Alzheimer's disease and other dementias are now the leading cause of death in England and Wales, knocking heart disease off of the top spot for the first time, according to new figures from the Office of National Statistics (ONS).

In 2015, of the 529,655 deaths registered during 2015, dementia accounted for 11.6 percent (61,686), while ischaemic heart disease accounted for 11.5 percent.

The rise in dementia deaths is largely down to the ageing population as life expectancy continues to improve, as well as a better understanding of the condition which has led an increase in diagnoses and thus listing of the condition on death certificates, the ONS said.

"These figures once again call attention to the uncomfortable reality that currently, no-one survives a diagnosis of dementia," said Hilary Evans, chief executive of Alzheimer's Research UK.

"With growing numbers of people living with dementia, we urgently need treatments that can stop or slow the diseases that drive this devastating condition," she said, and stressed the potential for medical research and public policy "to make a positive impact on the health of our nation".

"Thanks to better treatments and prevention programmes, deaths from many other serious conditions have been steadily dropping: now we must do the same for dementia. Dementia is not an inevitable part of ageing, it's caused by diseases that can be fought through research, and we must bring all our efforts to bear on what is now our greatest medical challenge."

The ONS data also showed that for males, ischaemic heart diseases continued to be the leading cause of death, accounting for 14.3 percent of all male deaths in last year versus 14.8 percent in 2014, while for women it was dementia and Alzheimer disease, causing for 15.2 percent of all female deaths, up from 13.4 percent the year before.