Study finds naturally-derived trehalose inhibits fat cell hypertrophy

Hayashibara Biochemical Laboratories, Inc. based in Okayama City, Okayama Prefecture, Japan, has confirmed that the naturally-derived functional saccharide trehalose has the effect of inhibiting fat cell hypertrophy. The finding will be presented to the 31st conference of the Japan Society for the Study of Obesity (JASSO), scheduled to be held at Maebashi Terrsa in Gunma Prefecture on October 1 and 2.

Focuses

Confirmation of trehalose's effectiveness in "inhibiting fat cell hypertrophy" and "inhibiting the progression of insulin resistance"

Trehalose's existing use in over 20,000 types of products due to its diverse functionality

The latest study potentially opening a new market segment that differs from the recently-booming market of "zero or reduced sugar/fat" products

Presentation overview

This study was conducted to identify the effects of trehalose in preventing metabolic syndrome. Metabolic syndrome is triggered when abdominal fat cells become hypertrophic, and induce insulin resistance. The study involved tests on mice that were fed a high-fat diet (HFD) and given a range of saccharides for comparison. The results showed that trehalose can effectively inhibit the hypertrophy of fat cells, which usually occurs in HFD. Furthermore, the saccharide was found to inhibit the progression of insulin resistance, normally triggered by HFD. The findings point to the possibility of developing a new approach to prevent metabolic syndrome while consuming necessary saccharides.

Significance of this study

Today, Japanese people are increasingly embracing the Western-style high-fat and high-calorie diet. Consequently, the proportion of people with obesity resulting from excessive intake of fat and sugar has increased over the last decade, especially among middle-aged and senior citizens. In recent years, the food market has seen a surge of products with "zero or reduced" calories, sugar and fat amidst strong support from consumers.

However, saccharides are one of the essential nutrients required to sustain life, serving various beneficial roles in our bodies. For example, saccharides (glucose) are the source of energy for our brain. Its deficiency causes performance deterioration and emotional instability. When the brain does not feel satisfied as in a saccharide-deficient diet, it interprets the situation as a state of starvation, and triggers excessive eating to supplement energy, thereby causing eating disorders.

Trehalose is turned into glucose by our bodies and serves a vital role as a vital nutrient. In carrying out a study focused on the already-proven effect trehalose had in evoking lower insulin secretion, it was identified in this study that trehalose inhibits the hypertrophy of fat cells.

In other words, this study presents an extremely novel possibility that "saccharides," which previously carried a "fattening" image, can become a tasty alternative to "zero/reduced" products as a kinder way of preventing metabolic syndrome.

Research overview

Objectives

In order to examine trehalose's effectiveness in preventing metabolic syndrome, mice on a high-fat diet (HFD) were given trehalose and other saccharides for comparison to gauge its effect on fat cell hypertrophy, as well as other saccharides for comparison.

Testing method

Seven-week-old mice were divided into seven groups: one on a normal diet and water; one on HFD and water; and five on HFD and various saccharide solutions (trehalose, etc.). They were kept on their respective diets for eight weeks. The mice were then subjected to a glucose tolerance test in Week 7, and had the diameter and area of their visceral fat (mesenteric fat cells) measured in Week 8, in order to determine the effect of trehalose in inhibiting the hypertrophy of fat cells.

Measurement items

1) Diameter and area of mesenteric fat cells

2) Fasting blood sugar/insulin levels

Results

Microscopic photography was taken on visceral fat samples from all groups in Week 8 to compare the extent of their hypertrophy. Group B on HFD showed hypertrophy of mesenteric fat cells compared to Group A on ordinary diet (fat cell diameter: 40-50 micrometer in Group A [normal group] and 80-90 micrometer in Group B [control group]). Growth in fat cell size for Group C, which was given trehalose solution to drink, was inhibited (fat cell diameter: 60-70 micrometer). No such inhibition was demonstrated in Groups on other types of saccharide (fat cell diameter: 85-100 micrometer in Group D, 80-90 micrometer in Group E, 80-90 micrometer for Group F, and 85-100 for Group G).

As for mesenteric fat cell area, Group G on HFD had a larger per-cell area than Group A on ordinary diet. Area increase for fat cells of Group C on trehalose was inhibited, while Groups on other saccharide (Group D, Group E, Group F and Group G) had greater per-cell area than Group B.

*For the measurement of mesenteric fat cells, an optical microscope (at 200x magnification) was used to take a photograph of five randomly-selected fields. The number of fat cells per microscopic view (0.267mm2) was counted to work out the per-cell area.

Sample fasting serum insulin and insulin resistance were examined in Week 7. Compared to Group A on ordinary diet, Group B on HFD showed a raised level of fasting blood sugar and fasting serum insulin, as well as insulin resistance index (HOMA-IR), which is calculated with the two figures.  Meanwhile, increase in fasting serum insulin for Group C, which was trehalose solution, was inhibited. This, in turn, lowered the HOMA-IR index to indicate improvement in insulin resistance. This effect was not observed in groups on other saccharides (Group D, Group E, Group F and Group G).

*This study has also confirmed trehalose's effectiveness in inhibiting the progression of glucose tolerance impairment and protecting pancreatic beta cells, which secrete insulin.