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Health Measures

Why are we sampling Saliva?

From saliva we can measure two chemicals - IgA, part of the immune system, and cortisol, which helps us adapt to stress.

IgA is the shortened name for an antibody called Immunoglobulin A. IgA is responsible for recognising and stopping germs such as bacteria and viruses when we breathe or eat. Many things affect IgA, including exposure to germs, our diet, exercise, tiredness and stress. We are studying IgA because it reflects our capacity to fight disease now, and could be important for future health.

Cortisol reflects how the body is responding to stress. It helps us adapt to everyday challenges by preparing our bodies for action. Cortisol can also influence the immune system and how we metabolise blood sugar, which may also be important for predicting future health.

 

How do we take the saliva samples?

Taking saliva samples is quick, simple, and non-invasive. We need three samples to get a good measure of IgA and cortisol, and they must be kept frozen.
We use sterile cotton tipped sticks, like a pointy cotton-bud. Simply put two of the cotton sticks into your mouth (between the gum and cheek or under the tongue) and hold for one minute or until completely wet. They are then kept frozen until we return to pick them up.

 

 

 

What affects the sample?

Four things affect IgA and cortisol - sickness, sleeping, time of day and eating. That is why we ask you to take the samples only between 4pm and 7pm, before food (or at least an hour after food), to wait at least half an hour after having a sleep, and not to take a sample if you (or your child) are sick.

How can we tell how much IgA and cortisol is in saliva?

We measure the amount of IgA and cortisol in your saliva in a laboratory. A colour is produced when we treat the saliva with a series of chemicals. The amount of colour shows much IgA or cortisol is present, which is calculated by a computer.

Why are we taking afternoon/evening samples?

Both cortisol and IgA are naturally produced in a daily rhythm. Levels of IgA and cortisol are usually highest in the morning before waking, and then fall during the day. For most people, levels are stable between 4pm and 7pm, which is why we try to get the samples then.

What about privacy?

Your name, address and contact details are securely stored separate from your samples and data. No sample is identified by name. No identifying Information about you or your family will ever be published.