Ever noticed that you’re more likely to catch a cold when you’re feeling stressed and run down? Paul Keogh explains how stress affects your immune health and suggests strategies to support both your ability to cope under pressure and your resistance against minor infections.

As healthy people, each of us has different and fluctuating levels of susceptibility to minor infections like colds and flu.

These natural variations in immune responses can be influenced by a number of factors, including your age and genetic make-up, your lifestyle (including your diet and exercise habits, and whether you smoke or drink), and whether you’ve had an infection recently.

Chronic stress and the common cold

Not everyone who’s exposed to a cold virus gets infected, and not everyone who’s infected by a cold virus ends up and experiencing symptoms.

However, being stressed can increase the likelihood that both of these will occur.

Interestingly, short bursts of stress may temporarily boost certain kinds of immune cell activity.

On the other hand, chronic stress (stress that persists for a month or more) may have a dampening effect on key types of immune cells, which may, in turn, diminish resistance to infection.

For example, long-term stress has been shown to decrease the activity of NK cells, specific immune cells that play an important role in defending us against infections by viruses (including the rhinoviruses responsible for causing colds), and to reduce their numbers. Other immune cells called T cells and B cells are also affected.

What types of stress affect immune resistance?

Links to reduced immune function and increased susceptibility to the common cold have been documented for many different forms of stress, including:

• Mental and emotional stress
• Overwork and work-related stress
• Social stress, such as ongoing family conflict or problems with friends
• Financial stress, as measured by unemployment or under-employment
• Physical stress, such as participating in very strenuous exercise
• Acute and chronic sleep deprivation

Herbs to support immune health and boost stress resistance

Astragalus is used to support immune defenses, reduce the frequency of colds and flu and aid recovery after an illness in traditional Chinese medicine (TCM).

Siberian ginseng is traditionally used in a similar way in Western herbal medicine to help maintain immune health, address lowered resistance to mild infections and support convalescence.

Both herbs have been shown to support healthy immune responses, including the stimulating activity of NK cells, which have an antiviral role in the immune system.

Both are also used in their respective herbal traditions to relieve fatigue, and improve vitality and general wellbeing, with Siberian ginseng having additional benefits for improving the ability to cope with stress.

Herbal relief for coughs and colds

If you do catch a cold or a mild upper respiratory tract infection, taking andrographis may help your symptoms feel better and reduce their duration. Think of it for relieving symptoms like a sore throat, runny nose, sinus congestion, headache, and mild fever. It may also help relieve the symptoms of mild tonsillitis and laryngitis.

Other herbs to consider if you’re feeling under the weather include the Western herbs elecampane and white horehound and Chinese herb pinellia, which are traditionally regarded as having expectorant properties and taken to ease the coughing of mild bronchitis and bronchial coughs. These herbs are suitable for use with both wet (productive) and dry (non-productive) coughs.

If your cough is particularly dry and irritating, consider Chinese licorice and aster, which are used to address dryness of the airways and support healthy lung function in TCM.

Low zinc intake and immune health

Dietary issues should also be taken into consideration when immune resistance against infection is poor.

For example, data from the Australian Bureau of Statistics (ABS) indicates that a significant percentage of Australians don’t consume the recommended quantities of zinc, which is important for healthy immune function. This issue is particularly concerning for males, among whom more than a quarter of all teenagers, more than a third of adults under 50 and more than half those aged in their 60s and older have inadequate intakes.

When levels of zinc in the diet are inadequate, taking a zinc supplement may help strengthen lowered resistance to infection.

TIP: Look for a formula containing zinc glycinate, which is a highly bioavailable form of zinc, and is more readily absorbed than some other forms (such as zinc sulfate).

Zinc works alongside vitamin C, which also supports immune health, and can also be taken with immune-boosting herbs like andrographis and the traditional Western herb echinacea.