Day 033 - 10 Oct 94 - Page 31


     
     1        association.  It did not find a statistical association
     2        between fat and breast cancer.  This study has been widely
     3        criticised on the grounds that the range of fat intake was
     4        quite narrow.
     5
     6        To put this in context, when Japan's breast cancer rates
     7        were quite low -- they are still low but they have risen
     8        quite dramatically as the fat intake has gone up in Japan
     9        -- when they were at their low point (I am speaking of
    10        1940s, around that time) the fat intake in Japan was seven
    11        to ten per cent of calories; in the United States it is 37
    12        per cent.
    13
    14        Well, in the nurses' study there was no group that looked
    15        at fat intakes of seven per cent or 17 per cent or 20 per
    16        cent.  If memory serves -- I do not have the study in
    17        front of me -- but my recollection is that the median fat
    18        intake of the lowest quintile in that study was 27 per
    19        cent of calories.  They did not look lower than that.  The
    20        high end was somewhat higher than average, but this is a
    21        rather narrow band.  One would not have expected to see
    22        differences in breast cancer rates within that band.  In
    23        other words, it is rather like if you have  -----
    24
    25   Q.   Are you saying that the -----
    26
    27   MR. JUSTICE BELL:  I understand what he is saying.
    28        A.  If we have a group of smokers, some smoke three packs
    29        a day and some smoke two packs a day ----
    30
    31   Q.   The difference in intake was not pronounced enough, you
    32        contend, to draw any satisfactory conclusion from it?
    33        A.  Yes, I would contend that.  That has been a common
    34        criticism of Willett's study.
    35
    36   MR. MORRIS:  It is not just the range of fat, is it?  It is
    37        also the fact that the range was actually at a high level
    38        in any case?
    39        A.  Both are true.  The range was narrow and the range was
    40        quite high; rather like, as I said, with cigarette
    41        smoking, if you have a group that smokes three packs a day
    42        of cigarettes and another that smokes two packs a day of
    43        cigarettes, one might not be very surprised to find very
    44        little difference in the risk of lung cancer between the
    45        two groups.  In fact, if you look at the cancer data, it
    46        is exactly what you find.
    47
    48        One would argue -- I would certainly argue -- that the
    49        range in Willett's study was quite narrow; that all the
    50        subjects were Americans following a typical American diet, 
    51        some slightly higher fat intakes, some slightly lower; but 
    52        the differences were not enough to demonstrate any effect 
    53        on breast cancer risk.
    54
    55   MR. JUSTICE BELL:  So the lower line was just within the
    56        recommendations?
    57        A.  If memory serves, their median intake was about 27 per
    58        cent, and many cancer research groups have suggested that
    59        the diet should be below 30 per cent of calories from fat,
    60        although I should say that that limit is -- at least

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