A plant-based diet in overweight adults in a 16-week randomized clinical trial: The role of dietary acid load

The association of diet-dependent acid load with gastrointestinal cancer risk in the Cancer Screenee Cohort in Korea

BACKGROUND/OBJECTIVES

Diet-induced acidosis is a determinant of gastrointestinal (GI) cancer susceptibility. However, the current evidence remains insufficient to establish a link between an acidogenic diet and cancer because the majority of previous studies were restricted to a case‒control design. We investigated whether the dietary acid load is involved in GI carcinogenicity.

SUBJECTS/METHODS

We conducted a prospective cohort study of 10,741 participants who attended check-ups from October 2007 to December 2020 at the National Cancer Center, Korea. The participants were followed up until December 2020 to determine incident GI cancer cases. A Cox proportional hazards regression model was used to examine the dietary acid load, as reflected by the potential renal acid load (PRAL), the net endogenous acid production (NEAP), and net acid excretion (NAE), in relation to GI cancer risk.

RESULTS

A total of 208 incident GI cancer cases were identified during the follow-up period. We observed a significantly increased GI cancer risk among male participants with high PRAL, NEAP, and NAE scores (hazard ratios (HRs) = 1.53 (95% confidence interval (CI): 1.05-2.22), 1.51 (1.04-2.19), and 1.73 (1.18-2.53), respectively). Importantly, acidogenic foods seem to have detrimental effects even in individuals who are not obese.

CONCLUSIONS

Our findings add substantial evidence to the argument that diet-dependent acid load plays certain roles in GI carcinogenesis, especially in males. Thus, attention should be given to the dietary acid‒base load for the prevention of GI cancer.

Effectiveness of Resistance Training Program on Body Composition in Adults Following Vegan Diet versus Omnivorous Diet; Developed in Mobile Health Modality

BACKGROUND

The vegan diet (VEGD) has gained popularity in recent years for ecological and ethical reasons, as well as for its health benefits. In addition to the type of diet, the resistance training program (RTP) plays a fundamental role as one of the main natural anabolic stimuli to increase musculoskeletal mass and reduce fat mass.

METHODS

The study was a 16-week non-randomized controlled clinical trial consisting of three RTP sessions per week. The sample included 70 Chilean individuals, aged between 18 and 59 years, who had been following a VEGD or omnivorous diet (OMND) for the past 6 months. Four groups were established: Vegan Diet Resistance Training Program (VEGD-RTP), Vegan Diet Control (VEGD-C), Omnivorous Diet Resistance Training Program (OMND-RTP), and Omnivorous Diet Control (OMND-C).

RESULTS

The sample consisted of 47 women and 23 men, with a mean age of 30.1 (±8.6) years. A reduction of 1.20% in the percentage of fat mass (%FM) was observed in the VEGD-RTP group (r = 0.554, p = 0.016), as well as a reduction of 0.70 kg in kilograms of fat mass (KFM) (r = 0.480, p = 0.036). The OMND-RTP group decreased %FM by 0.90% (r = 0.210, p = 0.432) and KFM by 0.50 kg (r = 0.109, p = 0.683).

CONCLUSIONS

RTP combined with VEGD or OMND significantly reduced the percentage of fat mass, although its effect was more significant in the VEGD-RTP participants.

A Review of Plant-Based Diets for Obesity Management

OBJECTIVE

Obesity is the most prevalent chronic disease in the United States with over 70% of the American population suffering from overweight/obesity. Recently, the popularity of plant-based diets (PBDs) has grown, with individuals adopting these diets for ethical, health and environmental reasons. Our aim is to evaluate the effect of a PBD on weight loss among patients who are overweight or obese.

METHODS

A literature review of PBDs for the treatment of obesity was conducted using PubMed and Scopus. Our search yielded 27 intervention trials (3361 participants) and 6 metanalyses (9168 participants, 61 trials).

RESULTS

Among the intervention trials evaluated, 75% showed a significant increase in weight loss or decrease in weight in the intervention group, on average -5.0 kg (range -1.8 to -12.1 kg). Other outcomes included energy intake (-420 Kcal/d), systolic blood pressure (-3.78 mmHg), fasting plasma glucose (-2.0 mmol/L), hemoglobin A1c (-0.5%, -3.4 mmol/L), total cholesterol (-0.40 mmol/L), low-density lipoprotein (-0.38 mmol/L), triglyceride levels (+0.13 mmol/L), and fiber intake (+10.8 g/d). The 6 meta-analyses showed weight loss (average -2.9 kg, range -2.02 kg to -4.1 kg), body mass index reduction, and improvements in hemoglobin A1c, low-density lipoprotein, and total cholesterol.

CONCLUSION

PBDs result in significant weight loss and improve metabolic outcomes. PBDs offer a sustainable approach to long-term weight loss maintenance. Health care providers should encourage open discussions with their patients regarding their dietary habits to assist them in setting feasible lifestyle goals and consider shared medical appointments to support patients in transitioning to PBDs.

Plant-based and Early Time-restricted Eating for Prevention and Treatment of Type 2 Diabetes in Adults: A Narrative Review

Type 2 diabetes (T2D) is a significant public health challenge for which effective lifestyle interventions are needed. A growing body of evidence supports the use of both plant-based eating patterns and early time-restricted eating (eTRE) for the prevention and treatment of T2D, but research has not yet explored the potential of these dietary strategies in combination. In this narrative review, we assessed the evidence by which plant-based diets, in conjunction with eTRE, could support T2D care. The electronic databases MEDLINE and the Web of Science were searched for relevant articles published throughout the last decade. Observational research has shown that healthy plant-based eating patterns and eTRE are associated with reductions in T2D risk. Interventional trials demonstrated that plant-based diets promote improvements in glycated hemoglobin, insulin resistance, glycemic management, and cardiometabolic risk factors. These changes may be mediated, in part, by reductions in oxidative stress, dietary acid load, and hepatocellular and intramyocellular lipids. The eTRE strategies were also shown to improve insulin resistance and glycemic management, and mechanisms of action included enhanced regulation of circadian rhythm and increased metabolic flexibility. Integrating these dietary strategies may produce additive benefits, mediated by reduced visceral adiposity and beneficial shifts in gut microbiota composition. However, potential barriers to concurrent implementation of these interventions may exist, including social challenges, scheduling constraints, and tolerance. Prospective trials are needed to examine their acceptability and clinical effects.

Plant foods, healthy plant-based diets, and type 2 diabetes: a review of the evidence

Type 2 diabetes (T2D) is a metabolic chronic disease in which insulin resistance and insufficient insulin production lead to elevated blood glucose levels. The prevalence of T2D is growing worldwide, mainly due to obesity and the adoption of Western diets. Replacing animal foods with healthy plant foods is associated with a lower risk of T2D in prospective studies. In randomized controlled trials, the consumption of healthy plant foods in place of animal foods led to cardiometabolic improvements in patients with T2D or who were at high risk of the disease. Dietary patterns that limit or exclude animal foods and focus on healthy plant foods (eg, fruits, vegetables, whole grains, nuts, legumes), known as healthy, plant-based diets, are consistently associated with a lower risk of T2D in cohort studies. The aim of this review is to examine the differential effects of plant foods and animal foods on T2D risk and to describe the existing literature about the role of healthy, plant-based diets, particularly healthy vegan diets, in T2D prevention and management. The evidence from cohort studies and randomized controlled trials will be reported, in addition to the potential biological mechanisms that seem to be involved.

Dietary acid load and risk of diminished ovarian reserve: a case-control study

BACKGROUND

The epidemiologic evidence on the association between acid load potential of diet and the risk of diminished ovarian reserve (DOR) is scarce. We aim to explore the possible relationship between dietary acid load (DAL), markers of ovarian reserve and DOR risk in a case-control study.

METHODS

370 women (120 women with DOR and 250 women with normal ovarian reserve as controls), matched by age and BMI, were recruited. Dietary intake was obtained using a validated 80-item semi-quantitative food frequency questionnaire (FFQ). The DAL scores including the potential renal acid load (PRAL) and net endogenous acid production (NEAP) were calculated based on nutrients intake. NEAP and PRAL scores were categorized by quartiles based on the distribution of controls. Antral follicle count (AFC), serum antimullerian hormone (AMH) and anthropometric indices were measured. Logistic regression models were used to estimate multivariable odds ratio (OR) of DOR across quartiles of NEAP and PRAL scores.

RESULTS

Following increase in PRAL and NEAP scores, serum AMH significantly decreased in women with DOR. Also, AFC count had a significant decrease following increase in PRAL score (P = 0.045). After adjustment for multiple confounding variables, participants in the top quartile of PRAL had increased OR for DOR (OR: 1.26; 95%CI: 1.08-1.42, P = 0.254).

CONCLUSION

Diets with high acid-forming potential may negatively affect ovarian reserve in women with DOR. Also, high DAL may increase the risk of DOR. The association between DAL and markers of ovarian reserve should be explored in prospective studies and clinical trials.

Citrate-based dietary alkali supplements available in Germany: an overview

BACKGROUND

Fruits and vegetables are abundant in alkali precursors and effectively reduce the Potential Renal Acid Load (PRAL) from diet. Oral alkali supplements are supposed to exert comparable alkalizing effects on the human body, and have been shown to beneficially affect bone and kidney health. A comparative analysis of the available dietary alkali supplements in Germany was performed, contrasting their potential PRAL-lowering potential.

METHODS

We reviewed the currently available dietary citrate-based alkali supplements sold in Germany with a special focus on their mineral content, their PRAL-lowering potential and other characteristics inherent to each product. Supplements containing either potassium-, calcium- or magnesium citrate or any combination of these organic salts were reviewed. The total alkali load (TAL) was calculated based on the recommended daily dosage (RDD).

RESULTS

Sixteen supplements with a mean alkali powder content of 220.69 ± 111.02 g were identified. The mean magnesium content per RDD was 239.93 ± 109.16 mg. The mean potassium and median calcium content were 550 ± 325.58 mg and 280 (240) mg, respectively. Median TAL was 1220 (328.75) mg. The PRAL-lowering potential from a single RDD ranged from - 51.65 mEq to -8.32 mEq. Substantial price differences were found, and the mean price of the examined supplements was 16.67 ± 5.77 Euros. The median price for a 1 mEq PRAL-reduction was 3.01 (3.14) cents, and ranged from 0.77 cents to 10.82 cents.

CONCLUSIONS

Noticeable differences between the identified alkali supplements were encountered, warranting an individual and context-specific approach in daily clinical practice.

Quantifying the potential renal acid load of edible mushrooms

The capability of any food to alter net endogenous acid or base production can be estimated using the potential renal acid load (PRAL) estimation method. The PRAL of edible mushrooms has been rarely examined; thus a quantification study of n = 37 edible mushroom species was performed. Results revealed a heterogeneous picture: although the most commonly consumed mushrooms (e.g., Agaricus bisporus, Lentinula edodes, and Pleurotus ostreatus (white)) have alkalizing properties, several acidifying species (Volvariella volvacea, Pleurotus flabellatus) were identified, which may be attributable to their high phosphorus content.

The association of diet-dependent acid load with colorectal cancer risk: a case-control study in Korea

Acid-base disequilibrium is a contributor to cancer development because it affects molecular activities such as insulin-like growth factor 1 levels and adiponectin production. However, evidence of an association of diet-induced acid-base imbalance with colorectal cancer (CRC) is limited. We examined whether colorectal carcinogenesis is attributable to a diet with a high acid load. We recruited a total of 923 CRC cases and 1846 controls at the National Cancer Center in Korea for inclusion in a case-control study. We collected information on nutrient intake and specific clinical parameters of CRC by using a semiquantitative FFQ and medical records, respectively. Potential renal acid load (PRAL) and net endogenous acid production (NEAP) were used to estimate diet-dependent acid load. We used an unconditional logistic regression model to analyse the association. Dietary acid load scores had a positive association with the odds of CRC (OR = 2·31 (95 % CI 1·79, 2·99) and OR = 2·14 (95 % CI 1·66, 2·76) for PRAL and NEAP, respectively, Pfor trend < 0·001). A stronger positive association was observed for females (OR = 3·09, 95 % CI 1·93, 4·94) than for males (OR = 1·71, 95 % CI 1·27, 2·31). Furthermore, acidogenic diets appeared to affect rectal cancer more strongly than colon cancer in females. Our study contributes to reinforcing epidemiological evidence regarding a detrimental effect of acidogenic diets on colorectal carcinogenesis. Thus, it is important to pay attention to the balance of acidogenic (e.g. poultry and red meat) and alkalinogenic foods (e.g. fruits and vegetables) in CRC prevention, especially for females.

Effects of 8-week alkaline diet and aerobic exercise on body composition, aerobic performance, and lipid profiles in sedentary women

Background

Diet composition can affect systemic pH and acid-base regulation, which may in turn influence exercise performance.

Purpose

It was aimed to determine the effects of the alkaline diet and 8 weeks of aerobic exercises on body composition, aerobic performance, and blood lipid profiles in sedentary women.

Methods

Thirty-two sedentary women participated in the study voluntarily. The research was designed with a true-experimental design and the participants were divided into four different groups as the control group, aerobic exercise group, alkaline diet group, and alkaline diet + aerobic exercise group. The body compositions, aerobic exercise performances, and lipid profiles of sedentary women were measured as pre-test and post-test. In the analysis of the obtained data, One-Way ANOVA with Bonferroni post hoc test was used.

Results

It was observed that the alkaline diet consumed with 8 weeks of aerobic exercises caused a 5.17% decrease in BMI and an increase of 42.07 and 37.62% in VO2max and aerobic test durations, respectively (p < 0.05). In addition, when lipid profiles were examined, it was determined that there was no statistically significant difference in HDL-C levels (p > 0.05). Despite that, there were statistically significant differences in TG and LDL-C levels (p < 0.05). According to this result, it was determined that there was a decrease in TG and LDL-C levels by 37.61 and 20.24%, respectively.

Conclusion

An alkaline diet consumed with 8 weeks of aerobic exercises in sedentary women has positive effects on improving body composition, aerobic exercise performances, and TG and LDL-C levels.

Dietary acid load decreases with age and is associated with sagittal abdominal diameter: a nationally representative quantification study in US adults

BACKGROUND

Dietary acid load (DAL) has been associated with frailty and hip fractures in older adults, who often have a reduced kidney function and thus compromised buffering capacities. Studies to quantify DAL in older adults are scarce and controversies persist as to whether DAL in- or decreases with age.

AIM

To enhance the understanding of DAL in older individuals, we examined its relationship with increasing age and selected anthropometric data in a well-characterized sample of US adults.

METHODS

Secondary data analysis of nationally representative data from the National Health and Nutrition Examination Surveys data (NHANES 2011-2016). The sample included n = 3018 adults aged 60+, which may be extrapolated to represent n = 45,113,471 Americans. DAL was estimated using 4 formulas, including Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP).

RESULTS

All employed DAL scores tended to decline with increasing age. Participants aged 80 years or older yielded the lowest DAL scores. The average US citizen aged 60+ consumed an acidifying diet, yet there were sex-specific differences in the adjusted means for some scores. NEAP was positively correlated with both body mass index (r = 0.26, p < 0.001) and the sagittal abdominal diameter (r = 0.31, p < 0.001) in this nationally representative sample.

CONCLUSION

The previously reported phenomenon of increasing DAL values in older people in non-Western countries may not apply to the US. Our findings may constitute an important step towards a better understanding of DAL in older US adults, and highlight the need for additional population-specific research in the field.

Dietary Acid Load Correlates with Serum Amino Acid Concentrations after a Four-Week Intervention with Vegan vs. Meat-Rich Diets: A Secondary Data Analysis

Chronic low-grade metabolic acidosis is now a common phenomenon in the Western world. The high dietary intake of sulfur-containing amino acids in the form of processed meats results in an excessive release of acid in the form of protons and non-metabolizable acidic anions. The kidneys produce increasing amounts of ammonia to excrete this acid. This process requires the breakdown of the nitrogenous amino acid glutamine, which the body provides by breaking down muscle tissue. Hitherto not examined, we hypothesized that a high dietary acid load (DAL) could alter the serum concentrations of selected amino acids. Using secondary data from a 4-week dietary intervention study conducted in 2017, we examined the associations between various amino acids and DAL in n = 42 individuals who either consumed a meat-rich or vegan diet. Results from this secondary data analysis suggested that DAL (as measured by the potential renal acid load and net endogenous acid production) is positively correlated with higher serum concentrations of lysine and 1-methyl-histidine (r = 0.50 and 0.43, respectively) and negatively correlated with glutamine and glycine (r = -0.43 and -0.47, respectively). The inverse association with glycine and glutamine warrants special attention, as both play an important role in many metabolic disorders and the immune system.

The Impact of Plant-Based Diets on Dietary Acid Load Metrics in Venezuela: A Cross-Sectional Study

Dietary acid load (DAL) is an important determinant of the acid-base balance in humans and has been associated with several chronic non-communicable diseases. Plant-based diets, including vegetarian and vegan diets, decrease DAL-although their alkalizing potential varies substantially. Their net effect on common DAL scores, including potential renal acid load and net endogenous acid production, has been insufficiently quantified and is poorly understood-particularly in populations outside of Europe and North America. We assessed the associations between three plant-based dietary patterns (flexitarian vs. lacto-ovo-vegetarian vs. vegan diet) and DAL scores in a healthy Venezuelan population in the metropolitan area of Puerto La Cruz, Venezuela. Substantial differences in DAL scores were observed, whereby the vegan diet yielded the highest alkalizing potential, followed by the lacto-ovo-vegetarian and the flexitarian diet. DAL scores were substantially lower in comparison to European and North American plant-based populations, probably due to the higher potassium intake (exceeding 4000 mg/d in vegans), the higher magnesium intake (390.31 ± 1.79 mg/d in vegans) and the lower intake of protein in vegans and lacto-ovo-vegetarians. Additional studies in other non-industrialized populations are warranted to allow for a better understanding of the (numeric) impact of plant-based dietary patterns on DAL scores, potentially allowing for an establishment of reference ranges in the near future.

Diet quality and dietary acid load in relation to cardiovascular disease mortality: Results from Fasa PERSIAN cohort study

Dietary intake is a determining factor in the morbidity and mortality of chronic disorders. However, not many documents have investigated this relationship. The aim of this study was to evaluate the associations of the Mediterranean dietary score (MDS), Alternative Healthy Eating Index (AHEI), Dietary Inflammatory Index (DII), DASH score, and dietary acid load with cardiovascular disease (CVD) mortality. A total of 2158 CVD patients (mean age of 54.73 ± 8.62 years) from the Fasa cohort study, Iran, participated in the current study. Diet quality indices including DII, AHEI, MDS, DASH, and dietary acid load (NEAP score) were computed using a validated 125-item Food Frequency Questionnaire (FFQ). Cox regression analyses were used to determine HRs and 95% CIs. During a follow-up of 3 years, we documented 59 CVD deaths. After adjusting for relevant confounders (age, gender, family history of CVD, smoking, physical activity, alcohol intake, and HTN) in the final model, we found that higher DII scores and dietary acid load were significantly related to increased mortality due to CVD (HR = 1.11; 95% CI = 1.01-1.24; and HR = 1.02; 95% CI = 1.01-1.03). However, the DASH score was insignificantly associated with decreased CVD mortality by 20.4% (HR = 0.79; 95% CI = 0.57-1.09). There was no significant relationship among AHEI score, MDS, and CVD mortality. This study showed that increasing dietary acidity and the use of inflammatory food compounds could contribute to CVD mortality. Also, adherence to the DASH diet may be associated with reduced CVD mortality.

How Well Do Low-PRAL Diets Fare in Comparison to the 2020-2025 Dietary Guidelines for Americans?

The regular consumption of net acid-producing diets can produce "acid stress" detrimental to human health. Alkalizing diets characterized by a negative potential renal acid load (also called low-PRAL diets (LPD)) enjoy uninterrupted popularity. However, the nutritional adequacy of said diets has rarely been assessed in large populations. Using data from the National Health and Nutrition Examination Surveys, we estimated nutrient intake in individuals consuming an LPD and contrasted the results in an age- and sex-specific manner to individuals on an acidifying diet (high-PRAL diet, HPD). Both groups were compared with the daily nutritional goals (DNG) specified in the 2020-2025 Dietary Guidelines for Americans (DGA). Our analysis included 29,683 individuals, including 7234 participants on an LPD and 22,449 participants on an HPD. Individuals on an LPD numerically met more nutritional goals than individuals on an HPD, yet both failed to meet the goals for several nutrients of public health concern (vitamin D and calcium). As opposed to individuals on an HPD, LPD consumers met the DGA recommendations for saturated fat and potassium. Individuals on an LPD consumed significantly more fiber than individuals on an HPD, as well as yielded a more favorable potassium-to-sodium intake ratio.

Long-term dietary acid load is associated with depression in multiple sclerosis, but less evidence was found with fatigue and anxiety

BACKGROUND

Diet-dependent acid-base load has been associated with worsening in mental health, but to date no study has examined this in people with multiple sclerosis (PwMS). We examined the association between potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores and depression, anxiety, and fatigue in PwMS.

METHODS

Participants with a first clinical diagnosis of CNS demyelination were followed prospectively as part of the AusLong Study (aged 18-59 years at cohort entry). At baseline, 5- and 10-year reviews, PRAL and NEAP scores were calculated using dietary intake in the preceding 12 months calculated from a food frequency questionnaire. At 5- and 10-year reviews, the Hospital Anxiety and Depression Scale was used to assess depression and anxiety, and the Fatigue Severity Scale assessed fatigue.

RESULTS

Higher PRAL and NEAP scores were associated with increased subsequent absolute value and change in HADS depression scores over five years' follow-up (e.g., highest vs lowest PRAL quartile, 5-year change in HADS-D score: β=+3.01, 95%CI= 1.54, 4.48, p<0.001). The level of depression at the 10-year review was determined by both the baseline dietary acid scores and baseline-5-year changes in dietary acid scores (e.g., PRAL change from baseline to 5-year review, 10-year review HADS-D score: β=+0.09, 95%CI= 0.03, 0.15, p<0.001, NEAP change from baseline to 5-year review, 10-year review HADS-D score: β=+0.07, 95%CI= 0.01, 0.14, p=0.03). Some associations were observed with anxiety and fatigue but were much weaker and less consistent.

CONCLUSION

Our findings indicate that a higher dietary acid load potentially has a long-term influence on the level of depression in PwMS. The evidence is less convincing for anxiety and fatigue.

The association between dietary acid load and body composition in physical education students aged 18-25 years

AIM

To find the association between dietary acid load (DAL) and body composition in physical education students.

METHODS

This study was carried out on 207 students of both genders aged 18-25 years. DAL was calculated based on potential renal acid load (PRAL) and net endogenous acid production (NEAP) methods. Anthropometric indices were measured. Bioelectric impedance was used to assess body composition and other related items.

RESULTS

The mean score of NEAP and PRAL was 80.18 ± 31.30 and 33.94 ± 22.11, respectively. The mean weight and fat mass of subjects were 64.05 ± 9.72 kg and 20.28 ± 0.67 kg, respectively. Participants in the highest tertile of PRAL had a higher weight (64.56 ± 1.14 kg) in comparison with participants in the lowest tertile (61.65 ± 1.19 kg) (P = 0.027). After adjusting for confounders, a significant positive association was found between NEAP score and hip circumference (β = 0.206, P = 0.039), body mass index (β = 0.214, P = 0.031), fat mass (β = 0.218, P = 0.001) and body adiposity index (β = 0.182, P = 0.037). Furthermore, a statistically significant negative association was observed between total body water and NEAP score (β = - 0.217, P = 0.001) and the percentage of fat-free mass and NEAP (β = - 0.229, P = 0.001).

CONCLUSION

Individuals with a higher DAL score may have a higher weight, fat mass and hip circumference and a lower fat-free mass. In addition, there might be an association between DAL and obesity.

Observational and clinical evidence that plant-based nutrition reduces dietary acid load

Contemporary diets in Western countries are largely acid-inducing and deficient in potassium alkali salts, resulting in low-grade metabolic acidosis. The chronic consumption of acidogenic diets abundant in animal-based foods (meats, dairy, cheese and eggs) poses a substantial challenge to the human body's buffering capacities and chronic retention of acid wherein the progressive loss of bicarbonate stores can cause cellular and tissue damage. An elevated dietary acid load (DAL) has been associated with systemic inflammation and other adverse metabolic conditions. In this narrative review, we examine DAL quantification methods and index observational and clinical evidence on the role of plant-based diets, chiefly vegetarian and vegan, in reducing DAL. Quantitation of protein and amino acid composition and of intake of alkalising organic potassium salts and magnesium show that plant-based diets are most effective at reducing DAL. Results from clinical studies and recommendations in the form of expert committee opinions suggest that for a number of common illnesses, wherein metabolic acidosis is a contributing factor, the regular inclusion of plant-based foods offers measurable benefits for disease prevention and management. Based on available evidence, dietary shifts toward plant-based nutrition effectively reduces dietary-induced, low-grade metabolic acidosis.

Carbohydrate Intake and Its Association With Dietary Acid Load in U.S. Adults: Results From a Cross-Sectional Study

Background: The safety profile of low-carbohydrate diets is controversial and poorly understood. We investigated the effects of low-moderate carbohydrate intake on dietary acid load (DAL), an emerging health risk factor and novel clinical marker associated with numerous adverse clinical outcomes. Methods: We used data from the National Health and Nutrition Examination Surveys to investigate how low-moderate carbohydrate intake quantitatively affects DAL (as assessed by PRAL and NEAP scores) and to contrast the results to DAL scores in individuals that meet carbohydrate intake recommendations. Results: We analyzed data from 23 825 individuals, of which 4891 consumed a low-moderate carbohydrate diet. Said individuals derived 37.84% of energy from carbohydrates, tended to be male, had a mean BMI of 28.47 kg/m2, and consumed significantly more energy from fat and protein ( P≤.01 for both) than individuals that met carbohydrate recommendations Low-moderate carbohydrate intake was associated with a significantly higher DAL. Mean PRALR, NEAPR, and NEAPF values were 26.12, 71.02, and 68.98 mEq/d, respectively. Multivariate regression revealed the highest DAL scores in individuals on a low-carbohydrate diet, obtaining <26% of energy from carbohydrates. Conclusions: Low-moderate carbohydrate intake is associated with increased DAL scores, which has been repeatedly associated with various health repercussions.

Dietary Acid Load in Gluten-Free Diets: Results from a Cross-Sectional Study

The gluten-free diet (GFD) ensures improvement of clinical symptoms in the vast majority of celiac disease (CD) patients. Despite stable CD rates in many countries, an increasing number of healthy individuals are adopting gluten-free diets, believing that this diet is an inherently healthier choice. The health effects of gluten-free diets are controversial, and a recent study added to the debate by reporting a lower acidogenic potential of this diet. The effects of the GFD on potential renal acid load (PRAL) and net endogenous acid production (NEAP)—two important markers of dietary acid load (DAL)—are poorly understood, and have never been examined in a Western population. Using cross-sectional data from the National Health and Nutrition Examination Surveys, we estimated DAL in U.S. individuals reporting a GFD and contrasted the results to the general U.S. population consuming gluten and denying special diets. The GFD was associated with significantly lower crude DAL scores, and after adjustments for confounders in multivariate regression, the results remain significant. Yet, our study could not confirm the reported alkalizing properties of the GFD. Although overall DAL scores were significantly lower in the GFD group, they were comparable to Western diets producing 50–75 mEq of acid per day.

Reduced dietary acid load in U.S. vegetarian adults: Results from the National Health and Nutrition Examination Survey

Dietary acid load (DAL) is an important determinant of systemic pH and acid-base homeostasis. Diets abundant in acidogenic foods, such as meat and meat products, induce a low-grade metabolic acidosis state that has been associated with cardiovascular disease, type-2-diabetes, and an increased cancer risk. Fruits and vegetables have alkalizing properties and beneficially affect DAL. It has thus been suggested that a plant-based diet (restricting or excluding animal products) may be a powerful tool in reducing DAL; yet studies in that particular field are scarce. To explore these associations in greater detail, we examined DAL in self-identified vegetarians from the United States National Health and Nutrition Examination Survey (2007-2010). We compared dietary intake and two widely used markers of DAL (PRAL (potential renal acid load) and NEAP (net endogenous acid production; NEAPF and NEAPR)) among 8,398 nonvegetarians and 191 lacto-ovo-vegetarians with reliable dietary intake aged 18 years or older. Vegetarians had a more favorable body mass index and consumed fewer calories (1862.31 kcal/d) than nonvegetarians (2041.12 kcal/d). Vegetarians consumed fewer protein (34.17 g/1000 kcal) and phosphorus compared to nonvegetarians (39.50 g of protein/1000 kcal) but had a higher intake of magnesium and potassium. Nonvegetarians exhibited higher median DAL scores (PRAL: 11.90 mEq/d, NEAPF: 53.59 mEq/d, NEAPR: 55.67 mEq/d) than vegetarians (PRAL: -0.44 mEq/d, NEAPF: 39.60 mEq/d, NEAPR: 41.30 mEq/d). Vegetarians had more favorable DAL scores compared to nonvegetarians in this descriptive epidemiologic study. Future (interventional) trials are warranted to examine the varying acid load in different plant-based dietary patterns.

Plant-Based Diets and Cancer Risk: What is the Evidence?

PURPOSE OF REVIEW

The purpose of this review is to summarize the recent (past 5 years) available evidence regarding the association between plant-based diets on cancer risk from clinical trials and observational studies. Biological mechanisms and gaps in the current literature will also be discussed.

RECENT FINDINGS

There is a lack of intervention studies but there are abundant observational studies assessing the association between plant-based diets and cancer risk, including multiple longitudinal cohort studies and similar data from case-control studies that demonstrate a decreased overall cancer risk with plant-based diets. Case-control studies support a decreased risk of colorectal and breast cancers with plant-based diets, but results for specific cancers remain inconsistent in cohort studies. Current evidence from observational studies indicates an inverse association between plant-based diets and overall cancer risk. Future research should include intervention studies, address inconsistencies in dietary assessment methods and provide greater detail on underrepresented groups.

Nutrient Intake and Dietary Acid Load of Special Diets in the NHANES: A Descriptive Analysis (2009-2018)

Western diets are characterized by a high dietary acid load (DAL), which has been associated with adverse clinical outcomes, including type-2-diabetes and metabolic syndrome. Effective dietary strategies to lower DAL are urgently warranted. Plant-based diets (PBD), including vegetarian and vegan diets, are an effective measure to reduce DAL. Notably, not every individual wishes to adopt a PBD. Instead, many people rely on special diets promising comparable health benefits. The effects of those diets on DAL have rarely been investigated. Using data from the National Health and Nutrition Examination Surveys, we aimed to quantify DAL and nutrient intake in the most popular special diets in the United States, including weight-loss, low fat, low salt, low sugar, and diabetic diets. Our analysis included 3552 individuals on a special diet. The most popular diets were the weight-loss diet (n = 1886 individuals) and the diabetic diet (n = 728). Energy intake was below 2000 kcal/d for all diets; however, there were no statistically significant intergroup differences. DAL scores were positive for all special diets (>9 mEq/d), suggesting acidifying properties. Acid load scores of special diets did not differ significantly and were comparable to a standard Western diet. None of the examined diets was associated with alkaline properties.

Quantifying dietary acid load in U.S. cancer survivors: an exploratory study using NHANES data

BACKGROUND

Diet is an important determinant of systemic pH and acid-base regulation. A frequent consumption of acid-inducing foods (including processed meats and cheese) combined with a low intake of base-inducing foods (such as fruits, legumes and vegetables) increases Dietary Acid Load (DAL), which has been associated with an increased risk for certain cancers. DAL also appears to be of paramount importance in cancer survivors, in whom it was associated with increased mortality and poor overall physical health. Literature on DAL in cancer survivors, however, is scarce and limited to a few studies.

METHODS

Using cross-sectional data from the National Health and Nutrition Examination Surveys (NHANES), we sought to quantify DAL in U.S. cancer survivors and contrasted the results to the general population. DAL was estimated using established formulas (Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP)).

RESULTS

Our study comprised 19,413 participants, of which 1444 were self-reported cancer survivors. Almost 63% of cancer survivors were female (weighted proportion) with a mean age of 61.75 (0.51) years. DAL scores were consistently higher in cancer survivors (as compared to the general population) after adjustment for confounders in multivariate regression models. These differences, however, were not statistically significant (p = 0.506 for NEAPF, 0.768 for PRALR and 0.468 for NEAPR, respectively). Notably, DAL scores were positive throughout (> 0 mEq/d) in cancer survivors, suggesting an acidifying diet. Specific examples include mean PRALR scores > 11 mEq/d in cancer survivors aged 55 years and mean NEAPF scores > 50 mEq/d in cancer survivors aged 40-60 years).

CONCLUSIONS

The acidifying diet in this sample of cancer survivors warrants caution and requires further investigation. Comparably high DAL scores have been associated with adverse health outcomes and an increased mortality in previous studies in breast cancer survivors. Thus, increased awareness as well as additional clinical trials in this field are urgently warranted.

Dietary acid load and cardiovascular diseases

Diet affects the body's acid-base balance by providing acid or alkali precursors in the metabolism. The importance of the acid-base balance of the diet for cardiovascular diseases, which have become the most important cause of morbidity on the global scale, has started to take its place in the literature. The prediction of endogenous acid production in dietary acid-base balance is expressed as dietary acid load. Although the available information about the effect of dietary acid load on cardiovascular diseases is limited, possible mechanisms are indicated as excessive calcium and magnesium excretion from the kidneys, reduced urinary citrate excretion, and excessive cortisol production. Metabolic acidosis has an important role in the development of cardiometabolic abnormalities, especially insulin resistance. Studies examining the relationship between dietary acid load and cardiovascular disease are limited and there is an inconsistency between studies. Practices for determining risk factors for cardiovascular diseases and preventing their effects are very important for the protection and improvement of health. Considering dietary acid load when planning a diet for individuals with cardiovascular diseases can help increase the effectiveness of the diet. The purpose of this review is to examine the effect of dietary acid load on cardiovascular diseases.

Analysis of S-Adenosylmethionine and S-Adenosylhomocysteine: Method Optimisation and Profiling in Healthy Adults upon Short-Term Dietary Intervention

S-adenosylmethionine (SAM) is essential for methyl transfer reactions. All SAM is produced de novo via the methionine cycle. The demethylation of SAM produces S-adenosylhomocysteine (SAH), an inhibitor of methyltransferases and the precursor of homocysteine (Hcy). The measurement of SAM and SAH in plasma has value in the diagnosis of inborn errors of metabolism (IEM) and in research to assess methyl group homeostasis. The determination of SAM and SAH is complicated by the instability of SAM under neutral and alkaline conditions and the naturally low concentration of both SAM and SAH in plasma (nM range). Herein, we describe an optimised LC-MS/MS method for the determination of SAM and SAH in plasma, urine, and cells. The method is based on isotopic dilution and employs 20 µL of plasma or urine, or 500,000 cells, and has an instrumental running time of 5 min. The reference ranges for plasma SAM and SAH in a cohort of 33 healthy individuals (age: 19-60 years old; mean ± 2 SD) were 120 ± 36 nM and 21.5 ± 6.5 nM, respectively, in accordance with independent studies and diagnostic determinations. The method detected abnormal concentrations of SAM and SAH in patients with inborn errors of methyl group metabolism. Plasma and urinary SAM and SAH concentrations were determined for the first time in a randomised controlled trial of 53 healthy adult omnivores (age: 18-60 years old), before and after a 4 week intervention with a vegan or meat-rich diet, and revealed preserved variations of both metabolites and the SAM/SAH index.

Non-Pharmacological Treatments for Insulin Resistance: Effective Intervention of Plant-Based Diets—A Critical Review

Plant-based diets are becoming increasingly popular. Vegetarian diets are better for the environment and exhibit health benefits. A correctly balanced plant-based diet is appropriate at every stage of life. Compared to omnivores, vegetarians consume more fruits and vegetables, more fibre, vitamins C and E, magnesium and less saturated fats. In general, they have better nutrition knowledge, and they are slimmer, healthier and live longer than omnivores. It also seems that following a plant-based diet prevents the onset of chronic diseases such as cardiovascular diseases, hypertension, type 2 diabetes, obesity and some cancers. Food intake has a key influence on insulin resistance. Consumption of calorie-rich and highly processed foods, meats and sweetened beverages is a characteristic element of Western diets. They promote and elevate insulin resistance and type 2 diabetes. In contrast, intake of pulses and exclusion of meats as well as animal products bring significant benefits to vegetarian diets. According to studies, vegetarians and vegans have better blood parameters, including better glucose, insulin, total cholesterol, and LDL cholesterol levels. Their homeostatic model assessment for insulin resistance (HOMA-IR) test results are also better. More plant-based foods and fewer animal foods in a diet result in lower insulin resistance and a lower risk of prediabetes and type 2 diabetes. The aim of the study was to investigate the effect of plant-based diets on insulin resistance. In this review, we focused on presenting the positive effects of vegetarian and vegan diets on insulin resistance while showing possible clinical applications of plant-based diets in the treatment and prevention of modern-age diseases. Current and reliable publications meeting the requirements of Evidence-Based Medicine (EBM) were taken into account in this review.

Circulating Inflammatory Markers May Mediate the Relationship between Healthy Plant-Based Diet and Metabolic Phenotype Obesity in Women: A Cross-Sectional Study

BACKGROUND

It has been posited that both metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUHO) could be emergent from diet and inflammatory markers. Thus, we sought to investigate the influence of plant-based diet on MHO and MUHO phenotypes mediated by inflammatory markers in overweight and obese women.

METHODS

This cross-sectional study was conducted on 289 women aged ≥18 years, with a body mass index (BMI) ≥25 kg/m². Dietary intake was measured using 147 item food frequency questionnaire, as well as anthropometrics and biochemistry panel, in all participants. Metabolic health phenotypes were considered using Karelis score, while plant-based diet indices (PDI) were evaluated based on 18 food groups, where healthy and unhealthy PDI were identified.

RESULTS

Accordingly, 26.9% of women had MHO and 73.1% had MUHO phenotypes. After adjusting for potential confounders, TGF-β1 had a significant inverse association with hPDI (β: -0.28; 95% CI: 452.99, -85.25; P: 0.004). Moreover, we found that women with higher hPDI had lower odds of MUHO (OR: 0.95; 95% CI: 0.39, 2.30; P: 0.03). Regarding the mediatory effect of the inflammatory markers, TGF-β1 (P: 0.73), IL-β1 (P: 0.14), and MCP1 (P: 0.51) played a role in decreasing the odds of MUHO among hPDI tertiles.

CONCLUSION

There was a significant inverse relationship between adherence to hPDI and MUHO phenotype in overweight and obese Iranian women. This association appeared to be mediated by TGF-β1, IL-β1, and MCP1.

Placing a Well-Designed Vegan Diet for Slovenes

Interest in vegan diets has increased globally as well as in Slovenia. The quantity of new scientific data requires a thorough synthesis of new findings and considerations about the current reserved position of the vegan diet in Slovenia. There is frequently confusion about the benefits of vegetarian diets that are often uncritically passed on to vegan diets and vice versa. This narrative review aims to serve as a framework for a well-designed vegan diet. We present advice on how to maximize the benefits and minimize the risks associated with the vegan diet and lifestyle. We highlight the proper terminology, present the health effects of a vegan diet and emphasize the nutrients of concern. In addition, we provide guidance for implementing a well-designed vegan diet in daily life. We conducted a PubMed search, up to November 2021, for studies on key nutrients (proteins, vitamin B12, vitamin D, omega-3 long chain polyunsaturated fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), calcium, iron, zinc, iodine and selenium) in vegan diets. Given the limited amount of scientific evidence, we focus primarily on the general adult population. A well-designed vegan diet that includes a wide variety of plant foods and supplementation of vitamin B12, vitamin D in the winter months and potentially EPA/DHA is safe and nutritionally adequate. It has the potential to maintain and/or to improve health. For physically active adult populations, athletes or individuals with fast-paced lifestyles, there is room for further appropriate supplementation of a conventional vegan diet according to individuals' health status, needs and goals without compromising their health. A healthy vegan lifestyle, as included in government guidelines for a healthy lifestyle, includes regular physical activity, avoidance of smoking, restriction of alcohol and appropriate sleep hygiene.

A Vegan Diet Is Associated with a Significant Reduction in Dietary Acid Load: Post Hoc Analysis of a Randomized Controlled Trial in Healthy Individuals

The composition of diet strongly affects acid–base homeostasis. Western diets abundant in acidogenic foods (meat and cheese) and deficient in alkalizing foods (fruits and vegetables) increase dietary acid load (DAL). A high DAL has been associated with numerous health repercussions, including cardiovascular disease and type-2-diabetes. Plant-based diets have been associated with a lower DAL; however, the number of trials exploring this association is limited. This randomized-controlled trial sought to examine whether an isocaloric vegan diet lowers DAL as compared to a meat-rich diet. Forty-five omnivorous individuals were randomly assigned to a vegan diet (n = 23) or a meat-rich diet (n = 22) for 4 weeks. DAL was determined using potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores at baseline and after 3 and 4 weeks, respectively. After 3 weeks, median PRAL (−23.57 (23.87)) and mean NEAP_R (12.85 ± 19.71) scores were significantly lower in the vegan group than in the meat-rich group (PRAL: 18.78 (21.04) and NEAP_R: 60.93 ± 15.51, respectively). Effects were mediated by a lower phosphorus and protein intake in the vegan group. Our study suggests that a vegan diet is a potential means to reduce DAL, whereas a meat-rich diet substantially increases the DAL burden.