What should I avoid eating if I have a cold sore?

December 4, 2025 •

4 min read

According to the World Health Organization, an estimated 3.7 billion people under age 50 have herpes simplex virus type 1 (HSV-1), which is the most common cause of oral herpes or cold sores. While diet alone cannot cure a cold sore, avoiding certain foods during an outbreak can minimize discomfort and may help shorten the healing process.

Quick Summary

Certain foods, particularly those high in arginine or acidic content, can aggravate cold sores and potentially prolong an outbreak. Limiting these foods while focusing on a lysine-rich diet can help manage symptoms and aid recovery.

Key Points

Avoid High-Arginine Foods: Limit items like nuts, chocolate, and whole grains during an outbreak, as the herpes virus needs this amino acid to replicate.
Steer Clear of Acidic and Spicy Foods: Citrus, tomatoes, and spicy meals can cause a burning and stinging sensation on an active cold sore, increasing pain and discomfort.
Say No to Salty and Crunchy Snacks: These foods can irritate or even break the delicate scab of a healing cold sore, delaying the recovery process.
Eat Soothing, Lysine-Rich Foods: Opt for gentle, soft foods like soups and smoothies, and increase your intake of lysine-rich dairy, fish, and chicken.
Support Your Immune System: Focus on a balanced diet rich in vitamins C and zinc, found in foods like bell peppers, broccoli, and poultry, to aid healing.
Stay Hydrated: Drink plenty of water to avoid dehydration, which can slow down the healing of a cold sore.

The Link Between Diet and Cold Sores

Cold sores are caused by the herpes simplex virus (HSV-1), which remains dormant in the body and can be reactivated by triggers like stress, a weakened immune system, or certain foods. The key to understanding the dietary link is the balance between two amino acids: arginine and lysine. The herpes virus needs arginine to replicate, so a diet high in arginine and low in lysine could potentially fuel an outbreak. By contrast, lysine helps block arginine's function and may inhibit viral growth.

Foods High in Arginine to Avoid

To help deprive the virus of the resources it needs to thrive, it is often recommended to reduce your intake of arginine-rich foods during an outbreak.

Nuts and Seeds: These are among the most common culprits. This includes almonds, peanuts, walnuts, hazelnuts, pumpkin seeds, and sunflower seeds. Peanut butter is also high in arginine.
Chocolate: Particularly dark chocolate, has a high arginine content and is often cited as a cold sore trigger.
Whole Grains: Foods like whole wheat, oats, and brown rice contain significant levels of arginine.
Legumes: Lentils, chickpeas, and soybeans are plant-based sources of arginine.
Certain Meats: Some cuts of meat, like turkey and pork, can be high in arginine.
Gelatin: Found in many gummy sweets and marshmallows, gelatin is a concentrated source of arginine.

Foods That Irritate a Cold Sore Outbreak

Even if a food doesn't affect the virus itself, certain items can physically irritate an active blister, causing pain and delaying healing.

Acidic Foods: The high acidity in citrus fruits (oranges, grapefruits), tomatoes, and vinegar-based products like pickles can cause a painful stinging sensation.
Spicy Foods: Hot curries, chili, and other spicy meals can intensify irritation and discomfort around the mouth.
Salty Foods: Snacks like salted nuts and chips can sting the sensitive skin of a cold sore, causing a burning sensation.
Hard and Crunchy Foods: Toast, crusty bread, or hard snacks can scrape or crack the blister or scab, which can prolong the healing time.
Pizza: While not inherently irritating, the wide mouth stretch required to eat a large slice can be problematic in the later stages of an outbreak when scabs are vulnerable to splitting.

The Arginine vs. Lysine Ratio

Rather than completely eliminating arginine, focusing on balancing the ratio can be more effective. Below is a comparison of some high-arginine and high-lysine foods.


Food Category	High in Arginine (Best to avoid)	High in Lysine (May be beneficial)	Effect on Outbreak
Protein	Turkey breast, pork loin, gelatin	Chicken, beef, fish, cheese	Arginine may promote viral growth, while lysine may inhibit it.
Nuts & Seeds	Almonds, peanuts, hazelnuts, pumpkin seeds	None (most nuts/seeds are high in arginine)	High arginine can fuel the virus, so limiting is key.
Dairy	Yogurt (some types)	Milk, cheese (especially parmesan)	Some dairy is high in lysine, which counteracts arginine.
Grains	Whole wheat, oats, brown rice	Quinoa, millet	High arginine grains are best limited during an outbreak.
Sweets	Chocolate, gelatin-based products	N/A (avoid sugary items)	High sugar can weaken the immune system and should be limited.

What to Eat for Cold Sore Healing

Instead of focusing only on what to avoid, incorporate foods that support healing and your immune system.

Lysine-Rich Foods: Add more cheese, milk, fish, chicken, and legumes (in some cases) to your diet. Check the table above for specific examples.
Vitamin C and Zinc: These nutrients are crucial for immune function and wound healing. Sources include bell peppers, broccoli, spinach, and zinc-rich items like poultry and chickpeas.
Soft, Bland Foods: Smoothies, soups, warm stews, mashed potatoes, and scrambled eggs are gentle on the sore and easy to consume.
Hydrating Drinks: Stay well-hydrated with water and mild vegetable juices to prevent dehydration. Avoid caffeinated and sugary beverages.

Conclusion

When a cold sore appears, adjusting your diet is a practical step to manage discomfort and support your body's healing process. By being mindful of the foods you eat, particularly those high in arginine or acidic content, you can reduce irritation and avoid potentially worsening an outbreak. Prioritizing a balanced, immune-supportive diet with an emphasis on lysine-rich foods will help get you on the fast track to recovery. For persistent or severe cases, always consult a healthcare professional for the best course of action. For more in-depth research on the arginine-lysine antagonism, you can find relevant studies through the National Institutes of Health. Relation of arginine-lysine antagonism to herpes simplex...

Remember: Always consult with a doctor or dietitian for personalized advice regarding your health conditions. This article provides general information and is not a substitute for professional medical guidance.

Frequently Asked Questions

Yes, many sources suggest that chocolate, especially dark chocolate, is a trigger for cold sores due to its high concentration of arginine, an amino acid the herpes virus needs to replicate.

Acidic foods like citrus fruits (oranges, lemons) don't trigger the virus, but their acidity can irritate the sensitive blister area, causing a painful burning sensation during an active outbreak.

Yes, spicy foods can cause further irritation and discomfort on and around a cold sore, potentially intensifying the pain of the outbreak.

Nuts, including peanuts, almonds, and walnuts, are high in arginine and are often listed as a food to limit or avoid if you are susceptible to cold sore outbreaks.

The herpes virus uses arginine to replicate and thrive. Lysine, another amino acid, is thought to inhibit the activity of arginine, helping to reduce viral growth. Maintaining a diet with a better lysine-to-arginine ratio is often recommended.

Limiting caffeine and alcohol is advised during an outbreak. Both can contribute to dehydration, which can slow down the healing process and potentially weaken your immune system.

Whole grains like oats and wheat contain significant amounts of arginine, so it may be beneficial to limit them during an active outbreak.