A posteriori dietary patterns and risk of pancreatic and renal cancers

Metabolic syndrome in relation to dietary acid load: a dose-response meta-analysis of observational studies

Background and aim

Several studies have identified that dietary acid load (DAL) may be associated with the odds of metabolic syndrome (MetS); however, the evidence is inconclusive. This dose-response meta-analysis aimed to examine the relation of DAL to MetS.

Methods

A systematic literature search was carried out in PubMed and Scopus up to April 2023 for pertinent studies evaluating the relation of DAL scores, including potential renal acid load (PRAL) and net endogenous acid production (NEAP), to the odds of MetS. The odds ratios (OR) with 95% confidence intervals (CI) were pooled using a random-effects meta-analysis to test the association.

Results

Eight studies, with an overall sample size of 31,351 participants, were included in this meta-analysis. Higher DAL scores were significantly related to the elevated odds of MetS (NEAP: OR = 1.42, 95%CI = 1.12-1.79; PRAL: OR = 1.76, 95%CI = 1.11-2.78), with significant evidence of heterogeneity across studies. The linear dose-response analysis proposed that a 10 mEq/day elevation in NEAP and PRAL was linked to a 2% (OR = 1.02, 95%CI = 1.001-1.05) and 28% (OR = 1.28, 95%CI = 1.11-1.47) increased odds of MetS, respectively. No non-linear association was observed between MetS and NEAP (P-non-linearity = 0.75) and PRAL (P-non-linearity = 0.92).

Conclusion

This study revealed a significant direct relationship between DAL and MetS. Therefore, lower acidogenic diets are suggested for the prevention of MetS.

The association between a priori dietary patterns and psychological disorders in military personnel

BACKGROUND

Studies have identified a high prevalence of poor mental health, including depression, anxiety, and stress in military occupations. A low quality diet is one of the potential factors related to mental disorders. This study aimed to investigate the association of a priori dietary patterns, including dietary approach to stop hypertension (DASH), the Mediterranean diet (MD), dietary inflammatory index (DII), and healthy eating index-2015 (HEI-2015) with the odds of depression, anxiety, and stress in military staff.

METHODS

This cross-sectional study was performed on a total of 400 military staff, aged 38.67 ± 5.22 (ranging from 30 to 60) years, recruited from Iranian military centers. The dietary intake of participants and adherence to the DASH, MD, DII, and HEI-2015 was measured using a 168-item food frequency questionnaire (FFQ). Mental health was evaluated with the use of the Depression, Anxiety, and Stress Scale - 21 (DASS-21).

RESULTS

The prevalence of depression, anxiety, and stress was 64.5%, 63.2%, and 61.3%, respectively. Individuals with the highest adherence to HEI-2015, compared to those with the lowest adherence, were significantly at lower odds of anxiety (OR = 0.51, 95%CI: 0.27-0.96, p = 0.03), while higher adherence to DII was related to a 2.74-fold increased odds of anxiety (OR = 2.74, 95%CI: 1.06-7.04, p = 0.03). Compared to those with the lowest adherence (quartile 1), quartile 2 of the HEI-2015 was associated with decreased odds of stress (p = 0.04). No association was identified between dietary patterns and depression.

CONCLUSION

Greater adherence to HEI-2015 and lower adherence to DII are associated with lower odds of anxiety in military staff.

What Dietary Patterns and Nutrients are Associated with Pancreatic Cancer? Literature Review

This narrative review summarizes the main findings of observational studies (case-control and cohort) as well as systematic reviews and meta-analyses on the role of nutrients and dietary patterns on pancreatic cancer (PC) risk and elucidates possible mechanisms for the association between nutrients or specific food components and the risk of PC. A literature search of MEDLINE (PubMed), Google Scholar, ScienceDirect, and Scopus was performed. An extensive search of related articles published in the English language from 1985 to 2022 was carried out. Our search included macro- and micronutrient intake as well as dietary patterns associated with PC. In conclusion, the consumption of a diet high in nutrients such as sugar, fats, and red and processed meats can increase the risk of PC. Conversely, a high dietary intake of fresh fruit and vegetables and their associated nutrients like fiber, antioxidants, and polyphenols may prevent PC. Dietary patterns loaded with red and processed meats were also linked to an increased risk of PC, whereas dietary patterns rich in plant-based foods like vegetables, fruits, whole grains, and legumes were associated with a reduced risk of PC. Dietary fiber, fat-soluble vitamins, water-soluble vitamins, and minerals might also play a protective role against PC.

Iron supplementation does not aggravate impaired glucose tolerance and sugar overload-induced genotoxicity in rats

High sugar intake is a major risk factor for metabolic disorders. Genotoxicity is an important factor in diabetes onset, and iron (Fe) may be an aggravating element. However, this relationship is still poorly established. Thus, this study evaluated whether Fe supplementation could aggravate obesity, impaired glucose tolerance, and sugar overload-induced genotoxicity in rats. A total of 24 rats were treated with different diets: standard diet (SD, n = 8), invert sugar overload (320 g/L, HSD, n = 8), or Fe plus invert sugar overload (2.56 mg/L of Fe²⁺, Fe-HSD, n = 8) for four months. After treatment, the Fe-HSD group showed no excessive weight gain or impaired glucose tolerance. DNA damage in blood, as assessed by comet assay, gradually increased in HSD during treatment (p < 0.001), whereas Fe-HSD showed a nonlinear increase in DNA damage. Moreover, Fe-HSD presented 0.6-fold more DNA damage compared with SD (p = 0.0055) in the 1st month of treatment. At months 2 and 3, results show a ≥ 1.4-fold increase in HSD and Fe-HSD DNA damage, respectively, compared with SD (p < 0.01). At the end of the experiment, only HSD DNA damage differed from SD (1.5-fold more, p = 0.0196). Fe supplementation did not aggravate the invert sugar-induced DNA damage (p > 0.05). In the pancreas, results showed no differences in DNA damage. Mutagenicity, evaluated by micronucleus testing, was not observed regardless of treatment (p = 0.428). Fe supplementation, in the evaluated concentration, did not aggravate weight gain, impaired glucose tolerance, and sugar overload-induced genotoxicity in rats.

Diets, Dietary Patterns, Single Foods and Pancreatic Cancer Risk: An Umbrella Review of Meta-Analyses

Pancreatic cancer (PC) represents the third leading cause of cancer death in 2020. Despite the fact that, in 2018, the World Cancer Research Fund report concluded that there is still a lack of evidence on the role of foods or diets and risk for PC, a flourishing body of evidence has been published and needs to be analyzed. For this reason, we conducted an umbrella review on the association between different dietary patterns/food components and PC. Data sources PubMed/MEDLINE, Scopus, Web of Science, EMBASE, and the Cochrane Collaboration were searched. The Joanna Briggs Institute Umbrella Review Methodology was used. The protocol was registered in PROSPERO. A total of 23 articles were included, covering a wide range of dietary patterns/food components: healthy/prudent dietary patterns (n = 4), Mediterranean diets (MedDiet) (n = 1), plant-based diets (n = 2), the Dietary Inflammatory Index (DII) (n = 2), western diets (n = 2), and, lastly, unhealthy diets (n = 2). Regarding dietary components, the following were assessed: total fruit (n = 2), citrus fruit (n = 1), total vegetables (n = 2), cruciferous vegetables (n = 1), red meat (n = 6), processed meat (n = 4), poultry (n = 2), eggs (n = 1), fish (n = 5), whole grain (n = 2), potato (n = 1), and nuts (n = 2). The methodological quality of the included meta-analyses was generally low or critically low. Although the strength of evidence was generally weak, convincing or suggestive evidence was found for a healthy/prudent, plant-based diet, fruit and vegetables, and lower risk of PC, whereas a high intake of red meat was associated with a higher risk of PC at a convincing level of evidence. Further studies are needed to confirm the role of the other dietary patterns/food components and the risk of PC.

Meat consumption and the risk of general and central obesity: the Shahedieh study

Objective

This study aimed to investigate the relations of total meat intake and its subtypes, including red and processed meat, white meat, poultry, fish, and organ meat to the risk of general/central obesity.

Methods

This cross-sectional study included a total of 7312 Iranian adults with the age range of 35–70 years from the Shahedieh cohort study, Yazd, Iran. Dietary intake of subjects was evaluated using a validated 120-item Food Frequency Questionnaire. General obesity was defined as body mass index ≥ 30 kg/m2 and central obesity as waist circumference ≥ 102 cm in men and ≥ 88 cm in women.

Results

After controlling for potential covariates including energy intake, age, marital status, gender, physical activity, supplement use, house possession, education, family size, current smoking, night shift working, history of thyroid disease and depression, and intakes of vegetables, legumes, nuts, fruits, whole grains, and dairy, a significant direct association was found between the higher consumption of white meat (OR = 1.31; 95% CI: 1.06–1.61) and poultry (OR = 1.23; 95% CI: 1.04–1.45) with odds of general obesity. Processed meat was a significant predictor for central obesity in the fully adjusted model, so that individuals in the fourth quartile of processed meat intake, compared with those in the first quartile, had a 22% (OR = 1.22; 95% CI: 1.04–1.43) increased risk to be centrally obese.

Conclusion

This study reveals that higher intakes of white meat and poultry are associated with increased risk of general obesity, while, processed meat consumption was associated with central obesity.

The role of diet in renal cell carcinoma incidence: an umbrella review of meta-analyses of observational studies

BACKGROUND

Evidence associating diet with the incidence of renal cell carcinoma (RCC) is inconclusive. We aimed to summarize evidence associating dietary factors with RCC incidence and assess the strength and validity of this evidence.

METHODS

We conducted an umbrella review of systematic reviews or meta-analyses (SRoMAs) that assessed the association between diet and RCC incidence. Through April 2021, PubMed, Web of Science, Embase, The Cochrane Library, Scopus, and WCRF were searched. Two independent reviewers selected studies, extracted data, and appraised the quality of SRoMAs. According to credibility assessment criteria, evidence can be divided into five categories: convincing (class I), highly suggestive (class II), suggestive (class III), weak (class IV), and nonsignificant (class V).

RESULTS

Twenty-nine meta-analyses were obtained after screening. After excluding 7 overlapping meta-analyses, 22 meta-analyses including 502 individual studies and 64 summary hazard ratios for RCC incidence were included: dietary patterns or dietary quality indices (n = 6), foods (n = 13), beverages (n = 4), alcohol (n = 7), macronutrients (n =15), and micronutrients (n =19). No meta-analyses had high methodological quality. Five meta-analyses exhibited small study effects; one meta-analysis showed evidence of excess significance bias. No dietary factors showed convincing or highly suggestive evidence of association with RCC in the overall analysis. Two protective factors had suggestive evidence (vegetables (0.74, 95% confidence interval 0.63 to 0.86) and vitamin C (0.77, 0.66 to 0.90)) in overall analysis. One protective factor had convincing evidence (moderate drinking (0.77, 0.70 to 0.84)) in Europe and North America and one protective factor had highly suggestive evidence (cruciferous vegetables (0.78, 0.70 to 0.86)) in North America.

CONCLUSIONS

Although many meta-analyses have assessed associations between dietary factors and RCC, no high-quality evidence exists (classes I and II) in the overall analysis. Increased intake of vegetables and vitamin C is negatively associated with RCC risk. Moderate drinking might be beneficial for Europeans and North Americans, and cruciferous vegetables might be beneficial to North Americans, but the results should be interpreted with caution. More researches are needed in the future.

TRIAL REGISTRATION

PROSPERO CRD42021246619.

Diet quality in relation to the risk of hypertension among Iranian adults: cross-sectional analysis of Fasa PERSIAN cohort study

BACKGROUND

Hypertension is a common chronic disease with various complications and is a main contributing factor to cardiovascular disease (CVD). This study aimed to assess the association of diet quality, assessed by dietary diversity score (DDS), Mediterranean dietary score (MDS), diet quality index-international (DQI-I), and healthy eating index-2015 (HEI-2015) with the risk of hypertension.

METHODS

This study recruited a total of 10,111 individuals (45.14% male) with mean age of 48.63 ± 9.57 years from the Fasa Cohort Study, Iran. Indices of diet quality, including MDS, HEI-2015, DQI-I, and DDS were computed by a 125-item Food Frequency Questionnaire. Participants were diagnosed as hypertensive if they had a diastolic blood pressure (DBP) ≥90 mmHg, systolic blood pressure (SBP) ≥140 mmHg,, or used antihypertensive drugs.

RESULTS

Hypertension was prevalent in 28.3% of the population (21.59% in males and 33.74% in females). In the whole population, after adjustment for potential covariates, including daily energy intake, age, gender, physical activity, smoking, family history of hypertension, body mass index, and the level of education, higher adherence to the MDS (OR: 0.86, 95%CI = 0.75-0.99) and HEI-2015 (OR: 0.79, 95%CI = 0.68-0.90) was significantly associated with decreased risk of hypertension. The protective effect of HEI-2015 against hypertension remained significant for both males (OR: 0.80, 95%CI = 0.64-0.99) and females (OR: 0.78, 95%CI = 0.66-0.94), while, for MDS, this relationship disappeared in the subgroup analysis by gender. DQI-I and DDS were not related to the odds of hypertension.

CONCLUSIONS

Adhering to MDS and HEI-2015 diets could contribute to the prevention of hypertension.

The association of dietary inflammatory index with urinary risk factors of kidney stones formation in men with nephrolithiasis

Objective

Inflammation plays a leading role in the pathogenesis of nephrolithiasis. The association of the dietary inflammatory index (DII) with urinary lithogenic factors is unclear. This study aimed to evaluate the relation of DII to urinary risk factors of kidney stones formation.

Results

Of 264 participants, 61.4% (n = 162), 72% (n = 190), 74.6% (n = 197), 68.6% (n = 181), and 80.3% (n = 212) had hyperoxaluria, hypercreatininuria, hypercalciuria, hyperuricosuria, hypocitraturia, respectively. There was a significant increasing trajectory in urinary calcium, uric acid, and creatinine as well as a decreasing trend in urinary citrate across tertiles of DII score (all P = ≤0.001). After multivariate adjustment for energy intake, age, physical activity and body mass index, high DII scores were associated with elevated odds of having hypercreatininuria (OR = 2.80, 95%CI: 1.10–7.12, P_trend = 0.04), hypercalciuria (OR = 7.44, 95%CI: 2.62–21.14, P_trend ≤ 0.001), hyperuricosuria (OR = 2.22, 95%CI: 1.001–4.95, P_trend = 0.05), and hypocitraturia (OR = 5.84, 95%CI: 2.14–15.91, P_trend ≤ 0.001). No association was identified between DII and hyperoxaluria.

The association of Dietary Approaches to Stop Hypertension-style diet with urinary risk factors of kidney stones formation in men with nephrolithiasis

OBJECTIVE

The relation of the Dietary Approaches to Stop Hypertension (DASH)-style diet to urinary lithogenic factors is unclear. This study aimed to assess the association between adherence to the DASH diet and urinary risk factors of kidney stones formation.

METHODS

A total of 264 men apparently with nephrolithiasis, aged 18-89 years, participated in this cross-sectional study. The food item-based DASH diet based on 8 components (nuts and legumes, red and processed meat, low-fat dairy products, sweetened beverages, fruits, vegetables, sodium, and whole grains) and nutrient-based DASH score based on 9 target nutrients (protein, fiber, total fat, saturated fat, cholesterol, sodium, calcium, potassium, and magnesium) were calculated using a food frequency questionnaire. Urine analysis was performed to measure hypercalciuria, hypocitraturia, hyperoxaluria, hyperuricosuria, and hypercreatinuria as study outcomes. Multivariate logistic regression analysis was used to evaluate the relation of DASH diet to urinary factors.

RESULTS

After multivariate adjustment, high adherence to the food-based or nutrient-based DASH dietary patterns was significantly associated with lower odds for hypercreatininuria, hypocitraturia, and hypercalciuria. Higher nutrient-based DASH diet scores were related to lower odds of hyperuricosuria and moderate adherence to the food-based DASH score increased odds for hyperoxaluria. Moreover, expect for "Nuts and legumes" and sodium, other components of DASH diet were significantly related to urinary lithogenic factors.

CONCLUSION

Adherence to the DASH diet may be a strong preventive approach to decrease urinary risk factors of kidney stone formation.

Healthy and unhealthy dietary patterns and the risk of chronic disease: an umbrella review of meta-analyses of prospective cohort studies

We aimed to fully review the association of empirical dietary patterns with the risk of non-communicable chronic diseases and to rate the quality of the evidence. Published meta-analyses of observational studies investigating the association of empirically derived dietary patterns with the risk of chronic diseases were identified by searching PubMed and Scopus till September 2019. Two independent reviewers extracted the information and rated the quality of the evidence by NutriGrade score. For each meta-analysis, cross-sectional and case–control studies were excluded and then summary relative risk was recalculated by using a random-effects model. Sixteen meta-analyses of prospective cohort studies, reporting eighteen SRR for healthy dietary patterns and sixteen SRR for unhealthy patterns obtained from 116 primary prospective cohort studies with 4·8 million participants, were included. There was moderate quality of evidence for the inverse association of healthy dietary patterns with the risk of type 2 diabetes (T2D), fracture and colorectal and breast cancers. There was also low-quality evidence for the inverse relation between healthy dietary patterns and the risk of all-cause and cardiovascular mortality, depression, CHD and respiratory diseases. There was moderate quality of evidence for a positive association between unhealthy dietary patterns and the risk of T2D, fracture and the metabolic syndrome. Adopting a healthy dietary pattern may reduce the risk of T2D, CHD and premature death. More research is needed for outcomes for which the quality of the evidence was rated low, such as respiratory disease, mental illness and site-specific cancers.