Is Allulose REALLY the best sweetener? | Safety profile and latest evidence review

Product reviewed: Allulose (rare sugar sweetener)

Key claims / features

• Tastes like sugar: Classified as a rare sugar naturally found in foods (e.g., raisins, figs, maple syrup).
• Sweetness level: About 70% as sweet as sucrose (table sugar).
• No “chemical aftertaste”: Claimed to compare favorably against sweeteners like aspartame and sucralose (Splenda).
• GI tolerance (compared to sugar alcohols): Reported as nearly fully absorbed in the small intestine, so it’s positioned as less likely to cause nausea/bloating/diarrhea typical of sugar alcohols (e.g., xylitol/erythritol), except at high doses.
• Metabolism / calories: Labeled as a carbohydrate, but the body excretes ~90% via kidneys without converting it into energy, resulting in negligible calories.
• Blood sugar effect:
  • The FDA stopped labeling allulose as added sugar (2019).
  • It does not raise blood sugar and may even lower glucose/insulin when combined with other carbs.

Main evidence cited (human studies and reviews)

• Meta-analysis (Clinical Nutrition, 2020):
  • 40 trials, ~400 subjects
  • Small doses lowered glycemic index / post-meal glucose when taken alongside other carbohydrates.
• BMJ study (reported as last year):
  • Small double-blind randomized crossover
  • 30 non-diabetic subjects
  • Allulose + 50 g sugar reduced postprandial plasma glucose and insulin vs placebo.
• Ramadan-related fasting study (published last month):
  • Adding allulose before iftar helped glucose stay “in range”
  • Reduced glucose excursion outside target range.
• Randomized controlled study (2018, 121 Korean subjects):
  • Allulose supplementation decreased body fat percentage
  • Reduced abdominal fat mass measured by CT vs placebo.

Safety profile (as described)

• FDA GRAS status: Generally recognized as safe (2012) under intended use.
• 12-week safety study (Fundamental Toxicological Sciences, 2019):
  • Included people with borderline diabetes and type 2 diabetes
  • No clinical problems reported
  • Reported improvement in hepatic function
• Dose-related GI effects:
  • Typically well tolerated until about 0.4 g/kg body weight
  • Above that, nausea and diarrhea can occur
  • Example cited: for a 70 kg person, up to ~28 g before GI symptoms.
• Practical note: Many people may not reach GI-problem doses in coffee/tea, but baking/cooking could involve larger quantities.

Potential downsides / who should be cautious

• Limited size/scope of human safety evidence:
  • Human trials exist but are described as small, so long-term certainty may be weaker than for some older sweeteners.
• Frequent UTIs / recurrent urinary issues:
  • Rationale given: Allulose is excreted into urine and may behave in a way similar to SGLT2 inhibitor diabetes drugs (e.g., Farxiga/dapagliflozin, Jardiance/empagliflozin, Invokana/canagliflozin), which increase glucose in urine.
  • These drugs carry UTI warnings.
  • Video’s conclusion: Likely safe for most people, but extra monitoring is recommended if you get frequent UTIs or yeast infections.
  • Mitigation mentioned: Later monitoring of SGLT2 inhibitors reportedly did not show higher UTI risk overall; the speaker referenced no bladder cancer risk evidence from these drugs.
• Theoretical gut/oral microbiome concern (in vitro):
  • A paper (British Journal of Nutrition) suggested allulose could enable Klebsiella pneumoniae overgrowth (since it can use allulose as a substrate).
  • Concern is mainly for immunocompromised people or those with lung disease.
  • The speaker downplays this as test-tube (in vitro) only, with no human confirmation yet.

Pros (explicitly emphasized)

• Doesn’t raise blood sugar; may lower glucose/insulin response when taken with other carbs.
• Promising weight/fat effects (reported reduction in body fat and abdominal fat in a small RCT).
• Better GI profile than sugar alcohols for typical use.
• No added-sugar labeling and very low caloric impact (as described).

Cons (explicitly emphasized)

• Human safety data not extensive; described as promising but still limited.
• GI side effects at higher doses (nausea/diarrhea threshold discussed).
• Caution for people with recurrent UTIs (monitor for symptom changes).
• Theoretical infection risk concern via Klebsiella (not strongly supported in humans yet).

Comparisons with other sweeteners

• Versus sugar alcohols (xylitol/erythritol):
  • Allulose is framed as having fewer GI issues at normal doses.
• Versus chemical sweeteners (aspartame/sucralose):
  • Allulose is described as tasting more like sugar and avoiding “chemical aftertaste.”
• If you don’t choose allulose:
  • Suggested alternative: monk fruit
  • Note from the speaker: monk fruit is often mixed with other sweeteners, making “pure extract” harder to find.

Overall user experience / guidance from the video

• Likely favorable for everyday use in coffee/tea.
• Be mindful of dose, especially for baking/cooking.
• Stop and reassess if you notice GI symptoms at lower doses or more UTIs/yeast infections after switching.

Verdict / recommendation (speaker’s conclusion)

• The speaker recommends allulose over other sweeteners available today, with primary cautions:
  • Monitor if you have frequent UTIs
  • Watch for GI symptoms (especially at higher doses)

Unique points mentioned (consolidated)

1. Allulose is a rare sugar naturally present in small amounts in foods.
2. Tastes like sugar; about 70% as sweet as sucrose.
3. Less aftertaste than aspartame/sucralose.
4. Nearly fully absorbed in the small intestine; fewer GI effects than sugar alcohols.
5. ~90% excreted via kidneys; negligible calories.
6. FDA stopped added-sugar labeling (2019).
7. Does not raise blood sugar; may lower glucose/insulin response to other carbs.
8. Animal studies suggested possible diabetes/insulin benefits; emphasis shifts to human evidence.
9. Meta-analysis (40 trials, ~400 subjects): lower glycemic index/post-meal glucose with small doses.
10. BMJ double-blind crossover (30 non-diabetics): reduced postprandial glucose/insulin with a 50 g sugar challenge.
11. Ramadan study: improved “in range” glucose and reduced excursion when used before iftar.
12. 2018 RCT (121 Korean subjects): reduced body fat % and abdominal fat (CT).
13. Main downside: limited human safety data (small trials/observational elements).
14. FDA GRAS status (2012).
15. 12-week human safety study (2019): no clinical problems; improved hepatic function.
16. GI symptom threshold around 0.4 g/kg; example ~28 g for 70 kg.
17. UTI caution: urinary glucose excretion concept (SGLT2 inhibitor analogy).
18. SGLT2 inhibitors: have UTI warnings; referenced monitoring allegedly didn’t show increased UTI overall; no bladder cancer evidence mentioned.
19. Theoretical Klebsiella concern from British Journal of Nutrition; speaker says it’s in vitro only.
20. Speaker personally recommends allulose; main caveats are UTIs and GI symptoms.
21. Alternative suggested: monk fruit, but often blended with other sweeteners.

Speakers/views

• Dr. Leonid Kim (primary speaker): Presents the evidence review, discusses benefits and safety, highlights conditional cautions, and concludes with a recommendation for allulose (with monitoring caveats noted).