Genes control lonely hearts

Many people have felt the odd pang of loneliness – but now scientists think it could be all down to our genes.

“Social isolation reaches down into some of our most basic internal processes – the activity of our genes.”

Recent research at the University of California Los Angeles (UCLA) and the University of Chicago has revealed that gene-expression patterns vary noticeably between people who feel lonely and people who don’t. The findings will aid the understanding of why social factors are linked to an increase risk of health problems.

The team think that for lonely individuals, undesirable health consequences are more than a result of reduced social resources such as physical or economic help. The lead author, Dr Steven Cole of UCLA School of Medicine said: “Social isolation reaches down into some of our most basic internal processes – the activity of our genes.”

Dr Cole and his group chose 14 participants – six who scored in the top 15% of the UCLA loneliness scale and eight who scored in the bottom 15%.  By using DNA microarrays to monitor the activity of the known human genes in the white blood cells they found that over 200 transcripts were differentially expressed between the two groups.

Those rated ‘highly-lonely’ showed overexpressed genes including many involved in the immune system, however several key genes such as those responsible for antibody production and antiviral responses were underexpressed.

Dr Cole said: “The differences we observed were independent of other known risk factors for inflammation, such as health status, age, weight, and medication use. The changes were even independent of the objective size of a person’s social network.  What counts, at the level of gene expression, is not how many people you know, its how many you feel really close to over time.”

The group hope to use the transcriptional fingerprint as a biomarker to judge the effectiveness of new methods to reduce the impact of social distance on health.
Leila Sattary