Eating Well with Asthma: Foods That May Help

Why your diet matters when you have asthma

Good asthma care starts with the basics: taking your preventer inhaler as prescribed, keeping your reliever to hand, and following your personal asthma action plan. Nothing on your plate will replace those. But the food you eat day to day plays a supporting role that is easy to overlook, and it is one of the few things you have genuine control over.

A balanced diet helps in two main ways. First, it supports your immune system, so you are better placed to cope with the colds and viruses that so often trigger flare-ups. Second, it helps you stay at a healthy weight. Carrying extra weight puts pressure on your chest, reduces lung capacity and is linked to more frequent symptoms and more severe asthma. Losing even a modest amount, if you are overweight, can noticeably improve how well you breathe.

There is no asthma diet, and no single food that will cure anything. Think of it instead as stacking the odds in your favour.

Fruit and vegetables: the everyday foundation

People who eat plenty of fruit and vegetables tend to report fewer asthma symptoms, and there is good reason to believe the antioxidants and fibre in them are part of why. Fibre feeds the beneficial bacteria in your gut, and a healthier gut microbiome is increasingly linked with lower airway inflammation.

The NHS 5 A DAY target is a reasonable aim, and it is easier than it sounds:

• A portion is roughly 80g — a handful of berries, one apple, three heaped tablespoons of peas or carrots.
• Frozen, tinned and dried options all count. Tinned tomatoes, frozen spinach and frozen berries are cheap, last for months and keep their nutrients.
• Add fruit to breakfast cereal or porridge, and sneak an extra vegetable into soups, pasta sauces and curries.
• Fruit juice and smoothies count as one portion a day only, however much you drink, because they lack the fibre of whole fruit.

If your budget is tight, the NHS Healthy Start scheme may help if you are pregnant or have young children. Local food banks and community larders can also help — there is no shame in using them.

Oily fish and omega-3 fats

Oily fish is rich in omega-3 fatty acids, which have anti-inflammatory effects. Some studies suggest that people who eat oily fish regularly have a lower risk of asthma symptoms, though the evidence is not strong enough to call it a treatment.

Aim for two portions of fish a week, one of them oily. Good, affordable options include tinned sardines, mackerel, pilchards and salmon — often far cheaper than fresh fillets and just as nutritious. Try them mashed on toast, stirred through pasta, or in fishcakes. If you do not eat fish, walnuts, flaxseed, chia seeds and rapeseed oil are useful plant sources, though the type of omega-3 they contain is less readily used by the body.

Vitamin D and the UK winter

Vitamin D matters for immune function, and low levels are common across the UK because we simply do not get enough sunlight between October and March. The NHS advises everyone to consider a daily supplement of 10 micrograms (400 IU) during the autumn and winter months.

Food sources include oily fish, egg yolks, red meat and fortified breakfast cereals and spreads, but it is hard to get enough from diet alone. A daily supplement is inexpensive, widely available and one of the simplest steps you can take.

Foods and habits that may make things worse

Triggers vary from person to person, so it is worth noting what seems to affect you rather than cutting things out on guesswork.

• Weight gain from steroids. If you take regular oral steroids, you may notice increased appetite and weight gain. This is worth discussing with your GP or asthma nurse — it is a common issue and there is support available.
• Salt. A high-salt diet is generally bad for health, and some people with asthma find it aggravates symptoms. Most of our salt comes from processed foods rather than the salt cellar.
• Sulphites. Found in dried fruit, some wines, and processed meats, sulphites trigger symptoms in a small number of people. If you suspect them, keep a symptom diary and speak to your clinician before excluding whole food groups.
• Reflux. Heartburn and acid reflux can irritate your airways. Eating smaller meals, and avoiding large meals close to bedtime, often helps.
• Cold drinks and food. Some people find very cold food or drink provokes a cough. If so, let things come up to room temperature.

Making it work in real life

Small, repeatable changes beat ambitious overhauls every time. Batch-cook a vegetable-heavy soup or stew at the weekend and freeze portions. Keep a bag of frozen mixed vegetables in the freezer for the days when cooking feels like too much. Swap one processed snack a day for a piece of fruit or a handful of nuts.

Stay well hydrated, especially when you are using your reliever inhaler more often, as it can leave your mouth dry — and always rinse your mouth after using a steroid inhaler to prevent oral thrush.

Finally, remember the practical side. In Scotland, Wales and Northern Ireland, prescriptions are free. In England, a prepayment certificate can save you money if you need more than a couple of items a month. And if you have not had an asthma review in the past year, book one. Diet is a helpful companion to good treatment — never a substitute for it.