Final answer:
Longer lifespans have been associated with a healthy diet, regular physical activity, better public health systems, and advancements in medicine, including immunizations. Observations from Blue Zones and historical trends show these factors contribute to increased life expectancy.
Step-by-step explanation:
When examining the factors that contribute to higher lifespan, several elements have been identified based on observations of Blue Zones and various health studies:
- Adherence to a healthy diet high in vegetables and low in animal products, with exceptions for eggs and fish.
- Engaging in regular physical activity and maintaining a lively social life.
- Improvements in public health infrastructure, such as providing clean water and safe disposal of human waste.
- Advancements in medicine, including the development of immunizations and public health campaigns that promote behaviors like hand washing and smoking reduction.
These practices have contributed to significant increases in life expectancy over the past century, shifting the average in the United States from 47 years in 1900 to 79 years by 2015.