From overdoing the wine to using the wrong oil, the clues to a healthier immune system can be found in what you eat and drink every day.
With cold and flu season upon us, and long COVID affecting up to one in 10 Australians, there are many of us with an interest in optimising immunity.
While there are plenty of expensive supplements, pills, potions and powders that claim to hold the key to immune function, the reality is that the immune system is complex, and influenced to a far greater extent by our dietary patterns over time as opposed to whether we dose up on vitamin D.
Here, the synergistic effect of different foods over time affects the balance of the gut microbiome, which controls the inflammatory response of the body’s cells. This in turn directs and controls immune response and the body’s ability to prevent and fight off infection.
For this reason, if you do find yourself especially susceptible to picking up whatever bug or virus is doing the rounds, it may be time to pay closer attention to the way you eat daily, rather than searching for a miracle pill or powder that simply doesn’t exist.
Overdoing the wine
We’re not talking about a single glass of red with dinner; it’s the regular overconsumption of alcohol, or more than 14 standard drinks a week, or five to six drinks on a single occasion, that is associated with impaired immune function. Immediately after consumption, alcohol as a molecule immediately affects the gut microbiome, which modulates immune function. Specifically, a high consumption of alcohol is associated with an increased inflammatory and immune response. In the case of the respiratory system, the lungs are especially susceptible to the effects of alcohol, meaning that a high alcohol intake is associated with a higher risk of developing respiratory illness over time.
Immune-boosting solution
When it comes to alcohol consumption, moderation is the key. You are much better off enjoying a drink or two each day, with a couple of alcohol-free days each week, than you are binge-drinking on multiple occasions when socialising.
Eating too late at night
The more we come to learn about the human body, the more we understand that a number of the body’s systems are heavily influenced by the circadian rhythm. This includes our immune system, which appears to regulate and restore more efficiently when in an extended fasted state overnight. This means that eating heavy meals at night, which can limit the overnight fast to just six to eight hours, is insufficient to support optimal digestive health and immune response.
Immune-boosting solution
If you routinely eat late, make lunch your largest meal of the day, eat a light snack by 6 or 7pm and give yourself 12 hours overnight without food.
Overdoing the stimulants
Whether you load up on multiple coffees each day; drink endless cups of tea or reach for a couple of energy drinks to get through the afternoon, chances are you are not drinking anywhere near enough water to keep optimally hydrated. Dehydration does not directly affect immune function, but it does alter our ability to deal with stress daily, resulting in higher blood pressure, increased heart rate and higher cortisol levels, which indirectly can impair immune function.
Immune-boosting solution
Match any caffeinated drink with a glass of water; seek out herbal tea more frequently and start the day with a glass or two of water rather than reaching for the coffee straight up.
Too much ultra-processed food
If by chance you grabbed a muffin or pastry for breakfast today; then had a wrap or burger and fries for lunch and picked up takeaway on the way home, most of your daily intake is coming from ultra-processed foods. These are foods that bear little resemblance to whole, natural foods and do more damage nutritionally than they do good. There is growing evidence to show that the regular consumption of fried, fast and processed snack foods has a direct effect on gut health, and as such directly affects immune-related function. People who eat a diet high in ultra-processed foods have been shown to have a heightened pro-inflammatory response at a cellular level, which adversely affects the development and functioning of our immune cells.
Immune-boosting solution
Proactively limit your intake of highly processed snacks and takeaway food options. When out, seek food that resembles whole natural foods such as grills, stir-fries and sashimi, and avoid fried foods altogether.
Using the wrong oil
Of all the dietary patterns associated with improved immune function and reduced risk of disease, the Mediterranean routinely comes out on top of the list, and one of the key components of this diet is a high intake of extra virgin olive oil, upwards of 40-50 millilitres each day. The most common oils consumed in Australia are canola and palm oil, and even the olive oil that is consumed is not always the high-antioxidant Australian-made extra virgin olive oil, which is the variety associated with the anti-inflammatory and immune-benefiting outcomes.
Immune-boosting solution
Swap any oil at home for Australian extra virgin olive oil, and aim for a couple of tablespoons with your salad or vegetables every day.
Not getting out
Up to 30 per cent of Australians are dealing with low vitamin D levels through the winter months. And with vitamin D playing a significant role in the regulation of immune cells in the body, one of the easiest ways you can support your own immune function is by making it a priority to get some sun. This means long days in an office minus fresh air and sunlight is far from ideal, and exposing as much flesh as is decently possible is the key to optimise the body’s natural production of vitamin D.
Immune-boosting solution
Make it a priority to take your lunch break at work, especially when the sun is out, and spend at least five to 10 minutes in direct sunlight with as much of your body exposed as possible.
Not getting enough fresh food
Busy lives mean we often get food on the run. The downside of this is we don’t get anywhere near enough fresh, whole foods known to nourish the gut and support natural immune function. Ideally, we need to eat at least 30 different varieties of plant-based food every week, which requires serious focus.
Immune-boosting solution
Start each day with nutrient-rich mixed vegetable juice and base at least one meal a day on vegetables or salad or soup. Snack on nuts and seeds and order extra vegetables or salad when eating out, to boost your daily intake of plant-based foods.
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