It's also important to remember that "correlation does not imply causation"
with a study like this.
From that Wikipedia article:
In a widely-studied example, numerous epidemiological studies showed that women who were taking combined hormone replacement therapy (HRT) also had a lower-than-average incidence of coronary heart disease (CHD), leading doctors to propose that HRT was protective against CHD. But randomized controlled trials showed that HRT caused a small but statistically significant increase in risk of CHD. Re-analysis of the data from the epidemiological studies showed that women undertaking HRT were more likely to be from higher socio-economic groups (ABC1), with better than average diet and exercise regimens. The use of HRT and decreased incidence of coronary heart disease were coincident effects of a common cause (i.e. the benefits associated with a higher socioeconomic status), rather than cause and effect as had been supposed.
It could certainly be the case that there are more basic factors that predispose women of Australia both to developing "mood and anxiety disorders" AND to the inclination to eat less red meat.
It could very well be that for those
women, eating more red meat could exacerbate
their "mood and anxiety disorders".
The professor quoted in the Gizmodo article, from the Telegraph article
, goes on to say:
"We found that regularly eating more than the recommended amount of red meat was also related to increased depression and anxiety," Professor Jacka added.
It's also interesting that the Australian government recommends a minimum
amount of red meat specifically. Hmm. And surely the benefit to the Australian meat industry is only a coincidence.