The intake of MCTs has been reported to benefit athletes, increase fat oxidation during exercise in normal-weight and overweight individuals, as well as improve the physical health of elderly requiring long-term care.
However, few studies have examined the effects of MCTs supplementation on quality of life (QOL) and subjective health, which are increasingly prioritised.
As such, a group of Japanese researchers conducted a placebo-controlled, double-blind and parallel-group trial to investigate the effects of continuous intake of MCTs supplements and moderate-intensity walking routine on the QOL and subjective health of healthy, older individuals.
The study was funded by Japan-based manufacturing company Nisshin OilliO Group, which produces edible oils and oil-based products.
The participants, who were aged between 60 and 74, and had below-average BMI for the age group and no exercise habits, were randomly allocated into four groups.
During the 12-week intervention, the participants in each group took one packet of supplement (3g) after any two of three daily meals.
Specifically, the four supplements are the control supplement, decanoic acid supplement, high-dose octanoic acid supplement, and low-dose octanoic acid supplement.
The oils in the three supplements were long-chain triglycerides or LCTs (rapeseed oil), and MCTs (Nisshin MCT oil and Nisshin MCT-C10R), all of which were supplied by Nisshin OilliO Group.
The Japanese standard version of SF-36v2, a health-related QOL (HRQOL) questionnaire, was used to assess subjective health.
Based on the results, physical function (PF), general health (GH), vitality (VT), and mental component summary (MCS) showed significant increases in scores for all MCT supplement groups, as compared to the control group.
In addition, there was a marked rise in mental health (MH) scores in the decanoic acid and low-dose octanoic acid groups, compared to the control group.
“The biggest effects were found in improving the mental aspect of QOL. This suggests that the combination of continuous daily intake of 2g or more of MCTs and walking exercise may have an effect on HRQOL, and may help improve subjective physical and mental health in sedentary middle-aged and older adults with low BMI,” the authors wrote.
During the study period, the participants were instructed to walk for 40 ± 10 minutes at their habitual walking speed on two non-consecutive days each week, and to record their performance on a lifestyle questionnaire.
Other than the exercise intervention, the participants were asked to avoid excessive physical activity and maintain normal lifestyle habits. Any non-routine household chores requiring physical effort or recreational trips for unavoidable reasons were to be stated on the questionnaire.
Knee extension strength were measured before the intervention, and at four weeks, eight weeks and 12 weeks of the trial.
Results indicated an increase from baseline in right knee extension strength for all MCT supplement groups, compared to the control group.
For left knee extension strength, only the decanoic acid supplement and low-dose octanoic acid supplement groups showed higher values than the control group.
“The increase in lower limb muscle strength associated with MCTs consumption may have had a small positive effect on subjective health and fatigue, which in turns lowers the psychological barrier to walking. It has been reported that SF-36 scores are more likely to decrease in individuals with reduced muscle strength, suggesting that physical function correlates with HRQOL.
“Previous studies have also observed that continuous intake of MCTs increases metabolism-related enzymes in skeletal muscle. It is hypothesised that increased fatty acid oxidation capacity provides an ample energy supply for muscle activation, which may have contributed to the improvement in muscle strength, consequently leading to the increase in PF scores.”
Extending healthy life expectancy
The percentage of people aged 65 years and older comprised 28.9% of the total Japanese population in 2021, and is estimated to reach 31.2% by 2030.
According to the authors, the gap between average life expectancy and healthy life expectancy — the time period during which support or long-term care is required — has remained at around 10 years for both men and women over the past dozen years.
“Increasing the number of people who can live independently and extending healthy life expectancy not only improve individual QOL, but also reduce health care costs and caregiving burden.
“Reports have noted that enhancing physical function alone does not improve QOL in community-dwelling older adults in Japan. Additionally, subjective health has also been linked to healthy life expectancy. Therefore, it is important to address not only the physical aspects of health, but also to improve QOL and subjective health,” the authors concluded.
“Effect of medium-chain triglycerides supplements and walking on health-related quality of life in sedentary, healthy middle-aged, and older adults with low BMIs: a randomized, double-blind, placebo-controlled, parallel-group trial”
Authors: Haruna Ishikawa, et al