Effects of Palm Stearin versus Butter in the Context of Low-Carbohydrate/High-Fat and High-Carbohydrate/Low-Fat Diets on Circulating Lipids in a Controlled Feeding Study in Healthy Humans

Abstract

Background. Foods rich in saturated fatty acids (SFAs) have been discouraged by virtue of their cholesterol-raising potential, but this effect is modulated by the food source and background level of carbohydrate. Objective. We aimed to compare the consumption of palm stearin (PS) versus butter on circulating cholesterol responses in the setting of both a low-carbohydrate/high-fat (LC/HF) and high-carbohydrate/low-fat (HC/LF) diet in healthy subjects. We also explored effects on plasma lipoprotein particle distribution and fatty acid composition. Methods. We performed a randomized, controlled-feeding, cross-over study that compared a PS- versus a Butter-based diet in a group of normocholesterolemic, non-obese adults. A controlled canola oil-based ‘Run-In’ diet preceded the experimental PS and Butter diets. All diets were eucaloric, provided for 3-weeks, and had the same macronutrient distribution but varied in primary fat source (40% of the total fat). The same Run-In and cross-over experiments were done in two separate groups who self-selected to either a LC/HF (n = 12) or a HC/LF (n = 12) diet track. The primary outcomes were low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL)-C, triglycerides, and LDL particle distribution. Results. Compared to PS, Butter resulted in higher LDL-C in both the LC/HF (13.4%, p = 0.003) and HC/LF (10.8%, p = 0.002) groups, which was primarily attributed to large LDL I and LDL IIa particles. There were no differences between PS and Butter in HDL-C, triglycerides, or small LDL particles. Oxidized LDL was lower after PS than Butter in LC/HF (p = 0.011), but not the HC/LF group. Conclusions. These results demonstrate that Butter raises LDL-C relative to PS in healthy normocholesterolemic adults regardless of background variations in carbohydrate and fat, an effect primarily attributed to larger cholesterol-rich LDL particles.

The Effects of Carbohydrate versus Fat Restriction on Lipid Profiles in Highly Trained, Recreational Distance Runners: A Randomized, Cross-Over Trial

“…These results were anticipated for several reasons. Firstly, LCHF interventions have previously shown to increase serum lipids in both sedentary [ 34 , 35 , 36 ] and trained populations [ 5 , 13 , 16 , 24 , 25 , 27 ], albeit not always in athletes [ 20 , 21 ]. In our case, highly trained endurance athletes did experience a significant change over time in TC and LDL that was significant from day 14 and thereafter.…”

“…Dietary cholesterol is overall a poor surrogate of serum cholesterol in healthy individuals due to homeostatic feedback inhibition on endogenous cholesterol synthesis [ 41 ]. Fatty acid saturation, however, particularly SFA, has shown to have the largest influence on TC and LDL (including small density LDL) species, and is used more reliably to describe effects on blood cholesterol [ 34 , 37 , 42 ]. Although LDL particle size was not included in our analysis goals, the literature indicates that ketogenic diets may favor large, “buoyant” LDL species over smaller, pro-atherogenic “dense” LDL that correlate with cardiovascular injury [ 43 ], whereby HCLF may not promote buoyant LDL subclasses [ 34 , 42 ].…”

“…Fatty acid saturation, however, particularly SFA, has shown to have the largest influence on TC and LDL (including small density LDL) species, and is used more reliably to describe effects on blood cholesterol [ 34 , 37 , 42 ]. Although LDL particle size was not included in our analysis goals, the literature indicates that ketogenic diets may favor large, “buoyant” LDL species over smaller, pro-atherogenic “dense” LDL that correlate with cardiovascular injury [ 43 ], whereby HCLF may not promote buoyant LDL subclasses [ 34 , 42 ]. The plateau in TC and LDL concentrations at day 28 and thereafter suggests that no further increase was expected in these lipid parameters.…”

The effects of a 6-week controlled, hypocaloric ketogenic diet, with and without exogenous ketone salts, on cognitive performance and mood states in overweight and obese adults

“…Glucose-lowering is a well-established benefit of ketogenic diets (Yuan et al, 2020;Hyde et al, 2021), and this effect was not augmented by the addition of ketone salts. On the other hand, participants that followed the LFD showed glucose fluctuations with decreased glucose levels at week 4 that returned to baseline levels at week 6.…”

Impact of Malaysian palm oil on sustainable development goals: co-benefits and trade-offs across mitigation strategies

“…These reviews are notably limited by a small number of studies and publication biases based on funding source, widespread consumption, and difficulty to single out PO from other food items (Ismail et al 2018;Sun et al 2015). A recent randomized controlled-feeding trial in healthy normocholesterolemic adults showed that butter raised LDL cholesterol higher than palm stearin regardless of background consumption of carbohydrate and fat (Hyde et al 2021). Thus far, the oft-cited negative effects of saturated fats from PO remains inconclusive.…”