In a study published in the Journal of Cancer Research, Dr. Fahed
Hakim, of Rambam Health Care Campus, concluded that poor-quality sleep marked
by frequent awakenings can speed cancer growth, and increase tumor
aggressiveness, malignancy, and invasiveness. This is the first time a
connection has been made between poor sleep and cancer.
For the project, Hakim, a pediatric pulmonary and sleep expert at Rambam,
spent two years at the University of Chicago, and led a joint team, composed of
researchers from that institution and the University of Louisville.
While studies have long connected fragmented sleep with fatigue and
irritability, this research project indicated far more dramatic effects.
According to Hakim, over the long term, disrupted sleep dampens the immune
system’s ability to eradicate tumor cells and contributes to the spread of the
Hakim and his fellow researchers observed two sets of mice. One group was
allowed to sleep normally, while the other had its sleep interrupted. The mice
were injected with two different types of cancer cells—all the mice began to
develop malignant tumors. After a month, the researchers found that tumors of
mice with fragmented sleep were twice as large as those from mice that had
In a subsequent experiment, researchers found that the
cancerous tumors in sleep-disrupted mice were not only larger, but more
malignant and aggressive than those in mice that slept normally. The tumors of
the sleep-disrupted group were not static, but invaded surrounding muscle and