At what age does your immune system weaken?

As we age our immune function can naturally start to weaken, but when does this actually happen? In this article, I explore at what age your immune function starts to decline, factors that can cause it to weaken earlier and how can you help protect it.

At what age does your immune system weaken?

The effects of an 'ageing' immune system, called immunosenescence, is thought to affect over 60's. However, pro-inflammatory habits including smoking and stress can cause your immune system to weaker much earlier, from as young as in your 30's. However, healthy lifestyle practices such as eating well or sleeping more could help delay these processes.

How does the immune system change with age?

Your immune system may become less effective in a number of ways as you age:

You become more likely to fall ill. This can happen as some of your innate immune barriers become less robust (such as your skin or stomach acid), or if your immune cells become slower to respond or less able to communicate as effectively.
Recovery from illness takes longer. This happens as many of your immune cells such as white cells become fewer or less capable of fighting infections and allowing you to recover.
You may not respond quite as well to vaccines. Your response to vaccines is still somewhat reliant on a strong immune function. You need specific immune cells such as T cells to be working optimally in order to be able to respond optimally to vaccinations, and these can risk depleting in numbers and function as we get older too. (1)

Whilst inflammation is also an important part of our immune response, research suggests that a younger person's immune system can usually easily switch off the pro-inflammatory response after an infection or injury, this may not be so effective in older individuals. This can result in an accumulation of low-grade inflammation as we age, often called 'Inflammaging' which may make immune dysfunction even more apparent. (2)

Who’s most at risk of depleted immune functions?

Underlying inflammation undermining functions of the immune system is thought to more common in the over 60's. However, some research suggests that other groups may also be more at risk and here's why:

Over 30's – As well as the over 60's, researchers have also flagged another age range where significant changes could potentially affect immune function and that is those in their late 30's to early 40's. This age range marked a risk for a significant change in immune function. (2,3)
Menopausal women – The changes going on in a women's body during menopause put the body under a degree of stress. Unfortunately stress and the immune system don't often work well together, especially when the source of stress is chronic, meaning it isn't particularly short-lived. Our Menopause expert Eileen explores more on this topic in one of her recent blogs.
Men – As much as the menopause may have some negative effects on immune functions, it seems that men aren't exactly exempt. In fact, it seems by post-menopausal age, men start to overtake women and become more vulnerable to declining immunity once more.

See, some research suggests that men may experience more pronounced immuno sescence in their early to mid-60's, whilst women only become more affected by the time they reach late 60s and even into their 70's, on average. Interestingly, this age difference also mimics the difference in the average life expectancy between the sexes, highlighting just how important maintaining a robust immune function is. (2,3)

What can help your immune function stay stronger for longer?

Despite certain groups being slightly higher risk, everything you do in terms of your diet and lifestyle can help to keep your immune functions healthier for longer. The same applies to younger people – if you hit your immune system with a barrage of unhelpful habits, your immune system could risk aging before its years at the hands of excess inflammation.

To help limit inflammation and keep your immune system fighting fit for longer, my advice is as follows:

1. Follow an anti-inflammatory diet

As inflammation seems to be the underlying process that ages your immune system, routinely including lots of anti-inflammatory dietary components seems like the best approach in tackling the issue. Some of my favourite anti-inflammatory foods that have lots of immune-supporting research behind them include: omega-3 oils found in oily fish and nuts and seeds including walnuts or chia seeds (4), spices such as turmeric (5), or colourful antioxidant-rich berries. (6)

Remember, the key is to include these routinely in your diet, in their original food states where possible, and as part of a healthy balanced diet elsewhere.

2. Sleep more

Sleep is an underrated anti-inflammatory activity. During this relaxed state many of your bodily systems are actually at their most active, including your immune system. If you routinely don't get a sufficient quantity (7-9 hours for most), and good quality sleep (something that certain medications, or stress states can scupper), then your immune system could suffer.

If you're keen to do something to help support better sleep, my advice would be to retire to bed slightly earlier in the evening. The immune-boosting potential of sleep may be even more powerful in these earlier hours, which we may struggle to get back if we nod off too late.

3. Keep moving

Keeping fit and active is good at any age, but perhaps it's even more important as you get older in order to help further support your immune system during these years. A short spell of exercise puts your body into a mild state of 'stress' which actually helps to stimulate your immune function. However, if you over-do it, this can have the opposite effect which is why over-training isn't advised. (7)

So, little and often is key, which seems much more manageable for most anyway!

4. Avoid inflammatory practices

Many of the most pro-inflammatory habits are fairly obvious such as stopping smoking or reducing your alcohol consumption. But others may be less obvious such as managing stress that little bit better, maintaining a healthy body weight, reducing exposure to toxins in our environment such as pesticides in food or chemicals in beauty or cleaning products, plus, always practicing sensible sun exposure.

Remember, every little helps in reducing your inflammatory load and helping to keep your immune system youthful.