overweight/obese females could shift their carbohydrate intake for higher cereal fiber to decrease T2DM risk, but higher GL may cancel-out this effect.

Carbohydrate quality and human health: a series of systematic reviews and meta-analyses

BACKGROUND

Previous systematic reviews and meta-analyses explaining the relationship between carbohydrate quality and health have usually examined a single marker and a limited number of clinical outcomes. We aimed to more precisely quantify the predictive potential of several markers, to determine which markers are most useful, and to establish an evidence base for quantitative recommendations for intakes of dietary fibre.

METHODS

We did a series of systematic reviews and meta-analyses of prospective studies published from database inception to April 30, 2017, and randomised controlled trials published from database inception to Feb 28, 2018, which reported on indicators of carbohydrate quality and non-communicable disease incidence, mortality, and risk factors. Studies were identified by searches in PubMed, Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials, and by hand searching of previous publications. We excluded prospective studies and trials reporting on participants with a chronic disease, and weight loss trials or trials involving supplements. Searches, data extraction, and bias assessment were duplicated independently. Robustness of pooled estimates from random-effects models was considered with sensitivity analyses, meta-regression, dose-response testing, and subgroup analyses. The GRADE approach was used to assess quality of evidence.

FINDINGS

Just under 135 million person-years of data from 185 prospective studies and 58 clinical trials with 4635 adult participants were included in the analyses. Observational data suggest a 15-30% decrease in all-cause and cardiovascular related mortality, and incidence of coronary heart disease, stroke incidence and mortality, type 2 diabetes, and colorectal cancer when comparing the highest dietary fibre consumers with the lowest consumers Clinical trials show significantly lower bodyweight, systolic blood pressure, and total cholesterol when comparing higher with lower intakes of dietary fibre. Risk reduction associated with a range of critical outcomes was greatest when daily intake of dietary fibre was between 25 g and 29 g. Dose-response curves suggested that higher intakes of dietary fibre could confer even greater benefit to protect against cardiovascular diseases, type 2 diabetes, and colorectal and breast cancer. Similar findings for whole grain intake were observed. Smaller or no risk reductions were found with the observational data when comparing the effects of diets characterised by low rather than higher glycaemic index or load. The certainty of evidence for relationships between carbohydrate quality and critical outcomes was graded as moderate for dietary fibre, low to moderate for whole grains, and low to very low for dietary glycaemic index and glycaemic load. Data relating to other dietary exposures are scarce.

INTERPRETATION

Findings from prospective studies and clinical trials associated with relatively high intakes of dietary fibre and whole grains were complementary, and striking dose-response evidence indicates that the relationships to several non-communicable diseases could be causal. Implementation of recommendations to increase dietary fibre intake and to replace refined grains with whole grains is expected to benefit human health. A major strength of the study was the ability to examine key indicators of carbohydrate quality in relation to a range of non-communicable disease outcomes from cohort studies and randomised trials in a single study. Our findings are limited to risk reduction in the population at large rather than those with chronic disease.

FUNDING

Health Research Council of New Zealand, WHO, Riddet Centre of Research Excellence, Healthier Lives National Science Challenge, University of Otago, and the Otago Southland Diabetes Research Trust.

Dietary glycemic index, glycemic load, and refined carbohydrates are associated with risk of stroke: a prospective cohort study in urban Chinese women

BACKGROUND

Epidemiologic evidence on dietary carbohydrates and stroke risk remains controversial. Very few prospective cohort studies have been conducted in Asian populations, who usually consume a high-carbohydrate diet and have a high burden of stroke.

OBJECTIVE

We examined dietary glycemic index (GI), glycemic load (GL), and intakes of refined and total carbohydrates in relation to risks of total, ischemic, and hemorrhagic stroke and stroke mortality.

DESIGN

This study included 64,328 Chinese women, aged 40-70 y, with no history of cardiovascular disease, diabetes, or cancer. A validated, interviewer-administered food-frequency questionnaire was used to assess usual dietary intakes at baseline and during follow-up. Incident stroke cases and deaths were identified via follow-up interviews and death registries and were confirmed by review of medical records and death certificates.

RESULTS

During mean follow-ups of 10 y for stroke incidence and 12 y for stroke mortality, we ascertained 2991 stroke cases (2750 ischemic and 241 hemorrhagic) and 609 stroke deaths. After potential confounders were controlled for, we observed significant positive associations of dietary GI and GL with total stroke risk; multivariable-adjusted HRs (95% CIs) for high compared with low levels (90th compared with 10th percentile) were 1.19 (1.04, 1.36) for GI and 1.27 (1.04, 1.54) for GL (both P-linearity < 0.05 and P-overall significance < 0.05). Similar linear associations were found for ischemic stroke, but the associations with hemorrhagic stroke appeared to be J-shaped. Similar trends of positive associations with stroke risks were suggested for refined carbohydrates but not for total carbohydrates. No significant associations were found for stroke mortality after multivariable adjustment.

CONCLUSION

Our results suggest that high dietary GI and GL, primarily due to high intakes of refined grains, are associated with increased risks of total, ischemic, and hemorrhagic stroke in middle-aged and older urban Chinese women.

Occult endocrine dysfunction in patients of cerebrovascular accident

Background:

Cerebrovascular disorders are common conditions leading to significant morbidity and mortality in the population. Occult endocrine disorders also contribute to the morbidity and we studied the prevalence of endocrine dysfunction in patients of cerebrovascular accident (CVA).

Materials and Methods:

We evaluated 30 patients of CVA (aged 18-75, admission within 72 h of symptoms and positive neuroimaging) in this prospective, observational study. All subjects were assessed clinically and biochemically for hormonal dysfunction at admission and for mortality at the end of 1 month. The patients were divided into two groups: Group 1 (infarct, n = 20) and Group 2 (hemorrhage, n = 10) and the data were analyzed with appropriate statistical tests using GraphPad Prism Software, version 6.

Results:

The study participants (24M:6F) had a mean age of 60.7 ± 11.4 years and body weight of 67.2 ± 11.4 kg. Fourteen out of 30 patients showed results consistent with an endocrine disorder, including sick euthyroid syndrome (SES) and central hypothyroidism (n = 10), secondary hypogonadism (n = 3), subclinical hypothyroidism (n = 1), and growth hormone (GH) deficiency in two patients. The endocrine conditions did not differ significantly between both the groups and nine out of 30 patients succumbed to their illness within 1 month. None of the hormonal parameters studied, could predict the 30 day mortality.

Conclusion:

Endocrine disorders are common in acute stage of CVA and commonest finding is a SES. Hormonal dysfunction did not differ based on the etiology of the CVA. Long-term follow-up is essential to understand the morbidity contributed by the hormonal alterations.

Dietary non-enzymatic antioxidant capacity and the risk of myocardial infarction: a case-control study in Italy

BACKGROUND AND AIMS

Oxidative processes have been related to atherosclerosis, but there is scanty information on the role of dietary antioxidants in the prevention of acute myocardial infarction (AMI).

METHODS AND RESULTS

The relationship between non-enzymatic antioxidant capacity (NEAC) and the risk of nonfatal AMI was investigated in a case-control study conducted in Milan, Italy, between 1995 and 2003. Cases were 760 patients below 75 years with a first episode of AMI and controls were 682 patients admitted to hospitals for acute conditions, who completed an interviewer-administered food frequency questionnaire, tested for validity and reproducibility. NEAC (excluding coffee) was measured using Italian food composition tables in terms of ferric reducing-antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC) and total radical-trapping antioxidant parameter (TRAP). The odds ratios (OR) of AMI, and the corresponding 95% confidence intervals (CI), were obtained by multiple logistic regression models including terms for main risk factors of AMI and total energy intake. NEAC was inversely related with the risk of AMI. The ORs for the highest quintile compared with the lowest one were 0.41 (95% CI, 0.27-0.63) for FRAP, 0.42 (95% CI, 0.27-0.65) for TEAC and 0.41 (95% CI, 0.27-0.62) for TRAP, with significant trends in risk. The inverse relationship was apparently stronger in women and in subjects aged ≥ 60 years.

CONCLUSIONS

Our results support a favorable role of dietary NEAC in the prevention of AMI, and encourage a high consumption of fruit and vegetables and a moderate consumption of wine and whole cereals.