“What can I take to boost my immune system?” is one of the most common questions I get asked, whether in winter or summer.
People want to stay healthy and protect themselves and their families, and avoid courses of antibiotics and rounds of antihistamines. However, the immune system just doesn’t work that way. As the name suggests, it’s not a single thing but a system incorporating many organs and biological functions.
How does the immune system work?
The immune system is divided into two branches: innate (first line of defence) and adaptive (more specific) immunity. When the immune system encounters a bacteria or virus it doesn’t recognise, the innate branch acts first. It’s fast but can leave a mess – think Ghostbusters dealing with a ghost in a haunted house. It spreads slime in the passages and doorways to try to flush it out, so you fill up with mucus. It fiddles with the thermostat to try to boil it (so you run a fever), and it shuts down the building until the problem is solved (you get lethargic so you don’t go out and pick up another infection while you’re busy dealing with the current invasion).
All of this slows the replication of the bug but doesn’t stop it. That’s the job of “Special Forces” in the adaptive branch, who are producing specific antibodies to deal with the bug and wipe it out. It takes five to 10 days for the immune system to manufacture antibodies to unknown bugs.
You can think about the immune system like a delicately balanced scale. If it’s not functioning properly, you’ll pick up every infection around you – this is what happens in HIV patients whose T cells are being attacked. But tip too far to the other side, and the “overactive” immune system can start targeting our own cells. In extreme cases, this causes autoimmune diseases like rheumatoid arthritis and multiple sclerosis.
A very vigorous immune response can cause inflammation, which is like friendly fire in the war between the immune system and invading bugs. When we think about enhancing the immune system, we need to remember inflammation. Out-of-control inflammation causes a huge amount of damage to the body.
“You can think about the immune system like a delicately balanced scale. If it’s not functioning properly, you’ll pick up every infection around you.”
Stick to the basics
What we do every day can have a bigger effect than what we do sporadically when we are getting sick. So, make sure you have the basics covered.
- Don’t smoke, and never smoke around your children.
- Eat the rainbow – a diet high in fruits and vegetables of every colour.
- Exercise regularly and encourage this habit in your children.
- Maintain a healthy weight.
- If you drink alcohol, drink only in moderation.
- Get adequate sleep.
- Handwashing prevents many infections from spreading.
- Prepare meats properly.
- Take care of your children’s and your mental health to try to minimise stress.
Be wary of antibacterial hand soaps and cleaning products. The immune system needs to come into contact with various bugs to develop, and this is especially true for children. We also have a “standing army” of our unique microbiome (or friendly bacteria) on our skin and in our gut and lungs. We don’t want to disrupt that delicate system that defends the body by crowding out the “bad” invaders.
If the immune system is your army then the saying “an army marches on its stomach” has never been more appropriate. The immune system needs to be well-nourished. Malnourished populations are more vulnerable to infectious diseases. “Micronutrient malnutrition” is very common in picky eaters who are deficient in some essential trace vitamins and minerals.
- Zinc deficiency affects about a third of the world’s population. It can lead to loss of appetite, growth retardation and impaired immune function in children. Studies have shown that taking zinc at the start of a cold reduces the length of the illness by shutting down inflammation, ensuring that the immune response is controlled. If there’s not enough zinc available, the inflammation continues. The body doesn’t store zinc, so daily intake is essential. The RDA for children aged one to eight years is three to five milligrams, increasing as the child gets older.
- An apple a day keeps the doctor away and in a way, it’s true! It’s the vitamin C in the apple that we’re after. Studies show that supplementing with vitamin C can prevent and treat respiratory and systemic infections by helping the cells that form a barrier to the invading pathogens (bugs). When the body is fighting an infection, the levels in the blood dramatically drop, and requirements rise. Your body does not store vitamin C or produce it on its own, and excess is flushed out of the body via urine (people who are prone to kidney stones should avoid large doses). Vitamin C supplements are cheap, easy to take and give to children, and readily available, so they go in my top three immune supporters. Remember to look at the ingredients and make sure there are no additives like fillers or sweeteners in your supplements.
- We tend to think that because we live in such a sunny country that we get plenty of vitamin D, which is produced in the skin after exposure to sunlight. But many of us cover ourselves in the sun. We put our children in sunsuits and slather them in sunscreen, which blocks vitamin D absorption. Infants and children, the elderly and those with darker skins are most at risk for low vitamin D levels. Vitamin D can modulate innate and adaptive immune responses. Deficiency in vitamin D is associated with increased autoimmune disease as well as increased susceptibility to infection. Low levels have particularly been shown to lead to frequent respiratory tract infections.
- Elderberry has a long history of traditional use, and for good reason. The flowers and berries of Sambucus nigra, are the most studied. One random study showed taking 15ml of the syrup four times a day saw flu-like symptoms clear up on average four days earlier than participants who took a placebo syrup. Another study showed that elderberry extract can inhibit coronavirus which causes bronchitis and pneumonia. Elderberry can be used as both a preventative tonic and as a treatment. The berries have a low risk of adverse effects but other parts of the plant, however, should not be eaten. Always ensure you are taking a properly prepared extract.
Disclaimer: Always speak to your doctor before beginning a course of treatment.