Can You Eat Sour Foods During a Fever? Here’s What Science Says!

Can You Eat Sour Foods During a Fever? Here’s What Science Says!

Fever is an increase in body temperature that exceeds the normal daily variation for the site of measurement, indicating a rise in the hypothalamic set point.1 It is considered as a fever when the rectal temperature exceeds 38.0°C, oral temperature surpasses 37.8°C and axillary temperature is above 37.2°C.2 It can occur due to the presence of pyrogens, including microbial toxins and whole microorganisms, which stimulate the body’s immune response.1Fever is often accompanied by some dietary restrictions.   One common belief is that sour foods should be avoided during fever, especially in children. In this article, we examine whether there is any scientific basis for this recommendation or if it is merely a misconception.

 

 

What Are Sour Foods?

  Sour foods have a distinct tangy or acidic taste, which is primarily due to the presence of organic acids such as citric acid, acetic acid, lactic acid, tartaric acid, and ascorbic acid (vitamin C).3 These acids contribute to the characteristic sourness of various fruits, fermented foods, and certain dairy products.  

Examples of Sour Foods:

  • Fruits (Rich in Citric and Ascorbic Acid): Lemons, oranges, pineapples, tamarind, green mangoes, cranberries.
  • Fermented Foods (High in Lactic Acid and Probiotics): Yogurt, pickles, kimchi.
  • Dairy Products (Contain Lactic Acid): Buttermilk, sour cream, cheese.
  • Other Sources: Tomatoes, probiotic drinks, and various types of vinegar, including apple cider vinegar and balsamic vinegar

 

Nutritional Value of Sour Foods

  Sour foods vary in nutrient composition, but they generally contain organic acids, vitamin C (especially in citrus fruits), essential minerals like calcium (found in dairy products) and probiotics (present in fermented foods). These components contribute to various health benefits, from supporting digestion to boosting immunity.  

  1. Vitamin C

Vitamin C plays a crucial role in strengthening the immune system and promoting collagen synthesis. It also enhances the absorption of non-heme iron, making it beneficial in the management of anemia and stress-related conditions.4 Research suggests that vitamin C can help reduce the duration and severity of the common cold, potentially prevent colds in certain populations and support recovery from infections like pneumonia. Overall, it is a vital antioxidant that helps to protect the body from oxidative stress and enhances immune defense.5  

  1. Organic Acids

Organic acids, combined with natural sugars, contribute to the sour taste of certain foods, such as citrus fruits.6 These acids offer several health benefits:

  • Antioxidant Protection: Citric acid in citrus fruits helps combat oxidative stress, reducing the risk of chronic diseases such as cancer and cardiovascular conditions.
  • Digestive Support: Organic acids stimulate the production of digestive enzymes, improving digestion and reducing bloating.
  • Antibacterial Properties: They help inhibit the growth of harmful bacteria and other microorganisms in the digestive tract, lowering the risk of foodborne illnesses.7

 

  1. Calcium

Calcium is a vital mineral essential for bone formation and metabolism. It also plays a key role in various physiological functions, including:

  • Vascular Function: Regulating blood vessel contraction and relaxation.
  • Muscle Function: Enabling proper muscle contraction.
  • Nerve Transmission: Supporting efficient nerve signaling.
  • Hormonal Secretion: Assisting in the release of various hormones.
  • Cellular Communication: Facilitating intracellular signaling pathways.8

 

  1. Probiotics

Probiotics are beneficial live microorganisms that promote gut health and support overall digestion. A balanced gut microbiome is essential for maintaining various bodily functions. The effectiveness of probiotics is enhanced when paired with prebiotics, forming synbiotics. These beneficial microbes contribute to health by:

  • Strengthening the intestinal barrier, preventing harmful substances from entering the bloodstream.
  • Promoting the adhesion of beneficial bacteria while inhibiting harmful pathogen attachment.
  • Modulating the immune system to enhance the body’s defense mechanisms.
  • Producing bioactive compounds that suppress the growth of harmful microorganisms. (9,10)

Incorporating sour foods rich in these nutrients can be beneficial for overall health, improving digestion, immunity, and metabolic functions.    


Does Eating Sour Foods Worsen Fever?

  There is no strong scientific evidence directly linking sour foods to worsening fever or prolonging illness. However, recommendations to avoid sour foods during fever are based on certain physiological and symptomatic considerations.

 

  1. Potential Irritation of a Sore Throat:

A sore throat is a common symptom of upper respiratory tract infections, affecting the mucosal lining of the throat.11 For individuals with sensitive oral mucosa, the high acidity in citrus fruits, vinegar and other sour foods can cause irritation, leading to a stinging or burning sensation. This irritation may exacerbate throat discomfort or trigger sores, making it advisable to limit sour foods in such cases.  

  1. Aggravation of Gastrointestinal (GI) Symptoms:

Certain viral fevers are associated with gastrointestinal symptoms such as nausea, vomiting and diarrhea, which may be induced by the infectious microorganisms or by the secondary effects of antibiotic and antiviral drugs used in treatment.12 These symptoms can disrupt gut microbiota and influence cytokine production, potentially worsening inflammation. Vomiting can lead to acidic stomach contents entering to the esophagus, causing irritation or injury to the esophageal lining.13 Since sour foods are naturally acidic, they may further irritate the digestive tract, exacerbating discomfort in individuals experiencing these symptoms.  

  1. Altered Taste Perception

Fever can lead to changes in taste perception, contributing to appetite loss and alterations in eating habits.14 Temperature plays a significant role in how we perceive flavors, and cooling of the tongue is known to enhance sourness.15 Since fever already raises body temperature, consuming sour foods which have a cooling effect may overstimulate sour-sensitive neurons, intensifying taste distortions (dysgeusia) and making food taste unpleasant.

 

 

Conclusion: is it a misconception?

  It is not purely a misconception. While there is no strong evidence suggesting that sour foods directly worsen a fever, they may cause discomfort in individuals with symptoms such as sore throats, gastrointestinal disturbances or altered taste perception. However, some people can tolerate sour foods without experiencing irritation. If you’re dealing with any of these symptoms, it might be helpful to temporarily limit sour foods until you’re feeling better. If you’re not experiencing any symptoms, consuming sour foods can be beneficial, as they are rich in nutrients and may help boost immunity against infections.

 
References:

 

  1. Tom E. Fletcher, Chantal P. Bleeker-Rovers, Nick J. Beeching. Fever. Medicine. 2013; 41(2):70–76.
  2. Adeniyi Adeboye, Rafeek A Yusuf and Olusimbo K Ige. Fever: A Literature Review of Perceptions, Perspectives and Practices. Journal of Traditional Medicine & Clinical Naturopathy. 2017, 6(4):249.
  3. Frank, Hannah & Amato, Katie & Trautwein, Michelle & Maia, Paula & Liman, Emily & Nichols, Lauren & Schwenk, Kurt & Breslin, Paul & Dunn, RobertThe evolution of sour taste. Proceedings of the Royal Society B: Biological Sciences. 2022;289:20211918.
  4. Economos and W.D. Clay. Nutritional and health benefits of citrus fruits (A paper presented at the Twelfth Session of the Intergovernmental Group on Citrus Fruit, 22 to 25 September 1998, Valencia, Spain). Published 1999. Accessed on February 22, 2025. Available on: https://www.fao.org/4/X2650t/X2650t03.pdf
  5. Hemilä H. Vitamin C and Infections. Nutrients. 2017 Mar 29;9(4):339.
  6. Franco Famiani, Alberto Battistelli, Stefano Moscatello, Juan Guillermo Cruz-Castillo, Robert P. Walker. The organic acids that are accumulated  in  the flesh of fruits: occurrence, metabolism and factors affecting their contents – a review. Revista Chapingo Serie Horticultura. 2015:21(2):97-128.
  7. Qiu X. Sour and tangy: The importance of acids in food and their impact on health. J Food Technol Pres. 2023;7(3):173.
  8. Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium; Ross AC, Taylor CL, Yaktine AL, et al., editors. Dietary Reference Intakes for Calcium and Vitamin D. Washington (DC): National Academies Press (US); 2011. 2, Overview of Calcium. Available from: https://www.ncbi.nlm.nih.gov/books/NBK56060/
  9. Sarita B, Samadhan D, Hassan MZ and Kovaleva EG. A comprehensive review of probiotics and human health-current prospective and applications.  Microbiol. 2025;15:1487641.
  10. Vijayaram, Srirengaraj. Probiotics: The Marvelous Factor and Health Benefits. Biomedical and Biotechnology Research Journal (BBRJ).2018;2:1-8.
  11. Kenealy T. Sore throat. BMJ Clin Evid. 2014 Mar 4;2014:1509.
  12. Delgado-Gonzalez P, Gonzalez-Villarreal CA, Roacho-Perez JA, Quiroz-Reyes AG, Islas JF, Delgado-Gallegos JL, Arellanos-Soto D, Galan-Huerta KA, Garza-Treviño EN. Inflammatory effect on the gastrointestinal system associated with COVID-19. World J Gastroenterol. 2021 Jul 14;27(26):4160-4171.
  13. Aliye Özenoğlu, Nejla Anul, Büşra Özçelikçi. The relationship of gastroesophageal reflux with nutritional habits and mental disorders. Human Nutrition & Metabolism. 2023;33:200203.
  14. Risso D, Drayna D, Morini G. Alteration, Reduction and Taste Loss: Main Causes and Potential Implications on Dietary Habits. Nutrients. 2020 Oct 27;12(11):3284.
  15. Cruz A, Green BG. Thermal stimulation of taste. Nature. 2000 Feb 24;403(6772):889-92.

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