No benefit of veg and fruit consumption in t2 diabetes!

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 Fig 4 Hazard ratios for incidence in diabetes type 2 for highest versus lowest intake of fruit and vegetables combined. Weights are from random effects analysis

Newly published meta-study in BMJ:

Fruit and vegetable intake and incidence of type 2 diabetes mellitus: systematic review and meta-analysis

Quote:

Results Six studies met the inclusion criteria; four of these studies also provided separate information on the consumption of green leafy vegetables. Summary estimates showed that greater intake of green leafy vegetables was associated with a 14% (hazard ratio 0.86, 95% confidence interval 0.77 to 0.97) reduction in risk of type 2 diabetes (P=0.01). The summary estimates showed no significant benefits of increasing the consumption of vegetables, fruit, or fruit and vegetables combined.

I have to add a comment:
   There is only one supposedly significant, positive correlation found in this study - the one with green veg (hazard ratio 0.86).  It is possible [but see also (*)] that the significancy results from pooling four separate studies together. When you look at the individual studies on FIG5 : three are only marginally positive, that is their error estimates touch 1.0, while one large study [39] (Women’s Health Study) shows the hazard ratio of 1.0 which indicates no effect.

This paper  [37] (Nurses' Health Study data) is also interesting because it is one of the largest and longest of its kind. Again, no benefit overall from vegetable consumption and miniscule benefit from greens alone. It also shows this interesting graph:

Note (*): There is a discrepancy in the data. The resulting hazard ratio may also turn out to be not statistically significant for green vegetables, since the overall P=0.18 as per FIG.5 while at the same time it is written as P=0.01 in the abstract for the same result. Given the wide spread 0.77-0.97, my guess is that the abstract figure of 0.01 may be a typo, but I am not 100% sure.

China Study says wheat is associated with vascular disease

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... but probably not with cancer!

The following graphs are based on the Raw China Study data  , using 1989 part of the study, total M+F, 3-rd "xiang".  My original spreadsheet is here in OpenOffice 3.2 Calc format.  The following graphs represent raw scatter plots for specific disease mortality (all vascular or all cancer)  against each of the independent variables, with no data processing of any kind.

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I have to add a paper I found quoted by Denise Minger in her laterst response, that is definitely worth a note:

Nunes and Silva, 2009, "Systemic Correlates of Angiographic Coronary Artery Disease"

Quote:

Significant correlation values versus CADB [coronary artery disease burden] were seen with age (r 0.19, p 0.04), uric acid (r 0.18, p 0.048) and fasting plasma glucose (r 0.33, p<0.001).  

Interestingly, in addition to plasma glucose, uric acid correlates with fructose consumption. Both point to metabolic syndrome and pre-diabetes as the main causative factor behind atherosclerosis in this particular study. How is Chinese wheat consumption fitting in here? Since rice does not correlate with vascular risk while wheat does, it may indicate a presence of another factor associated with wheat that correlates positively and perhaps causuatively with the metabolic syndrome and thus with the vascular disease. I am going to come back to this issue in the future posts.

Updated 7-Aug-2010

The situation is very confusing, since some studies done in the West such as those reviewed in this compilation or the Nurses' Study  tend to indicate that consumption of the whole grain wheat correlates with lower heart disease. I can't think of any obvious explanation of that contradiciton.   Perhaps one of the following possibilities may be playing a role:
(a) China Study is wrong or is showing a spurious correlation (albeit a very strong one M059 over D038 is +56%, see page 215); (b) Western medical studies are wrong or showing a spurious (weak -17% to -29%) correlation masking some other underlying factor such as an overal carbohydrate intake? (overall carbs intake also correlated with vasc disease in China Study!); (c) It may depend on what wheat consumption is compared against - either wheat compared against rice or whole wheat consumption compared against refined wheat and sugar? In the latter case the problem is what toxic factor playes the role in the refined wheat but not in the whole wheat? Logic would dictate that it should be the other way around, for example wheat germ agglutins (ref) should be more aboundand in the whole wheat products than in the refine flour products.

China Study says animal fat is healthy!

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The following graphs are based on the Raw China Study data  , using 1989 part of the study, total M+F, 3-rd "xiang".  My original spreadsheet is here in OpenOffice 3.2 Calc format.  The following graphs represent raw scatter plots for specific disease mortality (all vascular or all cancer)  against each of the independent variables, with no data processing of any kind.

The China Study corroborates Kwasniewski's diet

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The data seem to corroborate Dr. Kwasniewski's Optimal Diet, to some extent, in terms of the trend.  That is, a higher fat shows a trend towards better health, where as the more protein and more carbs tend towards higher mortalities. At the same time the raw data I have seen so far do not seem to support an idea that plant based very low fat nutrition is healthier!

Dr. Kwasniewski's diet is high in animal fat, low in protein (unlike Atkins) and low in carbohydrates. Similar to Atkins but puts a restriction on protein (1g/kg of ideal body weight, per day) and does not advocate an "induction" stage followed by an increase in carbohydrates.

The following graphs are based on the Raw China Study data  , using 1989 part of the study, total M+F, 3-rd "xiang".  My original spreadsheet is here in OpenOffice 3.2 Calc format.  (Sorry, no Excel, got tired of loosing data).  The following graphs represent raw scatter plots for specific disease mortality (all vascular or all cancer)  against each of the independent variables, with no data processing of any kind.  You be the judge!   :)

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VASCULAR DISEASE MORTALITY VERSUS MACRONUTRIENTS AND TOTAL BLOOD CHOLESTEROL

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ALL CANCER MORTALITY VERSUS MACRONUTRIENTS AND TOTAL BLOOD CHOLESTEROL

"..The ‘Grand Prix’...the most comprehensive large study ever undertaken of the relationship between diet and the risk of developing disease....tantalizing findings"
The New York Times