the desir study is a prospective study of 5,212 subjects at inclusion ( 2,576 men and 2,636 women , aged 3065 years ) , recruited from volunteers who were offered periodic health examinations free of charge by the french social security system in 10 health examination centers from the western part of france . they were clinically and biologically evaluated at visits every 3 years , and the final examination was 9 years after inclusion . for the purpose of these analyses , in addition , subjects who declared that they were on a diet and those who did not answer all the questions in the food frequency questionnaire were excluded . in consequence , the 3,435 subjects ( 1,710 men , 1,725 women ) with a food frequency questionnaire at baseline and/or at 3 years remained for this study . the study was approved by the ethics committee of the kremlin bictre hospital , and all participants signed an informed consent . venous blood samples were collected in the morning after subjects had fasted for 12 h. systolic and diastolic arterial pressures were measured with a mercury sphygmomanometer adapted for arm size after 5 min of rest with participants in a supine position . two measures of blood pressure were taken , and means were used for the analysis . a detailed description of laboratory measurements including fasting triglycerides , hdl - c , glucose , and insulin is provided elsewhere ( 6 ) . in the present work , two definitions for the mets were used . according to the international diabetes federation ( 7 ) , it was defined as waist circumference 94/80 cm for men / women plus two of the following factors : 1 ) elevated triglycerides : 1.70 mmol / l or specific treatment for this lipid abnormality ; 2 ) reduced hdl - c : 1.03 mmol / l for men and 1.29 mmol / l for women or specific treatment for this lipid abnormality ; 3 ) elevated blood pressure :  130/85 mmhg or treatment of previously diagnosed hypertension ; and 4 ) elevated fasting glycemia  5.6 mmol / l or previously diagnosed type 2 diabetes ( treated by glucose lowering drugs and/or fasting glycemia  7.0 mmol / l ) . according to the national cholesterol education program - adult treatment panel iii ( 8) , it was defined as three of the following factors : 1 ) waist circumference > 102/88 cm for men / women ; 2 ) elevated triglycerides : 1.70 mmol / l ; 3 ) reduced hdl - c : 1.03 mmol / l for men and 1.29 mmol / l for women ; 4 ) elevated blood pressure : systolic blood pressure  130 or diastolic  85 mmhg ; and 5 ) elevated fasting glycemia 6.1 mmol / l . incident cases for mets and/or ifg / t2d were defined as subjects free of disease at entry who developed the disease at any time during the follow - up . a 23-item questionnaire was completed by each participant to determine the frequency and level of consumption of different foods . this questionnaire has been validated by comparison with the dietary history method consisting of 30-min interviews by trained dietitians . this validation study enabled the determination of multiple linear regression equations to estimate the main nutrient intakes ( including calcium ) from the questions on the consumption of different foods ( 9 ) . two groups of dairy products were defined : cheese or milk and other dairy products ( except cheese ) . one portion was defined as 30 g for cheese , and 125 ml for milk or milk products . there were four responses for the intake of dairy products ( never ; < 1 portion / day ; 12 /day ; > 2 /day ; coded 1,2,3,4 ) and 3 for cheese intake ( 01 portion / day ; 23 /day ; > 3/day ; coded 1,2,3 ) . calcium density of the diet was defined as the amount of calcium ingested per 1,000 kcal ( excluding alcohol ) . analyses used the average dietary data from year 0 and year 3 to take into account the variability over time ; 212 participants with only one dietary record were also included ; their exclusion did not change the results . we categorized the dairy intake and the cheese intake in 4 groups and 3 groups , respectively , according to their responses to both questionnaires . the dairy intake groups were defined as group 1 for an average response 2 , group 2 for an average response of 2.5 , group 3 for an average response of 3 , and group 4 for an average response > 3 . the cheese intake groups were defined as group 1 for an average response of 1 , group 2 for an average response of 1.5 , and group 3 for an average response 2 . these limits were chosen in order to have comparable frequencies in the groups . for calcium , we calculated sex - specific quartiles of the mean calcium density at year 0 and year 3 ( 3 ) . multiple logistic regression analysis was used to evaluate associations between the dairy consumption variables , and the odds of developing mets or ifg / t2d during the 9-year study . two models were used : in model 1 , the covariates were age , sex , alcohol consumption ( continuous covariate ) , smoking ( yes / no ) , physical activity ( three classes used as a continuous covariate ) , fat intake ( from the questions on the consumption of meat , fish , pork products , fried foods , butter , cheese , and other dairy products ) ; in model 2 , the same covariates as well as bmi as a covariate . to take into account the variation in bmi over the 9 years , we used as covariate the mean of bmi at entry and at 9 years . odds ratios indicate the risk of a change from one category to the next , e.g. , from one quartile of calcium density to the next quartile . ancova with repeated measures was used to test for the average effect of dairy products and the effects on changes between baseline and the end of the follow - up ( 9 years ) , adjusted for age , sex , alcohol , smoking , physical activity , fat intake , and bmi . results are presented as least squares means adjusted for covariates with the sem , or as geometric means with 95% ci for skewed variables . venous blood samples were collected in the morning after subjects had fasted for 12 h. systolic and diastolic arterial pressures were measured with a mercury sphygmomanometer adapted for arm size after 5 min of rest with participants in a supine position . two measures of blood pressure were taken , and means were used for the analysis . a detailed description of laboratory measurements including fasting triglycerides , hdl - c , glucose , and insulin is provided elsewhere ( 6 ) . in the present work , two definitions for the mets were used . according to the international diabetes federation ( 7 ) , it was defined as waist circumference 94/80 cm for men / women plus two of the following factors : 1 ) elevated triglycerides : 1.70 mmol / l or specific treatment for this lipid abnormality ; 2 ) reduced hdl - c : 1.03 mmol / l for men and 1.29 mmol / l for women or specific treatment for this lipid abnormality ; 3 ) elevated blood pressure :  130/85 mmhg or treatment of previously diagnosed hypertension ; and 4 ) elevated fasting glycemia  5.6 mmol / l or previously diagnosed type 2 diabetes ( treated by glucose lowering drugs and/or fasting glycemia  7.0 mmol / l ) . according to the national cholesterol education program - adult treatment panel iii ( 8) , it was defined as three of the following factors : 1 ) waist circumference > 102/88 cm for men / women ; 2 ) elevated triglycerides : 1.70 mmol / l ; 3 ) reduced hdl - c : 1.03 mmol / l for men and 1.29 mmol / l for women ; 4 ) elevated blood pressure : systolic blood pressure  130 or diastolic  85 mmhg ; and 5 ) elevated fasting glycemia 6.1 mmol / l . type 2 diabetes was defined as fasting plasma glucose 7 mmol / l or treatment by antidiabetic agents . incident cases for mets and/or ifg / t2d were defined as subjects free of disease at entry who developed the disease at any time during the follow - up . a 23-item questionnaire was completed by each participant to determine the frequency and level of consumption of different foods . this questionnaire has been validated by comparison with the dietary history method consisting of 30-min interviews by trained dietitians . this validation study enabled the determination of multiple linear regression equations to estimate the main nutrient intakes ( including calcium ) from the questions on the consumption of different foods ( 9 ) . two groups of dairy products were defined : cheese or milk and other dairy products ( except cheese ) . one portion was defined as 30 g for cheese , and 125 ml for milk or milk products . there were four responses for the intake of dairy products ( never ; < 1 portion / day ; 12 /day ; > 2 /day ; coded 1,2,3,4 ) and 3 for cheese intake ( 01 portion / day ; 23 /day ; > 3/day ; coded 1,2,3 ) . calcium density of the diet was defined as the amount of calcium ingested per 1,000 kcal ( excluding alcohol ) . analyses used the average dietary data from year 0 and year 3 to take into account the variability over time ; 212 participants with only one dietary record were also included ; their exclusion did not change the results . we categorized the dairy intake and the cheese intake in 4 groups and 3 groups , respectively , according to their responses to both questionnaires . the dairy intake groups were defined as group 1 for an average response 2 , group 2 for an average response of 2.5 , group 3 for an average response of 3 , and group 4 for an average response > 3 . the cheese intake groups were defined as group 1 for an average response of 1 , group 2 for an average response of 1.5 , and group 3 for an average response 2 . these limits were chosen in order to have comparable frequencies in the groups . for calcium , we calculated sex - specific quartiles of the mean calcium density at year 0 and year 3 ( 3 ) . multiple logistic regression analysis was used to evaluate associations between the dairy consumption variables , and the odds of developing mets or ifg / t2d during the 9-year study . two models were used : in model 1 , the covariates were age , sex , alcohol consumption ( continuous covariate ) , smoking ( yes / no ) , physical activity ( three classes used as a continuous covariate ) , fat intake ( from the questions on the consumption of meat , fish , pork products , fried foods , butter , cheese , and other dairy products ) ; in model 2 , the same covariates as well as bmi as a covariate . to take into account the variation in bmi over the 9 years , we used as covariate the mean of bmi at entry and at 9 years . odds ratios indicate the risk of a change from one category to the next , e.g. , from one quartile of calcium density to the next quartile . ancova with repeated measures was used to test for the average effect of dairy products and the effects on changes between baseline and the end of the follow - up ( 9 years ) , adjusted for age , sex , alcohol , smoking , physical activity , fat intake , and bmi . results are presented as least squares means adjusted for covariates with the sem , or as geometric means with 95% ci for skewed variables . the consumption of dairy products other than cheese and the calcium density of the diet were inversely associated with the incidence of the mets , whatever the definition , and with the incidence of ifg / t2d during the 9-year follow - up ( table 1 ) . the consumption of cheese was negatively associated with the incidence of the mets ( table 1 ) . the consumption of dairy products other than cheese was associated with the incidence of type 2 diabetes alone ( multiple adjustment without bmi , model 1 : odds ratio 0.82 [ 95%ci 0.710.92 ] ; p = 0.02 ) , but this association was no longer significant after taking bmi into account ( model 2 , p = 0.07 ) . neither cheese nor calcium density were associated with type 2 diabetes alone ( data not shown ) . incidence of the mets and ifg / t2d according to dairy product consumption in the desir cohort data are n ( % ) or odds ratio ( 95% ci ) unless otherwise indicated . odds ratios were calculated by logistic regression and indicate the risk for a change from one category to the next . model 1 : adjustment for sex , age , smoking , total fat intake , physical activity . model 2 : same as model 1 plus adjustment for mean bmi ( mean of bmi at baseline and at 9 years of follow - up ) . the three dairy parameters were associated with lower 9-year diastolic blood pressure and with lower bmi gain over this period ( supplementary table a13 ) . higher cheese intake and calcium density were associated with lower triglyceride levels and a lower 9-year increase in waist circumference both in men and women ( supplementary tables a2 and 3 ) . calcium density was also associated with a lower systolic blood pressure and a lower 9-y increase in plasma triglycerides levels ( supplementary table a3 ) . few significant interaction effects with sex were observed : time changes in systolic blood pressure for dairy intake ( supplementary table a1 ) , and insulin levels for calcium density ( supplementary table a3 ) , which were significant only in women . intake of dairy products was associated with lower hdl - c levels in men , but the decrease with time was also lower . intake of cheese was associated with a higher average bmi , but also with a lower increase with time . in the desir prospective study with a 9-year follow - up , we found that the consumption of dairy products and cheese as well as dietary calcium density , were associated with a lower incidence of the mets . the consumption of dairy products , cheese excluded , and calcium intake , were also associated with a lower incidence of ifg or type 2 diabetes . when looking at phenotypes associated with the mets , these parameters were also generally associated with a more beneficial profile during the follow - up , or with a better change in profile over the 9-year period . these results support the hypothesis of beneficial effects of milk products on cardiovascular risk , despite their saturated fat content . in a meta - analysis of prospective studies ( 10 ) , it was shown that milk and dairy consumption was associated with a lower risk of incident vascular events . this might be explained by beneficial associations with the mets and associated parameters and/or type 2 diabetes , such as those found in the current study and by other groups . in this respect , warensj et al . ( 11 ) found , in a prospective study , a negative association between the risk of myocardial infarction and biomarkers of milk fat , which disappeared when adjusted for variables related to the mets ( diabetes , blood pressure , bmi ) . our results are consistent with those obtained in the prospective atherosclerosis risk in communities ( aric ) study ( 12 ) where subjects in the highest quintile of dairy consumption had a 13% lower risk of the mets when compared with the lowest quintile . in another prospective study , cardia ( 4 ) , ( 12 ) , the differences between studies may be the result of different methods used , for example definition of outcome , population , age , dietary assessment , and statistical methods . both the desir and the aric studies were in the middle - aged , but the cardia study was in young adults , aged 1830 years . in prospective studies , for men with a 12-year follow - up ( 13 ) , as in women with a 10-year follow - up ( 14 ) , there was a negative association between dairy intake and type 2 diabetes incidence . in these two studies , the association with dairy was mainly due to low - fat dairy . unfortunately , we do not have specific data on low - fat or high - fat dairy products in our study , but we believe that our results are in accordance with this differential effect as dairy products included milk which is consumed as 80% low - fat and are associated beneficially with ifg/ t2d , whereas cheese , which is high - fat , is not significantly associated with ifg / t2d risk . in the nurses health study ( 15 ) , women who consumed three or more servings per day had an 11% lower risk of type 2 diabetes compared with women who consumed less than one serving per day of dairy . after adjustment for total vitamin d and calcium intake , this association was attenuated , showing that the association with dairy food was due in large part to these nutrients . in desir study , the calcium density of the diet was also very significantly associated with ifg / t2d and the mets , but since it was not directly measured but only calculated from food intake mainly from dairy variables ( therefore very linked to the assessment of dairy intake ) , we could not adjust for this variable in order to test whether the beneficial effects of dairy were due to calcium in desir . unfortunately , we do not have data on vitamin d. compounds other than calcium and vitamin d may be involved in these associations : peptides or conjugates of linoleic acid ( 1,16,17 ) . dairy consumption and calcium intake have been described in epidemiological studies to be associated with lower bmi or to lower body weight in intervention studies , in humans as well as in animal models ( 18,19 ) . in our longitudinal study , we did not find an overall association with bmi , but there was a lower increase in bmi and/or waist circumference over the 9-year follow - up . a similar finding was found in the cardia study ( 4 ) , in which high dairy intake appeared to protect against weight gain . in contrast , this result was not found in the hoorn study ( 5 ) . in the french supplementation en vitamines et mineraux antioxydants ( su.vi.max ) study , a high consumption of dairy products was associated with a lower weight gain over 6 years , but this result was obtained only in overweight men ( 20 ) . in the desir study , no significant interaction with sex was found for bmi changes , but we observed a significantly lower bmi increase only in men ( p = 0.07 , 0.05 , and 0.002 for dairy products , cheese , and calcium density respectively ) . the effects on bmi did not explain all of the effects on the mets , as we adjusted for bmi in all our analyses . these results are very similar to those from the cardia study ( 4 ) . the adjustments that we systematically used bmi , fat intake , physical activity and alcohol  might have lessened or cancelled these associations . here we observed a negative association between cheese and triglycerides which has been found sometimes ( 21,22 ) , but not always ( 23,24 ) , in cross - sectional studies . this was found in the cross - sectional analysis of the hoorn study ( 24 ) but not in the prospective data ( 5 ) . in our study , only the mean effect was found to be significant , but generally there was no effect on changes . dairy nutrients , notably calcium , have been shown to have a blood pressure lowering effect . dairy peptides may also act as ace inhibitors ( 16 ) consistently with the results concerning the mets and/or ifg / t2d , we found a negative association between the calcium density of the diet and insulin levels . this association , which was detected only in women , might be explained by the higher dietary calcium density in women than in men ( 3 ) . a negative trend was also found with cheese intake ( p = 0.07 ) . in acute effect , milk intake has been associated with higher insulin levels due to insulin - secretagogue peptides ; nevertheless , its chronic effect has rather been linked to an improvement in insulin sensitivity and thus , presumably , with lower insulinemia . dairy foods may beneficially alter adiponectin levels independently of changes in body weight ( 18 ) . it has also been observed that milk and whey appear insulinotropic as an acute effect but that the addition of fermented milk ( yogurt ) lowered postprandial insulin and glucose as compared with a reference meal alone ( 17 ) . moreover , whey protein was associated with a 40% lower plasma insulin after 6 weeks in insulin - resistant rats ( 17 ) . there was no significant interaction between dairy variables and sex on the risk of the mets or on ifg / t2d ( actually the results were very similar [ data not shown ] ) , and very few significant interactions were observed for associations with continuous variables . our study has several strengths but also some limitations . among the strengths are the prospective nature of the data and the large number of participants included , who were from the general population , and selected with a 1:1 sex ratio and in age strata . we were also able to adjust for confounders such as lifestyle factors . the relationships we observed with the characteristics of the mets are modest , but they were obtained after adjustment for lifestyle variables , including physical activity , smoking , alcohol consumption , and dietary fat intake . moreover , the adjustments for bmi show that there may be a specific independent effect of dairy intake on the mets characteristics . nevertheless , it has been validated by a more sophisticated questionnaire ( 9 ) and is suitably short to be well answered in an epidemiological study . as with all food - frequency questions , the accuracy of the responses ( under- or over - consumption ) is difficult to evaluate . we may have over - evaluated the consumption of calcium with a semiquantitative questionnaire , but the range of our values is not too far removed from the range of intake observed in the 19981999 cross - sectional french enquete inca ( individuelle et nationale sur les consommations alimentaires ) food consumption survey ( 3 ) . we have used the same food frequency questionnaire , completed at baseline and at the 3-year visit , and using mean values will reduce the variability of the responses . our questionnaire does not allow the separation of low - fat and high - fat products , or to estimate the effects of the different dairy products . however , we could separate cheese from other dairy products . as already stated , it can be assumed that in france , cheese is high - fat , but that the milk included in other dairy products is low fat . in summary , a higher consumption of dairy products and calcium was associated with a lower incidence of the mets and ifg / t2d during a 9-year follow - up period , in a large cohort drawn from the french general population . these results indicate that dairy product consumption could be associated with a lower cardiovascular risk .
objectivein the french data from the epidemiological study on the insulin resistance syndrome ( desir ) cohort , cross - sectional analyses have shown that a higher consumption of dairy products and calcium are associated with a lower prevalence of the metabolic syndrome ( mets ) . 
 we assess the influence of dairy products on 9-year incident mets and on impaired fasting glycemia and/or type 2 diabetes ( ifg / t2d).research design and methodsmen and women who completed a food frequency questionnaire at baseline and after 3 years were studied ( n = 3,435 ) . 
 logistic regression models were used to study associations between the average year 0 and year 3 consumption of milk and dairy products , cheese , dietary calcium density , and incident mets and ifg / t2d after adjusting for 1 ) sex , age , alcohol , smoking , physical activity , fat intake and 2 ) additionally for bmi . 
 associations between dairy products and continuous variables were studied by repeated - measures ancova , using the same covariates.resultsdairy products other than cheese , and dietary calcium density , were inversely associated with incident mets and ifg / t2d ; cheese was negatively associated with incident mets . 
 all three parameters were associated with lower diastolic blood pressure , and with a lower bmi gain . 
 higher cheese intake and calcium density were associated with a lower increase in waist circumference and lower triglyceride levels . 
 calcium density was also associated with a lower systolic blood pressure and a lower 9-year increase in plasma triglyceride levels.conclusionsa higher consumption of dairy products and calcium was associated with a lower 9-year incidence of mets and ifg / t2d in a large cohort drawn from the general population .