A saliva test could predict how long we have got left to live, scientists claim.

Researchers found that levels of a particular antibody falls the nearer a person gets to death. To reach their conclusion, took samples from 639 adults in 1995 and tracked them over 19 years. They found that the levels of secretory immunoglobin A (IgA) fell the nearer the person got to death. Antibodies are used by the body to fight infection and are secreted by white blood cells.

The researchers said the chemical appears to be a marker of mortality risk, and is much less invasive than blood sampling. Testing levels of IgA could be used as way of looking at overall health by professionals as part of a general check-up.

Dr Anna Phillips, from the University of Birmingham, said: “There are a number of factors that can affect how well we produce antibodies and maintain their levels. There are some that we have no control over, such as age, heritability or illness, but our general state of health can also affect their levels; stress, diet, exercise, alcohol and smoking can all influence those levels. Quite how saliva samples could be used in check-ups remains to be seen, as we need to better understand what secretion rate would be considered cause for concern - what we call the protective level. We could certainly say that, if found to be extremely low, it would be a useful early indicator of risk.”

The team believe that the next step would be to follow up with a larger longitudinal study, to investigate the link with infectious diseases and the development progression of disease like cancer to provide a greater understanding of the mechanisms behind the association found in the study.

Other methods of predicting how long a person has to live have been developed based on questionaires. For anyone who can’t wait until the saliva test is developed, an online test called the UK Longevity Explorer has been developed which can determine whether someone will live for the next five years. The test could be used as way of looking at overall health by professionals as part of a general check-up

Can a person learn to empathize with strangers?

In order to put words peace on earth and goodwill to all into action, psychologists suggest that a person must feel empathy toward strangers - a quality not everyone possesses. A new study, however, claims such a quality can be learned.

Researchers suggest it is possible to learn to empathize with strangers.

Study co-author Grit Hein, a neuroscientist and psychologist from the University of Zurich in Switzerland, and colleagues found that surprisingly positive experiences with a stranger trigger a learning signal in brain cells that can increase empathy - the ability to understand a person’s feelings or experiences from their perspective. They recently published their findings in the Proceedings of the National Academy of Sciences.

Hein and colleagues note that a lack of empathy or compassion towards strangers is often what fuels conflict between individuals from different cultures and nationalities, suggesting that an increase in empathy could help alleviate such conflict.

For their study, the team conducted an experiment to determine whether a person can learn to empathize with strangers through positive experiences.

The research included two groups of participants; both groups were told they would be receiving a painful shock to the back of their hands, but they were also told a member of their own group (in-group members) or another group (out-group members) - representing strangers - could spare them the shock by parting with money.

The empathic brain responses of each participant were measured before and after they observed an in-group or out-group member experience pain.

At the beginning of the experiment, the researchers found that participants showed weaker empathic brain responses upon witnessing an out-group member experience pain, compared with an in-group member.

However, after only a few positive experiences with out-group members - in which out-group members paid money to stop members of another group experiencing pain - the team found in-group members showed increased empathic brain responses when seeing any member of the out-group suffer pain.

The researchers found that the stronger an individual’s positive experience was with a stranger, the greater the empathic brain response.

What is more, the team found that the increased empathic response was triggered by a learning signal in brain cells that occurs when one experiences a surprisingly positive experience with a stranger.

Based on their findings, the team believes just a handful of positive learning experiences with a stranger could enable a person to become more empathic.

Scientists from the University of Copenhagen in Denmark identified greater brain activity in five brain areas - linked to a number of emotional and spiritual functions - of participants who celebrated Christmas in response to Christmas-themed images, compared with participants who did not celebrate Christmas.

The team said their findings could lead to a treatment for what they call “bah humbug” syndrome.