Trans-vaccenic acid reprograms CD8+ T cells and anti-tumour immunity.

Diet-derived nutrients are inextricably linked to human physiology by providing energy and biosynthetic building blocks and by functioning as regulatory molecules. However, the mechanisms by which circulating nutrients in the human body influence specific physiological processes remain largely unknown. Here we use a blood nutrient compound library-based screening approach to demonstrate that dietary trans-vaccenic acid (TVA) directly promotes effector CD8+ T cell function and anti-tumour immunity in vivo. TVA is the predominant form of trans-fatty acids enriched in human milk, but the human body cannot produce TVA endogenously1. Circulating TVA in humans is mainly from ruminant-derived foods including beef, lamb and dairy products such as milk and butter2,3, but only around 19% or 12% of dietary TVA is converted to rumenic acid by humans or mice, respectively4,5. Mechanistically, TVA inactivates the cell-surface receptor GPR43, an immunomodulatory G protein-coupled receptor activated by its short-chain fatty acid ligands6-8. TVA thus antagonizes the short-chain fatty acid agonists of GPR43, leading to activation of the cAMP-PKA-CREB axis for enhanced CD8+ T cell function. These findings reveal that diet-derived TVA represents a mechanism for host-extrinsic reprogramming of CD8+ T cells as opposed to the intrahost gut microbiota-derived short-chain fatty acids. TVA thus has translational potential for the treatment of tumours.

Characterization of highly pathogenic avian influenza virus in retail dairy products in the US.

In March 2024, clade 2.3.4.4b H5N1 highly pathogenic avian influenza virus (HPAIV) was detected in dairy cattle in the US, and it was discovered that the virus could be detected in raw milk. Although affected cow's milk is diverted from human consumption and current pasteurization requirements are expected to reduce or eliminate infectious HPAIV from the milk supply, a study was conducted to characterize whether the virus could be detected by quantitative real-time RT-PCR (qrRT-PCR) in pasteurized retail dairy products and, if detected, to determine whether the virus was viable. From 18 April to 22 April 2024, a total of 297 samples of Grade A pasteurized retail milk products (23 product types) were collected from 17 US states that represented products from 132 processors in 38 states. Viral RNA was detected in 60 samples (20.2%), with qrRT-PCR-based quantity estimates (non-infectious) of up to 5.4log1050% egg infectious doses per mL, with a mean and median of 3.0log10/mL and 2.9log10/mL, respectively. Samples that were positive for type A influenza by qrRT-PCR were confirmed to be clade 2.3.4.4 H5 HPAIV by qrRT-PCR. No infectious virus was detected in any of the qrRT-PCR-positive samples in embryonating chicken eggs. Further studies are needed to monitor the milk supply, but these results provide evidence that the infectious virus did not enter the US pasteurized milk supply before control measures for HPAIV were implemented in dairy cattle.IMPORTANCEHighly pathogenic avian influenza virus (HPAIV) infections in US dairy cattle were first confirmed in March 2024. Because the virus could be detected in raw milk, a study was conducted to determine whether it had entered the retail food supply. Pasteurized dairy products were collected from 17 states in April 2024. Viral RNA was detected in one in five samples, but infectious virus was not detected. This provides a snapshot of HPAIV in milk products early in the event and reinforces that with current safety measures, infectious viruses in milk are unlikely to enter the food supply.

Associations between low- and high-fat dairy intake and recurrence risk in people with stage I-III colorectal cancer differ by sex and primary tumour location.

We previously demonstrated that intake of low-fat dairy, but not high-fat dairy, was associated with a decreased colorectal cancer (CRC) recurrence risk. These risks, however, may differ by sex, primary tumour location, and disease stage. Combining data from two similar prospective cohort studies of people with stage I-III CRC enabled these subgroup analyses. Participants completed a food frequency questionnaire at diagnosis (n = 2283). We examined associations between low- and high-fat dairy intake and recurrence risk using multivariable Cox proportional hazard models, stratified by sex, and primary tumour location (colon and rectum), and disease stage (I/II and III). Upper quartiles were compared to lower quartiles of intake, and recurrence was defined as a locoregional recurrence and/or metastasis. During a median follow-up of 5.0 years, 331 recurrences were detected. A higher intake of low-fat dairy was associated with a reduced risk of recurrence (hazard ratio [HR]: 0.60, 95% confidence interval [CI]: 0.43-0.83), which seemed more pronounced in men (HR: 0.51, 95% CI: 0.34-0.77) than in women (HR: 0.84, 95% CI: 0.47-1.49). A higher intake of high-fat dairy was associated with an increased risk of recurrence in participants with colon cancer (HR: 1.60, 95% CI: 1.03-2.50), but not rectal cancer (HR: 0.88, 95% CI: 0.54-1.45). No differences in associations were observed between strata of disease stage. Concluding, our findings imply that dietary advice regarding low-fat dairy intake may be especially important for men with CRC, and that dietary advice regarding high-fat dairy intake may be specifically important in people with colon cancer.

Specific dairy foods and risk of frailty in older women: a prospective cohort study.

BACKGROUND: Dairy contains a complex mixture of lipids, proteins, and micronutrients. Whether habitual dairy consumption is associated with health benefits is not well established. Since dairy is high in nutrients that are potentially protective against frailty, the association between dairy products and the risk of frailty is of interest. METHODS: We analyzed data from 85,280 women aged ≥ 60 years participating in the Nurses' Health Study. Consumption of milk, yogurt, and cheese was obtained from repeated food frequency questionnaires administered between 1980 and 2010. Frailty was defined as having at least three of the following five criteria from the FRAIL scale: fatigue, low strength, reduced aerobic capacity, having ≥ 5 chronic illnesses, and a weight loss of ≥ 5%. The occurrence of frailty was assessed every four years from 1992 to 2018. Cox proportional hazard models were used to examine the association between the intake of dairy foods and frailty. RESULTS: During follow-up we identified 15,912 incident cases of frailty. Consumption of milk or yogurt was not associated with the risk of frailty after adjustment for lifestyle factors, medication use, and overall diet quality. Cheese consumption was positively associated with risk of frailty [relative risk (95% confidence interval) for one serving/day increment in consumption: 1.10 (1.05, 1.16)]. Replacing one serving/day of milk, yogurt, or cheese with one serving/day of whole grains, nuts, or legumes was associated with a significant lower risk of frailty, while replacing milk, yogurt, or cheese with red meat or eggs was associated with an increased risk. When milk was replaced with a sugar-sweetened or artificially sweetened beverage, a greater risk of frailty was observed, while replacing milk with orange juice was associated with a lower risk of frailty. CONCLUSIONS: The results suggest that the association between milk, yogurt, and cheese and frailty partly depends on the replacement product. Habitual consumption of milk or yogurt was not associated with risk of frailty, whereas cheese consumption may be associated with an increased risk.

Bone health: biology and nutrition.

PURPOSE OF REVIEW: Recent findings in the influence of dietary patterns, dairy products, beverages and microbiota composition and function on bone health are reviewed and discussed. RECENT FINDINGS: Evidence is accumulating on the increased risk of fracture in individuals following a vegan diet. Meta-analysis of randomized controlled trials indicates a favourable, though of low amplitude, effect of dairy products on bone mass accrual during childhood and adolescence. Though mostly based on results from observational studies, it seems that dairy product consumption, particularly fermented dairy products, is associated with a lower risk of hip fracture. Regular green tea drinkers may have a lower fracture risk than tea abstainers. Magnesium intake is beneficial for bone health. Prune supplements prevents bone loss in untreated postmenopausal women. This seems to be associated with modification of gut microbiota. SUMMARY: This information should help the medical practitioners facing questions from their patients on how to protect bone health through nutrition.

Replacement of Milk and Dairy Products with Soy-Based Alternatives-How to Avoid Nutrient Deficiencies in a Milk-Free Diet?

BACKGROUND: In Germany, milk and dairy products are increasingly replaced by their plant-based alternatives. Although they can be used as substitutes, they differ significantly in their nutrient composition; thus, substitution could lead to nutrient deficiencies. So far, there are no food-based dietary recommendations that show which foods can replace milk and dairy products in a healthy way when switching to a plant-based substitute. OBJECTIVES: Against this background, the question arises as to how to ensure adequate intake of critical nutrients when plant-based alternatives are consumed instead of milk and dairy products. To answer this question, this study aims to analyze what dietary changes would be required to avoid possible nutrient deficiencies and what types of foods can be consumed instead. METHODS: To answer the research question, 3 different models are compared using the linear programming method: healthy diets with 1) milk and dairy products, 2) nonfortified plant-based alternatives, and 3) fortified plant-based alternatives. The models are applied to omnivorous, pescatarian, and vegetarian diet types. RESULTS: The results show that when consuming nonfortified soy alternatives, an adequate supply of calcium and, in the case of a vegetarian diet, vitamin B12 can only be achieved if significant dietary changes are made compared to the average diet. This includes a significantly higher consumption of fruit and vegetables, whereby within the groups, calcium-rich varieties should be chosen (e.g., green leafy vegetables). When consuming fortified soy-based alternatives instead, the absence of milk and dairy products can be well compensated by the nutrients currently added to commercially available products. CONCLUSIONS: Given the trend to consume less milk and dairy products or to abstain from them altogether, public health measures should point out possible nutrient deficiencies as well as necessary dietary changes, especially because in Germany, many plant-based alternatives are not fortified.

Modeling the Impact of Substituting Meat and Dairy Products with Plant-Based Alternatives on Nutrient Adequacy and Diet Quality.

BACKGROUND: Novel plant-based meat and dairy alternatives are designed to mimic and replace animal-sourced products, yet their nutritional composition differs from traditional alternatives such as legumes and beans. The nutritional impacts of switching from animal-sourced to traditional or novel plant-based alternatives remains unclear. OBJECTIVES: This study aimed to model the impact of partial and complete substitution of animal-sourced meat and dairy products with traditional or novel plant-based alternatives on diet quality and nutrient adequacy in a nationally representative sample of Australian adults. METHODS: Dietary data (1 24-h recall) from the Australian Health Survey 2011-2013 (n = 9115; ≥19 y) were analyzed. Four models simulated partial or complete substitution of animal-sourced meat and dairy with traditional or novel plant-based alternatives. Diet quality was assessed using the Dietary Guideline Index (DGI), and nutrient adequacy was determined using age- and sex-specific nutrient reference values. Modeled diets were compared to a baseline diet using survey-weighted paired t tests. RESULTS: DGI scores improved by 0.3% to 6.0% for all models across all sex and age groups compared to baseline. Improvements in diet quality were greatest for the complete substitution to traditional alternatives (5.1% average increase in DGI). Overall, inclusion of plant-based alternatives (complete or partial) decreased saturated fat and increased dietary fiber. Long-chain n-3 polyunsaturated fatty acids decreased to below adequate intakes for all complete substitution models. Substitution with traditional alternatives decreased sodium and increased calcium, whereas substitution with novel alternatives increased sodium and decreased calcium. CONCLUSIONS: All models using traditional alternatives, and the partial substitution using novel alternatives, showed small but statistically significant improvements in diet quality. Nutrient adequacy varied between models, with nutrients including saturated fat, sodium, calcium, and long-chain fatty acids implicated. Findings highlight the importance of informed choices when switching to traditional or novel plant-based alternatives to prevent suboptimal dietary intake.

Graded Replacement of Carbohydrate-Rich Breakfast Products with Dairy Products: Effects on Postprandial Aminoacidemia, Glycemic Control, Bone Metabolism, and Satiety.

BACKGROUND: Postprandial metabolic responses following dairy consumption have mostly been studied using stand-alone dairy products or milk-derived nutrients. OBJECTIVE: Assessing the impact of ingesting dairy products as part of a common breakfast on postprandial aminoacidemia, glycemic control, markers of bone metabolism, and satiety. METHODS: In this randomized, crossover study, 20 healthy young males and females consumed on 3 separate occasions an iso-energetic breakfast containing no dairy (NO-D), 1 dairy (ONE-D), or 2 dairy (TWO-D) products. Postprandial concentrations of amino acids, glucose, insulin, glucagon-like peptide-1 (GLP-1), calcium, parathyroid hormone (PTH), and markers of bone formation (P1NP) and resorption (CTX-I) were measured before and up to 300 min after initiating the breakfast, along with VAS-scales to assess satiety. RESULTS: Plasma essential and branched-chained amino acids availability (expressed as total area under the curve (tAUC)) increased in a dose-dependent manner (P<0.05 for all comparisons). Plasma glucose tAUCs were lower in ONE-D and TWO-D compared with NO-D (P<0.05 for both comparisons). Plasma GLP-1 tAUC increased in a dose-dependent manner (P<0.05 for all comparisons), whereas no differences were observed in plasma insulin tAUC between conditions (P>0.05 for all comparisons). Serum calcium tAUCs were higher in ONE-D and TWO-D compared with NO-D (P<0.05 for both comparisons), along with lower PTH tAUCs in ONE-D and TWO-D compared with NO-D (P=0.001 for both comparisons). In accordance, serum CTX-I concentrations were lower in the late postprandial period in ONE-D and TWO-D compared with NO-D (P<0.01 for both comparisons). No differences were observed in P1NP tAUCs between conditions (P>0.05). The tAUC for satiety was higher in TWO-D compared with NO-D and ONE-D (P<0.05 for both comparisons). CONCLUSIONS: Iso-energetic replacement of a carbohydrate-rich breakfast component with one serving of dairy improves postprandial amino acid availability, glycemic control, and bone metabolism. Adding a second serving of dairy in lieu of carbohydrates augments postprandial amino acid and GLP-1 concentrations while further promoting satiety. This study was registered at https://doi.org/10.1186/ISRCTN13531586 with Clinical Trial Registry number ISRCTN13531586.

Association of nutritional intake with clinical and imaging activity in pediatric multiple sclerosis.

BACKGROUND: Understanding nutrition's role in multiple sclerosis (MS) can guide recommendations and intervention-based studies. OBJECTIVE: Evaluate the association between nutrition and pediatric-onset MS outcomes. METHODS: Prospective longitudinal multicenter study conducted as part of the US Network of Pediatric MS centers. Predictors were collected using a food screener estimating intake of various dietary food groups (e.g. dairy and fruits) and additional calculated indices (e.g. Healthy Eating Index (HEI)). Outcomes included time-from-enrollment to clinical relapse, new magnetic resonance imaging (MRI) T2 lesions, and Expanded Disability Status Scale (EDSS) increase. RESULTS: 353 children with MS were enrolled (mean ± SD age 15.4 ± 2.9, follow-up 3.9 ± 2.6 years). Multivariable analysis demonstrated that increased dairy by 50% of recommended intake was associated with increased relapse risk by 41% (adjusted hazard ratio (HR) 1.41, 95% CI 1.07-1.86), and risk of T2 progression by 40% (1.40, 1.12-1.74). Increased intake of fruit or vegetable above recommended, and every five-point HEI increase decreased relapse risk by 25% (0.75, 0.60-0.95), 45% (0.55, 0.32-0.96), and 15% (0.84, 0.74-0.96), respectively. No associations were found with EDSS. CONCLUSION: This work supports the influence of dietary intake on MS course, particularly with dairy intake. Future prospective study is required to establish causation.

Intestinal Bacteria Fluctuating in Early-Stage Colorectal Cancer Carcinogenesis are Associated with Diet in Healthy Adults.

This hospital-based, cross-sectional study aimed to explore the association between diet and fluctuating intestinal bacteria in early-stage colorectal cancer (CRC) (Atopobium parvulum, Actinomyces odontolyticus, Solobacterium moorei, and Bifidobacterium longum). Healthy participants (n = 212) who underwent total colonoscopy at National Cancer Center Hospital (Tokyo, Japan) were divided into two groups according to the relative abundance of bacteria in their feces: those in the top 25% of relative bacterial abundance as cases and the bottom 25% as controls. The participants were divided into three groups (low, medium, and high) according to their intake of food groups associated with CRC. Multivariable logistic regression analysis was conducted to estimate the association between dietary intake and higher relative abundance of bacteria. Dairy products were inversely associated with a higher relative abundance of A. parvulum, A. odontolyticus, and S. moorei, with odds ratios (high vs. low) and 95% confidence interval as follows: 0.16 (0.06-0.44), 0.25 (0.08-0.82), and 0.29 (0.11-0.78), respectively. Additionally, dietary fiber was inversely associated with a higher relative abundance of S.moorei (0.29 [0.11-0.78]). No association was observed between diet and B.longum. In conclusion, healthy adults with a higher intake of dairy products and fiber had lower odds of having a higher relative abundance of CRC-associated microbiota.

Genome-based taxonomic identification and safety assessment of an Enterococcus strain isolated from a homemade dairy product.

The aim of this study was to explore the taxonomic identification and evaluate the safety of a bacterium, Enterococcus lactis IDCC 2105, isolated from homemade cheese in Korea, using whole genome sequence (WGS) analysis. It sought to identify the species level of this Enterococcus spp., assess its antibiotic resistance, and evaluate its virulence potential. WGS analysis confirmed the bacterial strain IDCC 2105 as E. lactis and identified genes responsible for resistance to erythromycin and clindamycin, specifically msrC, and eatAv, which are chromosomally located, indicating a minimal risk for horizontal gene transfer. The absence of plasmids in E. lactis IDCC 2105 further diminishes the likelihood of resistance gene dissemination. Additionally, our investigation into seven virulence factors, including hemolysis, platelet aggregation, biofilm formation, hyaluronidase, gelatinase, ammonia production, and ß-glucuronidase activity, revealed no detectable virulence traits. Although bioinformatic analysis suggested the presence of collagen adhesion genes acm and scm, these were not corroborated by phenotypic virulence assays. Based on these findings, E. lactis IDCC 2105 presents as a safe strain for potential applications, contributing valuable information on its taxonomy, antibiotic resistance profile, and lack of virulence factors, supporting its use in food products.

Dairy products and brain structure in French older adults.

Among food groups with putative benefits for brain structures, dairy products (DP) have been poorly studied. The sample included participants without dementia from the ancillary brain imaging study of the Three-City cohort who were aged 65+ years, had their DP intake assessed with a FFQ at baseline and underwent an anatomical scan 3 years (n 343) or 9 years (n 195) after completing the dietary survey. The frequencies of consumption of total DP, milk and cheese were not associated with brain structure. Compared with the lowest frequency, the highest frequency of fresh DP (F-DP) consumption (< 0·5 v. > 1·5 times/d) was significantly associated with a lower medial temporal lobe volume (MTLV) (ß = -1·09 cm3, 95 % CI - 1·83, -0·36) 9 years later. In this population-based study of older adults, the consumption of F-DP more than 1·5 times/d was associated with a lower MTLV, which is considered an early biomarker of Alzheimer's disease, 9 years later. This original study should be replicated in different settings before conclusions are drawn.

High consumption of dairy products and risk of major adverse coronary events and stroke in a Swedish population.

The association between the consumption of dairy products and risk of CVD has been inconsistent. There is a lack of studies in populations with high intakes of dairy products. We aimed to examine the association between intake of dairy products and risk of incident major adverse coronary events and stroke in the Swedish Malmö Diet and Cancer cohort study. We included 26 190 participants without prevalent CVD or diabetes. Dietary habits were obtained from a modified diet history, and endpoint data were extracted from registers. Over an average of 19 years of follow-up, 3633 major adverse coronary events cases and 2643 stroke cases were reported. After adjusting for potential confounders, very high intakes of non-fermented milk (>1000 g/d) compared with low intakes (<200 g/d) were associated with 35 % (95 % CI (8, 69)) higher risk of major adverse coronary events. In contrast, moderate intakes of fermented milk (100-300 g/d) were associated with a lower risk of major adverse coronary events compared with no consumption. Intakes of cheese (only in women) and butter were inversely associated with the risk of major adverse coronary events. We observed no clear associations between any of the dairy products and stroke risk. These results highlight the importance of studying different dairy foods separately. Further studies in populations with high dairy consumption are warranted.

Consumption of milk and other dairy products and incidence of Parkinson's disease: a prospective cohort study in French women.

Previous studies showed positive associations between milk intake and Parkinson's disease (PD) in men but not in women, but few studies were available in women. Due to the long prodromal PD phase, reverse causation represents a major threat to investigations of diet in PD; cohort studies with a long follow-up are needed. We investigated associations between intake of milk and other dairy products with PD incidence in women from the E3N cohort study (1993-2018). PD diagnoses were validated using medical records and drug claim databases. Diet was assessed via a dietary questionnaire. Hazard ratios (HR) were estimated using multivariable Cox regression models. Exposures were lagged by 5y in main analyses and longer lags in sensitivity analyses. We examined the impact of adjustment for premotor symptoms (constipation/depression). During a mean follow-up of 18.8y, 845 of 71,542 women developed PD. Main analyses showed a J-shaped association between total milk intake and PD (P-non linearity = 0.045), with a significant linear positive association among drinkers (HR/1-SD = 1.09, 95% CI = 1.01-1.18, P = 0.024), that was explained in secondary analyses by a different pattern of association for plain milk (alone or with cereals) and milk added to drinks (tea/coffee/chicory). PD incidence increased significantly with plain milk consumption (HR/1-SD = 1.08 [1.02-1.14], P = 0.014). A U-shaped relation was observed for milk added to drinks (P-non linearity = 0.038), with lower PD incidence in women with moderate consumption (HR = 0.77 [0.61-0.97], P = 0.030) and no difference between non-drinkers and those with the highest consumption (HR = 0.98 [0.79-1.21], P = 0.848). Findings were similar in analyses using longer lags and adjusted for constipation/depression. Consumption of other dairy products was not associated with PD. A J-shaped association between total milk intake and PD was explained by a different pattern of association for plain milk intake and milk added to drinks. Reverse causation is unlikely to explain a positive association of plain milk with PD incidence in women. The U-shaped relation for milk added to drinks could be explained by an interaction between milk and coffee/tea/chicory. Further studies are warranted to elucidate the underlying mechanisms.

Contribution of plant-based dairy and fish alternatives to iodine nutrition in the Swiss diet: a Swiss Market Survey.

PURPOSE: With dairy products and fish being major sources of iodine in Switzerland, the growing popularity of plant-based alternatives may impact iodine nutrition. This study aimed to assess the iodine content in plant-based dairy and fish alternatives available in the Swiss market and compare them with conventional products. METHODS: In 2022, a market survey was conducted in Zurich, Switzerland, to identify the plant-based dairy and fish alternatives available and assess their iodine content. To evaluate the impact of plant-based alternatives on iodine consumption in Switzerland, we modeled dietary scenarios by substituting the intake of dairy and fish items with plant-based alternatives. In addition, we investigated fortification with calcium, vitamins B2, B12, and D. RESULTS: Out of 477 identified products, only four milk-alternative products were iodine fortified (median iodine concentration: 22.5 µg/100 ml). The median iodine concentration in unfortified plant-based alternatives was negligible compared to conventional dairy and fish products (milk: 0.21 vs 9.5 µg/100 ml; yogurt 0.36 vs 6.1 µg/100 g; cheese: 0.10 vs 20 µg/100 g; fish 0.50 vs 44 µg/100 g). Three portions of dairy per day as recommended by the Swiss Food Pyramid provide 25% of the RDA for iodine (150 µg/day), whereas substituting those with unfortified alternatives provides only 0.7% of the RDA. CONCLUSION: Only four out of 477 plant-based alternative products are iodine fortified in the Swiss market. Thus, the risk for consumers to miss out on the ca. 25% of the RDA for iodine by consuming plant-based alternatives is high, placing them at a risk for inadequate iodine intake.

Impact of dairy fat manipulation on endothelial function and lipid regulation in human aortic endothelial cells exposed to human plasma samples: an in vitro investigation from the RESET study.

PURPOSE: Longer-term intake of fatty acid (FA)-modified dairy products (SFA-reduced, MUFA-enriched) was reported to attenuate postprandial endothelial function in humans, relative to conventional (control) dairy. Thus, we performed an in vitro study in human aortic endothelial cells (HAEC) to investigate mechanisms underlying the effects observed in vivo. METHODS: This sub-study was conducted within the framework of the RESET study, a 12-week randomised controlled crossover trial with FA-modified and control dairy diets. HAEC were incubated for 24 h with post-intervention plasma samples from eleven adults (age: 57.5 ± 6.0 years; BMI: 25.7 ± 2.7 kg/m2) at moderate cardiovascular disease risk following representative sequential mixed meals. Markers of endothelial function and lipid regulation were assessed. RESULTS: Relative to control, HAEC incubation with plasma following the FA-modified treatment increased postprandial NOx production (P-interaction = 0.019), yet up-regulated relative E-selectin mRNA gene expression (P-interaction = 0.011). There was no impact on other genes measured. CONCLUSION: Incubation of HAEC with human plasma collected after longer-term dairy fat manipulation had a beneficial impact on postprandial NOx production. Further ex vivo research is needed to understand the impact of partial replacement of SFA with unsaturated fatty acids in dairy foods on pathways involved in endothelial function.

Differential association between dairy intake patterns and incident prostate cancer: a potential dairy matrix effect.

OBJECTIVE: To evaluate the association between dairy intake patterns and the risk of prostate cancer (PC), and its histological differentiation, among men from Mexico City. METHODS: We analyzed the information from 394 incident PC cases paired by age (± 5 years) with 794 population controls. According to the Gleason score at diagnosis, cases were classified as well- (≤ 6), moderately- (= 7), and poorly differentiated PC (≥ 8). Based on a semiquantitative-food frequency questionnaire and using energy-density approach, we estimated the energy-adjusted daily intake of whole milk, cheese (fresh, Oaxaca, and Manchego), cream, and yogurt. Through a principal component analysis, we identified three dairy intake patterns: whole milk, cheese, and yogurt. The association between each dairy intake pattern and PC was evaluated from independent nonconditional logistic regression models. We also evaluated the mediator role of calcium and saturated fat intake. RESULTS: After adjustment, a high intake of whole milk pattern was associated with a 63% increased risk of PC (ORhigh vs low: 1.63; 95% CI 1.17-2.25, p trend = 0.002); at expenses of moderately (ORhigh vs low: 1.77; 95% CI 1.09-2.85, p trend = 0.015) and poorly differentiated PC (ORhigh vs low: 1.75; 95% CI 1.05- 2.92, p trend = 0.031). The association was mainly mediated by calcium intake (proportion mediated = 1.17; p < 0.01). No associations were found between cream and yogurt intake patterns with risk of PC, and its histological grade. CONCLUSIONS: A differential association of dairy intake patterns with risk of PC, and the poorly differentiated PC, was identified. This association seems to be determined by different dairy matrices and it is mediated by calcium content. Longitudinal studies are needed to confirm these findings and be able to identify other potential mediators in the etiology of PC.

Associations of plant-based foods, red and processed meat, and dairy with gut microbiome in Finnish adults.

PURPOSE: Population-based studies on the associations of plant-based foods, red meat or dairy with gut microbiome are scarce. We examined whether the consumption of plant-based foods (vegetables, potatoes, fruits, cereals), red and processed meat (RPM) or dairy (fermented milk, cheese, other dairy products) are related to gut microbiome in Finnish adults. METHODS: We utilized data from the National FINRISK/FINDIET 2002 Study (n = 1273, aged 25-64 years, 55% women). Diet was assessed with 48-hour dietary recalls. Gut microbiome was analyzed using shallow shotgun sequencing. We applied multivariate analyses with linear models and permutational ANOVAs adjusted for relevant confounders. RESULTS: Fruit consumption was positively (beta = 0.03, SE = 0.01, P = 0.04), while a dairy subgroup including milk, cream and ice-creams was inversely associated (beta=-0.03, SE 0.01, P = 0.02) with intra-individual gut microbiome diversity (alpha-diversity). Plant-based foods (R2 = 0.001, P = 0.03) and dairy (R2 = 0.002, P = 0.01) but not RPM (R2 = 0.001, P = 0.38) contributed to the compositional differences in gut microbiome (beta-diversity). Plant-based foods were associated with several butyrate producers/cellulolytic species including Roseburia hominis. RPM associations included an inverse association with R. hominis. Dairy was positively associated with several lactic producing/probiotic species including Lactobacillus delbrueckii and potentially opportunistic pathogens including Citrobacter freundii. Dairy, fermented milk, vegetables, and cereals were associated with specific microbial functions. CONCLUSION: Our results suggest a potential association between plant-based foods and dairy or their subgroups with microbial diversity measures. Furthermore, our findings indicated that all the food groups were associated with distinct overall microbial community compositions. Plant-based food consumption particularly was associated with a larger number of putative beneficial species.

Effect of high in comparison to low dairy intake intervention on markers of bone and cartilage remodeling and phosphate metabolism in healthy adults with overweight.

BACKGROUND: In the ageing population, issues with bone and joint health are highly prevalent. Both beneficial and potential risks of dairy products on bone and joint health are reported in epidemiological studies. Furthermore, the phosphorus (P) load from dairy could potentially lead to unfavorable changes in P metabolism. OBJECTIVE: To investigate the effect of dairy intake on markers of bone and joint metabolism and P metabolism in an intervention study with high and low dairy intake. METHODS: In a post hoc analysis of a randomized cross-over trial with overweight adults, the effect of a standardized high dairy intake [HDI (5-6 dairy portions per day) versus low dairy intake (LDI, ≤ 1 dairy portion/day)] for 6 weeks on markers of bone and joint health was assessed using enzyme-linked immunosorbent assays and electrochemiluminescence immunoassays. Markers indicative for cartilage breakdown, including urinary CTX-II, serum COMP and 4-hydroxyproline, and markers indicative for bone remodeling, such as serum CTX-I, PTH, 25(OH)D, osteocalcin, P1NP and FGF23, were investigated using linear mixed models. Furthermore, changes in P metabolism, including the main phosphate-regulating hormone FGF23 were explored. RESULTS: This study was completed by 46 adults (57% female, age 59 ± 4 years, BMI 28 ± 2 kg/m2). Following HDI, markers such as urinary CTX-II excretion, COMP, 25(OH)D, PTH and CTX-I were significantly lower after HDI, as compared to LDI. For example, CTX-II excretion was 1688 ng/24 h at HDI, while it was 2050 ng/24 h at LDI (p < 0.001). Concurrently, P intake was higher at HDI than at LDI (2090 vs 1313 mg/day, p < 0.001). While plasma P levels did not differ (1.03 vs 1.04 mmol/L in LDI, p = 0.36), urinary P excretion was higher at HDI than at LDI (31 vs 28 mmol/L, p = 0.04). FGF23 levels tended to be higher at HDI than at LDI (76.3 vs. 72.9 RU/mL, p = 0.07). CONCLUSIONS: HDI, as compared to LDI, reduced markers that are indicative for joint and bone resorption and bone turnover. No changes in P metabolism were observed. CLINICAL TRIAL REGISTRY: This trial was registered at https://trialsearch.who.int/Trial2.aspx?TrialID=NTR4899 as NTR4899.

Low ß-carotene bioaccessibility and bioavailability from high fat, dairy-based meal.

PURPOSE: The original aim of the study was to determine, in a double-blind 3-arm crossover human trial (n = 7), the effect of supplemental levels of iron (25 mg) and zinc (30 mg) on ß-carotene (synthetic) bioavailability (10 h postprandial). However, despite the high dose of supplemental ß-carotene (15 mg) consumed with the high fat (18 g), dairy-based breakfast test meal, there was a negligible postprandial response in plasma and triglyceride rich fraction ß-carotene concentrations. We then systematically investigated the possible reasons for this low bioavailability of ß-carotene. METHODS: We determined (1) if the supplemental ß-carotene could be micellised and absorbed by epithelial cells, using a Caco-2 cell model, (2) if the fat from the test meal was sufficiently bioavailable to facilitate ß-carotene bioavailability, (3) the extent to which the ß-carotene could have been metabolised and converted to retinoic acid/retinol and (4) the effect of the test meal matrix on the ß-carotene bioaccessibility (in vitro digestion) and Caco-2 cellular uptake. RESULTS: We found that (1) The supplemental ß-carotene could be micellised and absorbed by epithelial cells, (2) the postprandial plasma triacylglycerol response was substantial (approximately 75-100 mg dL-1 over 10 h), indicating sufficient lipid bioavailability to ensure ß-carotene absorption, (3) the high fat content of the meal (approximately 18 g) could have resulted in increased ß-carotene metabolism, (4) ß-carotene bioaccessibility from the dairy-based test meal was sixfold lower (p < 0.05) than when digested with olive oil. CONCLUSION: The low ß-carotene bioavailability is probably due to a combination of the metabolism of ß-carotene to retinol by BCMO1 and interactions of ß-carotene with the food matrix, decreasing the bioaccessibility. TRAIL REGISTRATION: The human trail was retrospectively registered (ClinicalTrail.gov ID: NCT05840848).