Meat vs Wheat: Tales From T Colin Campbell's China Study

OK, probably many readers know that T. Colin Campbell believes that animal foods promote disease and plant foods prevent disease.

In 1996, Campbell and his colleagues published a paper entitled Association of dietary factors and selected plasma variables with sex hormone-binding globulin in rural Chinese women.

In this very interesting report of data from the China study, Campbell et al presented the relationships between various foods and sex hormone-binding globulin (SHBG) in Chinese women.  SHBG binds sex hormones, reducing their effects on tissues.

I am going to quote extensively because I want you to get it from the horse’s mouth, so to speak. In the introduction, Campbell et al write:

“In women, SHBG is clinically implicated in several conditions, ranging from cancer and cardiovascular disease to polycystic ovarian disease and hirsutism (5-8). Lapidus et al (9)

found that a decrease in the concentration of SHBG was a significant risk factor for 12-y overall mortality, concluding that SHBG, androgens, and estrogens should be evaluated as risk factors for cardiovascular disease and death. Suggested positive physiologic regulators of SHBG include testosterone, prolactin, growth hormone, somatomedin-C, and insulin, whereas enterolactone, oral estrogen, and thyroid hormone are potential negative regulators (10).

“Recently however, a growing body of research supports insulin as the primary regulator of SHBG (1 1-14). Furthermore, SHBG has been shown to be an independent predictor of

insulin resistance (15), which is itself suggested to be the common denominator in non-insulin-dependent diabetes mellitus (NIDDM), obesity, hypertension, dyslipidemia, and atherosclerotic

cardiovascular disease, otherwise known in the aggregate as insulin resistance syndrome (IRS) or syndrome X (16, 17). Thus, plasma SHBG itself may be an important indicator for assessing IRS risk.”

In short, the data suggests that low SHBG may play a role in the development of several diseases and associates with increased overall mortality.  Thus, oversimplified, low SHBG=bad, and higher SHBG=good (maybe). 

So Campbell et al went about teasing out associations between foods and SHBG levels in Chinese women using the China Study data.

One of the things they did was throw out data they had collected in Tuoli province, where the people raise animals for milk and meat: 

“Tuoli county from the province of Xinjiang was not included in the analyses because of unreliable data due to measurement problems for several of the covariates of interest.”

Well, that’s convenient.  Apparently, according to Campbell, the people in Tuoli were ‘feasting’ on the day that they collected data. 

I imagine a conversation about this with Dr. Campbell:

Me:  Well, Dr. Campbell, why did you throw out the data from Tuoli?

Campbell:  Because they were feasting when we collected the data.

Me:  Why do you say that they were feasting?

Campbell:  Because they were eating a lot of animal products.

Me:  Don't you expect people who raise animals for milk and meat to eat milk and meat?

Campbell:  Only at feasts.

Me:  What else would pastoralists eat?

Campbell:  Rice and vegetables.

Me:  But they probably can’t grow rice or many vegetables at that latitude and in that climate. That’s why they raise animals!

Campbell:  Look, by definition, if you are eating animal products, you are feasting.  Therefore, I can throw out of the China Study data all data that shows Chinese people eating meat or dairy on a regular basis.

Anyway, leaving aside why Campbell left out of the data set the data from the county that had the highest intake of animal products, let’s take a look at the correlations his team found between foods and SHBG.  In the table below, taken directly from Campbell’s own work, positive numbers means that the food was associated with higher SHBG (good) and negative numbers means that the food was associated with lower SHBG (bad).  Click on image for larger version.

Well, get a load of that.  The “healthywholegrains” wheat, millet, sorghum, and corn, as well as ‘light-colored vegetables,’ carrots, and legumes, primarily soybeans, all have a negative correlation with SHBG whether using the data from the questionnaire or the 3-day diet survey.  That suggests that those things are ‘bad’ for SHBG status and health.

On the other hand, meat, fish, green vegetables, and rice all have a positive correlation with SHBG levels, suggesting these foods are ‘good’ for SHBG and health.

Also note that rice, green vegetables, meat, and fish have negative association with insulin levels, meaning that the women who ate more of these apparently had lower insulin levels.

Further, the negative correlation of legumes is greater than the positive correlation of meat, although not significantly.  This is very interesting given that the Chinese supposedly eat meat very infrequently and legumes very frequently.

This hardly looks like a ringing endorsement of a grain-based vegan diet, regardless of what grain provides the base. 

Huh.  Campbell et al did not miss this, as evident from this paragraph in the text (click on it for a larger version):

Of course, people committed to promoting a vegan diet have a hard time admitting any benefit to eating meat.  Campbell et al try to downplay the protective effect of meat by dismissing its importance in the Chinese diet in this passage:

Click on it to enlarge.

 In other words, they want to say that the beneficial effect of meat isn't important and we can ignore it because Chinese people hardly ever eat meat (except, perhaps, in Tuoli, but we threw that data out).

The paradox for Campbell here is that even those small amounts of meat and fish had strong positive relationships with an apparently protective factor (higher SHBG). In fact, as I noted above, the apparently positive effect of meat had the same magnitude of correlation as the apparently negative effect of legumes (mostly soy) that Chinese people eat quite frequently relative to meat.  This suggests that, per serving, meat has a much greater positive effect than the per serving positive effect of, for example, rice.  

The effect of wheat compared to rice was marked enough that Campbell et al spend a whole, long paragraph discussing the different effects had by rice and wheat on insulin secretion.  From that paragraph, two lines in particular stand out.  The first:

“Wheat may be unique in its relative capacity to stimulate insulin.”

Which they support by referring to several studies establishing a greater insulinogenic effect of wheat compared to rice.  And the second:

“The relative differences in the fatty acid proportions and/or amylose content for wheat and rice may thus be responsible for modulating serum SHBG, triacylglycerols, and insulin. Our study did not find insulin to be predictive of SHBG variation after the effect of the specific foods were adjusted for (particularly rice and wheat).”

In other words, Campbell et al admit that in the China Study data, the strongest predictor for low SHBG status was wheat consumption.

Meanwhile, meat had an inverse, i.e. protective, relationship with SHBG. 

So, there you have it.  According to this paper co-authored by Campbell himself, among Chinese women, wheat aligns with murder and meat aligns with medicine. 

Imagine that.