How to Age Better

Life expectancy has been increasing around the world over the past decades, a happenstance that is attributed to advances in public health and healthcare services.  However, the last few years have rocked this boat and it is predicted that the current generation of adolescents is likely to be the first to have a shorter life expectancy than their parents (1). How can this be?

The aging of a population is associated with increased risks of chronic non-communicable diseases such as cardiovascular disease; type-2 diabetes; obesity; cancers; respiratory, liver and kidney diseases; dementia; and auto-immune diseases, all of which culminate in physical or cognitive disability and premature death.  The mounting challenge of dealing with the rising incidence of chronic disease is overwhelming current medical care facilities and threatening economies.  Fortunately, we now know that many of the risk factors for chronic illnesses are modifiable and it has been widely acknowledged that unhealthy lifestyles are at the root of both the onset of disease and premature death. There is a critical need right now for both governments and healthcare providers to change their focus from new medications and disease treatments towards health policies that aim to preserve overall health and promote a lasting high quality of life for their citizens/patients as they age.  (2,3)

To this end, recent research has been looking into the potential beneficial effects on aging from a healthy lifestyle.  Two examples follow.

 

2018 Study – “Impact of Healthy Lifestyle Factors on Life Expectancies in the US Population” (2)

Scientists involved in this investigation wanted to examine the impact of low-risk lifestyle-related factors on life expectancy and premature death.

Method Details:

Using data from two very large and long-running cohort studies, the Nurses’ Health Study (NHS)(1980 to 2014) and the Health Professionals Follow-up Study (HPFS)(1986 to 2014), they quantified the association between low-risk lifestyle-related factors and death.  Next, data from the NHANES study (2013 to 2014) estimated the distribution of lifestyle-related factors among the US population.  Adding in death rates of Americans from the CDC WONDER database, the investigators were able to estimate the extended life expectancy associated with each individual lifestyle factor and with a combination of low-risk lifestyle factors.

Five modifiable low-risk lifestyle-related factors were defined as follows;

• Never smoking
• Body mass index (BMI) of 18.5 to 24.9 kg/m2
• At least 30 minutes per day of moderate to vigorous physical activity
• Moderate alcohol intake
• Eating a diet high in quality. Diet quality from all three trials, NHS, HPFS and NHANES, was assessed through the use of the Alternate Healthy Eating Index (AHEI) that is strongly associated with the onset of many chronic diseases in the general population.

 

Results:

• For those who followed no low-risk lifestyle-related factors, their life expectancy at the age of 50 was projected to be 79 years for females and 75.5 years for males.
• For those who followed all five low-risk lifestyle-related factors, their life expectancy at the age of 50 was projected to be 93.1 years for females and 87.6 years for males.
• In other words, adherence to low-risk lifestyle-related factors could prolong life expectancy at the age of 50 years by 14 years in women and 12.2 years in men.
• Results of the study’s sensitivity analysis further indicated that combinations of the healthy lifestyle factors were particularly powerful; the larger the number of low-risk lifestyle-related factors, the longer was the potential prolonged life expectancy, regardless of the combined factors.

 

2023 Study – “Association between plant-based dietary pattern and biological aging trajectory in a large prospective cohort.” (3)

The second investigation recruited 10,191 participants 50 years of age or older from four health clinics in Taiwan. The participants completed a self-administered questionnaire on their personal and family medical history, lifestyle and demographics (age, sex, education and marital status) and, at each health check-up during the study, underwent a physical examination along with blood and urinary tests. Dietary patterns were evaluated at the beginning of the trials through a validated food frequency questionnaire using the plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI). Researchers also employed a recently developed measure of biological aging at four time points within the first 5.1 years of this study to assess associations between aging and the intake of plant-based foods.  Biological age is considered a more accurate measure of aging than chronological age because it considers multiple measures of physical function and overall health.  After the data collection ended at 5.1 years, the participants were followed for a further time period of approximately 8.4 years.

Method Details

Since dietary intake was integral to this study, here are some details about how plant-based dietary patterns were evaluated. 

Foods were placed into 14 food groups and then divided into plant foods and animal foods.

The plant foods included whole grains, fresh vegetables, fresh fruit, rhizomes, legumes, sugar, refined grains, and salt-preserved vegetables.

The animal foods included milk, dairy products, fish and other aquatic products, eggs, meat and organ meats.

Participants were asked to fill out a questionnaire regarding how often on average during the previous year they had consumed a standard portion size of each food.

Scores were given for each food group according to intake frequency.  For example, a score of 5 was assigned for the highest frequency and 1 for the lowest frequency of plant foods (positive scores) while a score of 1 was given for the highest frequency and 5 for the lowest frequency of animal foods (reverse scores).  In other words, the higher the frequency of eating plant foods and the lower the frequency of eating animal foods, the higher was the PDI (plant-based diet index).

However, not all plant-based foods are beneficial to aging over the long term.  Accordingly, the healthy PDI (hPDI) and unhealthy PDI (uPDI) were created to represent healthy and unhealthy versions of a plant-based diet.

Healthy plant foods included whole grains, fruits, vegetables, rhizomes and legumes.

Less healthy plant foods included sugar, refined grains and salt-preserved vegetables.

To calculate hPDI, positive scores were assigned to healthy plant food groups and reverse scores were assigned to less healthy plant and animal food groups.

To calculate uPDI, positive scores were assigned to less healthy plant food groups and reverse scores were assigned to healthy plant and animal food groups.

The goal was that hPDI and uPDI would account for the quality of plant foods in calculating the overall PDI.

 

Researchers also determined a multi-dimensional aging measure based on a combination of chronological age and thirteen health biomarkers including systolic blood pressure; fasting blood glucose; BMI; platelet count; leukocyte count; forced expiratory volume; and levels of creatinine, albumin, urea and certain important enzymes.  This allowed the scientists to assess each participant as physiologically older or younger than their chronological age and was re-evaluated four times within the 8-year period after initial enrollment..

 

Thus participants were placed into one of three classes of accelerated aging trajectories.

• Slow aging trajectory: About 47.18% of the study participants made up this group and these individuals had a lower biological age than their chronological age over all four measurements taken.
• Medium-degree accelerated aging trajectory: About 47.63% of the study participants were grouped in the medium aging trajectory.  They displayed a medium level of aging at the beginning of the research which didn’t change appreciably throughout the whole study period.  They showed a disease rate of about 61.08% at the start of the study with 7.70% of them dying during the follow-up time.  Participants in this group had a 1.56-fold higher risk of dying from any cause during the follow-up time compared to those in the slow aging trajectory group.
• High-degree accelerated aging trajectory: The rest of the study participants (5.19%) were in this category, displaying a consistently high level of accelerated aging over the four measurements taken.  17% of these individuals died during the follow-up period.  Participants in the high-degree accelerated aging trajectory had a 3.72-fold high risk of dying from any cause during the follow-up time compared to those in the slow aging trajectory group.

Results of this study:

• Higher risks of death were shown for people in medium and high aging trajectories compared to those in a slow aging trajectory.
• Adopting an overall plant-based dietary pattern (PDI) was associated with lower odds of being in a medium or high aging trajectory.
• Adopting a healthful plant-based diet (hPDI) was more beneficial for aging than adopting an unhealthful plant-based diet (uPDI).
• Fresh fruits, fresh vegetables and legumes were the major contributors to the positive health effects from the hPDI while refined grain, salt-preserved vegetables, dairy products and organ meats were the major contributors to the negative effects from the uPDI.

 

Further to this, the investigation illustrated that;

• Diet is one of the primary modifiable lifestyle factors.
• Plant-based dietary patterns prevent the development of chronic diseases.
• Plant-based dietary patterns promote better neurological health during aging including lower risk of dementia and cognitive impairment
• Both overall plant-based dietary patterns (PDI) and healthy plant-based dietary patterns (hPDI) may slow the aging process.
• More frequent consumption of unhealthy plant-based dietary patterns (uHDI) can accelerate the aging process.

 

Take Home Message

These two scientific studies provide compelling evidence that people who consume a diet rich in whole plant-based foods may cut their risk of accelerated aging by about a third compared to people following an unhealthy plant-based or animal-based eating pattern.  Moreover, the participants of these studies were not youngsters.  The Nurses’ Health Study and the Health Professionals Follow-Up Study both began during the 1980s and their participants were followed for many years.  The participants of the 2023 study were all 50 years of age or older.  So don’t tell yourself that its too late to turn back the clock.

Governments and other large agencies like healthcare providers are notoriously slow in adapting major changes.  But there’s no need to wait until they do.  Embracing a healthy eating plan at any age that emphasizes fruits, vegetables, legumes and other plant-sourced foods can slow your personal rate of aging and lower your own risk of developing a chronic disease.  This not only means adding multiple years to your life but healthy years that are more likely to be enjoyable years.  Isn’t that what we are all hoping for?

  

SOURCES:

1  https://kenanfellows.org/curriculum_proj_ref/shorted-first-generation-shorter-life-expectancy-parents/

2  Li, Y., Pan, A., Wang, D.D., Liu, X., Dhana, K., Franco, O.H., Kaptoge, S., Di Angelantonio, E., Stampfer, M., Willett, W.C., Hu, F.B. Impact of Healthy Lifestyle Factors on Life Expectancies in the US Population. Circulation. 2018 Jul 24;138(4):345-355. Doi: 10.1161/CIRCULATIONAHA.117.032047.

3  Wang, S., Li, W., Li, S. et al. Association between plant-based dietary pattern and biological aging trajectory in a large prospective cohort. BMC Med 21, August 2023; 310.  https://doi.org/10.1186/s12916-023-02974-9.