Effect of palm olein oil in a moderate-fat diet on low-density lipoprotein composition in non-human primates

Aspalathin-Rich Green Rooibos Extract Lowers LDL-Cholesterol and Oxidative Status in High-Fat Diet-Induced Diabetic Vervet Monkeys

Type 2 diabetic patients possess a two to four-fold-increased risk for cardiovascular diseases (CVD). Hyperglycemia, oxidative stress associated with endothelial dysfunction and dyslipidemia are regarded as pro-atherogenic mechanisms of CVD. In this study, high-fat diet-induced diabetic and non-diabetic vervet monkeys were treated with 90 mg/kg of aspalathin-rich green rooibos extract (Afriplex GRT) for 28 days, followed by a 1-month wash-out period. Supplementation showed improvements in both the intravenous glucose tolerance test (IVGTT) glycemic area under curve (AUC) and total cholesterol (due to a decrease of the low-density lipoprotein [LDL]) values in diabetics, while non-diabetic monkeys benefited from an increase in high-density lipoprotein (HDL) levels. No variation of plasma coenzyme Q10 (CoQ₁₀) were found, suggesting that the LDL-lowering effect of Afriplex GRT could be related to its ability to modulate the mevalonate pathway differently from statins. Concerning the plasma oxidative status, a decrease in percentage of oxidized CoQ₁₀ and circulating oxidized LDL (ox-LDL) levels after supplementation was observed in diabetics. Finally, the direct correlation between the amount of oxidized LDL and total LDL concentration, and the inverse correlation between ox-LDL and plasma CoQ₁₀ levels, detected in the diabetic monkeys highlighted the potential cardiovascular protective role of green rooibos extract. Taken together, these findings suggest that Afriplex GRT could counteract hyperglycemia, oxidative stress and dyslipidemia, thereby lowering fundamental cardiovascular risk factors associated with diabetes.

Effect of Locally Manufactured Niger Seed Oil on Lipid Profile Compared to Imported Palm and Sunflower Oils on Rat Models

Background

Different types of dietary lipids have been shown to affect lipid metabolism and lipid profile differently.

Objective

This study aims to assess the effect of local niger seed oil on serum lipid profile compared to palm oil and sunflower oil in rats.

Methods

The effect of the 15% plant oils on serum lipid profile, body weight gain percentage, and feed efficiency ratio was assessed after 8 weeks of experimental period.

Results and Conclusion

The 15% niger seed oil showed decrease and increase in the level of lipid profile as compared to rats fed with 15% palm oil and sunflower oil (except Triacylglycerol), respectively. The 15% niger seed oil showed significant decrease and increase in body weight gain percentage as compared to the 15% palm oil and 15% sunflower oil, respectively. The feed efficiency ratio was significantly higher and lower in the 15% niger seed oil compared to rats fed with 15% sunflower oil and control group and the palm oil fed rats, respectively. The current study concluded that consumption of locally manufactured niger seed oil decreased the blood lipid profiles, body weight gain percentage, and feed efficiency ratio as compared to palm oil. Utilization of oils containing more unsaturated fatty acids like niger seed oil is recommended to reduce the risk of developing cardiovascular disease.

Modulation of postprandial lipaemia by a single meal containing a commonly consumed interesterified palmitic acid-rich fat blend compared to a non-interesterified equivalent

Purpose

Interesterification of palm stearin and palm kernal (PSt/PK) is widely used by the food industry to create fats with desirable functional characteristics for applications in spreads and bakery products, negating the need for trans fatty acids. Previous studies have reported reduced postprandial lipaemia, an independent risk factor for CVD, following interesterified (IE) palmitic and stearic acid-rich fats that are not currently widely used by the food industry. The current study investigates the effect of the most commonly consumed PSt/PK IE blend on postprandial lipaemia.

Methods

A randomised, controlled, crossover (1 week washout) double-blind design study (n = 12 healthy males, 18–45 years), compared the postprandial (0–4 h) effects of meals containing 50 g fat [PSt/PK (80:20); IE vs. non-IE] on changes in plasma triacylglycerol (TAG), glucose, glucose-dependent insulinotropic polypeptide (GIP), peptide YY (PYY), insulin, gastric emptying (paracetamol concentrations) and satiety (visual analogue scales).

Results

The postprandial increase in plasma TAG was higher following the IE PSt/PK versus the non-IE PSt/PK, with a 51 % greater incremental area under the curve [mean difference with 95 % CI 41 (23, 58) mmol/L min P = 0.001]. The pattern of lipaemia was different between meals; at 4-h plasma TAG concentrations declined following the IE fat but continued to rise following the non-IE fat. Insulin, glucose, paracetamol, PYY and GIP concentrations increased significantly after the test meals (time effect; P < 0.001 for all), but did not differ between test meals. Feelings of fullness were higher following the non-IE PSt/PK meal (diet effect; P = 0.034). No other significant differences were noted.

Conclusions

Interesterification of PSt/PK increases early phase postprandial lipaemia (0–4 h); however, further investigation during the late postprandial phase (4–8 h) is warranted to determine the rate of return to baseline values.

Trial registration number

Clinicaltrials.gov as NCT02365987.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-016-1284-z) contains supplementary material, which is available to authorized users.

Research advancements in palm oil nutrition

Palm oil is the major oil produced, with annual world production in excess of 50 million tonnes. About 85% of global palm oil produced is used in food applications. Over the past three decades, research on nutritional benefits of palm oil have demonstrated the nutritional adequacy of palm oil and its products, and have resulted in transitions in the understanding these attributes. Numerous studies have demonstrated that palm oil was similar to unsaturated oils with regards to effects on blood lipids. Palm oil provides a healthy alternative to trans-fatty acid containing hydrogenated fats that have been demonstrated to have serious deleterious effects on health. The similar effects of palm oil on blood lipids, comparable to other vegetable oils could very well be due to the structure of the major triglycerides in palm oil, which has an unsaturated fatty acid in the stereospecific numbers (sn)-2 position of the glycerol backbone. In addition, palm oil is well endowed with a bouquet of phytonutrients beneficial to health, such as tocotrienols, carotenoids, and phytosterols. This review will provide an overview of studies that have established palm oil as a balanced and nutritious oil.