As winter approaches many of us begin to think about natural ways to give our immune system a boost. It’s not hard to see why this is a question that is being asked more frequently as winter 2020 approaches.
As we all prepare ourselves for the uncertainty of what lies ahead, one thing is for certain: actively working to maintain a healthy immune system is a trend we’d all be wise to follow.
So what does that actually mean?
Do you need to drink your own body weight in orange juice every morning?
Is it even possible to take every supplement that claims to boost your immune system?
Do any of them actually work?
We have done the leg work for you and reviewed the nutritional research to identify our top 5 supplements to help boost immunity. But before we jump into the nutritional research, let’s quickly review what the immune system is, and how it helps protect the body against disease.
The immune system: what is it and how does it work?
Keeping your immune system healthy is key to preventing infection and disease.
Put simply, the immune system helps protect the body from invading pathogens, such as viruses and bacteria. The system is basically a group of immune-related cells that can be broadly categorized as either non-specific or specific immune cells, based on their different capabilities.
non-specific immune cells (such as phagocytes and macrophages) serve as the body’s first line of defence against pathogens. They will attack and invader, and are quick to respond to threats.
Specific immune cells (namely T cells and B cells) are slower to respond and, as their name suggests, respond to particular invading pathogens and destroy them. Importantly they are able to remember past infections for future defence. For example, B cells produce antibodies against the pathogens they encounter, and because of their ‘memory’ they are able to respond more quickly and efficiently during a second encounter with that pathogen. It is the response of these specific immune cells which gives us longer term immunity to a disease
Importantly, how well these two different groups of immune cells are able to coordinate their activities determines how effectively we can mount an immune response and stay healthy. One of the ways immune cells communicate with one another is by secreting molecules called cytokines. These attract other immune cells to the site of infection and regulate their activity.
Top 5 supplements to help boost immunity
Making healthy lifestyle choices by consuming nutritious foods and getting enough sleep and exercise are the most important ways to bolster your immune system.
Research has shown that certain supplements can improve our immune response and potentially protect against illness.
Let’s look in more detail at our 5 top picks.
#1 Vitamin C
Vitamin C is an essential vitamin which your body can’t produce.
It is found in many fruits and vegetables, including citrus fruits, raspberries, kiwi fruit, sweet peppers and green vegetables.
Vitamin C boosts the immune system by:
- Aiding the production of immune cells (phagocytes, B and T cells) which help protect the body against infection
- Helping these immune cells to work more effectively by protecting them from damage by free radicals.
- Strengthening the skin and reducing the time taken for wounds to heal.
The recommended daily intake for vitamin C is 75 mg for women and 90 mg for men. Whilst most people can get sufficient vitamin C through a healthy diet, supplements can be very helpful to boost your intake in the winter time or if you have a restricted diet.
#2 Vitamin D
The body can make vitamin D from direct sunlight on the skin when you are outdoors.
In the UK, from late March to the end of September, most people should be able to get all the vitamin D they need from sunlight, but between October and early March cannot make enough in this way.
Vitamin D is found in a small number of foods such as oily fish, red meat, liver, eggs and some breakfast cereals.
Vitamin D boosts the immune system by:
- Helping immune cells, including T cells and macrophages to work more effectively
- Helping to reduce inflammation.
- People who are vitamin D deficient appear to have decreased lung function and an increased risk of respiratory diseases, including tuberculosis and asthma, as well as viral and bacterial respiratory infections.
- People who are vitamin D deficient appear to be more vulnerable to autoimmune conditions.
Many people find it hard to get enough from the foods they eat. It is estimated that 20% of adults and up to 16% of children in the UK are deficient.
The NHS recommends adults and children over the age of 4 take a daily supplement containing 10 micrograms of vitamin D during the autumn and winter. People who have dark skin or do not get outdoors very often are recommended to take 10 micrograms of vitamin D throughout the year.
Zinc is a mineral micronutrient found in foods such as sesame seeds, beans, shellfish, meat, whole grains and nuts.
Zinc deficiency is more common than you might think, particularly in older people.
Zinc can boost the immune system by:
- Helping T and B cells work more efficiently.
- Helping to regulate the immune response in a way that prevents out-of-control inflammation.
- Helping with the manufacture and release of cytokines which enable immune cells communicate with one another.
The daily RDA for zinc is 7mg for women and 9.5mg for men. Supplementation can be very helpful in achieving these levels.
Probiotics are live microorganisms, usually bacteria, that have health benefits when eaten as part of a varied diet.
The best probiotic foods are live yoghurt, kefir, sauerkraut, pickles, miso, kimchi, tempeh and some cheeses.
Probiotics boost the immune system:
- Some have been shown to promote the production of an antibody called IgA in the body. These plays a crucial role in the immune function of mucous membranes found in the eyes, mouth, nose and gut.
- They could reduce the likelihood and duration of respiratory infections.
- Some have been shown to significantly reduce the risk of urinary tract infections (UTIs) in women.
If you want to experience these benefits to your immune system, it’s important that you consume adequate amounts.
Most of the studies showing benefits used dosages of 1 billion to 100 billion live organisms or colony-forming units (CFU) per day.
To achieve these levels most people find it more convenient to take probiotics as tablets, capsules and powders. These contain the bacteria in dried form.
Garlic differs from other members of the onion family because it has a compound called allicin in it.
Allicin gives garlic its distinctive smell and taste and contains lots of sulphur.
It also contains a number of nutrients that have been shown to be good for your health — arginine, oligosaccharides, flavonoids, and selenium.
Garlic boosts the immune system:
- It can increase the number of virus-fighting T-cells in your bloodstream. It is viruses that cause colds and flu.
- The sulphur in garlic helps your body absorb the zinc which helps the immune system in the ways we described earlier.
- It can reduce your production of stress hormones. Stress hormones, such as cortisol, have a negative impact on your immune system.
When taking garlic supplements The European Medicines Agency recommends 100-400mg a day for coughs and colds protection.
You are not recommended to take garlic supplements if you are take anti-coagulation or anti-platelet medicine or are pregnant or breast feeding.
Supplements to help boost immunity – final thoughts
Many supplements on the market claim to help improve immune health. Out top 5 have significant research evidence to support their immunity boosting claims.
Although these supplements may offer a benefit to your immune health, remember they should never be used as a replacement for a healthy lifestyle. Sleep, a nutritious, well balanced diet and regular physical activity remain the most important ways to help keep your immune system healthy.
It’s also important to remember that no supplement will cure or prevent disease. Despite what you may read to the contrary, there really is no scientific evidence to suggest that any supplement can protect against COVID-19 — even though some of them may have antiviral properties.