Milk Consumption and the Metabolic Syndrome in Menopausal Women
Condition: Cardiovascular Disease
MeSH terms: Cardiovascular Diseases; Metabolic Syndrome
Study type: Interventional

Summary: 
      Cardiovascular disease (CVD) represents the first cause of mortality in industrialized
      countries such as Canada and the United States. In that regard, it is being increasingly
      recognized that a significant proportion of CVD events may be attributable to the presence of
      a cluster of metabolic and physiological perturbations defined as the metabolic syndrome
      (MetS). The National Cholesterol Education Program- Adult Treatment Panel III (NCEP-ATP III)
      has recently proposed a clinical definition to identify individuals with the MetS. This
      definition is based on the presence of at least three of the following five characteristics:
      1- abdominal obesity, 2- hypertriglyceridemia, 3- reduced plasma HDL-C levels, 4- high blood
      pressure, 5- high fasting blood glucose levels. Recent data have suggested that the MetS
      based on this definition was associated with a 2 to 5 fold increase in the risk of CVD in men
      as well as in women. These are alarming figures since it has been suggested that as much as
      35 to 45% of female aged > 65 years in the US may have the MetS. It is therefore imperative
      to develop new preventive strategies that will be efficacious in attenuating the impact of
      the MetS on the progressing rates of CVD in women. In that context, there is accumulating
      evidence to suggest that milk and dairy products may beneficially modify several components
      of the MetS. However, most of the available data to date are based on observational studies
      or interventional studies with minimal nutritional control. Thus, metabolically controlled
      studies that document the impact of milk consumption on cardiovascular risk factors
      associated with the MetS in women defined a priori as having the MetS are utterly lacking.

      The purpose of this study was to investigate the impact of milk consumption on features of
      the MetS in menopausal women presenting one or more features of the MetS.
    

Detailed description: 
      The proposed research will be undertaken as a randomized, cross-over, nutritionally
      controlled study, with participants being subjected to two 6-week isocaloric diets separated
      by a 4-week washout period. No stratification was considered since the population recruited
      will be relatively homogeneous. The experimental diet (designed as 'Milk') will be formulated
      so that the percentage of daily calories from fat (30%), saturated fat (10%), carbohydrates
      (55%) and proteins (15%) will conform to most of the dietary recommendations of the American
      Heart Association and the NCEP for primary prevention of CVD, with the exception of saturated
      fats (slight excess) and fibers (slight deficit). The cholesterol content of the experimental
      diet will not exceed 200 mg/day. The only source of dairy products during the experimental
      phase will be from 2% fat milk. We have chosen to use 2% fat milk because this is the most
      frequently consumed dairy product in Canada. Two percent fat milk also goes through minimal
      processing compared to milk or to other dairy products such as yogurt and cheese. Thus,
      bioactive components in milk are more likely to be retained in the 2% fat milk than in other
      more extensively processed products. The energy intake from milk will represent 20% of the
      consumed kcal/day. Based on a reasonable 2000 kcal/day regimen, a 20% intake attributable to
      2% fat milk will correspond to 400 day/kcal, which will be derived from a 'daily dose' of 3
      portions of milk/day. This dose has been shown to be effective in previous uncontrolled
      studies. The Control diet will be virtually identical in terms of menus, calories and
      macronutrient composition, with the exception that milk will be formally excluded from the
      regimen. The energy intake and changes in macronutrient composition attributable to the milk
      component in the experimental diet will be compensated in the control diet by modifying the
      protein, carbohydrate and lipid component of the various recipes.

      A 4-week stabilization run-in period will precede the randomization of participants. During
      this run-in period, participants will be asked and instructed to comply to the NCEP-ATP III
      prudent diet. They will be asked to maintain their body weight constant during this period.
      Milk consumption will be adapted during this period to comply to the recommendations of
      NCEP-ATP III. The washout period between the two experimental diets will last 4 weeks and
      will also consist of NCEP-ATP III recommended diet. It must be stressed that foods will not
      be provided during the run-in and wash-out periods. These periods are imposed to minimize the
      inter- and intra-individual variability before and between the experimental phases.
    

Intervention name(s): MILK
Intervention type(s): Other
Intervention description(s): Consumption of the 2 experimental diets
Milk diet
Control diet
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Cardiovascular disease; Milk; Metabolic syndrome; Blood lipids; Menopausal women