Sugar is everywhere — and few things divide the nutrition world as much. Some demonize it as "sweet poison," while others warn against excessive avoidance. What's true? A sober look at the evidence.

Why Sugar Is So Hard to Resist

Sugar directly affects the brain's reward system. Sweetness triggers the release of dopamine — the same neurotransmitter that plays a central role in addictive substances. Animal studies impressively demonstrate this: rats even chose sweet water over cocaine. In humans, brain mechanisms are similar — those who eat a lot of sugar find their brains react less strongly to the pleasure signal over time, demanding more to feel the same effect.

Whether this can be called true "sugar addiction" is still debated among researchers. However, it is certain that sugar can trigger reward-like reactions — cravings, habituation, the feeling of not being able to stop. This isn't a lack of willpower; it's biology.

What Too Much Sugar Does

With consistently high consumption, excess sugar is considered a contributing factor to some of the most common lifestyle diseases:

  • Dental caries — the most well-documented harm of all
  • Obesity — especially from sugar-sweetened beverages (liquid calories are rarely satiating)
  • Type 2 diabetes — primarily as a consequence of obesity
  • Fatty liver and chronic inflammation

The World Health Organization therefore recommends limiting free sugars to less than 10% of daily energy — and ideally less than 5%. For an adult, this is about 25 grams, or roughly 6 teaspoons per day. For comparison: a single soda often contains 9 sugar cubes.

And the New Study on Sugar Avoidance?

A study recently presented at the ENDO-2026 congress made headlines: mice on a low-fat diet who completely avoided table sugar developed a disturbed gut microbiome and metabolic problems. However, this does not imply that sugar is healthy. Three important caveats:

  • It was a mouse study — results cannot be directly transferred to humans.
  • It has only been presented at a congress so far, not peer-reviewed in a scientific journal.
  • The study examined radical total avoidance — not a sensible everyday approach with low sugar.

The real lesson, therefore, is not "eat more sugar again," but rather: even when cutting back, a healthy balance is crucial — especially for gut flora.

The Right Measure — Avicenna's Principle

Avicenna taught 1000 years ago: not one extreme heals, but the right measure. This is precisely true for sugar. No one needs to forbid every gram — but drastically reducing ubiquitous industrial sugar remains one of the most effective steps for health.

Practically, this means:

  • Swap sugary drinks for water — the biggest lever
  • Identify hidden sugar (processed foods, sauces, "light" products)
  • Prefer natural sweetness: whole fruits, honey in moderation
  • Retrain your taste buds — after a few weeks, many things taste sweet enough on their own

Sources: World Health Organization (WHO), Guideline on free sugars; Lenoir et al., PLoS ONE, "Intense Sweetness Surpasses Cocaine Reward" (2007); The Endocrine Society, ENDO 2026 (congress contribution).