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Red meat: another inconvenient truth

BMJ 2017; 357 doi: (Published 11 May 2017) Cite this as: BMJ 2017;357:j2278

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Re: Red meat: another inconvenient truth

Red meat: another inconvenient truth

There are several odd findings in this study

1) to quote:
“Meat consumption has been on the rise in the US and Europe in the past 40 years.22 An increased risk of premature death associated with red meat intake, and evidence for greater longevity among adults with very low meat intake, have been seen in previous studies from Europe and the US.”

Yet in both Europe and the US death from cardiac events is falling.

2) It is suggested that oxidative stress could be involved. To quote:
Oxidative stress may be the underlying common mechanism for many of these findings. Oxidative stress is a plausible part of the aging process, and systematic markers of oxidative stress are associated with increased risk of chronic disease multimorbidity and all cause mortality in the older population. Oxidative stress has also been linked to many components of the metabolic syndrome and insulin resistance.

This is indeed a valid point and indeed I suspect that a low level of anti-oxidants may well be involved in many chronic conditions of the aged due to an excessive intake of pro-oxidants/reduced intake of anti-oxidants. However this aspect of the study and the observed results have been totally ignored in the failure to measure this factor.

3) From Table 1 it is stated that between low meat to high meat death rate doubles to quote:

Meat intake category 1 2 3 4 5
Diabetes (n=3717) 504 576 687 845 1105

yet more meat intake would probably mean a reduced carb intake or a increased total food intake with maintained high carb intake. High carb intake is well known for causing hyperinsulinaemia (the first early stage of diabetes - Kraft, R. “Diabetes Epidemic and you” (The very earliest diagnosis of diabetes is neither by fasting blood sugars nor by glycated hemoglobin but only by insulin assays with normal glucose - Kindle Locations 165-166)
(Note:I might add that this comment is based on 14,000+ actual insulin/glucose tolerance tests)

This result to me suggests that total food intake has been ignored and the level of anti-oxidant intake from say fruit and veg has also been ignored.

4) The information has been obtained by query of the participants, a notoriously difficult way of assessing food quality and quantity of a long term diet

5) Another interesting item from Table 1 relates to Never-smokers, to quote:

Meat intake category(%) 1 2 3 4 5
Never smoker 43458 (40.5) 39887 (37.1) 37413 (34.8) 35135 (32.7) 31579 (29.4)

I assume that the numbers here relate to the number and percentage of each intake category. This lead me to search for how this was handled. To quote:
In general, the increased mortality associated with red meat, heme iron, and nitrate/nitrite were stronger in never/former smokers,

This raises the question about the known effects of smoking in a variety of conditions.

I am afraid that this study and its relatively small differences and its data source will not affect my view of this “inconvenient truth”.

Competing interests: No competing interests

13 May 2017
Michael J. Hope CAWDERY
Retired veterinary researcher