“Immune ‘boosting’ is a phrase that I really can’t get along with,” says leading nutritional therapist and healthy eating expert Amelia Freer, when asked about the best immune-boosting advice for the coming months. In fact, according to Freer, we’ve been approaching it all wrong—and when it comes to our immune system, the aim isn’t to boost, but rather to balance it.
An overactive immune system can result in auto-immune disease, or a significant widespread inflammatory state, while an under-active or otherwise compromised immune system can increase our risk of infection—neither of which is ideal. “In the simplest of terms,” says Freer, “we want to be able to switch our immune function on appropriately, and then switch it off again when the infection risk has passed.”
As for how we can do this best, Freer suggests nurturing and supporting our overall health and wellbeing. “There are various nutrients that our body requires to mount and suppress an appropriate immune response,” she comments. “The best way to get these is through eating a balanced, nutritious and abundant diet, so including a wide variety of different whole foods into our diets throughout the winter is a great place to start.”
1. Load up on dark-green vegetables
“First up is dark-green vegetables such as kale, chard, spinach, rocket, Brussels sprouts, sprouting broccoli. They all provide a variety of beneficial phytonutrients, fibre, vitamin A, magnesium, folate and more. If there is one thing to add to our diets, it is this group of vegetables. Aim for at least one portion per day (remembering that when cooked, they tend to shrink considerably in terms of volume, making it easier to achieve this target).”
2. Opt for citrus fruits
“Citrus fruits are a good source of vitamin C and perfect for the coldest winter months—a little bit of concentrated sunshine just when we need it most. I particularly love the month or two that blood oranges are available [around December to April] — I have one almost every day when I can, as the most deliciously simple dessert.”
3. Make room for mackerel
“This is a cheap and readily available oily fish and a source of long-chain omega-3 fatty acids, which can help to regulate inflammation in the body. It also contains some food-based vitamin D, as well as protein, and it’s a great speedy choice for lunches. Top tip: look out for unsmoked, frozen mackerel fillets in the freezer section of some supermarkets. I’ve found that it’s the best fish to cook from frozen, and contains less salt than the smoked version.”
4. Swap in some squash or pumpkin
“There are a huge variety of orange-fleshed pumpkins to enjoy over winter. They provide a source of vitamin A, which, as a fat-soluble vitamin, is best absorbed alongside some healthy fats. I therefore tend to slow-roast my squash and pumpkins in a little olive oil, and then enjoy as they come, blended into sauces or soups, or tossed into salads with rocket, radicchio, some toasted hazelnuts and crumbled feta.”
5. Balance your diet with Brazil nuts
“Brazil nuts are a key source of the micronutrient selenium, which is an important mineral for optimal immune response. Just four or five Brazil nuts per week can meet our selenium requirements. It is, however, one of the few whole food nutrients that we can over-consume, so it’s best to mix things up and eat just a few each week alongside a variety of other nuts and seeds, too.”
6. Choose chickpeas or other pulses
“I adore pulses in all shapes and sizes, and I find them a convenient source of protein—I aim to have roughly a palm-sized portion of protein at each meal of the day. Protein is important for enabling the body to mount an appropriate immune response, as well as for repair and growth of our body’s tissues, and for appetite and blood-sugar regulation. I buy pulses in bulk in jars and add them to soups, make them into hummus and other dips, throw them into curries and stews, or eat them cold with some olive oil, lemon and a few chopped herbs.”
7. Switch to shellfish
“Shellfish is a good source of zinc and vitamin B12, and mussels and scallops are in season over the winter months. They are a bit of a treat, but it’s worth making the effort to cook them once in a while. Do check that they are sustainably sourced and if you’re unsure about cooking them yourself, it might be a good option to consider ordering if eating out.”
8. Start soaking your own oats
“Rolled oats are a great choice and can provide not only a warming and delicious porridge breakfast, but also a hefty dose of fibre, too. Soaking oats overnight can help to make the nutrients they contain more absorbable, as well as speeding up the cooking time.”
9. Introduce more eggs
“Eggs are such a versatile and useful ingredient to have on hand for quick meals and speedy snacks. They are also a source of vitamin B12, a little vitamin D, vitamin A, protein and some are even fortified with omega-3 fatty acids, all of which are important for balanced immune function.”
10. Drink lots of water
“Maintaining a good level of hydration can help to keep our mucosal barriers moist, such as those in our mouth and the lining of our nose. This might sound strange, but hydration of these tissues helps to support the natural immune function that exists within them, warding off infection before it has a chance to enter the body. Plus water won’t spoil your appetite for the abundance of nourishing whole foods awaiting you at your next meal.”
11. Increase your vitamin D
“The only supplement that is recommended for everyone to consider especially over the winter months is vitamin D. In some countries, the sunlight is not strong enough between October and early March for our skin to make enough vitamin D to meet our requirements.”
12. Optimise other aspects of your lifestyle
“I know it’s been said a thousand times before, but it really is what works: wash your hands, prioritise sleep, actively respond to and manage stress, move regularly, exercise, moderate alcohol and avoid smoking. It’s not original, but it is effective.”
