In their latest study, published in BMJ, researchers from the Harvard School of Public Health suggest that increased consumption of white rice may be linked to a higher risk of type 2 diabetes. There s just one small caveat: The association was only significant among Asian populations.
The study, which was a meta-analysis a review of four other studies included over 350,000 participants who answered food frequency questionnaires and were followed from anywhere between 4 and 22 years. After crunching some numbers, the researchers found that participants who ate the greatest amount of white rice had a 27 percent increased risk of developing type 2 diabetes, compared to those who ate the least. The link, however, was stronger among Asian participants, among whom the increase in risk of the disease was 55 percent in the high consumption group.
Although the risk of type 2 diabetes was heightened among Western populations, too, it did not reach statistical significance. This led Dr. Bruce Neal of the University of Sydney in Australia to observe that the interpretation of the observed association, and, in particular, determination of the likelihood of causality, are problematic.
ACSH s Dr. Ruth Kava, while in agreement with Dr. Neal s assessment, goes a bit further in her dismissal of the clinical relevance of this study: Such a meta-analysis is merely an estimate of an estimate, she says. These observational studies cannot distinguish a causal effect from correlation.