Day 033 - 10 Oct 94 - Page 42
1
2 Q. You have talked about and suggested mechanisms for a link
3 with saturated fats and diabetes. "Saturated fat
4 consumption may increase insulin secretion and lead to
5 insulin insensitivity". Do you want to just go into that?
6 It is the Snowden study, I think?
7 A. Yes. I regret to say I do not remember the details of
8 the study and I would I have to refer to it again
9 specifically. But there are many studies that have shown
10 that a high fat diet aggravates or reduces the capacity of
11 insulin to do its job effectively, suggesting that higher
12 and higher amounts of insulin are required simply to keep
13 glucose under control.
14
15 Q. What is the "fecal microbial enzyme activity" and
16 "estrogen synthesis"?
17 A. It is believed and has been reported that -- by "fecal
18 microbes" I simply mean the bacteria that are in the
19 colon, the bacteria that normally inhabit the digestive
20 track -- but, apparently, a diet that is high in saturated
21 fat can alter the enzymatic activity of these bacteria.
22 What that means is that these bacteria may be carrying on
23 the synthesis of bacterial products in a different way,
24 and also increasing the synthesis, the production of
25 oestrogen, if you will, which in turn was believed by
26 Snowden (and perhaps others) to impair insulin
27 sensitivity. This is apart from what I said earlier in
28 relation to fat affecting insulin sensitivity.
29
30 Q. If we can move on to the next point? You mention
31 gallbladder disease. Do you want briefly to summarise the
32 case on that?
33 A. Yes. Here again gallbladder disease is known to be
34 more common in individuals who are obese. In studies of
35 vegetarians, which again is a group remarkable for a very
36 low consumption of cholesterol and typically a low
37 consumption of fat, the incidence of gallbladder disease
38 is markedly reduced. In a study which I cite from 1985,
39 there is a group of non-vegetarians compared to a group of
40 vegetarians, and the difference -- and they were simply
41 tracked for their history of having required gallbladder
42 surgery -- the risk amongst the non-vegetarians was quite
43 substantially higher than that of the vegetarians.
44
45 This probably relates to more than one aspect of the
46 diet. It probably relates to both cholesterol and to
47 fat. The bile acids that are produced in the liver sent
48 down the bile ducts and take residence in the gallbladder
49 where stones may form, are formed, from cholesterol.
50
51 There have been suggestions that the same diet that is
52 high in fat and high in cholesterol that can produce high
53 serum cholesterol levels also makes it more likely that
54 gallbladder stones will form. Gallbladder surgery is
55 extremely common in western countries, extremely rare in
56 countries such as Africa or Asia where the populations
57 adhere to a very low fat diet.
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59 There is a role for fat and for fibre both because fibre
60 helps to eliminate bile acids and to eliminate cholesterol
