Is it bad to have sweets when sick?

October 24, 2025 •

4 min read

According to a study published in The American Journal of Clinical Nutrition in 1973, consuming large amounts of sugar temporarily impairs the function of infection-fighting white blood cells. This research sheds light on why it might be bad to have sweets when sick, as it can hinder your body's ability to recover effectively.

Quick Summary

This article explores the effects of consuming sweets and added sugars on the body during illness, focusing on its impact on the immune system, inflammation, and energy levels. It provides practical dietary advice for supporting a faster recovery, including beneficial foods and beverages to consume instead of sugary treats.

Key Points

Immune Suppression: High sugar intake can temporarily reduce the effectiveness of white blood cells, hindering your body's ability to fight off infections.
Increased Inflammation: Refined sugar contributes to inflammation in the body, which can slow down the overall recovery process when you are sick.
Dehydration Risk: Many sugary drinks and foods can cause dehydration, worsening symptoms and preventing proper fluid intake.
Digestive Issues: Consuming sweets can upset your digestive tract, potentially leading to or worsening symptoms like diarrhea, especially with stomach bugs.
Nutrient-Rich Alternatives: Opt for nourishing options like broths, herbal tea with honey, and vitamin-rich fruits to support your immune system and provide sustained energy.

The Surprising Science Behind Sugar and Sickness

When illness strikes, the natural inclination to seek comfort can often lead us toward sugary snacks and desserts. However, what feels like a comforting treat can actually undermine your body's recovery process. A significant body of research points to the adverse effects of refined sugar on immune function and inflammation, both of which play crucial roles in fighting off infections. Understanding the science can help you make better dietary choices when you're under the weather.

How Sugar Suppresses Your Immune Response

One of the most concerning aspects of consuming too much sugar while sick is its effect on your immune system. Studies have shown that a high intake of refined sugar can suppress the function of white blood cells for several hours. These cells are your body's primary defense against invading bacteria and viruses. By inhibiting their performance, you are essentially making it harder for your body to fight off the very infection that is making you feel unwell. Furthermore, some researchers have noted that vitamin C and sugar share a similar chemical structure, which can cause white blood cells to mistakenly absorb sugar instead of the essential vitamin C they need to combat infection effectively.

The Role of Inflammation

When your body is fighting a virus or bacterial infection, it undergoes an inflammatory response. While this is a normal part of the healing process, excessive or prolonged inflammation can be harmful and can even prolong your sickness. Added sugars are known to increase inflammation in the body. This means that by eating sugary foods, you could be exacerbating the body's inflammatory state, diverting resources away from the immune response and slowing down your recovery.

Dehydration and Digestive Distress

Many sugary foods and drinks, such as soda and fruit juice with added sugar, can lead to dehydration. Dehydration is particularly problematic when you have a fever or a cold, as proper hydration is essential for thinning mucus, flushing toxins, and maintaining overall bodily function. Additionally, consuming large amounts of refined sugar can upset your digestive system. This is especially true if you are already dealing with a stomach bug, as sugar can pull fluid into the gastrointestinal tract and worsen symptoms like diarrhea. For those with sensitive stomachs, many artificial sweeteners used in sugar-free products can also cause bloating, cramping, and other issues.

Better Alternatives to Sugary Treats

Instead of reaching for candy, cookies, or soda, consider some of the following nutrient-rich alternatives that can actually support your immune system:

Hydrating fluids: Herbal teas with honey (for ages 1 and up), broths, and coconut water can provide hydration and soothe a sore throat.
Fruits: While containing natural sugar, fruits like berries and citrus are packed with vitamins and antioxidants that help fight infection. The fiber also slows sugar absorption.
Soups and broths: Chicken soup is known for its comforting and nourishing qualities, providing fluids and nutrients that support recovery. Miso soup also offers beneficial probiotics.
Foods with natural anti-inflammatory properties: Ingredients like ginger and garlic can be added to broths or teas to provide anti-inflammatory and antiviral benefits.
Simple, easy-to-digest carbs (if needed): When an upset stomach is a factor, easy-to-digest carbohydrates like whole-wheat bread or oatmeal can provide energy without a rapid blood sugar spike.

Sugary Foods vs. Nutritious Foods When Sick


Feature	Sweets & Processed Sugar	Nutrient-Dense Foods (Fruits, Broth)
Effect on Immune System	Suppresses white blood cell activity	Provides vitamins and minerals to support function
Inflammatory Response	Increases inflammation	Contains anti-inflammatory properties (e.g., ginger)
Hydration	Can contribute to dehydration	Actively helps with hydration (e.g., broths, herbal tea)
Energy Source	Provides a temporary, short-lived energy spike	Offers sustained, longer-lasting energy
Nutritional Value	Low to none (empty calories)	Rich in essential vitamins and minerals
Digestive Impact	Can cause or worsen diarrhea and upset stomach	Gentle on the stomach and easy to digest

Conclusion: Prioritize Recovery Over Immediate Gratification

While the siren song of sugary treats when you're sick is powerful, the scientific evidence suggests that indulging can actually prolong your misery. Instead of providing the sustained energy and nutrients your body needs to fight infection, refined sugars can suppress your immune system, increase inflammation, and exacerbate symptoms like dehydration and stomach upset. By choosing nourishing, whole foods and hydrating beverages, you can give your body the proper fuel it needs to recover efficiently. Save the indulgent desserts for when you are back to full health.

For more information on the effects of a high-sugar diet on the immune system, the National Institutes of Health provides a wealth of research on metabolic regulation and immunity.

Frequently Asked Questions

Yes, high sugar intake can suppress the immune system and increase inflammation, which can potentially prolong the duration of a cold or flu.

Honey is an excellent alternative for a sore throat as it coats and soothes the throat. You can take it on its own or add it to a warm herbal tea. (Note: Do not give honey to infants under 1 year old.)

Opt for 100% fruit juice without added sugar, and consider diluting it with water to maintain hydration. Juice with added sugars offers little nutritional value and can contribute to dehydration.

While ice cream can be soothing for a sore throat, it contains high amounts of refined sugar and potentially dairy, which some find increases mucus. Small, moderate amounts may be acceptable, but it's not the best choice for recovery.

Sickness increases your body's energy demands, and sugary foods provide a quick, though temporary, energy boost. This craving can also be a comfort response and a hormonal reaction to stress.

No. While honey contains sugar, it also has antibacterial properties and can effectively soothe a cough. Refined table sugar does not offer these benefits and can hinder immune function.

Prioritize hydration with water and broths. Focus on nutrient-dense foods like fruits, vegetables, and whole grains. Soothing foods like soups, oatmeal, and ginger tea are excellent choices.