7 arginine-rich foods to avoid if you're prone to cold sores

Diet and cold sores

As with most health complaints, diet is an important factor for preventing cold sore outbreaks. A generally poor diet that lacks fruits, vegetables and complex carbohydrates, instead focusing on trans fats, sugar and meat, will weaken your immune system, leaving you more vulnerable to skin outbreaks too.

However, many of the foods that people turn to when looking to improve their diet are actually rich sources of arginine – a usually useful amino acid, but one that is thought to trigger cold sores in a lot of people.

Most people find that they can still enjoy the following foods within moderation, but if you're experiencing frequent recurring cold sore outbreaks, then avoiding certain foods high in arginine could be a useful tactic.

Foods to avoid with cold sores

Whilst we don't want to avoid foods unnecessarily, limiting certain foods may be helpful if you are experiencing recurrent cold sore infections:

1. Nuts

These are the worst offenders! While nuts are usually a great way to add to a healthy diet in order to pack in some extra protein, fibre and minerals, they are also a high source of arginine.

In particular, peanuts, walnuts and hazelnuts are the worst offenders so steer clear of these. This includes peanut butter and other nut butters, unfortunately! Nuts may often appear readily within spicy foods too, such as curries, which could have a double whammy effect if the spices irritate sensitive or cracked skin.

2. Pumpkin Seeds

Another super healthy, but unfortunately, high arginine foods is pumpkin seeds. You might also want to avoid eating sesame seeds, as these are packed full of arginine too.

However, apart from the nut and seed options mentioned here, these elements of your diet would still be a great way to support your overall health.

3. Chocolate

Chocolate is another one of the foods rich in arginine, and though we're often told that darker chocolate is better for us, this may not be true in this case as darker chocolate tends to have more arginine. Eat foods lower in chocolate during this time to be safe. 

4. Spirulina

This super healthy green super powder might not be so super for people who often get cold sores! This blue-green algae is typically added to smoothies and protein shakes for extra nutrition, but it’s also quite high in arginine. 

5. Squash

Squash might be your go-to winter veg, but like many foods listed above, it is actually a fairly rich source of arginine so may well be on the common triggers list, and may be best avoided! If you're opting for any warm soups or vegetable juices, just look to include other veg options instead.

In terms of fruit citrus fruits may be particularly tricky as they are quite acidic, and acidic foods could cause some nipping of any sensitive skin, such as with a cold sore outbreak. Applying ice cubes, on the contrary, could be more calming.

6. Oats 

Oats also contain a relatively high amount of arginine, so may be best avoided, especially if you feel one coming on.

This is a shame, as oats make a tasty, nutritious breakfast, but it is possible to swap in and satisfy your hunger without oats for breakfast, there are whole food options which are similarly healthy.

7. Wheat

More vital whole grains, but wheat, unfortunately, also contains high levels of arginine. This can be tricky to avoid, as it is found in most breads, pasta and baking – anything that contains flour really!

Opt for gluten-free varieties of these foods as these will be naturally free from wheat and use other grains instead.

Don’t forget about muscle-building supplements

Muscle-building supplements usually contain a mix of amino acids to help the muscles grow. One of these is usually arginine, so make sure to check your supplements for arginine before you take them! 

The role of lysine with a cold sore outbreak

Essential amino acids can play a vital role in the story when it comes to cold sores. Lysine is another amino acid that is thought to help counteract arginine, which can be very handy in the case of a cold sore symptoms outbreak. Therefore, the worst foods for you are those that are high in arginine and low in lysine. Those listed above have a low lysine to arginine ratio, so are not ideal for those who experience cold sores.

You may occasionally see claims that dairy is a rich source of arginine and should be best avoided. However, while dairy does contain a lot of arginine, it also contains a lot of lysine – usually more than twice as much! This balances out the arginine content.

When it comes to muscle-building supplements, I would recommend looking for one that doesn't contain arginine, rather than simply counteracting the supplement with extra lysine. This is because the arginine found in your muscle-building supplement will likely be highly concentrated and hard to offset. 

Cold sore treatment

If you're having trouble giving up these arginine-rich foods – which we'd understand as many of them are staple parts of a healthy, balanced diet – then you may want to consider taking a daily lysine supplement to help balance your arginine intake and add to your cold sore treatment plan. This may be the best idea since many of the above foods are rich sources of vitamins, minerals and complex carbohydrates. 

One good strategy is to make sure to balance out your high l arginine foods, are foods rich in lysine. For example, if you're eating a meal that contains wholewheat pasta, try balancing this out with some fish, beans or avocado. 

When it comes to home remedies for cold sores, adding some specific elements to your regime such as a petroleum jelly lip balm, or Bio-propolis ointment may also be protective against the unwanted symptoms of cold sores. Topically creams may naturally help to reduce the duration and severity of, or relieve some of the discomfort around an uncomfortable tingling sensation around the lips or mouth, or more painful blisters, as the symptoms develop.

Then, if symptoms persist or are severe, or if home remedies aren't doing the trick, antiviral medications may be available as another effective treatment option from your local pharmacist.

Supporting your immune system with herbs and nutrients such as echinacea, zinc, or vitamin C or D may also help to prevent cold sores in the future.

The Herpes simplex virus

Just a note on the underlying cause of cold sores. Cold sores are caused by a herpes simplex virus infection. Once you've had the herpes virus once, it remains in you dormant, and an outbreak can then be triggered by stress, a weakened immune system, or even hot or cold weather conditions.

Please note, a cold sore is caused by certain strains of the herpes simplex virus (HSV) and it is a HSV-1 infection that usually causes a cold sore around the lips. This is what our advice pertains to. This is separate to the HSV-2 herpes simplex virus, which can cause other illnesses such as genital herpes.

^{First published on 4/9/17, updated on 26/4/24}