Effects of palm oil consumption on biomarkers of glucose metabolism: A systematic review

Abstract

Introduction Vegetable oil is an important source of fatty acids, and as palm oil being the highest consumed vegetable oil in many countries, its high saturated fatty acid content has led many concerns on cardiometabolic health. Dietary fatty acids has also been linked to affect glucose metabolism and insulin sensitivity. This systematic review is aimed at critically evaluating the available evidence on the association of palm oil with the biomarkers of glucose metabolism as compared to other vegetable oils. Methods We systemically searched PubMed, CENTRAL and Scopus up to June 2018. We searched for published interventional studies on biomarkers of glucose metabolism (defined as fasting glucose, fasting insulin, HOMA, 2-hour post prandial glucose and HbA1C) that compared palm oil- or palm olein-rich diets with other edible vegetable oils (such as olive oil, canola oil and soybean oil). Two reviewers independently extracted data and assessed study risks of bias. Mean differences of outcomes were pooled for the meta-analysis. Results We identified 1921 potentially eligible articles with only eight included studies. Seven randomised cross-over trials and one parallel trial were included. Study population were among young to middle-aged, healthy, non-diabetic, and normal weight participants. Intervention duration ranged from three to seven weeks, and fat substitution ranged from 15% to 20% energy. There were insignificant differences in fasting glucose when compared to partially hydrogenated soybean oil [-0.15mmol/L (-0.46,0.16) P = 0.33, I 2 = 48%], soybean oil [0.05mmol/L (-0.09,0.18) P = 0.49, I 2 = 0%] and olive oil [0.04mmol/L (-0.09,0.17) P = 0.76, I 2 = 0%]. Insignificant effects were also seen on fasting insulin when compared to partially hydrogenated soybean oil [1.72pmol/L (-11.39,14.84) P = 0.80, I 2 = 12%] and olive oil diet [-0.14pmol/L (-4.87,4.59) P = 0.95, I 2 = 0%]. Conclusion Current evidence on the effects of palm oil consumption on biomarkers of glucose metabolism is poor and limited to only healthy participants. We conclude that little or no additional benefit will be obtained by replacing palm oil with other oils rich in mono or polyunsaturated fatty acids for changes in glucose metabolism.

No Palm Oil or Certified Sustainable Palm Oil? Heterogeneous Consumer Preferences and the Role of Information

“…While purchasing RSPO-certified palm oil might be an option for consumers who are concerned about the sustainability of conventional palm oil cultivation, potential health concerns might probably not be resolved in this way. Although there is still a lack of robust scientific evidence on the adverse health effects of palm oil consumption [99][100][101], many consumers still perceive palm oil as unhealthy. Potential health concerns have not been assessed in this study, but previous research suggests that such concerns might positively influence preferences for "palm-oil-free" products (e.g., [48,50,52]).…”

Wybrane Aspekty Technologiczne I Zdrowotne Stosowania Oleju Palmowego W Produkcji Żywności

“…Wyniki wielu badań wskazują, że całodzienna racja pokarmowa bogata w nasycone kwasy tłuszczowe przyczynia się do wzrostu stężenia frakcji LDLcholesterolu we krwi zwiększonego ryzyka wystąpienia chorób sercowo-naczyniowych (CVD) [47]. Mimo że olej palmowy zawiera znaczne ilości nasyconych kwasów tłuszczowych, to wiele badań nie potwierdza jego negatywnego wpływu na gospodarkę lipidową.…”

“…Wyniki badań wskazują na prodiabetogenny wpływ nasyconych kwasów tłuszczowych [2]. Dlatego postawiono hipotezę, że tłuszcz palmowy może wywierać niekorzystny wpływ na metabolizm węglowodanów [47].…”

“…Metaanalizę wyników badań, dotyczących porównania wpływu oleju palmowego z innymi olejami roślinnymi na wybrane parametry gospodarki węglowodanowej, przeprowadzili Zulkiply i wsp. [47]. Podsumowali oni wyniki 8 badań z udziałem zdrowych osób w młodym i średnim wieku o prawidłowej masie ciała.…”

How should we judge edible oils and fats? An umbrella review of the health effects of nutrient and bioactive components found in edible oils and fats

“…Schwingshackl, Strasser, & Hoffmann, 2011), one showing greater effect than PUFA (Qian et al, 2016). Replacing SFA or carbohydrate with plant-derived PUFA had a favorable albeit weak effect on glucose and insulin in predominantly healthy cohorts in a third review (Wanders et al, 2019); a fourth showed no effect of PUFA on glucose or insulin for people with T2DM (Telle-Hansen, Gaundal, & Myhrstad, 2019); and a fifth found replacement of liquids oils with palm oil did not affect glucose or insulin levels (Zulkiply, Balasubramaniam, Bakar, Rashed, & Ismail, 2019). TFAs did not affect glucose or insulin (Aronis et al, 2012).…”