Dietary acid load and risk of cardiovascular disease: a prospective population-based study.

BACKGROUND AND AIM: Considering the inconsistencies in the cardiovascular effects of dietary acid load and the impact of dietary acidity on the acid-base homeostasis within the body, we aimed to assess the association of dietary acid load and the risk of cardiovascular disease (CVD) in a prospective community-based study. MATERIALS AND METHODS: Participants (n = 2369) free of CVD at baseline (2006-2008) were included from the Tehran Lipid and Glucose Study (TLGS) and followed up for a mean of 6.7 ± 1.4 years. Dietary intakes of the participants were assessed using a semi-quantitative food frequency questionnaire (FFQ). The dietary acid load was evaluated by Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP) scores. Both scores have used the macronutrient and micronutrient data of the Food Frequency Questionnaires. Multivariate Cox proportional hazard regression models were used to estimate the 6-years incident risk of CVDs across tertiles of PRAL and NEAP scores. RESULTS: Mean age and body mass index of participants were 38.5 ± 13.3 years and 26.6 ± 4.8 kg/m2 at baseline. Within 6.7 ± 1.4 years of follow-up, 79 cases of cardiovascular events were reported. NEAP was significantly associated with the incidence of CVDs (HRs = 0.50, CI 0.32-0.96; P for trend = 0.032); however, after adjusting for potential confounders, no significant associations were observed between PRAL and NEAP scores and the risk of CVDs. CONCLUSIONS: This study failed to obtain independent associations between dietary acid load and the incidence of CVDs among an Asian population.

The Mediterranean diet and risk of type 2 diabetes in Iranian population.

BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is fast increasing in recent decades. Limited prospective studies are available on Mediterranean diet protective effect against T2D development. We assessed longitudinal association of the Mediterranean diet with T2D risk in Iranian men and women. SUBJECTS/METHODS: Diet was measured using a 168-item food frequency questionnaire in 2139 adults (free of T2D), aged 20-70 years. All individuals, based on the traditional Mediterranean diet score (MDS), received scores between 0 and 8 points. Multivariate hazard ratio (HR) and 95% confidence interval (CI) were reported for the association of T2D and the MDS, with adjustment of diabetes risk score (DRS) and dietary energy intakes. RESULTS: During follow-up, a total of 143 events occurred. Individuals who had higher intakes of fish/sea foods, legumes, nuts, and monounsaturated fatty acids (MUFAs) to saturated fatty acids (SFAs) ratio had a decreased risk of T2D. After adjustment for confounders, an inverse association was found between adherence to the MDS and T2D (HR = 0.48; 95% CI 0.27-0.83). CONCLUSIONS: Our findings demonstrated an inverse association between the Mediterranean diet score and incidence of T2D.

The Associations of Dietary Acid Load with Insulin Resistance and Type 2 Diabetes: A Systematic Review of Existing Human Studies.

BACKGROUND: Type 2 diabetes is a multifactorial disorder influenced by both genetic and environmental factors and is rising dramatically throughout the world. Recently, consideration to dietary acid-base load has been raised as a nutritional indicator that could have metabolic effects. OBJECTIVE: The aim of this study was to systematically investigate the associations of dietary acid load indices with glucose/insulin homeostasis and type 2 diabetes in a patent based review. METHODS: Systematic literature review was conducted using PubMed, Scopus and Google Scholar, from inception up to 10 January 2018. All human studies publications investigated the association of dietary acid load indices (PRAL or NEAP or Pro:K) and incidence of diabetes or glucose/insulin metabolism were included. RESULTS: In all, 174 studies were included for the title and abstract screening. A total of 164 articles were excluded because they did not meet the inclusion criteria. Finally, 10 articles (five crosssectional studies and five cohort studies) in accordance with our inclusion criteria were chosen for further evaluations that were published between 2008 and 2017. CONCLUSION: Although there are some evidence of an association between dietary acid load and type 2 diabetes, definitive declarations in this regard will be needed to intervention human studies modifying acid-base dietary intake.

Empirical dietary inflammatory pattern and risk of metabolic syndrome and its components: Tehran Lipid and Glucose Study.

BACKGROUND: The rising incidence of metabolic syndrome (MetS) is a major public health problem. The inflammatory potential of diet contributes to the development of MetS. The aim of this study was to investigate the relationship between empirical dietary inflammatory pattern (EDIP) and risk of MetS among the Tehranian population. Our hypothesis was that high EDIP would increase the risk of MetS and its components. METHODS: In this prospective study, 2216 adults were selected from among the Tehran Lipid and Glucose Study participants. The usual dietary intakes were estimated using a valid and reliable food frequency questionnaire. Biochemical and anthropometric measurements were assessed at baseline and over 6.2 years of follow up. MetS components were defined according to the modified national Cholesterol Education Program Adult Treatment Panel III. The inflammatory potential of diet was calculated using EDIP score; more positive scores means higher pro-inflammatory diet. Adjusted logistic regression models were used to estimate the occurrence of MetS and its components across quartiles of EDIP score. RESULTS: Mean ± SD for EDIP score was 0.61 ± 0.40 (range - 2.3 to 6.9). Participants with the highest EDIP scores, had a higher risk of MetS incidence compared to those with the lowest score (OR: 1.75, 95% CI 1.21-2.54, Ptrend = 0.003). Among the MetS components, hyperglycemia, abdominal obesity, and low HDL-C had a significant positive association with EDIP score; (OR: 1.46, 95% CI 1.03-2.08, Ptrend = 0.026), (OR: 1.43, 95% CI 1.03-1.97, Ptrend = 0.046), and (OR: 1.57, 95% CI 1.34-2.19, Ptrend = 0.015), respectively. No significant association was found between EDIP score, hypertension and hypertriglyceridemia. CONCLUSION: Our finding indicated that higher intake of the pro-inflammatory diet may be an independent risk factor for the development of MetS, hyperglycemia, low HDL-C and abdominal obesity in Tehranian adults.

Dietary Sodium to Potassium Ratio and the Incidence of Chronic Kidney Disease in Adults: A Longitudinal Follow-Up Study.

The aim of this study was to explore the association of dietary sodium to potassium (Na/K) ratio and the risk of chronic kidney disease (CKD) in general Iranian adults. In this prospective cohort study, 1,780 adults, free of baseline CKD with complete follow-up data, were selected from among participants of the Tehran Lipid and Glucose Study and followed for 6.3 years for development of CKD. Dietary sodium and potassium were assessed using a valid and reliable 168-item food frequency questionnaire. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease Study equation, and CKD was defined as eGFR <60 mL/min/1.73 m2. Mean dietary intakes of sodium and potassium were 4,547±3,703 and 3,753±1,485 mg/d, respectively, and their ratio was 1.35±1.29. No significant association was found between dietary intakes of sodium and potassium and the risk of CKD after 6.3 y of follow-up, whereas in the case of dietary Na/K ratio, participants in the highest compared to lowest tertile (2.43 vs 1.61) had a significantly increased risk of CKD (odds ratio=1.52, 95% confidence interval=1.01~2.30); an increasing trend in the risk of CKD across tertiles of dietary sodium to potassium ratio was also observed (P for trend=0.05). Present findings demonstrate that the dietary Na/K ratio is a stronger predictor of CKD than the dietary sodium or potassium per se. Decreased dietary Na/K ratio may be considered as an effective dietary approach to modify the risk of kidney dysfunction.