The Office for National Statistics (ONS) and Public Health England, have carried out analysis of weekly and monthly death figures.
This comes after the 2015 provisional data showed the highest number of deaths in a single year since 2003 and the highest year on year percentage increase since 1968.
Analysis showed the largest rise in the number of deaths in England and Wales in over a decade was a result of an increase in dementia and Alzheimer's related deaths and respiratory diseases (including flu) among older people.
Jeremy Hughes, Chief Executive of Alzheimer's Society, said:
'With 1 in 6 deaths in England and Wales of people over the age of 75 now attributed to dementia, these findings serve as a stark reminder of the need for good community care to support the most vulnerable.
'People living with dementia often have a lowered immune system and so are at a greater risk of contracting flu viruses. The condition also makes it harder for people to look after themselves and in the cold winter months this can become a real danger.
'This increase also reflects more accurate recording and increased awareness of dementia. Health and care staff are increasingly recognising dementia as a cause of death as opposed to a natural part of ageing. By 2025 over 1 million people will have the condition, with this number only set to increase, making it one of the biggest health and social care challenges we face.'