Allulose, also known as D-psicose, is a rare sugar that tastes just like white sugar, but only has 1/10 of its calories. It has potential anti-obesity and antidiabetic properties. In animal studies, it also protected from oxidative stress, inflammation, and fatty liver disease. Read on to discover the potential benefits of allulose and whether 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 simple sugars called monosaccharides, which includes fructose and glucose. However, allulose only contains 1/10 of the calories of these 2 sugars. It does, however, maintain a similar taste and texture [1, 2].
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 and reduce inflammation .
Natural Sources and Forms of Supplementation
Allulose occurs in small quantities in wheat and in the Itea plant genus [3, 4, 5].
Common food sources include brown sugar, dried figs, raisins, and Worcester sauce .
Today, it is mostly made industrially from fructose by using bacteria and is available in the form of sweetener or a food additive (honey or maple syrup) [7, 8].
Allulose has the same molecular formula as fructose and glucose (C6H12O6), 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 flushed with 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 bowel. This hormone circulates in the blood and binds to receptors in the brain, pancreas, gut, and kidneys [10, 11].
Allulose lowers blood glucose by [12, 13, 14, 15, 16] :
- 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 the usage of glucose in the liver
- Directly reducing the release of glucose into the bloodstream
- Inhibiting intestinal alpha-glucosidase and delaying sucrose digestion
Allulose decreases the amount of body fat tissue by [17, 18, 19]:
- Increasing the activity of three enzymes that break down fats: CPT1 (Carnitine palmitoyltransferase 2), CPT2, and beta-oxidase
- Increasing the number of a protein involved in energy use (uncoupling protein 1 or UCP1)
- Blocking the enzymes that produce fatty molecules (fatty acid synthase and acetyl-CoA carboxylase 1)
Allulose decreases the amount of liver fat by :
- Reducing the levels of the enzymes required for fat production (fatty acid synthase and phosphatidate phosphatase)
Allulose promotes satiety by:
- 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. Their activation results in a reduction of appetite [20, 18, 21].
- 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 [22, 23, 24].
- Allulose is easily absorbable but has a very low glycemic index. This means that consuming allulose does not cause a rise in blood glucose levels [25, 15].
- May help control blood sugar levels
- May help lose weight
- Similar taste to sugar with only 1/10 of its calories
- Insufficient evidence for all benefits
- High doses may cause digestive issues
In a 12-week trial on 26 people (15 prediabetic and 11 healthy), a single ingestion of 5 g of allulose decreased post-meal glucose spikes in those with borderline diabetes. The long-term (12 weeks) intake of allulose did not cause any side effects .
In another trial on 20 healthy people, single doses of allulose (5 or 7.5 g but not 2.5 g) reduced sugar and insulin spikes after a dose of maltodextrin (75 g) .
In the most recent clinical trial, allulose (5 or 10 g) reduced blood sugar spikes after the ingestion of glucose (75 g) in 24 people with type 2 diabetes .
However, this sugar was ineffective in a similar trial conducted on 27 healthy people .
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 [29, 18].
HbA1c, or glycated hemoglobin, is formed from a reaction between hemoglobin A and blood glucose. It is used as an indicator of poor blood sugar control [30, 31, 32].
In obese rats with type 2 diabetes, allulose decreased the level of HbA1c by maintaining normal blood sugar levels during eating and fasting .
Although the evidence suggests that allulose may help lower blood sugar spikes in people with diabetes or at risk of developing this condition, it’s based on very few trials on small populations and some animal research. Larger, more robust clinical trials are needed to confirm these preliminary findings.
2) Weight Loss
In a clinical trial on 121 overweight people, allulose significantly reduced body mass index and fat in the stomach and waist .
In another trial on 13 healthy, normal-weight people, allulose promoted fat burning after meals. This suggests that it could help maintain a healthy weight by promoting energy usage .
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 [13, 36].
High-fat diet-fed mice supplemented with allulose had ~50% less fat in the belly area and body .
In mice, allulose increased the activity of enzymes responsible for fat breakdown (beta-oxidase, CPT1, CPT2) while reducing fat production (by blocking fatty acid synthase) [37, 35].
In mice fed a high-fat diet, allulose 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 .
Again, the results are promising but the evidence comes from 2 clinical trials and some research in animals and cells. More clinical trials are needed to support the use of allulose as a weight-loss aid.
Animal and Cell Research (Lack of Evidence)
No clinical evidence supports the use of allulose for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies should not be interpreted as supportive of any health benefit.
Reducing Oxidative Stress and Inflammation
In rats with testicular injury, allulose-infused water (2% allulose) given for 14 days prevented the production of reactive oxygen species (ROS) and the progression of testicular damage. Additionally, allulose increased the levels of antioxidant proteins (glutathione peroxidase 1 and 2, and glutaredoxin 1) .
Type 2 diabetes is caused by a failure of beta-cells in the pancreas to respond to glucose levels. In rats with type 2 diabetes, oral allulose reduced the production of inflammatory molecules IL-6 and 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 cholesterol levels 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 nerve cells from cell death. It also increased levels of glutathione .
Fatty Liver Disease
In mice fed high-fat diets, allulose decreased the amount of fat buildup in the liver when given for 16 weeks. The sugar reduced the activity of enzymes responsible for fat synthesis (fatty-acid synthase, acetyl-CoA carboxylase 1, and phosphatidate phosphatase) while increasing fat breakdown (beta-oxidation) .
In obese mice, allulose decreased the liver triglyceride levels after 5 weeks of supplementation .
Enhancing Antibiotic Effects
In cells, the antibiotic metronidazole was more efficient in stopping the growth of a protozoa that affects cats and cattle (Tritrichomonas foetus) when combined with allulose than metronidazole alone. This suggests allulose may prove useful in overcoming antibiotic resistance to metronidazole .
Side Effects & Precautions
Keep in mind that the safety profile of allulose is relatively unknown, given the lack of well-designed clinical studies. The list of side effects below is not a definite one and you should consult your doctor about other potential side effects based on your health condition and possible drug or supplement interactions.
In a clinical trial on 30 healthy people, allulose doses of up to 0.4 mg/kg were well-tolerated and caused no gastrointestinal symptoms. However, severe diarrhea and gastrointestinal discomfort were noted at 0.4-0.5 mg/kg. Higher doses of up to 1 mg/kg also caused nausea, stomach pain, headache, and lack of appetite .
Based on this and other studies, the FDA warned that doses above 35 grams per day may cause gastrointestinal discomfort .
Limitations and Caveats
The main limitation is the lack and small size of clinical trials. Since most of the studies were carried out on animals, there is insufficient evidence to support all the potential benefits of allulose until more clinical research is conducted.
Dosages used in human studies were lower than those of 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.
Dosage & Supplementation
Because allulose is not approved by the FDA for any condition, there is no official dose. Users and supplement manufacturers have established unofficial doses based on trial and error. Discuss with your doctor if allulose may be useful as a complementary approach in your case and which dose you should take.
The FDA recommends doses below 35 g/day to avoid stomach discomfort. You can use allulose in place of sugar in your everyday food and drink. For all recipes that call for a certain amount of sugar, you can substitute the same amount of allulose instead .
The opinions expressed in this section are solely those of allulose users, who may or may not have medical or scientific training. Their reviews do not represent the opinions of SelfHacked. SelfHacked does not endorse any specific product, service, or treatment.
Do not consider user experiences as medical advice. Never delay or disregard seeking professional medical advice from your doctor or other qualified healthcare providers because of something you have read on SelfHacked. We understand that reading individual, real-life experiences can be a helpful resource, but it is never a substitute for professional medical advice, diagnosis, or treatment from a qualified healthcare provider.
Most users who incorporated allulose sweetener in their diets to replace sugar as a sweetener. They were generally satisfied with its low calorie count and ease to digest and dissolve.
The most common complaint was its high price. Other users noted that allulose provides only 70% of the sweetness of granulated sugar, meaning it requires higher amounts.
Users of allulose honey claimed that it was indistinguishable from normal honey and found it a great sugar replacement.