How Healthy Plant-Based Eating Can Ease the Burdens of Aging

Further to my last post about the role of protein in healthy aging, here is another perspective regarding the benefits of maintaining good health throughout a lifetime.

Robust physical function in seniors is important for many aspects of living.  In addition to making everyday tasks more difficult, limitations in strength and mobility are linked to higher rates of falls, chronic diseases and early death.  Loss of muscle mass (sarcopenia) occurs naturally as we age with muscle volume decreasing by approximately 1 to 3% every year and muscle strength declining by 2.5 to 4% a year. Fortunately, the onset of sarcopenia can be substantially slowed down by maintaining an active lifestyle and eating healthfully.  (1)

Recently a study published in the journal Nutrients considered how adherence to plant-based diets relates to physical performance in middle-aged and older adults.  The participants in this investigation were 1521 men and women aged 40 years and older (average age of 68 +/- 13 years) who were followed from 2005 to 2018.  Assessments were conducted every 4 years for those younger than 60, every 2 years for those aged 60 to 79 and every year for those of 80 years of age and over.  Data collected included measurements of muscle function including handgrip strength, lower body strength, balance and mobility along with the quality of food being consumed. (2)

 Dietary intake of the participants was evaluated through food frequency questionnaires.   Because plant-based diets can vary widely in their composition, this analysis used the plant-based index (PDI) evaluation of the quality of foods being consumed by the participants which separates 18 different food groups into three concise groups based on the healthfulness of their nutrients. (2);

• Seven groups were designated as healthy plant-based groups. This group encompasses whole grains, fruits, vegetables, nuts, legumes, vegetable oils, and tea/ coffee.
• Five groups were designated as unhealthy plant-based groups. This group encompasses fruit juices, refined grains, potatoes, sugar-sweetened beverages, and sweets.
• Six groups were designated animal-based food groups. This group encompasses animal fats, dairy products, fish, meat, eggs, and miscellaneous animal-based foods.

 From these food group classifications, three diet types emerge and the study participants were placed into one of the diet types through the information they provided on the food frequency questionnaires.

• PDI – Overall plant-based diet. Positive scores were assigned to all plant-based foods being consumed, both healthy and unhealthy
• hPDI – Healthy plant-based diet. Positive scores were assigned to the consumption of healthy plant-based foods and negative scores were assigned to unhealthy plant-based foods.
• uPDI – Unhealthy plant-based diet. Positive scores were assigned to the consumption of unhealthy foods and negative scores were assigned to healthy plant-based foods.

In all three of the above categories, animal-based food groups including meat, fish, eggs, dairy products, animal fats and miscellaneous animal-based foods were scored negatively. (2)

 

What Did This Study Reveal (2)?

While simply following an overall plant-based diet (PDI) did not yield notable improvements, focusing on healthier plant-based foods (hPDI) did. Participants who closely followed an hPDI rich in fruits, vegetables, whole grains, and legumes demonstrated better short-term physical performance in tests of walking, sit-to-stand, balance, grip strength and enhanced overall physical function. Conversely, those who consumed more unhealthy plant-based foods (uPDI), such as sugary beverages and refined grains, exhibited poorer physical performance. These associations remain strong even after adjusting for lifestyle factors, demographics and the presence of medical conditions.  (2,3)

 Intake of animal-sourced foods was relatively similar in the hPDI and uPDI groups.  But the sources of positive changes in physical function were linked to higher intakes of nutrient-dense foods like fruits, vegetables, whole grains, nuts, coffee and tea suggesting that a high-quality plant-based dietary pattern plays a more important role in health than the effects of limited animal sources of food. This is likely due to the many essential nutrients that are beneficial for age-related health found within plants but missing in animal-sourced foods.   Plants are rich in essential omega-3 fatty acids, fiber and prebiotics, vitamins D, C, E and K, phytonutrients such as carotenoids and polyphenols and antioxidants. (2)

Note:  Prebiotics are food sources for the healthy microbes living in the gut microbiome which respond by creating short-chain fatty acids that boost health through direct effects in the gut as well as by decreasing muscle wasting, strengthening immunity and lowering inflammation and oxidative stress.

A study from the UK published in 2018 came to similar conclusions.  Data from the National Survey of Health and Development examined the dietary patterns of 969 participants and found that the eating pattern that was associated with better physical performance in older age was one of higher quality that incorporated greater amounts of fresh fruit, leafy vegetables and whole-grain bread and reduced consumption of white bread, added sugar and processed meat.  This finding was consistent among people of different ages. (4)

 

Final thoughts:

Choosing to consume healthy plant-based foods such as fruits, vegetables, whole grains, nuts and beans supports muscle strength and healthy lower body function throughout a lifetime.  On the other hand, choosing unhealthy plant-based foods such as refined grains, sugary beverages and processed foods are not only less effective in boosting health but are detrimental for physical function.   In addition, a diet made up of high-quality plant-sourced foods seems to play a more important role here than simply the inclusion or exclusion of meat and other animal-sourced foods in a dietary pattern.

These findings highlight the fact that it is the quality, not just the quantity, of plant-sourced foods in a dietary pattern that matters the most.  Future research is needed to confirm these results and to clarify the underlying mechanisms, but the study suggests that focusing on nutrient-dense plant foods is a sizeable positive step towards supporting muscle strength and mobility in aging populations and increasing the possibility of vigour in the later years of life.

 

SOURCES:

1  https://www.nia.nih.gov/news/how-can-strength-training-build-healthier-bodies-we-age

2  Bigman, G., Rusu, M.E., Kleckner, A.S., et al. Plant-Based Diets and Their Associations with Physical Performance in the Baltimore Longitudinal Study of Aging. Nutrients, 2024, Doi: 10.3390/nu16234249, https://www.mdpi.com/2072-6643/16/23/4249

3  https://www.physio-pedia.com/Short_Physical_Performance_Battery

4  Robinson, S.M., Westbury, L.D., Cooper, R., Kuh, D., Ward, K., E Syddall, H., A Sayer, A., Cooper, C. Adult Lifetime Diet Quality and Physical Performance in Older Age: Findings from a British Birth Cohort. J. Gerontol. Ser. A. 2017;73:1532–1537. Doi: 10.1093/gerona/glx179.