You've probably still got some nuts leftover from Christmas, which is good news because they're packed with vitamins B6 and B9, which are great for your immune system. They also contain vitamin E and selenium, both recognised as aiding the production of immune system B-cells. Perfect for snacking, they fit snugly in a handbag or pocket. Or try whizzing them up and adding them to salad dressings, scattering over a salad of shaved cheese and pears and, if you have a sweet tooth, using them in biscuits and crushing them over ice cream.
Oranges are not the only citrus fruit to boost your immune system. Lemons help restore the body's internal acid and alkali balance – an acidic environment encourages harmful bacteria and viruses - allowing healthy bacteria to flourish. Like clementines, satsumas and most citrus fruit lemons contain lots of vitamin C, but don't forget the vitamin content is destroyed by heat so try and make sure your lemon intake is 'raw'. Add it to salad dressings in place of vinegar, make a quick homemade lemonade – lemon juice, water and sugar – or squeeze it over fish.
Mushrooms have moved into the health spotlight recently, recognised for their probiotic properties which help ward off illness and increase resistance to disease. Packed with antioxidants – they have three times more than tomatoes – they also have high levels of copper, and are rich in vitamins B and C. Out of the 38,000 different species of mushroom that exist, three have especial healing properties - reisihi, shiitake, and maitake, all of which have been shown to boost the immune system. Try them added to your favourite Asian recipe, or regular ones sauteed in butter with garlic, then splashed with crème fraiche and mustard. Slice button mushrooms thinly and serve raw with rocket and parmesan or try whole field mushrooms baked upside down with a spoonful of cooked pearl barley mixed with preserved lemons and feta cheese on top.
Much is made of the healthy bacteria found in drinking yoghurts, but a pot of natural yoghurt contains just as much of the bacteria which is good for your gut and immune system. On its own natural yoghurt can be a bit plain, but add a sprinkling of nuts, plus fresh fruit for an added vitamin boost, and you've got a nutritious, delicious breakfast or dessert that'll help keep the lurgy at bay, too.
Along with many other orange-coloured vegetables the sweet potato is very high in beta-carotene, the substance which helps boost the T-cells essential for well-being, and in antioxidants. Roast them whole or peel, steam and mash with a little butter, chives and chilli flakes for a yummy alternative to mashed potatoes. They can also be eaten raw - grated and tossed with some French dressing and toasted almond flakes - and are a great alternative to oven chips. Simply chop into finger-size pieces and roast with some olive oil, thyme and whole cloves of garlic.
Probably the most popular fish in the UK, this, along with many other oily fish, is high in selenium and zinc, both very good you. The omega-3 in salmon - and mackerel and sardines - is helpful in fighting the inflammation associated with many health problems such as heart disease, diabetes and cancer. And salmon is hugely versatile, it can be pan-fried, grilled, oven-roasted, steamed, poached and served hot or cold. The possibilities are endless.
Blueberries, goji berries – which have been used in traditional Chinese medicine for over 2,000 years - and recent headline-maker acai berries are all great for staving off colds and flu as they're all high in anti-oxidants. If you can't get hold of fresh ones, try snacking on dried berries. If you're lucky enough to have a supplier of fresh berries close to home try them scattered into yoghurt, whizzed into a milkshake or made into a sorbet. Blueberries can also be scattered into the base of a cake tin with the mixture poured on top to perk up a chocolate cake.