Healthy Lifestyle Increases Life Expectancy

Maintaining a healthy lifestyle during middle-age is associated with a longer life expectancy that is free from major chronic diseases, such as cancer, Type 2 diabetes and cardiovascular disease, reports a new study published in the British Medical Journal (BMJ). The study sheds new light on why life expectancy can be drastically reduced (ranging from 7.5 to 20 years) in middle-aged persons who suffer from the three major chronic diseases, compared to their peers without these conditions. The study was conducted by an international, multidisciplinary team of physician-scientists, led by the Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.

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Objectives of the Study

The primary objective of the study was to examine whether leading a healthy lifestyle during mid-life could prolong life expectancy and keep individuals free of chronic diseases such as cancer, Type 2 diabetes and cardiovascular disease.

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Study Design

This was a prospective cohort study. A total of 111,562 participants were recruited from two major studies:

• Nurses’ Health Study: Conducted between 1980-2014 (n=73,196)
• Health Professionals Follow-Up Study: Conducted between 1986-2014 (n=38,366)

Questionnaires were used to collect information from the participants on the following aspects:

• Age
• Ethnicity
• Regular use of multivitamins and aspirin
• Whether undergoing postmenopausal hormone replacement therapy
• Family history of diabetes, cancer, or myocardial infarction

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Lifestyle Factors

The following 5 low-risk lifestyle factors were taken into account:

• Smoking Status: Information on smoking status was self-reported by the participants. The smoking status was categorized as:
• Never smokers
• Current smokers
• Past smokers
• Current smokers were further categorized as:
• Smoking 1-14 cigarettes/day
• Smoking 15-24 cigarettes/day
• Smoking ≥ 25 cigarettes/day

• Body Mass Index (BMI): For calculating BMI (weight in kg/height in m²), the weight and height were self-reported by the participants. The BMI was considered to be healthy if it ranged between 18.5-24.9
• Physical Activity: Physical activity was assessed using a validated questionnaire. The intensity of physical activity, including brisk walking, ranged between moderate and vigorous for a duration of ≥ 30 minutes/day
• Alcohol Intake: Alcoholic drinks that were taken into consideration included red and white wine, beer, and spirits. Alcohol consumption of the participants was considered to be moderate if:
• Men consumed 5-30 g/day
• Women consumed 5-15 g/day
• Quality of Diet: The diet quality was assessed by the Alternate Healthy Eating Index (AHEI) Score. A diet was considered to be healthy if it had an AHEI Score in the top 40 percent of each cohort

Key Findings of the Study

• Total life expectancy at 50 years of age increased with the adoption of an increasing number of low-risk lifestyle factors. The life expectancy of the participants ranged between:
• Men: 31.3 to 39.4 years
• Women: 31.7 to 41.1 years
• Life expectancy of the participants who were free from cancer, Type 2 diabetes , and cardiovascular disease at 50 years of age, were as follows:
• Men who adopted no low-risk lifestyle factors: 23.5 years
• Men who adopted 4 or 5 low-risk lifestyle factors: 31.1 years
• Women who adopted no low-risk lifestyle factors: 23.7 years
• Women who adopted 4 or 5 low-risk lifestyle factors: 33.4 years
• The following categories of participants accounted for the lowest proportion (≤ 75%) of total life expectancy at 50 years of age:
• Men who were heavy smokers: ≥ 15 cigarettes/day
• Obese men and women: BMI ≥ 30

Expert Comments & Policy Recommendations

The researchers indicated: “Our findings suggest that promotion of a healthy lifestyle would help to reduce the healthcare burdens through lowering the risk of developing multiple chronic diseases, including cancer, cardiovascular disease, and diabetes, and extending disease-free life expectancy.”

With reference to framing policies, they added: “Public policies for improving food and the physical environment conducive to adopting a healthy diet and lifestyle, as well as relevant policies and regulations (for example, smoking ban in public places or trans-fat restrictions), are critical to improving life expectancy, especially life expectancy free of major chronic diseases.”

Concluding Remarks

The researchers concluded: “Using data from two large cohort studies, we observed that adherence to a low-risk lifestyle was associated with a longer life expectancy at age 50 free of major chronic diseases of approximately 7.6 years in men and 10 years in women compared with participants with no low-risk lifestyle factors.”

Reference:

1. Healthy Lifestyle and Life Expectancy Free of Cancer, Cardiovascular Disease, and Type 2 Diabetes: Prospective Cohort Study - (https://doi.org/10.1136/bmj.l6669)

Source-Medindia