Day 017 - 25 Jul 94 - Page 18

     
     1        Summary:  Breast cancer mortality and incidence in
              different countries show a strongly positive correlation
     2        with the per caput consumption of fat.  In addition, the
              disease has increased among the Japanese, both in Japan
     3        and in the United States, and in both groups fat
              consumption has been increasing.  In contrast, both
     4        case-control and prospective studies have on the whole
              failed to confirm the relationship.  Despite these
     5        negative findings, the hypothesis that fat causes breast
              cancer has continued to be popular.  The evidence for fat
     6        as a cause of breast cancer seems to have been
              exaggerated, and insufficient attention given to
     7        alternative explanations for the geographical correlations
              and for the changes among the Japanese in the frequency of
     8        the  disease".
 
     9        If you can cast your mind back seven years that --
              Dr. Kinlen says he thinks in 1987 that the evidence of fat
    10        as a cause of breast cancer seems to have been exaggerated
               -- casting your own mind back to that time, how does it
         seem to you that it was?
              A.  I think it was a very popular theory at that
    12        particular time, but I would agree with his statement that
              it was exaggerated.
    13
         Q.   He goes on:  "These include the effects on breast cancer
    14        risk of body weight, body size, age at menarche (all
              influenced by excess calories) and age at the birth of the
    15        first child, as well as effects of obesity on the fatality
              rate in breast cancer.  Evidence is lacking that the
    16        source of calories is important."
 
    17        Dr. Arnott, pausing there, if I may ask you to do this for
              us, what do you see as being, on the research so far and
    18        your knowledge of the subject, the important
              epidemiological factors in relation to the incidence of
    19        breast cancer?
              A.  The factors that he has actually specifically
    20        mentioned, for example, age at the time when a woman first
              starts to menstruate -- that is menarche for those who do
         not know the medical term -- the younger the more likely
              one is to develop breast cancer.  Other factors related to
    22        what is often a western way of life, like having a child
              late in life, there is an increased risk of developing
    23        breast cancer having one's first child over the age of 30
              compared with under 30.  Parity is also important.  It
    24        seems that the more children one has, there is a
              significant reduction in risk.
    25
         Q.   Can you pause there a moment?  I want you to continue in a 
    26        moment, but the age at which a woman first starts to 
              menstruate is presumably not something she can control? 
    27        A.  Only in the sense that it probably occurs at an
              earlier age in people who are well fed compared with
    28        people who are suffering from nutritional deprivation.
 
    29   Q.   It delays the onset of menarche?
              A.  Yes.
    30
         Q.   As you said yourself, a feature of western society,