Dairy product consumption and incident prediabetes in Dutch middle-aged adults: the Hoorn Studies prospective cohort

Dynamics of Dairy Product Consumption, Confounding Factors, and Their Influence on the Risk of Type 2 Diabetes

It has long been debated whether or not dairy consumption increases the risk of type 2 diabetes (T2D). This link has been assessed by a large number of case-control studies, prospective cohort studies, systematic reviews, and meta-analyses. The majority of their studies demonstrated an inverse relationship between the risk of T2D and dairy consumption. It is yet unclear how dairy products specifically contribute to metabolic diseases like type 2 diabetes. However, a surprising number of studies have indicated either no association or a positive correlation between the development of type 2 diabetes and certain dairy products. The objective of this narrative review is to collate research findings from diverse geographical contexts, exploring the impact of dairy product consumption on the incidence and risk of Type 2 diabetes (T2D). This review includes studies that addressed this research issue and were released between the years 2000 and 2023. This will help the public draw logical inferences and validate the body of recent research. To shed light on this matter, the writers conduct a comprehensive search of electronic scientific databases such as PubMed, Scopus, and Web of Science. Thus, this review emphasizes the connection between the usage of different dairy products and the risk of T2D. After controlling for confounding variables, this review indicates that the relationship between the incidence of type 2 diabetes and consumption of dairy products is context-dependent. In conclusion, not all dairy products help to prevent type 2 diabetes. There is no association between most other dairy products and T2D, while in some cases benefits of yogurt and other low-fat dairy products have been reported.

Dairy Intake in Relation to Prediabetes and Continuous Glycemic Outcomes: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

Background

Modest inverse associations have been found between dairy intake, particularly yogurt, and type 2 diabetes risk. Investigating associations of dairy intake with early onset of type 2 diabetes offers opportunities for effective prevention of this condition.

Objectives

This study aims to investigate the relationships between the intake of different dairy types, prediabetes risk, and continuous glycemic outcomes.

Methods

Systematic literature searches across multiple databases were performed of studies published up to September 2023. Included were prospective cohort studies in healthy adults that examined the association between dairy intake and prediabetes risk according to diagnostic criteria, or continuous glycemic markers. A dose-response random-effects meta-analysis was used to derive incremental relative risks (RRs) for associations of total dairy, fermented dairy, milk, yogurt, cheese (all total, high-fat, and low-fat), cream, and ice cream with prediabetes risk adjusted for sociodemographic, health and cardiometabolic risk factors, and dietary characteristics.

Results

The meta-analyses encompassed 6653 prediabetes cases among 95,844 individuals (age range 45.5-65.5 y) including 6 articles describing 9 cohorts. A quadratic inverse association was observed for total dairy intake and prediabetes risk, with the lowest risk at 3.4 servings/d (RR: 0.75; 95% confidence interval: 0.60, 0.93; I 2 = 18%). Similarly, total, and high-fat cheese exhibited nonlinear inverse associations with prediabetes risk, showing the lowest risk at 2.1 servings/d (0.86; 0.78, 0.94; I 2 = 0%, and 0.90; 0.81, 0.99; I 2 = 12%), but a higher risk at intakes exceeding 4 servings/d. Ice cream intake was linearly associated with prediabetes risk (0.85; 0.73, 0.99; I 2 = 0% at the highest median intake of 0.23 servings/d). Other dairy types showed no statistically significant associations. The systematic review on dairy intake and glycemic outcomes showed considerable variabilities in design and results.

Conclusions

The findings suggest an inverse association between moderate dairy and cheese intake in preventing prediabetes. The potential for reverse causation and residual confounding highlights the need for studies with comprehensive repeated measurements.

Trial registration number

PROSPERO 2023 CRD42023431251.

Dairy consumption and risk of prediabetes and type 2 diabetes in the Fenland study

BACKGROUND & AIMS

Limited observational evidence suggests that a higher intake of high-fat dairy may be associated with lower prediabetes risk, while opposite associations have been observed for low-fat milk intake. This study aimed to examine associations between baseline and changes in dairy consumption, risk of prediabetes, and glycaemic status.

METHODS

7521 participants from the prospective UK Fenland study were included (mean age 48.7 ± 2.0 years, 51.9 % female). Dairy intake was measured using self-reported food frequency questionnaires. Associations with prediabetes risk and glycaemic status were analysed using Poisson regression models adjusted for social demographics, health behaviours, family history of diabetes and food group intake.

RESULTS

At a mean follow-up of 6.7 ± 2.0 years, 290 participants developed prediabetes (4.3 %). Most dairy products were not significantly associated with prediabetes risk. A higher baseline intake of high-fat dairy (RRservings/day 1.20, 95%CI 1.03-1.39) and high-fat milk (RRservings/day 1.22, 1.01-1.47) were associated with higher prediabetes risk. Conversely, low-fat milk was associated with lower prediabetes risk (RRservings/day 0.86, 0.75-0.98). In the analyses evaluating dietary changes over time, increases in high-fat milk were inversely associated with risk of progressing from normoglycaemia to prediabetes or type 2 diabetes (RRservings/day 0.86, 95%CI 0.75-0.99).

CONCLUSIONS

This population-based study showed that most dairy products are not associated with prediabetes risk or progression in glycaemic status. Positive associations of high-fat dairy, high-fat milk, and the inverse association of low-fat milk with prediabetes risk found were inconsistent with prior literature and suggestive of the need for future research on environmental, behavioural, and biological factors that explain the available evidence.

Full-fat dairy products and cardiometabolic health outcomes: Does the dairy-fat matrix matter?

Reducing dairy fat intake is a common dietary guideline to limit energy and saturated fatty acid intake for the promotion of cardiometabolic health. However, research utilizing a holistic, food-based approach to assess the consumption of the fat found in dairy, a broad and diverse food group, may provide new insight into these guidelines. Dairy fat is comprised of a diverse assembly of fatty acids, triacylglycerols, sterols, and phospholipids, all uniquely packaged in a milk fat globule. The physical structure of this milk fat globule and its membrane is modified through different processing methods, resulting in distinctive dairy-fat matrices across each dairy product. The objectives of this narrative review were to first define and compare the dairy-fat matrix in terms of its unique composition, physical structure, and fat content across common dairy products (cow's milk, yogurt, cheese, and butter). With this information, we examined observational studies and randomized controlled trials published within the last 10 years (2013-2023) to assess the individual effects of the dairy-fat matrix in milk, yogurt, cheese, and butter on cardiometabolic health and evaluate the implications for nutrition guidance. Searches conducted on Ovid MEDLINE and PubMed® utilizing search terms for cardiometabolic health, both broadly and regarding specific disease outcomes and risk factors, yielded 59 studies that were analyzed and included in this review. Importantly, this review stratifies by both dairy product and fat content. Though the results were heterogeneous, most studies reported no association between intake of these individual regular-fat dairy products and cardiometabolic outcome measures, thus, the current body of evidence suggests that regular-fat dairy product consumption may be incorporated within overall healthy eating patterns. Research suggests that there may be a beneficial effect of regular-fat milk and yogurt intake on outcome measures related to body weight and composition, and an effect of regular-fat cheese intake on outcome measures related to blood lipids, but more research is necessary to define the directionality of this relationship. Lastly, we identify methodological research gaps and propose future research directions to bolster the current evidence base available for ascertaining the role of dairy fat in a healthy diet.

Whole milk dairy foods and cardiometabolic health: dairy fat and beyond

Bovine dairy milk is a nutrient-rich matrix, but consumption of full-fat dairy food varieties has been claimed historically to be associated with poorer cardiometabolic health, a notion often attributed to the saturated fat content. However, continued investigation that includes observational studies and randomized controlled trials (RCTs) provide evidence that favorably supports full-fat dairy foods and their bioactive components on cardiometabolic health. This review addresses this controversy by examining the evidence surrounding full-fat dairy foods and their implications for human health. Dairy foods are heterogeneous, not just in their fat content but also in other compositional aspects within and between fermented (e.g., yogurt, cheese) and nonfermented products (e.g., milk) that could differentially influence cardiometabolic health. Drawing from complementary lines of evidence from epidemiological studies and RCTs, this review describes the health effects of dairy foods regarding their fat content, as well as their polar lipids that are concentrated in the milk fat globule fraction. Observational studies have limitedly supported the consumption of full-fat dairy to protect against cardiometabolic disorders. However, this framework has been disputed by RCTs indicating that dairy foods, regardless of their fat content or fermentation, are not detrimental to cardiometabolic health and may instead alleviate certain cardiometabolic risk factors. As dietary recommendations evolve, which currently indicate to avoid full-fat dairy foods, it is essential to consider the totality of evidence, especially from RCTs, while also recognizing that investigation is needed to evaluate the complexity of dairy foods within diverse dietary patterns and their impacts on cardiometabolic health.

The dairy-derived peptide Miltin exerts anti-obesity effects by increasing adipocyte thermogenesis

Growing research has highlighted that the consumption of dairy products improves the metabolic health in obese individuals by functioning as regulatory modulators. However, the molecular basis of this effect remains largely unknown. Herein, we report a dairy-derived peptide, which we named Miltin, that activates the thermogenesis of brown adipocytes and increases white adipocyte browning. Previously, Miltin was merely identified for its antioxidant capacity, although it is commonly present in different dairy products. In this study, we revealed the effect of Miltin in modulating adipose thermogenesis and further explored its potential in treating obesity through in vivo and in vitro strategies. The administration of Miltin in mice fed with a high-fat diet resulted in enhanced thermogenesis, improved glucose homeostasis, and reduced body mass and lipid accumulation, indicating the anti-obesity effect of Miltin. Genomic analysis revealed that Miltin modulates thermogenesis by inducing the activation of the MAPK signaling pathway by preferentially interacting with GADD45γ to promote its stability. Together, our findings indicate that Miltin's role in initiating the thermogenesis of adipocytes makes it a potential anti-obesity therapy for future development.

Association between dairy products consumption and the prevalences of combined prediabetes and type 2 diabetes mellitus in Brazilian adolescents: a cross-sectional study

The association between dairy products consumption in adults and the likelihood of type 2 diabetes mellitus (T2DM) has been described, but more information on the adolescent population is needed. This nationally representative, cross-sectional school-based study aimed to describe the consumption of dairy products and their subtypes and to evaluate their association with prediabetes and T2DM in adolescents. The Study of Cardiovascular Risks in Adolescents (ERICA) includes adolescents aged 12-17 years. Dairy products consumption was evaluated by 24-h food recall. Associations with fasting glucose, glycated hemoglobin (HbA1c) and insulin resistance, as measured by homeostatic model assessment-insulin resistance (HOMA-IR), were evaluated by multivariate linear regression. Poisson regression was also used to assess the association between dairy products consumption and the combined prevalence of prediabetes and T2DM. Models were adjusted for sociodemographic, nutritional, behavioural and anthropometrics. The final sample analysed consisted of 35 614 adolescents. Total intake of dairy products was inversely associated with fasting blood glucose levels after adjusting for all covariates (β = -0·452, 95 % CI -0·899, -0·005). The associations were stronger for overweight and obese adolescents. Findings were similar for full-fat dairy products and yogurt. Higher consumption of low-fat dairy products and cheese were associated with a 46 % (prevalence ratio, PR 1·46, 95 % CI 1·18, 1·80) and 33 % (PR 1·33, 95 % CI 1·14, 1·57) higher combined prevalence of prediabetes and T2DM, respectively. The total consumption of dairy products and full-fat dairy products was associated with a lower combined prevalence of prediabetes and T2DM, while the consumption of cheese and low-fat dairy products was associated with higher combined prevalence of prediabetes and T2DM in Brazilian adolescents.

A Narrative Review on Strategies for the Reversion of Prediabetes to Normoglycemia: Food Pyramid, Physical Activity, and Self-Monitoring Innovative Glucose Devices

In 2019, "Nutrition Therapy for Adults with Diabetes or Prediabetes: A Consensus Report" was published. This consensus report, however, did not provide an easy way to illustrate to subjects with prediabetes (SwPs) how to follow a correct dietary approach. The purpose of this review is to evaluate current evidence on optimum dietary treatment of SwPs and to provide a food pyramid for this population. The pyramid built shows that everyday consumption should consist of: whole-grain bread or potatoes eaten with their skins (for fiber and magnesium) and low glycemic index carbohydrates (GI < 55%) (three portions); fruit and vegetables (5 portions), in particular, green leafy vegetables (for fiber, magnesium, and polyphenols); EVO oil (almost 8 g); nuts (30 g, in particular, pistachios and almonds); three portions of dairy products (milk/yogurt: 300-400 g/day); mineral water (almost 1, 5 L/day for calcium intake); one glass of wine (125 mL); and three cups of coffee. Weekly portions should include fish (four portions), white meat (two portions), protein plant-based food (four portions), eggs (egg portions), and red/processed meats (once/week). At the top of the pyramid, there are two pennants: a green one means that SwPs need some personalized supplementation (if daily requirements cannot be satisfied through diet, vitamin D, omega-3, and vitamin B supplements), and a red one means there are some foods and factors that are banned (simple sugar, refined carbohydrates, and a sedentary lifestyle). Three to four times a week of aerobic and resistance exercises must be performed for 30-40 min. Finally, self-monitoring innovative salivary glucose devices could contribute to the reversion of prediabetes to normoglycemia.

Cheese consumption and multiple health outcomes: an umbrella review and updated meta-analysis of prospective studies

This umbrella review aims to provide a systematic and comprehensive overview of current evidence from prospective studies on the diverse health effects of cheese consumption. We searched PubMed, Embase, and Cochrane Library to identify meta-analyses/pooled analyses of prospective studies examining the association between cheese consumption and major health outcomes from inception to August 31, 2022. We reanalyzed and updated previous meta-analyses and performed de novo meta-analyses with recently published prospective studies, where appropriate. We calculated the summary effect size, 95% prediction confidence intervals, between-study heterogeneity, small-study effects, and excess significance bias for each health outcome. We identified 54 eligible articles of meta-analyses/pooled analyses. After adding newly published original articles, we performed 35 updated meta-analyses and 4 de novo meta-analyses. Together with 8 previous meta-analyses, we finally included 47 unique health outcomes. Cheese consumption was inversely associated with all-cause mortality (highest compared with lowest category: RR = 0.95; 95% CI: 0.92, 0.99), cardiovascular mortality (RR = 0.93; 95% CI: 0.88, 0.99), incident cardiovascular disease (CVD) (RR = 0.92; 95% CI: 0.89, 0.96), coronary heart disease (CHD) (RR = 0.92; 95% CI: 0.86, 0.98), stroke (RR = 0.93; 95% CI: 0.89, 0.98), estrogen receptor-negative (ER-) breast cancer (RR = 0.89; 95% CI: 0.82, 0.97), type 2 diabetes (RR = 0.93; 95% CI: 0.88, 0.98), total fracture (RR = 0.90; 95% CI: 0.86, 0.95), and dementia (RR = 0.81; 95% CI: 0.66, 0.99). Null associations were found for other outcomes. According to the NutriGrade scoring system, moderate quality of evidence was observed for inverse associations of cheese consumption with all-cause and cardiovascular mortality, incident CVD, CHD, and stroke, and for null associations with cancer mortality, incident hypertension, and prostate cancer. Our findings suggest that cheese consumption has neutral to moderate benefits for human health.

Association of dairy consumption patterns with the incidence of type 2 diabetes: Findings from Alberta's Tomorrow Project

BACKGROUND AND AIMS

We aimed to extract dairy consumption patterns of men and women from a population-based cohort and then assess the association of each consumption pattern with incident T2D risk.

METHODS AND RESULTS

This prospective study was conducted within the framework of Alberta's Tomorrow Project (ATP), in which 8615 men and 15,016 women provided information on dietary intake by completing a food-frequency questionnaire at baseline, and then were followed up over time to determine the incidence of T2D via questionnaires. Principal Component Analysis (PCA) was used to extract dairy consumption patterns (DCPs). The association between each extracted pattern and T2D incidence was estimated using multivariable logistic regression models.The incidence of T2D among men and women was 3.8 and 3.2%, respectively, and the mean duration of follow-up was 5.2 years. Three major DCPs were identified. After controlling for potential confounders, the OR for risk of T2D in men in the highest compared with those in the lowest quartile of the DCP3 (whole milk, regular cheese, and non-fat milk as a beverage and in cereal) was 0.64 (95%CI: 0.47 to 0.88, P-trend=0.001), whereas it was not significant for women. DCP1 and DCP2 were not associated with incident T2D in men or women.

CONCLUSION

Adherence to a DCP characterized by higher consumption of whole milk, regular cheese, and non-fat milk was associated with decreased risk of incident T2D only in men. Our results support current evidence that a combination of different dairy products, regardless of their fat content, might be favorable for health maintenance, at least in men.

Association between dairy consumption and the risk of diabetes: A prospective cohort study from the China Health and Nutrition Survey

Diet is closely related to the risk of diabetes; yet the relationship between dairy consumption and the risk of diabetes is unclear with conflicting evidence from previous studies. This study used data from the Chinese Health and Nutrition Survey to investigate the association between dairy consumption and diabetes. A total of 15,512 adults were included; dairy consumption at each survey was assessed by the 3-day 24-h recall and weighed food record methods, and diabetes occurrence was derived from self-reported information. The association between dairy consumption and diabetes was explored using Cox regression and further stratified with BMI and energy intake. Results indicated that 12,368 (79.7%) participants had no dairy consumption, while 2,179 (14.0%) and 947 (6.1%) consumed dairy at 0.1-100 and >100 g/day, respectively. After adjusting for potential confounders, dairy consumption of 0.1-100 g/day was associated with lower risk of diabetes in all participants (HR 0.53, 95% CI:0.38 -0.74; P < 0.001) and males (HR 0.50, 95% CI: 0.31-0.80; P = 0.004). According to the restricted cubic splines (RCS), the protective effect on diabetes was significant in the total population with dairy consumption ranging from 25 to 65 g/day (HR <1, P = 0.025). In the stratified analysis, consuming 30-80 g/day was associated with reduced diabetes risk among the ≤ 2,000 kcal/day energy intake group (HR <1, P = 0.023). In conclusion, dairy consumption was inversely associated with a reduced diabetes risk in Chinese population. Further studies are required to examine the optimal level of dairy consumption for preventing diabetes in the Chinese population.

Dairy Product Consumption in Relation to Incident Prediabetes and Longitudinal Insulin Resistance in the Rotterdam Study

Evidence suggests neutral or moderately beneficial effects of dairy intake on type 2 diabetes mellitus risk. Nevertheless, evidence on associations with early phases of type 2 diabetes remains inconsistent. We aimed to examine associations between dairy-type intake with prediabetes risk and longitudinal insulin resistance. The analytic sample consisted of 6770 participants (aged 62 ± 4 years, 59% female) free of (pre-)diabetes at baseline from the prospective population-based Rotterdam Study. Dairy intake was measured at baseline using food frequency questionnaires. Data on prediabetes (fasting blood glucose 6.1-6.9 mmol/L or non-fasting 7.7-11.1 mmol/L) and the longitudinal homeostatic model assessment of insulin resistance (HOMA-IR) were available from 1993-2015. Associations with these outcomes were analyzed with dairy intake in quartiles (Q4 vs. Q1) and continuous using multivariable Cox proportional hazard models and linear mixed models. During a mean follow-up of 11.3 ± 4.8 years, 1139 incident prediabetes cases were documented (18.8%). In models adjusting for sociodemographic, lifestyle and dietary factors, a higher intake of high-fat yogurt was associated with lower prediabetes risk (HRQ4vsQ1 0.70, 95% CI 0.54-0.91 and HRserving/day 0.67, 0.51-0.89). In addition, a higher intake of high-fat milk was associated with lower prediabetes risk (HRQ4vsQ1 0.81, 0.67-0.97, HRserving/day 0.88, 0.79-0.99). Associations were found for low-fat dairy, low-fat milk and total cheese with a higher prediabetes risk (HRserving/day ranging from 1.05-1.07, not significant in quartiles). Associations with longitudinal HOMA-IR were similar to prediabetes for high-fat yogurt, low-fat dairy and low-fat milk. Fermented dairy, low-fat yogurt, high-fat cheese, cream and ice cream were not associated with the outcomes. In conclusion, a higher intake of high-fat yogurt was associated with a lower prediabetes risk and lower longitudinal insulin resistance. Additionally, high-fat milk was associated with a lower prediabetes risk. Some low-fat dairy types were inconsistently associated with these outcomes. Studies are needed to confirm associations and to examine the influence of confounding by population characteristics.