Open AccessEffects of palm oil consumption on biomarkers of glucose metabolism: A systematic review
Author(s) -
Siti Hafizah Zulkiply,
Vimala Balasubramaniam,
Nur Ain Abu Bakar,
Aswir Abd Rashed,
Suriani Ismail
Publication year - 2019
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0220877
Subject(s) - medicine , food science , soybean oil , population , canola , fatty acid , vegetable oil , insulin resistance , carbohydrate metabolism , diabetes mellitus , microbiology and biotechnology , biology , environmental health , endocrinology , biochemistry
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.