Day 035 - 12 Oct 94 - Page 53


     
     1        A.  Although, I regret to say -----
     2
     3   Q.   I do not mean to cut you short.
     4        A.  I regret to say those lines have blurred to a degree,
     5        but yes in some context that is important.
     6
     7   Q.   Then they go on here: "Hormones, particularly oestrogens,
     8        are known to be important promoters of both animal and
     9        human breast cancer, but there are conflicting reports on
    10        the effect of fat on circulating levels of oestrogen,
    11        other female sex hormone levels and sex hormone binding
    12        globulin", SHBG, as we can call it for short.  "Other
    13        suggested mechanisms include modulation of immune function
    14        and prostanoid synthetic pathways, and membrane lipid
    15        peroxidation."  Membrane lipid peroxidation is the sort of
    16        damage, which I think you have proposed in your book, may
    17        be done by free-radicals, is that right, eventually?
    18        A.  Yes, that is correct.
    19
    20   Q.   Pausing there, is there anything within that first section
    21        which seems to relate to breast cancer with which you
    22        would disagree?
    23        A.  I am not quite certain what they mean by "conflicting
    24        reports on the effects o fat on circulating levels of
    25        oestrogen, other female sex hormones and sex hormone
    26        binding globulin", because the literature in my reading is
    27        consistent enough that I think the word "conflicting"
    28        might not be justified; not to say that there are not some
    29        areas of disagreement, but it has been generally shown
    30        that higher-fat diets are linked with more free oestrogen,
    31        less SHBG.
    32
    33   Q.   The reference given is to a paper by Prentice and others
    34        in Cancer Research 1989 which is two years before this
    35        book was published.  Prentice is a well-known researcher
    36        in this field?
    37        A.  Yes.
    38
    39   Q.   May one take it -- one has not got the reference here,
    40        unfortunately -- would it be your guess that that article
    41        by Prentice is what we call a review of metastudy of
    42        existing evidence?
    43        A.  It is difficult for me to arrive at that conclusion
    44        based on the title.  Prentice's own work, interestingly,
    45        has shown that as fat is reduced oestrogen levels are
    46        significantly reduced.
    47
    48   MR. MORRIS:  Are significantly?
    49        A.  Are significantly reduced, that is, as fat levels in
    50        the diet are reduced, circulating oestrogen levels are 
    51        substantially reduced as well.  I am not suggesting he 
    52        necessarily says so in that particular article, but his 
    53        work has shown that and he has reported that and it has
    54        been relayed as well in publications by the National
    55        Cancer Institute.
    56
    57   MR. RAMPTON:  Then go on, the authors of this report:  "In
    58        bowel cancer, it has been proposed that the concentration
    59        of faecal bile acids is increased by high-fat diets and
    60        that secondary bile acids act as tumour promoters.

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