Our immune systems are constantly at work, all year round, but there is a definite shift in the seasons, as the weather turns colder and the nights draw in, that the focus really turns onto immunity.
This is no doubt because during the autumn and winter months, there appears to be greater prevalence of colds and ‘flu, which tends to mean there is greater awareness around the need to support the immune system. And while October usually marks the beginning of the cold season – generally once the kids have gone back to school – it’s worth bearing in mind that it can continue until the spring, and that’s before you consider the hay fever season. What this means is there is always demand for immune boosting products, and always a need for well-informed advice from health food stores.
“There are several theories as to why the colder weather brings with it more colds and infections. It may be just because we return to our place of work or study and are, therefore, in contact with many people once again (and in an indoor environment). Another school of thought suggests that decreased light exposure results in a lack of vitamin D, a deficiency of which weakens our immune health,” advised Alice Bradshaw, Head of Nutrition Education and Information at Terranova Nutrition.
Nutritional Therapist, Natalie Lamb, Technical Advisor at ADM Protexin, which has the Bio-Kult and Lepicol brands in its portfolio continued: “For some, the cold and flu season starts as early as October and can continue until the following May. However, the main peak of cold and ‘flu is typically in January and February. One of the reasons I put this down to is our dwindling levels of fat-soluble vitamin D. The sunshine vitamin that we make in the summer and store in our body’s fat cells throughout the winter months, essential to support the immune system. Other common theories are due to the cold weather, drier indoor climate and more time spent in proximity to others.”
Jenny Logan, Nutritional Therapist and Technical Training Manager at Natures Aid reminded that having kids has an effect.
“Autumn is when the children go back to school, and the classroom is the perfect breeding ground for all pathogens – bacteria and virus alike. Young children are not always the best at washing their hands, or at covering their mouth when they cough or sneeze, so germs are easily spread from one child to the next. Children then carry these germs home to their parents, who in turn tend to take them to their air-conditioned office with them – another perfect way to spread the pathogens around.”
However, she added: “It is not inevitable that we will suffer – those with a good, strong healthy immune system will be less likely to succumb, and if they do, their symptoms will be less severe. It is those who have a poor immune response, or younger children who are still developing their immune response, who will be most likely to develop symptoms.
Emma Thornton, Nutritionist at A.Vogel, pointed out that our changing diet plays a role.
“Research suggests that we may be tempted to eat more as the colder, darker nights creep in. A study in the US found that people ate, on average, 86 calories more per day during autumn versus spring. Then, depending on the quality of the food, this may also affect our immune functions, as from a study in this field, there was a trend for a greater intake of fat and saturated fats during the autumn months (September-November) when compared to spring. We also know that unhealthy saturated fats from fried foods, confectionery and animal products may drive inflammation and unhealthy immune responses in the body,” she advised.
Salma Dawood, Technical Assistant at Viridian Nutrition, also pointed out the colder weather impacts immunity.
“As the weather begins to change and days become cooler, infections can spread, causing an increase in colds and ‘flus. Studies also show that viruses are more stable in cooler weather, causing a potential increase in airborne illnesses. Additionally, as the air cools down, the mucus in the nasal passages may decrease as we breathe in, potentially impacting our body’s first line of defence against infectious viruses in circulation.”
Keeley Berry, Nutritional Expert and New Product Development Executive at BetterYou, agreed, adding: “The ‘flu season’ usually starts around October each year and often peaks at the height of winter, however, outbreaks can still stick around until May. The reason for it raising its head around this time may simply lie in the name ‘influenza’, from the Italian name ‘influenza di freddo’, meaning influence of the cold, however, the main reason is that the virus is happier in cold weather. While other factors may contribute, the influenza virus survives for longer in cold weather, so it has a greater chance of infecting another person.”
How the immune system functions
Our immune systems are incredibly clever, constantly working to fend off invaders and keep us healthy. Given what they do, you’d think we would be looking after them at all times, but the truth is so many of our modern lifestyle choices have a big impact on this area.
Patrick Holford, nutrition expert, author and founder of the Holford supplements brand, explained: “A weakened immune system can lead to diseases including cancer, the ‘flu and chronic fatigue syndrome. An overactive immune system can lead to auto immune diseases including multiple sclerosis (MS), Huntingdon’s disease and lupus. Allergies occur when your immune system mistakes harmless substances for threats and attacks these harmless substances. It is important to keep the immune system in balance and at peace. It is only when the immune system does wrong and does not recognise itself any more that auto-immune diseases occur.
“There are many signs that someone’s immune system is not up to scratch including if they are more prone to catching a cold, find it hard to shift an infection, if they suffer from hay fever or have an allergy problem.”
David Crooks, Nutrition Science and Communications Manager at Nature’s Bounty, continued: “The immune system plays an important role in managing the tissue healing process and low immunity may slow this down, leading to poor wound healing. Exhausted immune cells (T-cells) have been linked to irritable bowel syndrome (IBS-Diarrhoea-predominant) in research.
“Frequent colds and infections can be a sign that someone needs to take better care of their immune system, particularly if family and close friends/colleagues all appear to be keeping well. Also struggling to shift infections may indicate all is not well, most colds should clear up within a week. It is advisable to speak with your doctor if you feel that your immune system is not functioning properly.”
What we know is immune function is affected by many issues, including nutritional status.
Crooks advised: “The recent UK National Diet and Nutrition Survey found that mean intakes for all age groups are falling below the recommended five a day for fruit and vegetables and there was an overall downward trend in intakes of most vitamins and minerals. As fruits and vegetables are a key source of vitamin C, which is vital for normal function, these results are concerning. It was also found that 19 per cent of children aged four-10, 37 per cent aged 11-18 years and 29 per cent of adults had 25-OHD (vitamin D) below the deficiency threshold and all age/sex groups showed a significant reduction in vitamin A, both key nutrients for supporting the immune system.”
The gut and immunity
Much research has taken place to link a poorly functioning gut with lowered immunity and this area of health should form a crucial part of any advice you offer.
“As up to 70 per cent of our immune cells are located in the gut and supported by a strong microflora (mixture of bacteria and other microbes), it is incredibly important to keep these balanced. A healthy immune system is primed to provide a defence mechanism against invading pathogens and their toxic by-products that could otherwise cause infection,” Lamb explained.
“The immune system is responsible for the speed and effectiveness of the body’s defence response to an infection such as the common cold so it’s important to keep it working well. A healthy balance of beneficial bacteria plays an essential role in supporting a strong protective immune system and can be compromised if busy fighting a wider range of winter viruses, by antibiotic therapy, travel, stress, excess alcohol or a period of inadequate nutrition.”
Therefore, recommending a multi-strain probiotic is a worthwhile consideration.
Immune strong diet
Some foods need to be cut out, and others added in to ensure a balanced diet that supports a strong immune system.
Holford recommended what he called the immune power diet.
“Have two servings of beans, lentils, quinoa, tofu, or seed vegetables a day for protein or one serving of fish or free-range chicken. Include both grains and beans/lentils in your daily diet to increase protein quality if you are vegetarian. Eat plenty of complex carbohydrates, such as brown rice, millet, rye, oats, wholewheat, corn and quinoa as cereal, breads or pasta. Avoid any form of sugar, and white, refined or processed food,” he explained.
“Have five servings of fresh fruit and vegetables each day, such as apples, pears, bananas, berries, melon or citrus fruit, and a mixture of dark green, leafy and root vegetables, such as watercress, carrots, sweet potatoes, broccoli, spinach green beans, peas and peppers.”
Crooks advised of the areas to be aware of, commenting: “Large amounts of sugar (100g) have been shown to have a negative on the ability of white blood cells to destroy foreign particles and microorganisms so minimising intake, particularly when unwell, is a good idea. Alcohol can supress various immune responses. Too much alcohol also depletes the body of minerals such as zinc, which play an important role in supporting the immune function. Whilst one alcoholic drink will not impair the immune system, three or more drinks appear to have a marked detrimental effect.”
Lamb advocated plenty of fresh foods, opting for those that are antioxidant-rich.
“In particular, specific advice from mid-summer onwards could be to pick local berries and fruits such as blackberries, raspberries, strawberries, gooseberries, elderberries and blackcurrants, said to be rich in vitamin C and E and full of antioxidants to help build the immune system up before the winter months,” she explained.
“Traditionally, when feeling ill, your grandmother may have boiled up some fresh chicken stock considered a delicious nourishing meal to support the immune system, providing hydration, warmth and being easy to swallow and soothing if the throat is sore. This theory may be backed up in a modern study showing chicken soup to support the immune system and reduce symptoms of respiratory tract infections, including the common cold, by having a mild anti-inflammatory effect.”
Dawood added: “Eating lots of antioxidant-rich colourful fruit and vegetables may support the immune system. Citrus fruits and cherries are particularly rich in vitamin C and beneficial protective compounds.”
And Bradshaw continued: “Specifically, plant-based foods, especially organic fruits, vegetables, nuts and seeds contain phytonutrients that will be supportive to the immune system. Green foods (such as broccoli, kale and spinach, spirulina, barley grass), medicinal mushrooms, berries and garlic are some foods that have shown immune-supportive properties in research studies.”
Logan added: “Zinc can be increased by eating shellfish, pumpkin seeds and legumes like chickpeas, lentils and beans, whilst selenium can by topped up by eating brazil nuts, fish, mushrooms and sunflower seeds.”
For Berry, there are certain foods to consider.
“Garlic has a host of health benefits, including immune-boosting, antibacterial, antiviral and antifungal effects. It contains the compound allicin, which has been shown to be beneficial for immune function, so increasing your intake may boost the body’s ability to fend off germs,” she advised.
“Vitamin C may also help to protect the integrity of immune cells and as the body is unable to produce vitamin C itself, it’s important to consume foods high in the nutrient such as strawberries, peppers, spinach and broccoli. What many people may not know is that one of the greatest contributors of vitamin C to our diet is potatoes and because vitamin C presents itself in so many foods, it’s unlikely that you will need to take a supplement unless advised by a medical professional.”
Don’t forget the need for essential fats, with Thornton advising: “Good quality fats such as omega 3 are anti-inflammatory and also help support the absorption of fat-soluble nutrients, such as vitamin D. Vitamin D is well known to help support the optimal functioning of the immune system and unfortunately a deficiency in this nutrient could put at risk. Especially in countries where sunshine is somewhat limited (as are the food sources of this nutrient) a vitamin D supplement may be recommended, especially during the winter.