The death rate had already begun declining from about 1870 and continued to do so until 1930, rose slightly during 1930 and 1940 (the period of the great economic depression followed by World War), but since the 1950s
Accounted for up to half the reduction in death rate, and was particularly important in reducing the number of deaths from TB. Better nutrition increased resistance to infection and increased the survival chances of those who did become infected.
McKeown does not explain why females receive a smaller share of the family food supply or why deaths from some infectious diseases, such as measles and infant diarrhoea, actually rose at a time of improving nutrition
Improved medical knowledge and organisation did help to reduce death rates. These included the introduction of antibiotics, blood transfusion, improved maternity services, as well as the setting up of the National Health Service. More recently, improved medication, better surgery and other developments have reduced deaths from heart disease by one-third.
The greatest fall in death rates in the 20th century came not from medical improvements but simply from a reduction in the number of people smoking. However, in the 21st century, obesity has replaced smoking as the new lifestyle epidemic.
More effective central and local government with the necessary power to pass and enforce laws led to a range of improvements in public health and the quality of the environment. These included improvements in housing, better ventilated and less overcrowded accommodation, clean drinking water, laws to combat the adulteration of food and drink, the pasteurisation of milk, and improved waste disposal methods. Similarly, the Clean Air Act reduced pollution, such as the smog that led to 4,000 deaths in London in 1952.
The decline of dangerous manual occupations such as mining, smaller families reducing the spread of infection, and higher incomes allowing for a healthier lifestyle.
Males born in England in 1900 could expect on average to live until they were 50 (57 for females), while males born in the UK in 2018 can expect to live on average for 87.6 years (90.2 years for females)
The average age of the UK population is rising. In 1971, it was 34.1 years. By 2020, it stood at 40.4. By 2037, it is expected to reach 42.8. There are fewer young people and more old people. The number aged 65 or over equalled the number of under-15s for the first time ever in 2014.
Those living in the North and Scotland have lower life expectancy than those in the South, and working class men in unskilled or routine manual occupations are more likely to die before they are 65 than those in managerial or professional occupations
Those living in the poorest areas of England die on average seven years earlier than those in the richest areas, while the age of onset of disability-free life expectancy is 17 years lower
The effects of an ageing population include changes in family and household structures, as well as the economic and social consequences of a larger proportion of the population being elderly