Design and Feasibility of a Mediterranean Diet
Condition: Breast Cancer
Study type: Interventional

Summary: 
      Epidemiological observations indicate that a Greek-Mediterranean dietary pattern has great
      potential for cancer prevention, but more definitive data on the preventive effects of this
      diet are needed. Two distinct aspects of this eating pattern are the type of fat consumed and
      a high fruit/vegetable intake. If the diet is feasible, it could be used in future clinical
      trials of breast cancer prevention. In this study, women randomly receive either a control
      diet or an intervention diet for 6 months. The intervention diet replaces half of the typical
      American fat intake with foods such as olive oil and nuts. The fruit and vegetable goal is
      7-9 servings/day and includes several categories of fruits, vegetables, and herbs. Blood
      samples are drawn and analyzed for fatty acids derived from fats, micronutrients from fruits
      and vegetables, and markers of oxidative stress. This dietary trial will provide important
      data on the ability of women following typical American eating patterns to change their
      dietary intakes to reflect a Greek-Mediterranean pattern.
    

Detailed description: 
      It has been difficult to identify specific nutrients or food groups associated with breast
      cancer risk from epidemiological studies done in the U.S. Attention is now turning to the
      importance of overall eating patterns. A Greek-Mediterranean dietary pattern has great
      potential for cancer prevention. Two distinct aspects of this eating pattern are the type of
      fat consumed and a high fruit/vegetable intake relative to average intakes in the United
      States. We propose to develop and test an exchange list Greek-Mediterranean diet that could
      be used in future clinical trials of breast cancer prevention in women at increased risk. In
      this proposed study, women will be randomized to either continue their own usual diet or
      follow an intervention diet for 6 months. The intervention diet will be designed to decrease
      polyunsaturated (P) and saturated (S) fat intakes while increasing monounsaturated (M) fat
      intake. The P:S:M ratio of a typical American diet is about 1.0:1.5:1.7, and the goal for
      this intervention diet will be 1:2:5, which is much closer to that of the traditional Greek
      diet. A predominant source of fat will be olive oil. The fruit and vegetable goal will be 7-9
      servings/day, depending on energy intake. These dietary changes will be achieved using
      individualized telephone counseling and a monthly group session with a dietitian. Menus will
      be provided as examples, but the diets will be self-selected. Compliance to the dietary goals
      will be assessed by food records and levels of plasma fatty acids, lipids and carotenoids. As
      a feasibility investigation for the planning of larger trials, plasma 8-isoprostane, oxidized
      lycopene, insulin and glucose levels will also be assessed since these may lend insight into
      two possible mechanisms that may be responsible for the cancer preventive effects of this
      diet. This dietary trial will provide important data on the ability of women following
      typical American eating patterns to change their dietary intakes to reflect a
      Greek-Mediterranean pattern. This intervention approach can then be tested for its effects on
      markers of breast cancer risk in future studies.
    

Intervention name(s): dietary counseling
Intervention type(s): Behavioral
Intervention description(s): telephone counseling
Other intervention name(s): high MUFA diet
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: cancer prevention; diet; nutrition; polyunsaturated fat; olive oil