Updated: Feb 25
The cooler weather used to be the time to start talking about immunity, but that seems to have changed over the past 2 years, and now it feels like it's in the headlines every day. Does this leave you wondering about your own immune system and whether it's strong and ready to protect you?
Your immune system is pretty complex and when it's working well it can protect you and help you to stay healthy. Like an army, it protects your body across multiple fronts, from non-specific defences like the acid in your stomach that kills any bugs you swallow, to those very specific antibodies that are produced for particular invaders like viruses. These protective roles are divided between the 'innate' and the 'acquired' parts of your immune system. When your body detects invasion, it sends out non-specific soldiers in the form of white blood cells such as neutrophils. In fact, they should be 'on guard' at all times to ensure a speedy response. They can also trigger other parts of this initial response to cause a fever, and even changes in your heart rate and blood flow. The aim of this defence is to kill the bug before it can damage your body. The specific or 'acquired' part of your immune system kicks in a bit later when B cells, another type of white blood cell, make antibodies that are like a special key that only works for that particular bug. This kind of immune response is longer lasting so that if the same bug is identified again the key is ready to use. It's also this part of your immune system that is triggered when you receive a vaccine so that your body is prepared and can fight off infection by a particular bug.
The majority of the symptoms you experience when you are sick are actually caused by all this immune action. There is usually a lot of inflammation that's caused by increased fluid and blood flow and this can cause headaches and general aches and pains. Another way your body tries to get rid of infections is by producing lots of mucus and often this means a runny nose or a cough that comes with a cold or flu. Of course, there are some instances when your immune system produces a response that causes excessive inflammation. This is called a 'cytokine storm' because the chemicals that your body produce to trigger this response are called cytokines. It has been talked about frequently during the COVID-19 pandemic, and many people feel quite frightened about it. The response is due to an over-reaction by the immune system to try to eliminate the infection and it results in unchecked inflammation that can damage organs like your kidneys and heart.
A healthy immune response is one that is able to quickly detect infection and act to eliminate it with minimal inflammation and damage. To support a healthy immune response, you body needs good nutrition and a healthy gastrointestinal microbiome. You also need the barriers that protect you from invaders such as your skin and the mucus membranes in your nose and throat, to be strong. Along with these factors, there are some important lifestyle considerations that can impact the health of your immune system such as sleep and the management of stress. This is because high cortisol, that is produced in conditions of increased physical or mental stress is detrimental to healthy immune function. Poor sleep or not getting enough hours of sleep also has this effect because it increases sympathetic nervous system dominance and reduces the time your body spends in the 'rest and digest' phase.
To ensure that your immune system is in tip-top shape to keep you healthy, here are some things you can do:
Eat a whole food diet (sounds simple but it's so important). The food you eat contains the nutrients your immune system needs to function well. Make sure you're eating a rainbow of vegetables and fruit every day. Those brightly coloured ones contain antioxidants that help to reduce damage caused by inflammation. Add some pumpkin, sweet potato, beetroot and blueberries. Include a good source of protein from meat, chicken, fish, nuts/seeds and legumes as well as some healthy fats from foods including avocado, olive oil, walnuts, salmon and flax seeds. Carbohydrates are important to include but need to be complex such as wholegrains like brown rice, whole wheat rather than refined sources that are found in many packaged or processed foods. The take home message is to cook from fresh ingredients as much as possible.
Support a healthy gut. The bacteria in your gut play a huge role in regulating the response of your immune system. Eating a healthy diet (see above) and reducing processed or high sugar food promotes a healthy environment for good bacteria. Probiotic supplements can help but it's important to take the right kind to support your gut.
Move your body. This is another recommendation that seems too simple to be true! It's not though, studies show that regular, moderate exercise improves immune function. Aim for a brisk 30 minute walk or a swim, bike ride or even join a team to play your favourite sport. Every bit helps!
Get 7-9 hours of sleep. The science is in for this one too, lack of sleep is not good for your immune system. You need those hours for your body to rest and regenerate and those who burn the candle at both ends often report frequent infections or chronic illness. Get into a good sleep routine by turning off electronic screens, having a warm bath or shower and reading a book before bed. Try to go to bed at the same time each night to establish good habits.
Practice mindfulness. Everyone leads very busy lives with little time for self-care. Guided meditation can be really beneficial for managing stress and as little as 10 minutes each day can make a big difference. Studies have shown that levels of stress hormone 'cortisol' are reduced in people who practice meditation or deep breathing exercises. There are lots of online guided meditation resources online.
There are some specific immune enhancing nutrients and herbs that can be helpful to take as supplements but before you start, it's important to ensure that any nutritional or herbal medicine you plan to take is appropriate for you as they can interact with other medications you are currently taking.
So now is the time to ensure that your immune army is ready to meet whatever challenges are presented, rather than in the heat of battle when it may be too late.