The link between plant-based diet indices with biochemical markers of bone turn over, inflammation, and insulin in Iranian older adults

Unraveling the role of serum metabolites in the relationship between plant-based diets and bone health in community-dwelling older adults

The potential adverse effects of the plant-based dietary pattern on bone health have received widespread attention. However, the biological mechanisms underlying the adverse effects of plant-based diets on bone health remain incompletely understood. The objective of this study was to identify potential biomarkers between plant-based diets and bone loss utilizing metabolomic techniques in the Taizhou Imaging Study (TIS) (N = 788). Plant-based diet indexes (overall plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI)) were calculated using the food frequency questionnaire, and bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. A multinomial logistic regression was used to explore the associations of plant-based diet indexes with bone loss. Furthermore, mediation analysis and exploratory factor analysis (EFA) were performed to explore the mediated effects of metabolites on the association of plant-based diets with BMD T-score. Our results showed that higher hPDI and uPDI were positively associated with bone loss. Moreover, nineteen metabolites were significantly associated with BMD T-score, among them, seven metabolites were associated with uPDI. Except for cholesterol esters in VLDL-1, the remaining six metabolites significantly mediated the negative association between uPDI and BMD T-score. Interestingly, we observed that the same six metabolites mediated the positive association between fresh fruit and BMD T-score. Collectively, our results support the deleterious effects of plant-based diets on bone health and discover the potential mediation effect of metabolites on the association of plant-based diets with bone loss. The findings offer valuable insights that could optimize dietary recommendations and interventions, contributing to alleviate the potential adverse effects associated with plant-based diets.

Intake of dietary flavonoids in relation to bone loss among U.S. adults: a promising strategy for improving bone health

Dietary flavonoids have been recommended for improving bone health due to their antioxidant, anti-inflammatory and osteogenic properties. However, the effectiveness of each flavonoid subclass in the prevention and treatment of osteoporosis remains controversial. The objective of the current study was to examine the association between the intake of flavonoid subclasses and bone loss in 10 480 U.S. adults in the National Health and Nutrition Examination Survey. We employed a multinomial logistic regression model to calculate the odds ratios (OR) and 95% confidence intervals (95% CI). The intake of flavones, isoflavones, and flavanones was beneficially associated with osteoporosis (ORQ5 vs. Q1 = 0.44; 95% CI: 0.30-0.64 for flavones; ORQ5 vs. Q1 = 0.53; 95% CI: 0.37-0.77 for isoflavones; ORQ5 vs. Q1 = 0.66; 95% CI: 0.45-0.97 for flavanones). A higher intake of flavones and flavanones was significantly associated with a lower risk of bone loss at the femoral neck rather than the lumbar spine. Notably, stratified analysis showed that genistein had a harmful association with osteopenia in the population with lower serum calcium levels, whereas it had a beneficial association with osteoporosis in the population with higher serum calcium levels. Multiple sensitivity analyses were performed to test the robustness of the results, including subgroup analysis, exclusion of individuals' use of anti-osteoporosis, corticosteroid, and estrogenic medications, adjusting more potential confounders and calculation of the E-value. Overall, incorporating this modifiable diet into an individual's lifestyle could provide potential possibilities to prevent and ameliorate osteoporosis.

Vegan diet: nutritional components, implementation, and effects on adults' health

Vegan diet has emerged as a popular dietary choice for people worldwide in recent times, due to concerns such as health issues, animal rights and welfare, and the sustainability of the environment. The purpose of this literature review was to explain how a vegan diet may affect the health of adults and to point out beneficial components found in it as well as any difficulties associated with its implementation. Evidence supports that a vegan diet can reduce the risk of chronic diseases, such as type 2 diabetes, hypertension, and certain types of cancer. A well-planned vegan diet must include adequate calories and nutrients, as well as the necessary supplements, such as vitamin B12, vitamin D and EPA/DHA. Given the current growing interest in plant-based diets among the general population, it is crucial to understand both the barriers, risks, and benefits of the vegan diet among physicians, policy makers, and the general population.

Scoping review of the association of plant-based diet quality with health outcomes

Introduction

The association of plant-based dietary patterns with health outcomes has traditionally been assessed without considering nutritional value. The plant-based dietary index (PDI), first published in 2016, overcomes this limitation with both a healthful PDI (hPDI) and an unhealthful PDI (uPDI), based on the quality of plant foods consumed plus the frequency of animal foods. We sought to summarize the breadth of research using the hPDI and uPDI to gain insight into how the quality of plant-based dietary patterns might be associated with health outcomes.

Methods

Scoping review of studies that used the PDI, hPDI, or uPDI to report associations with health outcomes. Multiple databases were searched from 2010 through April 2023 with 2 authors independently assessing eligibility and extracting data. In addition to assessing the association of the indices to health outcomes, we determined the frequency of concordant or discordant findings for hPDI versus PDI and for hPDI versus uPDI.

Results

We included 95 articles (54% longitudinal, 37% cross-sectional, and 9% case-control) with a median sample size of 3,646. Higher hPDI levels were associated with favorable health outcomes in 36% of comparisons (most often for obesity, mortality, diabetes, cardiovascular disease, and psychiatric disorders), compared to 25% for the PDI and only 2% for the uPDI. Conversely, higher levels of the uPDI were associated with unfavorable health outcomes in 33% of comparisons, in contrast to under 1% for the hPDI and 2% for the PDI. When the hPDI association to an outcome was discordant with the uPDI or PDI, the significance and directionality always favored the hPDI over the uPDI, and nearly always favored the hPDI over the PDI.

Discussion

Dietary indices that account for the quality of plant foods can show health benefits that might be missed by a generic plant-based index. A greater focus on the quality of plant foods could improve nutrition guidelines, raise awareness about the benefits of adding unrefined plant foods to the diet, and empower consumers to make incremental additions of such foods to displace unhealthy foods. We anticipate increasing use of indices that address food quality in future research.

Interactions Between Genetic Risk Score and Healthy Plant Diet Index on Cardiometabolic Risk Factors Among Obese and Overweight Women

People with higher genetic predisposition to obesity are more susceptible to cardiovascular diseases (CVDs) and healthy plant-based foods may be associated with reduced risks of obesity and other metabolic markers. We investigated whether healthy plant-foods-rich dietary patterns might have inverse associations with cardiometabolic risk factors in participants at genetically elevated risk of obesity. For this cross-sectional study, 377 obese and overweight women were chosen from health centers in Tehran, Iran. We calculated a healthy plant-based diet index (h-PDI) in which healthy plant foods received positive scores, and unhealthy plant and animal foods received reversed scores. A genetic risk score (GRS) was developed based on 3 polymorphisms. The interaction between GRS and h-PDI on cardiometabolic traits was analyzed using a generalized linear model (GLM). We found significant interactions between GRS and h-PDI on body mass index (BMI) (p = 0.02), body fat mass (p = 0.04), and waist circumference (p = 0.056). There were significant gene-diet interactions for healthful plant-derived diets and BMI-GRS on high-sensitivity C-reactive protein (p = 0.03), aspartate aminotransferase (p = 0.04), alanine transaminase (p = 0.05), insulin (p = 0.04), and plasminogen activator inhibitor 1 (p = 0.002). Adherence to h-PDI was more strongly related to decreased levels of the aforementioned markers among participants in the second or top tertile of GRS than those with low GRS. These results highlight that following a plant-based dietary pattern considering genetics appears to be a protective factor against the risks of cardiometabolic abnormalities.

The Hidden Dangers of Plant-Based Diets Affecting Bone Health: A Cross-Sectional Study with U.S. National Health and Nutrition Examination Survey (NHANES) Data from 2005-2018

The plant-based dietary pattern has been recommended for its potential health and environmental benefits, but its association with bone loss needs to be further explored. This study aimed to investigate the association between three plant-based diet indexes and bone loss in 16,085 adults, using data from the National Health and Nutrition Examination Survey. Three plant-based diet indexes (PDI, hPDI, and uPDI) were calculated from two NHANES 24-h dietary recall interviews, to characterize a plant-based diet. A multinomial logistic regression model was used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI). Higher hPDI and PDI were associated with increased risk of bone loss (OR_{Q5 vs. Q1} = 1.50; 95% CI: 1.24-1.81 for hPDI; OR_{Q5 vs. Q1} = 1.22; 95% CI: 1.03-1.45 for PDI), while higher uPDI was associated with increased risk of osteoporosis (OR_{Q5 vs. Q1} = 1.48; 95% CI: 1.04-2.11). A harmful association between plant-based diet indexes (hPDI and PDI) and osteopenia was observed at the lumbar spine rather than the femoral neck. We conducted several sensitivity analyses to ensure the robustness of results, including subgroup analysis, exclusion of people taking anti-osteoporotic and estrogenic drugs, further adjustment for menopausal status, corticosteroid usage, and dietary supplements, and calculation of E-value. Our study demonstrates the deleterious effects of a plant-based diet on bone health and emphasizes the importance of a balanced diet.

Healthy plant-based diet index as a determinant of bone mineral density in osteoporotic postmenopausal women: A case-control study

Introduction

The association between plant-based diet indices and bone mineral density (BMD) of women with osteoporosis have not been studied in Iranian women. This study aimed to evaluate the association between plant-based diet indices and BMD in postmenopausal women with osteopenia/osteoporosis.

Materials and methods

The present research was a case-control study conducted on 131 postmenopausal women with osteoporosis/osteopenia and 131 healthy women. The BMD of the femoral neck and lumbar vertebrae was measured by the Dual-energy X-ray absorptiometry (DXEA) method. Participants were asked to complete a validated semi-quantitative food frequency questionnaire (FFQ). We used three versions of plant-based diet indices, including plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI). Two different multivariable logistic regression was used for the crude and adjusted model to assess the relationship between PDI, hPDI, and uPDI with odds of femoral and lumbar BMD.

Results

There was a reverse association between last tertile of hPDI with femoral BMD abnormality in the both adjusted model [Model 1: odds ratio (OR): 0.33; 95% confidence interval (CI): 0.19-0.63 and Model 2: OR: 0.30; 95% CI: 0.15-0.58, respectively]. Furthermore, we found a reverse relationship between hPDI with lumbar BMD abnormality in the first adjusted model (OR: 0.36; 95% CI: 0.19-0.67). On the other hand, a negative association was observed in the second and last tertile of hPDI with lumbar BMD abnormality (OR: 0.47; 95% CI: 0.24-0.90 and OR: 0.34; 95% CI: 0.17-0.64, respectively). According to the results, the association of femoral BMD abnormality in the last tertile of uPDI compared to the first tertile in the both adjusted models (Model 1: OR: 2.85; 95% CI: 1.52-5.36 and Model 2: OR: 2.63; 95% CI: 1.37-5.06) were significant. Also, we observed a positive relationship between the last tertile of uPDI with lumbar BMD abnormality compared to the lowest tertile in the both adjusted models (Model 1; OR: 4.16; 95% CI: 2.20-7.85, Model 2; OR: 4.23; 95% CI: 2.19-8.19).

Conclusion

Overall, the findings indicated that in postmenopausal women with osteoporosis, a healthy plant-based diet could prevent bone loss, and an unhealthy plant-based diet might have detrimental effects on BMD.

The value of dietary plant protein in older people

PURPOSE OF REVIEW

The current review provides an update on recent research regarding plant-based protein and their nutritional quality for older people.

RECENT FINDINGS

There is growing evidence that plant-based proteins may be a valuable strategy for older people to prevent the health risks associated with consuming animal products and to promote better protein intake, as plant-based protein sources are rich in fibres and micronutrients. Although plant-based proteins are less anabolic than animal-derived proteins due to lower digestibility and deficiencies in some essential amino acids, several innovations in food processing and nutritional strategies have been developed to improve the quality of plant-based proteins. For example, the use of protein blends or green-processes as fermentation or germination could improve the nutritional qualities of plant-based foods that could be beneficial for older people, especially to prevent sarcopenia or metabolic disorders such as diabetes, obesity and cardiovascular diseases.

SUMMARY

The use of plant-based protein sources could help older people diversify their protein sources and more easily meet recommended nutritional intake. Recent literature highlights several health benefits associated with increased consumption of vegetable foods. However, their efficiency on postprandial muscle protein synthesis remains to be evaluated and long-term studies are needed.