- A study of approximately 10,000 middle-aged Australian women examined the association between carbohydrate and saturated fat intake with cardiovascular disease (CVD) and deaths from any cause (mortality) over a 15 year period.
- The study split the women into five groups from lowest to highest intake of carbohydrate and then the same for saturated fat.
- It found that the middle group of carbohydrate intake (not the highest) was associated with lower incidence of CVD compared with the lowest group of carbohydrate intake.
- It found no association between carbohydrate intake and mortality or between saturated fat intake and CVD or mortality.
- It found that higher carbohydrate intake was associated with lower obesity, hypertension (high blood pressure) and diabetes. Higher saturated fat intake was also associated with lower obesity, hypertension and diabetes.
- The women in the lowest carbohydrate intake group were the least healthy in a number of important ways, which are connected to CVD and mortality. These differences should have been adjusted for, but the raw vs adjustment data raised alarm bells.
- As with all nutritional epidemiology, this study had many limitations. We should no more value a study that finds nothing against saturated fat than we should value a study that finds against saturated fat. We should no more value a study that finds little in favour of carbohydrate than we should value a study that finds much in favour of carbohydrate.