Effects of Avocado When Added to a Meat Patty on Inflammation in Healthy Men
Condition: Healthy Volunteers
Study type: Interventional

Summary: 
      Avocados are naturally rich in antioxidants, or beneficial compounds, that can help prevent
      many diseases, like atherosclerosis (hardening of the arteries). When foods that are high in
      fats are eaten, certain harmful compounds can be absorbed, which can lead to atherosclerosis.
      One harmful compound is called malondialdehyde, or MDA. This compound can be measured in the
      blood and the urine after a person eats a high fat meal. Antioxidants found in herbs and
      spices may lower the absorption of MDA, which could help prevent the development of
      atherosclerosis.

      This study will determine whether the beneficial compounds of avocado can reduce absorption
      of MDA. This will be tested by asking healthy males to eat a high fat ground beef patty with
      or without avocado and then measuring the amount of MDA in their blood and urine samples.
      Blood flow will also be measured. Healthy men have been chosen for this study because eating
      high fat hamburger patties can easily mimic in them the condition that causes
      atherosclerosis. Avocados are rich in antioxidants, which have been shown in previous studies
      to reduce the absorption of harmful compounds, like MDA, that are formed during cooking. The
      results from this study may help to explain how high fat foods can be harmful to the body and
      how beneficial antioxidants from herbs and spices can protect the body.

      This will be determined from blood and urine samples after the subjects are given two
      different meals: a) a plain cooked ground beef patty, and b) or avocado with a cooked ground
      beef patty.
    

Detailed description: 
      The Hass Avocado contains monounsaturated fat, lutein, glutathione, vitamin E, and other
      antioxidants. This study will determine whether avocado exerts a beneficial effect by
      inhibition of the absorption of malondialdehyde (MDA) which is a measure of lipid
      peroxidation. In a previous study, we demonstrated that spice antioxidants resulted in a 70
      percent decrease in the formation of MDA during cooking and that healthy volunteers consuming
      burgers made with spice excreted 50 percent less MDA in their urine than subjects consuming a
      control burger made without spices. Since the spices were added during cooking of the burger,
      it was not possible to assess the effects of the antioxidants in the stomach. Foods in the
      stomach continue to form lipid peroxidation products during digestion and this is called the
      "bioreactor" function of the stomach. In the proposed study known quantities of fresh avocado
      will be placed on top of a burger prior to consumption to determine whether the avocado
      inhibits formation of MDA from cooked burger meat in the stomach. Study demonstrated an
      increase in inflammatory and oxidative markers in mononuclear cells using Western blot
      analysis of nuclear factor-kappa light chain enhancer of activated B cells (NFkB) and NADPH
      oxidase subunits following a mixed high calorie meal. Considering the rich content of
      bioactive compounds in the avocado, we therefore selected these methods for the endpoint
      determinations as well in this proposed randomized, crossover study.

      We will accomplish the following specific aims:

        1. To measure plasma and urine malondialdehyde by high performance liquid chromatography
           before and over6 hours after consumption of the test burgers with or without fresh
           avocado added just prior to consumption.

        2. To measure insulin, glucose, triglycerides, tumor necrosis factor alpha (TNF-α),
           interleukin 6 (IL-6), Interleukin 8 (IL-8), NFkB activation, nitric oxide and peripheral
           arterial tonometry after each test burger.

      These studies will add to the evidence that antioxidants in a lipid phase can inhibit
      formation and/or absorption of cytotoxic lipid products such as malondialdehyde. Ultimately,
      a better understanding of the role of bioactive substances from plant foods such as the
      avocado may demonstrate the importance of plant-based antioxidants in human health.
    

Intervention name(s): Avocado
Intervention type(s): Other
Intervention description(s): Fresh Avocado
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Avocado, antioxidant