Omega-3 and plant sterol supplements reduce fasting blood glucose in pre-diabetics: China RCT

25-Jul-2019 - Last updated on 25-Jul-2019 at 01:39 GMT

A combination of omega-3 fatty acids and plant sterols dietary supplements may reduce fasting blood glucose in pre-diabetics. ©Getty Images

A combination of omega-3 fatty acids and plant sterols dietary supplements was found to significantly reduce fasting blood glucose and insulin resistance in people with impaired glucose regulation (IGR) or pre-diabetes, Chinese researchers said.

Published in the journal Lipids in health and disease, it is one of the first randomised clinical trials focused on the combinations’ potential to alter glucose and lipid metabolism in preventing and/or treating IGR.

The study reported that participants given the combination exhibited significantly decreased triglyceride, high-density lipoprotein cholesterol, fasting blood glucose, and glycosylated haemoglobin.

“These findings may provide a scientific basis for the development of nutritional products incorporating plant sterols (PS) and omega-3 fatty acids, and also for the development of nutritional supplement strategies aimed at preventing the development of disease in the IGR population,” the researchers said.

The clinical trial was conducted in a hospital in China over 12 weeks.

A total of 134 participants with IGR were randomly assigned to four intervention groups: placebo (soybean powder in placebo capsules), omega-3 fatty acids (2g fish oil with 1000mg EPA and 400mg DHA), PS (1.7g plant sterols), and combination of PS and omega-3 (1.7g plant sterols and 2g fish oil with 1000mg EPA and 400mg DHA).

Effect of omega-3

The findings revealed a significant decrease in fasting plasma glucose levels, and insulin resistance in both omega-3 fatty acids treatment group as well as the combination treatment group.

Researchers said, “Omega-3 fatty acids was found to improve glucose metabolism, insulin resistance, and inflammation via decreases in fasting blood glucose, insulin resistance and inflammatory factors.”

There is evidence from previous clinical trials and animal studies suggesting that omega-3 fatty acids inhibit inflammatory reactions.

They added, “Our results support studies that indicate omega-3 fatty acids may contribute to IGR treatment.”

However, there was no significant change in fasting insulin amongst the four treatment groups.

“These results demonstrate that PS had no effect on glucose metabolism in IGR individuals, while omega-3 fatty acids and the combination of these two interventions did.”

Effect of plant sterols

Researchers found a significant decrease in triglyceride concentration in both the PS group as well as combination group.

In the combination group, high-density lipoprotein cholesterol levels were also higher, compared to placebo group.

However, there was no significant effect of both interventions on total cholesterol and low-density lipoprotein cholesterol levels.

“These findings show that PS and combinatory interventions have positive effects on lipid metabolism in IGR individuals, whereas omega-3 fatty acids alone have no effect.”

In terms of inflammation factors, both PS group and omega-3 fatty acids group showed a decrease in high-sensitivity C-reactive protein. However, the effect was not seen in the combination group.

“These results suggest that a combined intervention cannot reduce inflammation in the IGR population.”

The researchers said, “We speculate that PS might prevent IGR progression to T2DM via improving lipid metabolism and inflammation.”

Recommendations

The researchers noted: “The combinatory intervention facilitated a more significant reduction in fasting blood glucose and insulin resistance than either PS or omega-3 fatty acids alone.”

Although the combined intervention had no synergistic effect on high-density lipoprotein cholesterol, triglyceride, and glycosylated haemoglobin, the findings may still offer a safe and effective therapeutic approach in IGR patients.

There is a need for additional studies to further investigate inflammatory markers and blood pressure in IGR individuals who take PS and omega-3 fatty acids. For example, greater sample size, longer observation period, and detecting more inflammatory factors.

Researchers also suggested collecting n-3 fatty acids levels in future participants, as they are known to decrease cardiometabolic complications in T2DM patients.

The researchers concluded, “This study provides support for a scientific approach to using plant sterols and omega-3 fatty acids for the treatment of IGR, as well as T2DM.”

Source: Lipids in health and disease

Doi: 10.1186/s12944-019-1048-x

‘‘A combination of omega-3 and plant sterols regulate glucose and lipid metabolism in individuals with impaired glucose regulation: a randomized and controlled clinical trial’’

Authors: Ji-fang Wang, Hai-ming Zhang, et al.