Diet & Long Covid recovery: anti-inflammatory vs. low histamine

There has been much written on diets to help recovery in Long Covid.  Two popular but very different diet approaches are the Low Histamine diet and the anti-inflammatory diet. If you look deeper into the details of each diet, you’ll see there are quite different foods that you can eat.  What you are advised to avoid on one diet is the very food you should be eating more of in the other one. This can be very confusing.

The theory behind what will aid recovery, and suggested causes for ongoing symptoms, is at present unproven.  Amongst most medical, qualified nutrition and dietetic experts, the general agreement is that the Mediterranean-type diet is considered to be an anti-inflammatory diet. The Mediterranean diet has more research and evidence supporting health benefits.

What is an anti-inflammatory diet?

Below are the key points of an anti-inflammatory or Mediterranean-type diet

• Each day, aim to have a diverse range of different colours and at least five portions of a variety of fruits and vegetables, for vitamins, minerals and fibre. Fresh, frozen, tinned or dried all count. Other plant-rich foods to enjoy are beans, pulses, nuts and seeds.

• Beans, pulses, nuts and seeds, fish, eggs and meat are good sources of protein. Eat red meat less often and small portions only of especially processed types like sausages, burgers, and bacon.

• Fish is low fat and good to include twice a week, especially oily types such as salmon or sardines, which are rich in omega 3.

• Base your meals on potatoes, bread, rice, pasta or other starchy carbohydrates, as they are a good source of energy. Wholegrain types are good for fibre and often release energy more slowly: this is known as a low glycaemic and may help when struggling with fatigue.  

• Milk, cheese and yoghurt are sources of protein and some vitamins. They’re also an important source of calcium, which keeps bones healthy. If choosing dairy alternatives, make sure they are fortified with calcium.

• Choose unsaturated oils and spreads in small amounts.

• Drink plenty of fluids, especially water, milk or sugar-free drinks.

What does the low histamine diet involve?

It has been suggested that some people with Long Covid may become sensitive to histamine in foods. This may be either because the body’s histamine levels rise during inflammation, or that it may struggle to break down dietary histamine. As yet, there is no evidence that a low histamine diet helps most people with Long Covid although some have reported this approach has helped them.

A low histamine diet involves a 2 to 4-week trial period of restricting the many foods high in histamine, and then reintroducing these one by one systematically to test tolerance.  Here are some, but not all, of the many foods that will need to be excluded:

• all cured meat and pork

• salmon

• tuna and other oily fish

• bananas, oranges, grapes, fresh fruit juices

• fermented food such as kefir and sauerkraut

• soya sauce pickles

• yeast extract

It is recommended to have support from a dietitian when doing this, to minimise nutritional risk and ensure it is safe.

The diet is time-consuming to prepare. Many have found it difficult to follow, especially with their fatigue and other debilitating symptoms. Although there are online lists of histamine content of foods, there is inconsistency with reported levels of histamine in these foods. Additionally, the foods avoided for a low histamine diet contradict the principles of the Mediterranean diet, for instance avoiding oily fish and certain fruits and vegetables.

When might I need the support of a dietitian?

• When you are unwell it can be difficult to eat well for a variety of reasons.  Fatigue, loss of appetite, loss of taste and smell can all your affect ability to eat. If you find you are experiencing unwanted weight loss, this also means you are losing muscle, and may delay recovery.  A dietitian can tailor advice to your individual needs to boost your energy intake and help you with weight management.

• If you are following a restrictive diet a dietitian can check that you are still eating all the nutrition your body needs.  The more you cut out of your diet the more you risk malnutrition and unwanted weight loss.  For instance, if you are cutting out dairy, you will need to compensate other calcium-rich foods for your bone health.