Dairy intake, blood pressure and incident hypertension in a general British population: the 1946 birth cohort

Dairy products and hypertension: Cross-sectional and prospective associations

BACKGROUND

The association between dairy intake and prevalence or incidence of hypertension remains controversial. We aimed to investigate the association between intake of different dairy products and prevalence and incidence of hypertension in a community-dwelling sample.

METHODS

Three cross-sectional studies (2009-12, 2014-17 and 2018-21) and one prospective study (2009-12 to 2018-21) were conducted in Lausanne, Switzerland. Dietary intake was assessed via a validated food frequency questionnaire. Dairy consumption was compared between participants with and without prevalent or incident hypertension.

RESULTS

For the cross-sectional analyses, data from 4437 (2009-12, 54.0% women, 57.7 ± 10.5 years), 2925 (2014-17, 53.4% women, 62.5 ± 10.0 years), and 2144 (2018-21; 53.3% women, 65.5 ± 9.6 years) participants were used. No consistent differences between participants with and without hypertension were found for all dairy products (total dairy, milk, yogurt, cheese, low-fat dairy, and full-fat dairy) although participants with hypertension tended to consume less cheese (51 ± 1 vs. 55 ± 1, p = 0.014, 52 ± 1 vs. 56 ± 1, p = 0.053, and 54 ± 1 vs. 56 ± 1 g/day for 2009-12, 2014-17 and 2018-21, respectively). For the prospective study, data from 2303 participants (60.8% women, 53.9 ± 9.0 years) were used. Irrespective of the dairy product considered, no association was found between quartiles of dairy consumption and development of hypertension. Similar findings were obtained after stratifying on dietary quality.

CONCLUSION

In this population-based study, no association was found between the consumption of different dairy products and the prevalence or incidence of hypertension.

The relationship between fermented and nonfermented dairy products consumption and hypertension among premature coronary artery disease patients: Iran premature coronary artery disease study

Dairy products may affect hypertension (HTN) risk. The aim of this study was to examine the association between fermented and nonfermented dairy foods and HTN in a sample of premature coronary artery disease (PCAD) subjects. This cross-sectional study was performed on 1854 PCAD patients. A 110-item food frequency questionnaire was used to assess dietary intakes. HTN was considered if systolic blood pressure was 140 mmHg and higher and/or diastolic blood pressure was 90 mmHg and higher. The odds ratio of HTN across the quartiles of different types of dairy products was evaluated by binary logistic regression. The mean (SD) of dairy products consumption was 339.8 (223.5) g/day, of which 285.4 g/day was fermented dairy products. In the crude model, participants in the fourth quartile of fermented dairy products had lesser risk of HTN compared to the bottom quartile (OR = 0.70, 95% CI: 0.52, 0.96; p for trend = .058). However, after considering the possible confounders, the significance disappeared. Subjects in the top quartile of high-fat fermented dairy products had 34% lower risk for HTN compared to the bottom quartile (95% CI: 0.49, 0.88; p for trend < .001). Adjustment for potential risk factors weakened the association but remained significant (OR = 0.73, 95% CI: 0.53, 1.01; p for trend = .001). Nonsignificant relation was detected between low-fat fermented, low-fat nonfermented, and high-fat nonfermented dairy products and HTN. Moderate consumption of high-fat fermented dairy products, in a population with low consumption of dairy foods, might relate to reduced likelihood of HTN.

Lack of change in blood pressure and arterial stiffness after high dairy intake in hyperinsulinemic subjects: a cross-over randomized controlled trial

To evaluate the effects of high dairy (HD) (≥4 servings/day), compared to adequate dairy (AD) (2-3 servings/day as per Canada's Food Guide for Healthy Eating (2007)), on blood pressure (BP) and measures of arterial stiffness in hyperinsulinemic subjects. In this cross-over clinical trial, hyperinsulinemic adults were randomized to AD and HD for 6 weeks. Anthropometric, glycemic, and lipid parameters were analyzed and dietary intake was evaluated; BP, carotid-femoral pulse wave velocity, augmentation index, and measures of arterial stiffness were assessed. Twenty-seven participants completed the study. Dairy intake was 2.2 ± 1.2 servings/day during AD. In addition, lower total and low-density lipoprotein (LDL) cholesterol were observed without significant change in BP or arterial stiffness between before and after AD. During HD, the subjects consumed 5.8 ± 1.9 servings/day of dairy products, providing a higher intake of protein, saturated fat, calcium, phosphorus, sodium, and potassium compared to the baseline diet. After the HD, subjects had higher body fat, fasting insulin, homeostatic model assessment for insulin resistance (HOMA-IR) index, and triglycerides without altering BP or arterial stiffness compared to before HD. Overall, adequate or high intake of total dairy did not modify BP or arterial stiffness in hyperinsulinemic adults after 6 weeks.

The relationship between the intake of fruits, vegetables, and dairy products with hypertension: findings from the STEPS study

BACKGROUND

The current research aimed to evaluate the relationship between fruit, vegetable (FV), and dairy consumption with the odds of developing hypertension based on nationwide Stepwise approach to surveillance (STEPS) data in Iran.

METHODS

This cross-sectional study was accomplished by the research center of non-communicable diseases (NCDs) in Tehran. In total, 29,378 individuals' data were analyzed. Participants were classified into normal, elevated BP, stage I, and stage II hypertension according to systolic blood pressure (SBP) and diastolic blood pressure (DBP) examinations. Based on the STEPS questionnaire, the consumption of FVs and dairy products was evaluated. Multinomial logistic regression was applied to assess the relationship between the consumption of FVs and dairy products with hypertension.

RESULTS

The findings revealed that only fruit consumption (≥ 2 servings/day) was negatively related to stage I hypertension (odds ratio (OR) = 0.81; 95% confidence interval (CI): 0.69-0.95) in two servings per day and OR = 0.81; 95% CI: 0.68-0.96 in > two servings per day) in the adjusted model. There was no significant relationship between consuming vegetables and dairy products with elevated BP and hypertension.

CONCLUSION

Our study showed that increasing fruit consumption was related to reducing hypertension odds. Regarding the consumption of dairy products and vegetables, no significant relationship was found with the odds of hypertension. More studies, especially cohorts, are needed to evaluate the impacts of FV and dairy products on the risk of hypertension.

Consumption of Dairy Products and the Risk of Overweight or Obesity, Hypertension, and Type 2 Diabetes Mellitus: A Dose-Response Meta-Analysis and Systematic Review of Cohort Studies

Dairy products have been suggested to be related to the prevention of overweight or obesity, hypertension, and type 2 diabetes mellitus (T2DM). These associations are currently controversial, however, and a systematic quantitative meta-analysis is lacking. In this study, we examined the associations between dairy products and the risk of overweight or obesity, hypertension, and T2DM and tested for dose-response relations. We comprehensively searched PubMed, Embase, and Web of Science up to April 2021. Cohort studies were included if dairy food consumption was reported at a minimum of 3 levels or as continuous variables, and the associations were assessed with overweight or obesity, hypertension, and T2DM. Summary RRs and 95% CIs were estimated for the dose-response association. Restricted cubic splines were used to evaluate the linear or nonlinear relations. Among the 9887 articles retrieved, 42 articles were included. For overweight or obesity, a linear association was observed for total dairy, milk, and yogurt. The risk decreased by 25%, 7%, and 12% per 200-g/d increase for total dairy, high-fat dairy, and milk, respectively, and by 13% per 50-g/d increment of yogurt. For hypertension, a nonlinear association was observed with total dairy, whereas significant inverse associations were found for low-fat dairy (RR: 0.94; 95% CI: 0.90, 0.98) and milk (RR: 0.94; 95% CI: 0.92, 0.97) per 200-g/d intake increase. For T2DM, all types of dairy food consumption except for milk and low-fat dairy products showed nonlinear associations, with total dairy and yogurt intake associated with 3% and 7% lower risk per 200-g/d and 50-g/d intake increase, respectively. In conclusion, our study suggests that total dairy is associated with a low risk of overweight or obesity, hypertension, and T2DM, especially milk and yogurt for overweight or obesity, low-fat dairy and milk for hypertension, and yogurt for T2DM.

Dairy products consumption and the risk of hypertension in adults: An updated systematic review and dose-response meta-analysis of prospective cohort studies

AIMS

With an increase in the number of published prospective cohort studies, we sought to summarize the relationship between dairy products consumption and the risk of hypertension (HTN).

DATA SYNTHESIS

We searched PubMed, Web of Science, Embase, Science direct, and Scopus. Pooled RRs and 95% CIs were calculated using a random effects model. The certainty of the evidence was assessed by Grading of Recommendations Assessment, Development and Evaluation (GRADE). Sixteen studies were included in the current meta-analysis. We found an inverse association between total dairy products (RR = 0.90; 95% CI: 0.87, 0.94; n = 16), low-fat dairy products (RR = 0.86; 95% CI: 0.77, 0.96; n = 8), milk (RR = 0.94; 95% CI: 0.90, 0.99; n = 11), and fermented dairy (RR = 0.95; 95% CI: 0.91, 0.99; n = 8) consumption and the risk of HTN. However, in subgroup analysis, despite a significant association for total dairy products in women, Americans, longer and larger studies, and self-reported HTN, no associations were found in males, Europeans, or Asians, and studies which followed participants for <10 years or had <3000 participants or measured HTN. Dose-response analysis revealed a non-linear association between total dairy products and milk consumption and the risk of HTN, but a linear association for low-fat dairy products.

CONCLUSIONS

Higher dairy products consumption was associated with reduced risk of HTN. This association was dependent on sex, geographical region of study, and the stage of HTN. However, the certainty of the evidence was graded either as low or very low.

[Factors associated with arterial hypertension: a systematic review]

A systematic review of demographic, socioeconomic, behavioral and anthropometric factors associated with hypertension. We included observational studies, of populations aged 18 or older, from the past ten years, published in English, Portuguese or Spanish from Pubmed, Web of Science, Scopus and Lilacs bases. The most found factors related to the greater chance of having hypertension were age and the Body Mass Index (BMI). Other factors associated with the disease were: gender (male), education (lower education), income (lower income) and waist circumference (high). Never having smoked, never having consumed alcohol and white skin color were characteristics related to a lower chance of having hypertension. As demonstrated, demographic, socioeconomic, behavioral and anthropometric characteristics are important factors associated with a greater chance of having hypertension in the adult population. However, while most of the factors associated with it are amenable to intervention, broader health promotion policies will be needed to reduce socioeconomic inequalities in the prevalence of the disease.

Dairy product consumption and hypertension risk in a prospective French cohort of women

BACKGROUND

Among potentially modifiable factors, dairy product consumption has been inconsistently associated with hypertension risk. The objective of this study was to investigate the relation between dairy product consumption and the risk of hypertension among middle-aged women.

METHODS

In a prospective cohort of 40,526 French women, there were 9340 new cases of hypertension after an average 12.2 years of follow up. Consumptions of milk, yogurt, and types of cheese were assessed at baseline using a validated dietary questionnaire. Hazard ratios (HRs) and 95% confidence intervals (95% CI) for hypertension were estimated with multivariate Cox models with age as the time scale.

RESULTS

The mean dairy consumption was 2.2 + 1.2 servings/day, as cottage cheese (0.2 + 0.2 servings/day), yogurt (0.6 + 0.5 servings/day), milk (0.4 + 0.7 servings/day), and cheese (1.1 + 0.8 servings/day). There was no association between risk of hypertension and total dairy consumption (multivariate HR for the fifth vs. first quintile HR_5vs.1 = 0.97 [0.91; 1.04]). There was no association with any specific type of dairy, except for a positive association between processed cheese consumption and hypertension (multivariate HR_{4vs.1 =} 1.12 [1.06; 1.18]; p trend = < 0.003).

CONCLUSIONS

In this large prospective cohort of French women, overall consumption of dairy products was not associated with the risk of hypertension. Results regarding processed cheese must be further confirmed.

Dairy Consumption in Relation to Hypertension Among a Large Population of University Students: The MEPHASOUS Study

BACKGROUND

Hypertension is a chronic condition that its prevalence is increasing at an alarming rate. Findings on the association between dairy consumption and hypertension are conflicting and few data are available in the Middle East.

AIM

To assess the association between dairy consumption and hypertension among a large population of university students.

MATERIALS AND METHODS

The current study was performed in the framework of the Mental and Physical Health Assessment of University Student (MEPHASOUS) project. Overall, 67,011 university students with complete information were included in the statistical analysis. To assess dairy consumption, a self-administered dietary habits questionnaire was employed. Blood pressure was measured using a standard protocol. The systolic/diastolic blood pressure of ≥140/90 mmHg was considered hypertension.

RESULTS

Hypertension was prevalent among 6.9% of students. A significant inverse association was found between dairy consumption and the odds of hypertension; such that after taking potential confounders into account, individuals in the highest levels of dairy consumption had 85% lower odds for having hypertension compared with those in the lowest levels (odds ratio (OR): 0.15, 95% confidence interval (CI): 0.13-0.18). Such an inverse association was also seen among males (OR: 0.14, 95% CI: 0.11-0.18) and females (OR: 0.16, 95% CI: 0.12-0.21), normal-weight students (OR: 0.15, 95% CI: 0.12-0.18) and those with overweight or obesity (OR: 0.15, 95% CI: 0.11-0.21), and individuals with (OR: 0.13, 95% CI: 0.11-0.16) and without (OR: 0.24, 95% CI: 0.17-0.35) family history of hypertension.

CONCLUSION

Our results support the previous findings on the inverse association between dairy consumption and hypertension among university students.

Long-term yogurt consumption and risk of incident hypertension in adults

OBJECTIVE

To evaluate the relation between yogurt consumption as well as cheese, milk, and total dairy, and high blood pressure (HBP) in two Nurses' Health Study cohorts (NHS, n = 69 298), NHS II (n = 84 368) and the Health Professionals Follow-Up Study (HPFS, n = 30 512).

METHODS

NHS, NHS II, and HPFS participants were followed for incident HBP for up to 30, 20, and 24 years, respectively. Hazard ratios were calculated using time-dependent multivariate-adjusted Cox proportional hazards models. Pooled risk estimates were derived from fixed effects meta-analyses.

RESULTS

Participants consuming at least five servings per week (vs. <1 serving per month) of yogurt in NHS, NHS II, and HPFS had 19% (95% CI 0.75-0.87), 17% (95% CI 0.77-0.90), and 6% (95% CI 0.83-1.07) lower HBP risks, respectively. In pooled analyses of these cohorts, higher yogurt consumption was linked with 16% (95% CI 0.80-0.88) lower HBP risk; higher total dairy (3 to <6 vs. <0.5 servings/day), milk (2 to <6/day vs. <4/week) and cheese (1 to 4/day vs. <1/week) were associated with 16% (95% CI 0.81-0.87), 12% (95% CI 0.86-0.90), and 6% (95% CI 0.90-0.97) lower HBP risks, respectively. After controlling for BMI as a possible causal intermediate, total dairy, yogurt, milk, and cheese were associated with 13, 10, 8, and 8% lower HBP risks, respectively. The combination of higher yogurt intake and higher DASH ('Dietary Approaches to Stop Hypertension') diet scores was associated with 30% (95% CI 0.66-0.75) lower HBP risk compared with lower levels of both factors.

CONCLUSION

Higher total dairy intake, especially in the form of yogurt, was associated with lower risk of incident HBP in middle-aged and older adult men and women.

Dairy food consumption is associated with a lower risk of the metabolic syndrome and its components: a systematic review and meta-analysis

A systematic review and a meta-analysis of observational studies were performed to assess the dose–response relationship between specific types of dairy foods and the risk of the metabolic syndrome (MetS) and its components. Studies of dairy foods and the risk of the MetS and its components published up to June 2016 were searched using PubMed, EMBASE and a reference search. Random-effects models were used to estimate the pooled relative risks (RR) with 95 % CI. Finally, ten cross-sectional studies, two nested case–control studies and twenty-nine cohort studies were included for the analysis. In a dose–response analysis of cohort studies and cross-sectional studies, the pooled RR of the MetS for a one-serving/d increment of total dairy food (nine studies) and milk (six studies) consumption (200 g/d) were 0·91 (95 % CI 0·85, 0·96) and 0·87 (95 % CI 0·79, 0·95), respectively. The pooled RR of the MetS for yogurt (three studies) consumption (100 g/d) was 0·82 (95 % CI 0·73, 0·91). Total dairy food consumption was associated with lower risk of MetS components, such as hyperglycaemia, elevated blood pressure, hypertriacylglycerolaemia and low HDL- cholesterol. A one-serving/d increment of milk was related to a 12 % lower risk of abdominal obesity, and a one-serving/d increment of yogurt was associated with a 16 % lower risk of hyperglycaemia. These associations were not significantly different by study design, study location or adjustment factors. This meta-analysis showed that specific types of dairy food consumption such as milk and yogurt as well as total dairy food consumption were inversely related to risk of the MetS and its components.

Food Groups and Risk of Hypertension: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies

The aim of this systematic review and meta-analysis was to summarize the evidence on the relation of the intakes of 12 major food groups, including whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages (SSBs) with the risk of hypertension. PubMed, Scopus, and Web of Science were searched systematically until June 2017 for prospective studies having quantitatively investigated the above-mentioned foods. We conducted meta-analysis on the highest compared with the lowest intake categories and linear and nonlinear dose-response meta-analyses to analyze the association. Summary RRs and 95% CIs were estimated by using a random-effects model. Overall, 28 reports were included in the meta-analysis. An inverse association for the risk of hypertension was observed for 30 g whole grains/d (RR: 0.92; 95% CI: 0.87, 0.98), 100 g fruits/d (RR: 0.97; 95% CI: 0.96, 0.99), 28 g nuts/d (RR: 0.70; 95% CI: 0.45, 1.08), and 200 g dairy/d (RR: 0.95; 95% CI: 0.94, 0.97), whereas a positive association for 100 g red meat/d (RR: 1.14; 95% CI: 1.02, 1.28), 50 g processed meat/d (RR: 1.12; 95% CI: 1.00, 1.26), and 250 mL SSB/d (RR: 1.07; 95% CI: 1.04, 1.10) was seen in the linear dose-response meta-analysis. Indication for nonlinear relations of the intakes of whole grains, fruits, fish, and processed meats with the risk of hypertension was detected. In summary, this comprehensive dose-response meta-analysis of 28 reports identified optimal intakes of whole grains, fruits, nuts, legumes, dairy, red and processed meats, and SSBs related to the risk of hypertension. These findings need to be seen under the light of very-low to low quality of meta-evidence. However, the findings support the current dietary guidelines in the prevention of hypertension.

Dairy consumption, systolic blood pressure, and risk of hypertension: Mendelian randomization study

Objective To examine whether previous observed inverse associations of dairy intake with systolic blood pressure and risk of hypertension were causal.Design Mendelian randomization study using the single nucleotide polymorphism rs4988235 related to lactase persistence as an instrumental variable.Setting CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) Consortium.Participants Data from 22 studies with 171 213 participants, and an additional 10 published prospective studies with 26 119 participants included in the observational analysis.Main outcome measures The instrumental variable estimation was conducted using the ratio of coefficients approach. Using meta-analysis, an additional eight published randomized clinical trials on the association of dairy consumption with systolic blood pressure were summarized.Results Compared with the CC genotype (CC is associated with complete lactase deficiency), the CT/TT genotype (TT is associated with lactose persistence, and CT is associated with certain lactase deficiency) of LCT-13910 (lactase persistence gene) rs4988235 was associated with higher dairy consumption (0.23 (about 55 g/day), 95% confidence interval 0.17 to 0.29) serving/day; P<0.001) and was not associated with systolic blood pressure (0.31, 95% confidence interval -0.05 to 0.68 mm Hg; P=0.09) or risk of hypertension (odds ratio 1.01, 95% confidence interval 0.97 to 1.05; P=0.27). Using LCT-13910 rs4988235 as the instrumental variable, genetically determined dairy consumption was not associated with systolic blood pressure (β=1.35, 95% confidence interval -0.28 to 2.97 mm Hg for each serving/day) or risk of hypertension (odds ratio 1.04, 0.88 to 1.24). Moreover, meta-analysis of the published clinical trials showed that higher dairy intake has no significant effect on change in systolic blood pressure for interventions over one month to 12 months (intervention compared with control groups: β=-0.21, 95% confidence interval -0.98 to 0.57 mm Hg). In observational analysis, each serving/day increase in dairy consumption was associated with -0.11 (95% confidence interval -0.20 to -0.02 mm Hg; P=0.02) lower systolic blood pressure but not risk of hypertension (odds ratio 0.98, 0.97 to 1.00; P=0.11).Conclusion The weak inverse association between dairy intake and systolic blood pressure in observational studies was not supported by a comprehensive instrumental variable analysis and systematic review of existing clinical trials.

Dairy Food Intake Is Inversely Associated with Risk of Hypertension: The Singapore Chinese Health Study

BACKGROUND

Epidemiological evidence from Western populations suggests that dairy food intake may reduce the risk of hypertension, probably through its calcium content. However, there are no epidemiological studies among Asian populations with generally lower dairy and calcium consumption.

OBJECTIVE

The relation between dairy or calcium intake and risk of hypertension was evaluated in a Chinese population in Singapore.

METHODS

The analysis included 37,124 Chinese men and women aged 45-74 y who participated in the Singapore Chinese Health Study in 1993-1998. The subjects included in the present study had no history of cancer, hypertension, or cardiovascular disease at baseline and completed ≥1 follow-up interview. Diet at baseline was assessed by using a validated 165-item semiquantitative food-frequency questionnaire. The occurrence of new, physician-diagnosed hypertension was ascertained through follow-up interviews during 1999-2004 and 2006-2010. The Cox proportional hazard regression method was used to compute HRs and 95% CIs with adjustment for potential confounders.

RESULTS

Dairy food intake was inversely associated with the risk of hypertension in a dose-dependent manner: HRs across quartiles were 1.00 (lowest quartile, reference), 0.97 (95% CI: 0.92, 1.02), 0.98 (95% CI: 0.92, 1.03), and 0.93 (95% CI: 0.88, 0.98) (P-trend = 0.01). Milk accounted for ∼80% of all dairy products consumed in this population. Daily milk drinkers had a lower risk of hypertension (HR: 0.94; 95% CI: 0.89, 0.99) than did nondrinkers. Nondairy calcium intake contributed 80% of total calcium intake. Although dairy calcium intake was associated with a lower risk of hypertension (HR comparing extreme quartiles: 0.88; 95% CI: 0.83, 0.94; P-trend < 0.001), there was no association for nondairy calcium intake (HR: 1.02; 95% CI: 0.94, 1.10; P-trend = 0.58).

CONCLUSIONS

Baseline dairy food intake, and specifically that of milk, may reduce the risk of developing hypertension in Chinese adults, and this may not be associated with the calcium component.

Impact of probiotic Lactobacillus plantarum TENSIA in different dairy products on anthropometric and blood biochemical indices of healthy adults

The blood pressure-lowering effect of dairy products holds the potential to decrease the risk of cardiovascular disease (CVD). An open question is if the successful expression of functional properties of the probiotic strain depends on host biomarkers and/or food matrix properties. The probiotic Lactobacillus plantarum strain TENSIA® (DSM 21380) is a novel microorganism with antimicrobial and antihypertensive functional properties. The aim of this study was to characterise the functional properties of the probiotic L. plantarum TENSIA and compare its effects on host anthropometric, clinical, and blood biomarkers when consumed with cheese or yoghurt. This study involved two double-blinded randomised placebo-controlled exploratory trials (ISRCTN15061552 and ISRCTN79645828) of healthy adults over a three-week period. The three-week consumption of probiotic L. plantarum TENSIA in a daily dose of 1×1010 cfu in probiotic cheese or a daily dose of 6×109 cfu in yoghurt with different content of carbohydrates, proteins, and lipids did not significantly change the body mass index (BMI), plasma glucose and lipid levels, or inflammatory markers in the blood. Reduced lowered systolic and diastolic blood pressure values were detected, regardless of food matrix or baseline values for blood pressure and BMI. In conclusion, our study showed that three-week consumption of the probiotic L. plantarum TENSIA either in cheese or yoghurt lowered diastolic and systolic blood pressure regardless of food matrix and baseline values of blood pressure and BMI, confirming the impact of the functional properties of the probiotic strain in decreasing CVD risk.

Longitudinal association of dairy consumption with the changes in blood pressure and the risk of incident hypertension: the Framingham Heart Study

We aimed to examine the longitudinal association of dairy consumption with the changes in blood pressure (BP) and the risk of incident hypertension (HTN) among adults. This study included 2636 Framingham Heart Study Offspring Cohort members who participated in the 5th through 8th examinations (1991-2008) and were free of HTN at their first examination during the follow-up. Data collected at each examination included dietary intake (by a validated FFQ), BP (following standardised procedures) and anti-hypertensive medication use (by physician-elicited self-report). HTN was defined as systolic BP (SBP)≥140 mmHg, or diastolic BP (DBP)≥90 mmHg or anti-hypertensive medication use. We used repeated-measure and discrete-time hazard regressions to examine the associations of dairy consumption with the annualised BP change (n 2075) and incident HTN (n 2340; cases=1026), respectively. Covariates included demographic, lifestyle, overall diet quality, metabolic factors and medication use. Greater intakes of total dairy foods, total low-fat/fat-free dairy foods, low-fat/skimmed milk and yoghurt were associated with smaller annualised increments in SBP and a lower risk of projected HTN incidence. However, with the exception of total dairy foods and yoghurt, these inverse associations with HTN risk were attenuated as the follow-up time increased. For yoghurt, each additional serving was associated with 6 (95 % CI 1, 10) % reduced risk of incident HTN. Total dairy and total low-fat/fat-free dairy intakes were found to be inversely related to changes in DBP. Dairy consumption, as part of a nutritious and energy-balanced diet pattern, may benefit BP control and prevent or delay the onset of HTN.

Fruit and vegetable consumption and cardiovascular risk factors in older Chinese: the Guangzhou biobank cohort study

OBJECTIVE

To examine the adjusted associations of fruit consumption and vegetable consumption with the Framingham score and its components in the non-Western setting of Southern China, considering health status.

METHOD

Linear regression was used to assess the cross-sectional associations of fruit and vegetable consumption with the Framingham score and its components, among 19,518 older Chinese (≥50 years) from the Guangzhou Biobank Cohort Study in Southern China (2003-2006), and whether these differed by health status.

RESULTS

The association of fruit consumption with the Framingham score varied by health status (P-value<0.001), but not vegetable consumption (P-value 0.51). Fruit consumption was associated with a lower Framingham score (-0.04 per portions/day, 95% confidence interval (CI) -0.08 to -0.004) among participants in poor health, adjusted for age, sex, recruitment phase, socio-economic position and lifestyle. However, similarly adjusted, fruit consumption was associated with a higher Framingham score (0.05, 95% CI 0.02 to 0.09) among participants in good health, perhaps due to a positive association of fruit consumption with fasting glucose. Similarly adjusted, vegetable consumption was associated with a higher Framingham score (0.03, 95% CI 0.01 to 0.05) among all participants, with no difference by health status.

CONCLUSION

This large study from a non-western setting found that fruit and vegetable consumption was barely associated with the Framingham score, or major CVD risk factors.

Dairy consumption is associated with a lower prevalence of metabolic syndrome among young adults from Ribeirão Preto, Brazil

OBJECTIVE

It has been suggested that a greater dairy consumption is a contributing factor to a lower prevalence of metabolic syndrome (MetS) as a result of the possible actions of some milk nutrients. However, results remain controversial. The aim of this study was to examine the association between dairy consumption and MetS and its components.

METHODS

Dairy consumption and biochemical and anthropometric parameters were determined in 2031 young adults ages 23 to 25 y. Food consumption was assessed using a food frequency questionnaire. The estimated habitual portion of dairy products consumed daily was divided into quintiles. The criteria of the International Diabetes Federation (IDF) and of the Joint Interim Statement (JIS) were used for the classification of MetS. Nonadjusted and adjusted odds ratios (ORs) were estimated by logistic regression.

RESULTS

The prevalence of MetS was 11.9% by the IDF criteria and 9% by the JIS criteria. A greater dairy consumption was associated with a lower prevalence of MetS according to both IDF (OR, 0.61; 95% confidence interval [CI], 0.38-0.97) and JIS (OR, 0.62; 95% CI, 0.39-0.98) criteria when the last quintile was compared with the first. The association persisted in the model adjusted for demographic, socioeconomic, dietary, and lifestyle variables according to the IDF (OR, 0.53; 95% CI, 0.30-0.93) and was borderline according to the JIS (OR, 0.59; 95% CI, 0.34-1.00), but lost significance when data were adjusted for calcium in both models.

CONCLUSIONS

A greater dairy consumption is associated with a lower prevalence of MetS, with calcium probably being the nutrient responsible for this association.

Diurnal eating rhythms: association with long-term development of diabetes in the 1946 British birth cohort

BACKGROUND AND AIMS

Few studies have described the association between time-of-day of macronutrient intake and diabetes. This study examined the prospective association between time-of-day and nutrient composition of eating occasions in relation to diabetes incidence in the 1946 British birth cohort.

METHODS AND RESULTS

The study included 1618 survey members who completed dietary assessment at age 43 (1989) and for whom data on glycosylated haemoglobin at age 53 years (1999) were available. Diet was assessed using 5d estimated diaries, divided into seven meal slots: breakfast, mid-morning, lunch, mid-afternoon, dinner, late evening and extras. Diabetes was defined by glycosylated haemoglobin (HbA1c) ≥ 6.5% or diabetes medication use. The association between time-of-day of macronutrient intake at age 43 years and diabetes at age 53 years was assessed using logistic multivariate nutrient density models after adjustment for potential confounders. There were 66 cases of diabetes at age 53 years. Survey members with diabetes obtained 50.4% of their energy from carbohydrate at breakfast compared to 55.9% in survey members without diabetes (P = 0.001). Increasing carbohydrate intake at breakfast at the expense of fat was related to lower odds ratio (OR) of diabetes (OR = 0.86; 95%CI = 0.79-0.93; P < 0.001). This relationship was attenuated after adjustment for body mass index and waist circumference.

CONCLUSION

Increasing energy intake from carbohydrate at the expense of fat at breakfast is inversely associated with 10-year diabetes incidence. However, further studies are required to elucidate whether the type or source of carbohydrates or fat influences the above association.

The role of dietary protein in blood pressure regulation

PURPOSE OF REVIEW

Despite a considerable amount of research, the blood pressure (BP) lowering effect of dietary proteins is still not fully established. This review discusses the most recent findings on BP lowering of dietary proteins and protein sources, the possible mechanisms and the safety of increasing protein intake.

RECENT FINDINGS

Recent short-term, strictly controlled, randomized clinical trials show a BP lowering effect of increased protein intake. Longer-term trials, however, show inconsistent results. Because all recent trials exchanged carbohydrates, and not fats, for proteins, the question remains whether potential beneficial effects of high protein diets are due to increased protein intake or decreased carbohydrate intake. No clear differences between plant protein and animal protein are found in observational studies, and trials comparing plant versus animal protein are lacking. Different protein sources may lower BP via different mechanisms, which might explain divergent findings. Potential harms of high protein diets are not confirmed in recent trials in healthy persons.

SUMMARY

Increasing dietary protein intake or decreasing carbohydrate intake within reasonable limits may be beneficial for BP. The most and least beneficial protein sources still need to be determined.