Lowering saturated fat intake did not lower saturated fat blood levels but increasing carbs raised levels of palmitoleic acid, a fatty acid associated with disease…
The study included 16 participants, all of whom had metabolic syndrome, marked by at least three risk factors that increased their risk for heart disease or diabetes. All participants were fed the same diet, which was altered every three weeks for a total duration of 18 weeks as levels of carbohydrates were progressively increased and saturated fats were decreased. All started with a baseline “low-carb” diet, with the highest carb level reaching over 55% of the daily nutrient intake.
By the end of the trial, participants had lost an average 22 pounds, and experienced significant improvements in blood sugar, insulin levels, and blood pressure. Throughout the study, participants’ blood levels of total saturated fats remained relatively stable and even fell in some when the baseline fat consumption was doubled.
In contrast, blood levels of palmitoleic acid (a fatty acid associated with an unhealthy effect on carbohydrates that promotes disease) went up as carbohydrate consumption was increased and fat consumption fell. Increased levels of palmitoleic acid in the blood suggest that more carbohydrates are being converted to fat instead of being burned as fuel. By reducing the amount of carbohydrate intake and adding controlled amounts of fat to the diet ensures that the body burned saturated fat rather than storing it.
Elevated levels of palmitoleic acid in the body stimulates a myriad of undesirable effects in the body such as increased triglycerides, high blood sugar, heart disease, and in some patients, aggressive prostate cancer. This marker could help in measuring how the body is converting carbs to fat resulting in the metabolic havoc.
The researchers concluded that, “High intakes of saturated fat (including regular consumption of whole eggs, full-fat dairy, high-fat beef and other meats) does not contribute to accumulation of plasma SFA in the context of a low carbohydrate intake. A progressive decrease in saturated fat and commensurate increase in carbohydrate intake, on the other hand, is associated with incremental increases in the proportion of plasma palmitoleic acid, which may be signaling impaired metabolism of carbohydrate, even under conditions of negative energy balance and significant weight loss. These findings contradict the perspective that dietary saturated fat per se is harmful, and underscore the importance of considering the level of dietary carbohydrate that accompanies saturated fat consumption.”
- Foods high in saturated fat do not drive up levels of ‘junk’ nutrient in the blood
- Higher consumption of carbohydrates, not saturated fat, are associated with changes linked to diabetes and heart disease
- This study is against the widely held view of harmful effects of eating too much saturated fat.
Brittanie M. Volk, Laura J. Kunces, published 21 Nov 2014 | PLOS ONE 10.1371/journal.pone.0113605