"In contrast, there was no particular ethnicity link for brown rice consumption: instead, people with a health conscious lifestyle and diet were the most likely to eat brown rice."
Observational study. People who pay more attention to their health are more likely to do things that are consistent with current beliefs about what constitutes a healthy diet. This means that they may do things that in fact do not contribute to their overall health - but because these things are frequently associated with healthy people, are falsely credited as being healthful.
An old favourite is the story about the man who walked five miles into town every day to buy - and eat - a raw onion. He credited his good health to the consumption of his daily onion, where the daily ten-mile walk was in fact the more likely candidate.
My .02
And I'll add how irritating I find these misleading observational studies which do nothing to inform the public about how to improve their health.
Case in point: I was obese and on Metformin when I ate brown rather than white rice.
I am now healthy and lean year round, and I rarely eat brown rice. I occasionally eat white rice. I routinely eat plenty of meat, vegetables, and healthy fats. And I keep my weight down.