Sugar intolerance is a condition in which the body has difficulty digesting sugar and other simple carbohydrates, leading to symptoms such as bloating, gas, abdominal pain, diarrhoea and nausea. This can occur due to a deficiency in certain enzymes needed to break sugars down in the gut. Unlike a food allergy, sugar intolerance doesn't involve an immune reaction and isn't life-threatening, though it can still cause significant discomfort.
What Health Conditions Can Too Much Sugar Cause?
Consuming excessive sugar regularly can contribute to a number of health problems, including:
- Obesity: excess sugar consumption can lead to weight gain, increasing the risk of several chronic diseases
- Tooth decay: sugar feeds the bacteria that form plaque on teeth
- Type 2 diabetes: excessive sugar consumption can contribute to insulin resistance
- Heart disease: high sugar intake is associated with increased cardiovascular risk, potentially raising blood pressure, triglycerides and LDL cholesterol
- Non-alcoholic fatty liver disease: excess sugar can contribute to fat buildup in the liver
- Chronic inflammation: sugar can trigger inflammation in the body, which is associated with increased risk of several chronic conditions, including certain cancers and arthritis
It's not just the amount of sugar consumed that matters, but also the frequency and source – sugar from processed foods and sugary drinks tends to be more harmful than the same amount consumed as part of whole foods.
Gut Health Connection
Your gut microbiome plays an important role in digestion. An imbalance in gut bacteria, or insufficient digestive enzymes, can contribute to sugar intolerance. A study found that undigested sugars can ferment in the gut, causing bloating, gas and other uncomfortable symptoms.
[... types of sugar section unchanged, genuinely solid content ...]What's the Difference Between Sugar Intolerance and a Sugar Allergy?
These are two different conditions. Sugar intolerance is a digestive issue that occurs when the body can't properly break down certain sugars, leading to symptoms like bloating, abdominal pain and diarrhoea. It's not a true allergy, and is more accurately described as a sensitivity or intolerance.
A true sugar allergy, by contrast, is a food allergy where the immune system reacts to specific proteins as though they were harmful, potentially causing itching, hives, swelling, difficulty breathing, or in severe cases, anaphylaxis. Genuine sugar allergies are very rare.
A sugar allergy is a medical condition requiring proper management; sugar intolerance is a digestive issue that can generally be managed through diet.
Common Sugar Intolerance Symptoms
- Bloating: discomfort and fullness caused by gas building up in the digestive tract
- Abdominal pain: ranging from mild to severe
- Diarrhoea: loose or more frequent stools than usual
- Nausea: sometimes accompanied by vomiting
- Flatulence: excessive gas causing discomfort
- Constipation: infrequent or difficult bowel movements
Symptoms typically appear within a few hours to a few days of consuming the trigger sugar, and severity can vary depending on the amount consumed, overall health, and individual gut microbiome. If you're experiencing these symptoms regularly, it's worth seeking medical advice to determine the underlying cause.
Is Glucose Intolerance the Same as Diabetes?
No. Glucose intolerance is an umbrella term for metabolic conditions resulting in higher-than-normal blood sugar, including prediabetes, impaired fasting glucose, impaired glucose tolerance, and diabetes itself. It doesn't have clear symptoms of its own, though it may present similarly to diabetes – fatigue, increased thirst, frequent urination, slow wound healing.
Diabetes is a specific metabolic disorder involving elevated blood glucose and the body's inability to properly use or store it, with two main types: Type 1 (an autoimmune condition where the pancreas stops producing insulin) and Type 2 (where the body becomes resistant to insulin, often linked to lifestyle factors). Glucose intolerance can progress to diabetes over time, so it's worth seeking medical advice if you have any concerns about your blood glucose levels.
Foods to Enjoy and Avoid
When managing sugar intolerance, focus on fresh, whole foods while minimising processed items.
Enjoy:
- Most fruits and vegetables (in moderation for higher-fructose options)
- Wholegrains: brown rice, quinoa, oats, wholewheat bread
- Lean proteins: fish, chicken, beans, lentils, tofu
- Unsweetened dairy products or lactose-free alternatives
- Healthy fats: nuts, seeds, olive oil, avocado
Minimise or avoid:
- Table sugar, syrups, molasses, honey
- Processed foods: sweets, baked goods, packaged snacks
- Sugary drinks: sodas, fruit juices
- Higher-fructose fruits in large quantities: mango, pear, watermelon (small portions are fine for most people)
- Alcohol, which can worsen gut imbalances
Alternative sweeteners: stevia, monk fruit extract and erythritol generally have a lower impact on blood sugar than processed sugar, though it's still worth using them in moderation.
Smart swaps:
- Trade sweetened yoghurt for plain with fresh berries
- Replace sugary cereals with oats and a sprinkle of cinnamon
- Swap sweets for a handful of nuts and dried fruit
Is There a Sugar Intolerance Test?
Our food intolerance tests can help identify sugar-related sensitivities as part of a wider panel – our food intolerance blood test measures IgG reactions across a wide range of food and drink items. See our full range of intolerance tests to find the one that best suits your needs.
