Amelia Freer: What to eat to boost your immune system for winter

As the weather turns colder and the nights draw in, the season of coughs and colds begins. Now is the perfect time to build up your body’s natural defences, by following my simple tips:

1. Are you eating enough food? Under-nutrition (often a result of juice fasts and crash diets) suppresses normal immune function. Don’t gorge, but eat a well-balanced, adequate and nourishing diet full of hearty soups and stews.
2. Sufficient carbohydrates (again, don’t go mad) also help to prevent protein being used for pure energy. Avoid processed carbs but go for starchy root vegetables (squash and potatoes) or unprocessed grains (oats, brown or wild rice, quinoa, amaranth or millet).
3. Our immune system needs all sorts of essential vitamins to function properly, so eat plenty of varied fruits and vegetables. The Government says five a day, but aim to eat six portions of vegetables and three of fruit, both raw and lightly cooked to maximise your absorption of nutrients. Good sources of vitamin C include yellow and red peppers, kiwis, tomatoes, oranges, broccoli and strawberries.
4. Vitamin D is crucial for immune health, but our bodies stop making it in winter. Food sources include fish, eggs and mushrooms, or  take a 10 microgram vitamin D3 supplement between October and March. Zinc can also help control the spread of viruses and shorten the length of a common cold. However, unlike vitamin D, it is possible to get your recommended daily zinc intake from food alone. Good sources include shellfish, lamb, beef, nuts, seeds and kidney beans.
5. There is evidence to suggest that dehydration lowers our natural barrier defences, so always drink plenty of fluids, particularly water. The aim is to drink just enough to keep your urine pale yellow or clear.