Effects of the Consumption of California Walnuts on Cardiovascular Health
Condition: Cardiovascular Health; Immune Function
Study type: Interventional
Phase: Phase 1

Summary: 
      The purpose of this study is to determine the effects of the 4-week consumption of California
      walnuts on vascular function and immune health in postmenopausal women of ages 50-70.

      Primary outcome measures:

        -  vascular endothelial function

        -  platelet reactivity

        -  indoleamine 2, 3-deoxygenase (IDO)

      Secondary outcome measures:

        -  relationship of walnut intake to lipoprotein, fatty acids and oxylipins
    

Detailed description: 
      Cardiovascular disease is the leading cause of morbidity and mortality in the United States.
      The initiation and progression of atherosclerotic vascular disease is multifactoral in
      nature, and includes endothelial dysfunction, triggered by chronic inflammation. The
      consumption of foods rich in flavonoids and other phytochemicals has been inversely
      associated with cardiovascular disease risk in several epidemiological studies.

      Aging is physiologically associated with a variable decline in several features of the immune
      function. In fact, immunosenescence, or aging of the immune system, is characterized by a
      reduced ability to fight infection and mount an adequate immune response once a novel
      infection is introduced. Both the innate and acquired immune systems can be affected with
      immune specific cells, cell signaling, cytokine production, and cell surface marker
      expression being all subject to age-related changes. The immune system cells within the
      digestive tract are an accessible and ideal target to stimulate immunity and diet-based
      nutritional interventions represent a non-invasive, relatively low-cost, and effective method
      of stimulating the immune function thus ultimately improving the antibody production in
      subjects at risk for immunosenescence. This is also based on the significant and dynamic
      interaction between luminal nutrients and the overall immune function. The study of
      nutritional influences on the immune system represents an area of growing interest to
      nutritionists, food scientists and immunologists. In general terms, dietary components have
      the potential to be an accessible and effective immune stimulant given the antigen presenting
      capacity of the intestine.

      Due to their age and menopausal status, postmenopausal women are at a greater risk population
      for developing CVD. Males tend to show greater rates of CVD than pre-menopausal women, while
      women following menopause show an increase in CVD development. This increase in CVD for
      postmenopausal women is associated with endothelial dysfunction that becomes worse with age.

      Recent studies have reported that consumption of walnuts is associated with beneficial
      effects in prevention of chronic diseases, such as cardiovascular disease (CVD), by favorably
      altering human serum profiles (i.e. decrease in LDL cholesterol and triglycerides and
      increase in HDL cholesterol and apolipoprotein A1). It has been shown that the consumption of
      walnuts, which mainly contain α-linolenic acid (ALA), L-arginine, and polyphenols, can
      beneficially alter vascular function and reduce inflammatory biomarkers. For example, Dr. Ros
      and his colleagues demonstrated that the addition of walnuts to a high-fat meal could improve
      endothelial function. This favorable influence on vasoactivity has been attributed to the
      antioxidant and anti-inflammatory properties of certain biofactors found in the walnuts.

      In this study, we will focus on defining the potential role of California walnuts and its
      effects on vascular health and immune function. We will determine whether short term (4 week)
      consumption of California walnuts, particularly rich in ALA, L-arginine and polyphenols will
      improve endothelial function, platelet reactivity and immune function in an at-risk
      population of postmenopausal women 55-70 years of age.
    

Intervention name(s): Walnuts
Intervention type(s): Dietary Supplement
Intervention description(s): The consumption of assigned walnuts once a day during 4 weeks
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Postmenopausal women; walnuts