We know that ageing is inevitable, and it will be accompanied by changes in the body, both internally and externally. As we age, we lose a few abilities – right from chewing our favorite foods to digestive issues, bone issues leading to frailty and falls, and loss of muscle (sarcopenia) that impacts strength.

What is really happening to the body’s metabolism as a result of ageing? Let’s have a basic understanding and know how to manage these issues.

Hallmark of ageing

Out of the many hallmarks of ageing, the primary hallmark is the environmental change causing genetic instability and alterations which leads to an antagonistic hallmark, that is responses to the damage – Mitochondria dysfunction. This is also a cause of oxidative stress where reactive oxygen species (ROS) increase.

Mitochondria are the primary source of energy production. Mitochondrial production dysfunction in the cells changes many metabolic processes such as the decrease in anabolic functions, decrease in muscle mass (sarcopenia), increase in body fat (due to less nutrient intake and sedentary lifestyle), and change in the muscle morphology that leads to a decline in strength. The decline in various metabolic processes will eventually lead to the onset of metabolic syndrome.

Pic credits: Natarajan et al., 2020

Metabolic Decline Due to Ageing

With age, there is a decline in every function in the body with mitochondrial dysfunction. As a result, there will be dysregulation of homeostasis, leading to cell death. The decline in ATP production results in less production of energy, which leads to disruptions, both physiologically and metabolically. The cell’s regenerative capacity is also reduced. Each interdependent process starting from low production of saliva from salivary glands, the changes in the intestinal biology and the microbiome, and low bioavailability of nutrients, eventually leads to malnutrition. All the body’s storage forms are utilized for energy, including the muscle. Muscle loss, the so-called sarcopenia, happens which would lead to low strength. The bone density also decreases which would lead to bone-related disorders such as osteoporosis, making the person more fragile and injury-prone.

The decline in muscle mass not only happens with the limbs but also in the oral mastication muscles which would hinder the proper ability to chew the food. Loss of teeth due to poor hygiene would also result in not being able to chew well.

What you understand here is just the basic knowledge of how metabolism is affected, and there are more physiological processes that are declined. This can be prolonged and managed by daily physical activity and a proper dietary intervention that makes it easy to chew and digest.

Tips to manage the declines from ageing

As it is already known, adequate nutrients from all the food groups are important. However, aged people may not be able to consume food due to the aforementioned reasons. A few of the major points that need to be considered are –

• Easy to consume foods – soft, mushy purées, or soups
• Adequate intake of protein (at least 1.2-1.8 g/kg per body weight) to help preserve muscle loss. A quality protein supplement such as whey can be advised for easy absorption.
• Supplement intake, such as calcium, vitamin D, wherever deficiency exists, and also multivitamins with a physician’s advice.
• Adequate fiber intake – supplements like psyllium husk
• Inclusion of unsaturated fats – omega-3 fatty acids or their supplements
• Physical activity, with a mix of neuromotor, aerobic, strength, and flexibility can be advised in an individualized approach.

References

• López-Otín, C. et al. (2013) ‘The Hallmarks of ageing’, Cell, 153(6), pp. 1194–1217. doi: 10.1016/J.CELL.2013.05.039.
• Bartke, A. et al. (2021) ‘Energy Metabolism and ageing’, The World Journal of Men’s Health, 39(2), pp. 222–232. doi: 10.5534/WJMH.200112.
• Natarajan, V. et al. (2020) ‘Mitochondrial Dysfunction in Age-Related Metabolic Disorders’, Proteomics, 20(5–6), pp. 1–11. doi: 10.1002/pmic.201800404.
• Rebelo-Marques, A. et al. (2018) ‘ageing hallmarks: The benefits of physical exercise’, Frontiers in Endocrinology, 9(MAY), pp. 1–15. doi: 10.3389/fendo.2018.00258.