Impact of Dairy Consumption on Inflammation: a Clinical Study (PLI)
Condition: Cardiovascular Disease
MeSH terms: Cardiovascular Diseases; Inflammation
Study type: Interventional

Summary: 
      Inflammation and endothelial dysfunction are being increasingly recognized as key etiological
      factors in the development of atherosclerosis and subsequent cardiovascular disease (CVD).
      These pro-atherogenic states are strongly correlated and often found co-segregating among
      individuals with obesity and the metabolic syndrome. There is increasing evidence to support
      the use in clinical practice of these novel markers of atherosclerosis and CVD risk. Recent
      data from the JUPITER study (Justification for the Use of Statins in Primary Prevention: An
      Intervention Trial Evaluating Rosuvastatin) has provided undisputable evidence that treating
      patients with elevated plasma CRP concentrations, a marker of systemic subclinical
      inflammation, leads to marked reduction in the risk of CHD even in patients with highly
      desirable LDL-C levels. There is also accumulating evidence associating endothelial
      dysfunction, which is defined as incapacity of the arteries to vasodilate when required, to
      an increased risk of CVD. While there are more and more studies on how diet affects
      inflammation and endothelial function, the impact of dairy consumption per se on these novel
      risk factors for CVD has not been well characterized.

      The purpose of this study was to investigate the impact of dairy consumption on markers of
      inflammation and other risk factors in men and women with low grade systemic inflammation.
    

Detailed description: 
      This research will be undertaken as a multicenter randomized cross-over controlled study. A
      total of 140 men and women with subclinical inflammation (plasma CRP 2-10 mg/l) but otherwise
      healthy will consume two diets, one rich in dairy and one without dairy, while consuming a
      diet low in saturated fat (<10% energy), in trans fat (<1% energy) and in cholesterol (<200
      mg/day). During the DAIRY diet, subjects will be asked to incorporate 3 servings of dairy
      (milk, yogurt, cheese) into their every day diet. During the CONTROL arm of the study,
      participants will be asked to consume energy equivalent replacement products. Each diet will
      be undertaken consecutively in random order and will have duration of approximately 28 days
      each (4 weeks).The primary analysis consists in comparing inflammation markers and related
      risk factors between the two treatments. The study is designed to detect a 12-16% difference
      in plasma CRP concentrations (the primary endpoint) between the control and the dairy diet.

      A 2-week stabilization run-in period will precede the randomization of participants. During
      this run-in period, participants will be asked and instructed to adapt their diet to a
      prudent dietary pattern low in saturated fat (<10% energy), in trans fat (<1% energy) and in
      cholesterol (<200 mg/day). The total amount of fat in the diet will not be restricted, with
      recommendations ranging from 25-35% of energy. However, substitution of saturated for
      unsaturated fat will be advocated. Sodium intake <2300 mg/d will also be recommended.
      Recommendations will also include advice on how to restrict the consumption of processed and
      energy dense foods. The run-in diet will not include specific recommendation on dairy
      products. Participants will have the choice to include/exclude dairy from their prudent diet,
      as long as they comply with the main dietary recommendations. This 2-week run-in period will
      allow participants to familiarize themselves with the dietary recommendations used during the
      intervention per se. The two diets will be separated by a 4-week wash out period and will
      also consist to the prudent dietary pattern recommended. 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): Dairy
Intervention type(s): Other
Intervention description(s): During the DAIRY diet, subjects will be asked to incorporate 3 servings of dairy (375 ml of milk, 175 g of yogurt, 30 g of cheese) into their every day diet.
During the CONTROL arm of the study, participants will be asked to consume energy equivalent replacement products (375 ml of fruit juice, 1 homemade cookie, 20 g of cashew).
Other intervention name(s): Dairy products, milk, cheese, yogourt
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Keywords;; Cardiovascular disease; Dairy; Inflammation; Blood lipids