Allulose, also known as D-psicose, is a rare sugar that tastes just like white sugar, but only has 10% of its calories. It has potential anti-obesity and antidiabetic properties. Allulose may also lower the risk of heart disease, normalize eating habits, and protect the body from oxidative stress. Read on to discover 6 potential benefits of allulose and why you should incorporate it into your diet.
What is Allulose?
Allulose is a rare sugar that occurs in small quantities in nature. It belongs to a group of compounds called monosaccharides, just like fructose and glucose. However, allulose only contains 10% of the calories of these 2 sugars. It does, however, maintain a similar taste and texture.
Industrially, allulose is produced from fructose. It can be purchased as a sweetener to substitute sugar in the diet.
Due to its low-calorie content, allulose may benefit people suffering from obesity, diabetes, and may promote overall weight loss. Additionally, it may have antioxidant properties that reduce inflammation.
Natural Sources and Forms of Supplementation
Allulose occurs in small quantities in wheat and in the Itea plant family [1, 2, 3].
It is also found in brown sugar, dried figs, raisins, and worcester sauce .
Today, it is mostly made from bacteria and fructose and available in form of sweetener or a food additive (honey or maple syrup).
Allulose has the same molecular formula (C6H12O6) as fructose and glucose, but the placement of chemical groups is slightly different. The rearrangement of chemical groups is enough to change its physical and chemical properties.
Mechanism of Action
Allulose is quickly excreted in the urine and cannot penetrate the blood-brain barrier. Therefore, direct action on the central nervous system is not possible .
Allulose acts mainly through the release of GLP-1 (Glucagon-Like Peptide-1). GLP-1 is produced by the large intestine (L-cells). It circulates in the blood and binds to receptors in the brain, pancreas, gut, and kidneys [6, 7].
Allulose lowers blood glucose by [8, 9, 10, 11, 12] :
Increasing insulin release in response to an after-meal glucose spike
- Increasing the efficiency of glucose transport into the cells
Increasing insulin sensitivity
- Suppressing glucagon release
- Increasing usage of glucose in the liver
- Directly reducing the release of glucose into the bloodstream
- Inhibiting intestinal alpha-glucosidase and delaying carbohydrate (sucrose in specific) digestion
Allulose decreases the amount of body fat tissue by [13, 14, 15]:
Increasing activity of CPT1 (Carnitine palmitoyltransferase 2), CPT2 and Beta-oxidase – enzymes responsible for the fat breakdown
- Increasing the number of UCP1 (uncoupling protein 1) – involved in energy use in the form of heat
- Decreasing the production of lipids (fatty acid synthase) and ACC2 (acetyl-CoA carboxylase 1)
Allulose decreases the amount of liver fat by :
- Reduction of lipid synthesis by decreasing levels of enzymes required for the reaction, FAS (fatty acid synthase), and PAP (phosphatidate phosphatase)
Allulose promotes satiety by:
Health Benefits of Allulose
Increasing the release of GLP-1, which travels through the bloodstream to the brain. In the brain, GLP-1 receptors are located in the brainstem, hypothalamus, and parietal cortex. It acts on receptors in these brain areas, ultimately resulting in a reduction of appetite (satiety). This leads to behavioral cut on eating [16, 14, 17].
GLP-1 also blocks the digestive system from emptying out food (ileal brake mechanism). This sends a signal to the brain that results in less hunger [18, 19, 20].
Allulose is easily absorbable but it has a very low glycemic index. This means that consuming allulose does not cause a rise in blood glucose levels [21, 11].
The health benefits of allulose have not yet been fully explored in humans. Therefore, the following list comprises all of the scientific evidence that has been conducted both clinically and preclinically on the effects of allulose.
1) May Help Control Blood Glucose and Insulin Levels
In a 12-week trial conducted on 26 diabetic patients, 5 g of allulose 3 times a day decreased post-meal glucose spike in diabetic patients .
In 15 prediabetic and 11 healthy patients, single ingestion of allulose reduced blood glucose levels in patients with borderline diabetes. Long-term (12 weeks) use of allulose did not cause any side effects .
In diabetic and healthy mice, allulose lowered general blood glucose down to normal levels without causing hypoglycemia in healthy animals. It also alleviated the post-meal glucose spike in both healthy and diabetic animals .
Insulin resistance is a condition in which cells fail to respond to insulin, resulting in high blood glucose levels. The main symptom of this condition is high insulin levels (hyperinsulinemia). In animals with hyperinsulinemia, allulose decreased insulin levels and lowered insulin resistance [22, 14].
In 121 overweight individuals, allulose significantly reduced fat in the stomach and waist. Additionally, it reduced the overall body mass index (BMI) .
In multiple mouse studies, allulose decreased fatty tissue in both obese and leptin-deficient mice. This effect was mediated by the release of GLP-1. Allulose use also corrected diabetes, fatty liver disease, and overeating [9, 24].
High-fat diet-fed mice supplemented with allulose demonstrated about 50% less fat in the belly area and body .
In mice, allulose increased the activity of enzymes responsible for the breakdown of fat (Beta-oxidase, CPT1, CPT2). It also decreased fat synthesis (fatty acid synthase) [25, 26].
In mice fed a high-fat diet (HFD), allulose for 16 weeks decreased fat synthesis and absorption in the small intestine. Additionally, it increased the removal of fats from the body (fecal excretion) .
In cell studies, the direct application of allulose prevented fat cells from replicating .
3) Allulose May Reduce Oxidative Stress and Inflammation
In rats with testicular injury, allulose-infused water (2% allulose) for 14 days prevented the production of reactive oxygen species (ROS) and prevented further injury. Additionally, allulose increased the number of antioxidant proteins (glutathione peroxidase 1 and 2, glutaredoxin 1) .
Type 2 diabetes is caused by a failure of B-cells in the pancreas to respond to glucose levels. In rats with type 2 diabetes, allulose for 60 weeks reduced the production of inflammatory molecules IL-6and TNF-alpha. It also increased the production of glutathione (GSH), an antioxidant that plays a protective role in the body and helps alleviate cell damage .
In rats supplemented with 5% allulose solution for 12 weeks, total body weight and cholesterollevels were reduced. Additionally, allulose reduced the expression of inflammatory genes (fos, mmp3, Fgf21, and abcd2) and genes responsible for fat synthesis .
In a cell model of Parkinson’s disease (6-OHDA treated PC12 cells), allulose protected neurons from cell death. It also increased levels of glutathione .
4) Allulose May Reduce Fat Storage in the Liver
In mice fed high-fat diets, allulose for 16 weeks decreased the amount of fat buildup in the liver. Enzymes responsible for the synthesis of fat (fatty-acid synthase [FAS], acetyl-CoA carboxylase 1 [ACC1], and phosphatidate phosphatase [PAP]) had reduced activity and fat breakdown (beta-oxidation) was increased .
In obese mice, allulose for 5 weeks decreased the number of fats (triglycerides) in the liver .
5) Allulose May Decrease Levels of HbA1c
HbA1c, or glycated hemoglobin, is formed from a reaction between hemoglobin A and blood glucose. It is used as an indicator of blood glucose levels over time and is a reliable marker for diabetes [31, 32, 33].
In obese rats with type 2 diabetes, allulose decreased the level of HbA1c by maintaining normal blood sugar levels during eating and fasting .
6) Allulose and Metronidazole
In cells, the antibiotic metronidazole in conjunction with allulose was more efficient in stopping the growth of the protozoa (Tritrichomonas foetus) than the metronidazole alone. Allulose may prove useful in overcoming antibiotic resistance to metronidazole .
Side Effects & Precautions
There have been no reported side effects caused by allulose. Doses above 35 grams per day may cause gastrointestinal discomfort .
The lack of reported side effects may be attributed to the fact that there have been a limited number of studies in humans. Therefore, consult your doctor before starting allulose [11, 36].
Limitations and Caveats
Since most of the studies mentioned here were on animals, caution should be taken when using allulose in humans. Most of the mechanisms and results were only observed in animals.
Dosages used in human studies were lower than in animal studies. Humans were served up to about 0.2 g of allulose/kg, while animals were given 0.2 to 3.0 g of allulose per kilogram of body weight. The observed benefits in animal models may be attributed to the increased dose of allulose.