One of my subscribers, a doctor with a specialist interest in gastroenterology, fatty liver disease and obesity, shared a study with me called "Dietary protein intake and mortality among survivors of liver cirrhosis: a prospective cohort study" by Daftari et al. The research looks into the potential link between dietary protein intake and death rate among liver cirrhosis patients.
Population studies often involve tens of thousands of people but this study, conducted in Iran, involved just 121 individuals who had had liver cirrhosis for over six months. The paper got off to a bad start by not presenting the characteristics of the people according to the topic of interest (protein).
Participants had an average age of 55, with a majority being male (68%). Surprisingly, the study revealed a substantial rate of smoking (39%) and alcohol consumption (23%) despite Iran's strict regulations against alcohol. Dietary intake was recorded via a comprehensive Food Frequency Questionnaire featuring 168 food items.
Over 48 months of follow-up, the study reported 43 deaths among the 121 participants. Liver failure, cardiovascular diseases, carcinoma, and other causes accounted for these deaths. That’s a really high death rate, confirming how serious cirrhosis of the liver is.
The study claimed that higher total protein and higher dairy protein intake were each associated with a 62% lower risk of mortality, while animal protein intake showed a 3.8-fold increase in mortality risk. Vegetable protein intake was not found to be associated with mortality. However, the 'findings' for total protein and dairy protein were not statistically significant and thus they were not findings. The animal protein finding looked like it would have been significant, but the paper didn't report the statistical value that we need (the p value) to conclude that it was a genuine finding. Hence all findings were not genuine findings and should not have been reported as findings.