What factors influence life expectancy and how can it be improved?

Factors Influencing Life Expectancy and Strategies for Improvement

Multiple lifestyle factors significantly impact life expectancy, with adoption of all eight key healthy lifestyle factors potentially extending life by up to 24 years for men and 20.5 years for women compared to those with no healthy lifestyle factors. 1

Key Determinants of Life Expectancy

Lifestyle Factors

• Never smoking, maintaining healthy physical activity levels, avoiding excessive alcohol consumption, getting restorative sleep, proper nutrition, stress management, maintaining social connections, and avoiding opioid use disorder collectively contribute to increased life expectancy 1
• Adherence to a Mediterranean-style diet, maintaining a healthy BMI (18.5-24.9 kg/m²), regular physical activity (≥30 min/day of moderate to vigorous activity), and moderate alcohol intake can extend quality-adjusted life years by up to 2 years 2
• Dietary changes alone can significantly impact longevity, with shifts from unhealthy to healthy dietary patterns potentially increasing life expectancy by 8.9 years for men and 8.6 years for women at age 40 3

Environmental and Social Determinants

• Environmental factors including diet quality, water and air pollution contribute to decreased healthy life years 4
• Socioeconomic factors such as lower socioeconomic position, chronic stress related to adverse childhood experiences, poverty, depression, and experiencing racism are linked to increased inflammation, early development of chronic conditions, and accelerated aging 4
• Limited community resources, socioeconomic opportunity, and healthcare access negatively impact life expectancy 4
• Racial and ethnic disparities exist in life expectancy, with significant gaps between different populations 4

Biological Aging Factors

• Biological age (as opposed to chronological age) is influenced by genotype, sleep quality, chronic stress, multiple chronic conditions, and environmental exposures 4
• Allostatic load (accumulated damage from life course exposures) manifests as deterioration across multiple physiological systems and predicts frailty, comorbidities, and mortality 4
• Sarcopenia (severe loss of muscle mass) predicts various health outcomes including physical function and mortality 4

The Paradox of Modern Life Expectancy

• While overall life expectancy tends to increase in Western countries, healthy life years (HLYs) are decreasing, resulting in approximately 20 years of life spent with chronic disease 4
• From 2008 to 2010, HLYs decreased by approximately 12 months in France, representing a 1% net loss of healthy life despite gains in overall longevity 4
• This paradox highlights the need to focus not just on extending life but on maintaining health throughout the lifespan 4

Strategies to Improve Life Expectancy

Individual-Level Interventions

• Adopt all five key lifestyle factors: never smoking, maintaining healthy BMI (18.5-24.9 kg/m²), regular physical activity, moderate alcohol intake, and high diet quality 5
• Increase consumption of whole grains, nuts, and fruits while reducing sugar-sweetened beverages and processed meats 3
• Maintain social connections and practice stress management techniques 1
• Ensure adequate, restorative sleep 1

Population-Level Approaches

• Implement preventive nutrition strategies focusing on holistic dietary patterns rather than isolated nutrients 4
• Address social determinants of health through policy interventions targeting poverty, education, and healthcare access 4
• Develop sensitive methods to screen for accelerated biological aging across broader age ranges 4
• Implement both population-wide and high-risk individual strategies for cardiovascular disease prevention 4

Measuring Impact on Life Expectancy

• The population-attributable risk of non-adherence to five low-risk lifestyle factors is 60.7% for all-cause mortality 5
• The estimated life expectancy at age 40 for men ranges from 23.0 years (with no healthy lifestyle factors) to 47.0 years (with all eight healthy lifestyle factors) 1
• For women at age 40, estimated life expectancy ranges from 27.0 years (with no healthy lifestyle factors) to 47.5 years (with all eight healthy lifestyle factors) 1
• The difference in life expectancy between those in the 90th vs. 10th percentile of lifestyle characteristics is 23 years for males and 18 years for females 6

Special Considerations for Specific Populations

• Hispanic populations in the US show higher life expectancy (80 years) compared to non-Hispanic whites (77.5 years) and non-Hispanic blacks (72.3 years), despite similar cardiovascular risk factors—a phenomenon known as the "Hispanic paradox" 4
• American Indian/Alaska Native populations experienced a decline in life expectancy from 72 years in 2019 to 68 years in 2021, which is 7 years less than the general US population 4
• When estimating life expectancy for clinical decision-making (such as in cancer care), biological age rather than chronological age should be considered 4

By addressing these multiple factors through comprehensive lifestyle changes and policy interventions, significant improvements in both life expectancy and healthy life years can be achieved at individual and population levels.