Day 033 - 10 Oct 94 - Page 27


     
     1        called natural killer cells.  Natural killer cells are so
     2        named because they are natural killers of cancer cells.
     3        They do not need to be primed.  One does not need an
     4        inoculation.  These cells do not need prior experience
     5        with cancer.  They can simply knock them out.  Natural
     6        killer cells' function is impaired when, if you will, they
     7        have to swim in an oil slick, if I can put it that way.
     8
     9        With regard to vegetarians, there has been an ongoing
    10        study of vegetarians at the German Cancer Research Centre
    11        in Heidelberg.  Vegetarians have been compared with
    12        individuals who are not vegetarians but are working at the
    13        Cancer Research Centre.  Their cancer death rates have
    14        been tracked and, not surprisingly, vegetarians have
    15        considerably lower cancer death rates.  For women, they
    16        have about 25 per cent less cancer death rates over an 11
    17        year period; for men it is about 50 per cent reduced.
    18
    19   Q.   Over an 11 year period, did you say?
    20        A.  Yes.  But when one actually looks at their immune
    21        systems one finds that the natural killer cell, what is
    22        called "natural killer cell activity", which means the
    23        natural killer cell's capacity to knock out a standardised
    24        sample of cancer cells is double that compared to
    25        non-vegetarian controls.  It is not known whether that is
    26        because the vegetarians have double the number of natural
    27        killer cells or if the ones they have are simply that much
    28        more ferocious against cancer.
    29
    30        What is quite clear, well established, well accepted, is
    31        that a diet that is high in fat can impair indices of
    32        defences against cancer.  This is believed to be yet
    33        another mechanism by which a high fat diet may make cancer
    34        more likely.
    35
    36        I should say, perhaps, that cancer cells arise in the body
    37        from time to time.  It is not as if every cancer cell that
    38        arises in the body immediately progresses and becomes
    39        cancer.  Without one's immune defences one would have
    40        cancers that would otherwise be recognised by the white
    41        blood cells and removed.
    42
    43   Q.   Just one question about that -- it may seem an obvious
    44        question -- why do many of the reports you refer to, not
    45        all of them but some of them, refer to vegetarians as a
    46        control sample or as an area of study?
    47        A.  Vegetarians are a very useful population to study and
    48        have been for many, many years because they consume diets
    49        that are low in fat, that are either low in animal fat or
    50        devoid of animal fat; they are typically high in fibre. 
    51        Studies that examine vegetarians will elaborate details on 
    52        each of these factors and allow their dissection in the 
    53        course of research.
    54
    55   Q.   In other words, the important thing is not whether they
    56        are vegetarians or not, but what the actual fat and fibre
    57        content in their diet is?  Is that what you are saying?
    58        A.  In most cases, yes, that is correct.  There have been
    59        some cases where researchers were particularly interested
    60        in vegetarians themselves but, yes; for example, the

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