Benefits
2-hour glucose versus sucrose over 12 weeks at 10 g a day
In 34 adults with a BMI of 23 or more, 10 g a day of trehalose with meals for 12 weeks lowered 2-hour glucose from baseline while sucrose did not, but across everyone the changes did not differ significantly between groups. In a higher truncal fat subgroup, weight, waist and systolic blood pressure changes favored trehalose. All authors worked for Hayashibara, the maker.
Post-load glucose with 3.3 g a day in healthy adults
In a 12-week double-blind trial in 50 healthy Japanese adults, 2-hour glucose after a 75 g glucose load stayed close to fasting with 3.3 g a day of trehalose but rose above fasting with sucrose. The trehalose group was lower than the sucrose group only in a subgroup with higher post-load glucose. All authors were employees of Hayashibara, the sponsor.
Glucose and insulin response compared with glucose
In 20 healthy volunteers, 25 g of trehalose gave a slower glucose rise and lower insulin and GIP responses than 25 g of glucose. In 10 overweight adults with impaired glucose tolerance, a trehalose drink taken with a meal gave a 33% smaller glucose rise and a 14% smaller insulin rise than a glucose drink. Trehalose is still digested to glucose.
Fasting glucose and HbA1c over 12 weeks at 3.3 g a day
In an independent placebo-controlled pilot in 40 adults with type 2 diabetes, 3.3 g a day of trehalose for 12 weeks did not change fasting glucose, HbA1c, insulin or insulin resistance compared with a sucrose placebo. C-reactive protein, an inflammation marker, was lower with trehalose.
Small artery function at 100 g a day in older adults
In a 12-week double-blind trial in 32 healthy adults aged 50 to 77, 100 g a day of trehalose improved forearm small artery dilation by about 30% only in people whose weight stayed within 2.3 kg; across everyone it did not differ from maltose. Large artery function, stiffness and inflammation markers did not change.
Mechanism of action
Split into glucose by intestinal trehalase
Trehalase, an enzyme on the lining of the small intestine, splits trehalose into two glucose molecules, so it is a digestible carbohydrate rather than a calorie-free sweetener. In human studies it raised blood glucose and insulin more slowly than the same weight of glucose. When trehalase activity is low, more trehalose reaches the colon, where it can draw in water and be fermented to gas.
Protein stabilization during drying and heat
Trehalose protects proteins under drying or heat stress by replacing water around them and forming a stable glass, which is why it is used to stabilize foods and biological products. This is a physical property and has not been shown to work this way inside the human body after oral intake.
Autophagy effects in cell and animal research (disputed)
In animal models of Parkinson and Huntington disease, trehalose was linked to autophagy activation and fewer protein aggregates. Cell results have been less certain, and one careful study found trehalose blocked the final step of autophagy rather than driving it. These findings do not show that oral trehalose has such effects in people.
Clinical trials
Double-blind trial with a sucrose control rather than an inert placebo; all authors were employees of Hayashibara, the trehalose maker. (Mizote et al. 2016, J Nutr Sci Vitaminol (Tokyo))
34 adults with a BMI of 23 or more taking 10 g a day of trehalose or sucrose with meals for 12 weeks, with measurements at 0, 8 and 12 weeks and a 4-week washout.
In the trehalose group, 2-hour glucose on an oral glucose tolerance test fell significantly from baseline after 12 weeks. In a subgroup with truncal fat near the upper end of normal, changes in body weight, waist circumference and systolic blood pressure were significantly smaller with trehalose than with sucrose. Across all participants, the changes did not differ significantly between the trehalose and sucrose groups.
Randomized, double-blind trial with a sucrose control; all authors were employees of Hayashibara, the sponsor, which paid all costs. (Yoshizane et al. 2020, Nutr J)
50 healthy Japanese adults taking 3.3 g of trehalose (n = 25) or sucrose (n = 25) daily for 78 days, with 75 g oral glucose tolerance tests at baseline and 12 weeks.
After 12 weeks, 2-hour glucose was significantly higher than fasting in the sucrose group but similar to fasting in the trehalose group. Body composition and serum chemistry did not differ between groups. In participants with relatively high post-load glucose, 2-hour glucose was lower with trehalose than with sucrose.
Crossover study; all authors were employees of Hayashibara, the trehalose maker. (Yoshizane et al. 2017, Nutr J)
20 fasted healthy Japanese volunteers taking 25 g of trehalose or 25 g of glucose in 100 mL water, with blood sampled over 3 hours.
Trehalose did not cause a rapid rise in blood glucose and stimulated less insulin and active GIP than glucose. Active GLP-1 was higher from 45 to 180 minutes after trehalose. The comparison was with glucose, not with sucrose.
Randomized, single-blind crossover comparing trehalose with glucose and isomaltulose with sucrose. (van Can et al. 2012, Br J Nutr)
10 overweight adults with impaired glucose tolerance, each tested four times with sugar drinks at breakfast or with a lunch meal.
Taken with a meal, trehalose gave a 33% smaller rise in glucose and a 14% smaller rise in insulin than glucose. Fat oxidation after trehalose did not differ from glucose.
Double-blind, randomized, placebo-controlled pilot with sucrose as the placebo; the authors declared no conflicts of interest. (Hashemian et al. 2023, Arch Med Sci)
40 adults with type 2 diabetes, 20 taking 3.3 g a day of trehalose and 20 taking sucrose for 3 months.
No between-group differences in fasting glucose, HbA1c, insulin or HOMA-IR after 12 weeks. C-reactive protein was significantly lower with trehalose. Depression, stress and quality of life scores differed at the end of the study, but between-group changes in these scores were not significant.
Randomized, double-blind 12-week trial funded by NIH; trehalose and maltose were bought from Hayashibara. (Kaplon et al. 2016, Aging (Albany NY))
32 healthy adults aged 50 to 77 who completed 12 weeks of 100 g a day of trehalose (n = 15) or maltose (n = 17).
Across all participants, forearm small artery dilation did not change differently between groups. In those whose weight stayed within 2.3 kg, dilation to acetylcholine rose about 30% with trehalose but not maltose. Brachial artery dilation, large artery stiffness and oxidative stress and inflammation markers did not change. Four people on trehalose reported bloating, flatulence or loose stools.