Introduction
The word longevity means ‘existence for a long duration’. Applied to humans, the term implies how long a person lives. (3) Metabolism—a process of life-sustaining chemical reactions continually occurring in your body that converts what you consume into energy—impacts longevity. When certain readings or biomarkers are within a prescribed range, it implies that one is in good metabolic health, which means having ‘suitable’ levels of blood sugar and blood pressure, cholesterol and a healthy body composition. (4)
A stable blood sugar level (one of the markers of metabolic health) is key to preventing the ill effects of age, including a lower lifespan. There are links between irregular blood sugar levels and diseases like Alzheimer’s, cancer and cardiovascular disease, among others. Poorly regulated blood sugar levels can lead to diabetes and are also associated with metabolic syndrome (a cluster of risk factors that comprise obesity, hypertension, insulin resistance and dyslipidemia) (32). However, type 2 diabetes can be kept in check or prevented through certain choices that also improve metabolic health and increase the odds in favour of longevity.
What connects metabolic health to longevity?
1. Diet modifications can lead to longevity
There are a variety of diet alterations and calorie-consumption methods and schedules that can positively impact longevity. These include intermittent fasting, a high-protein diet and ketosis, a state in which the body burns fat to fuel itself due to an insufficiency of carbohydrates. (37) Intermittent fasting is a time-led restriction of calorie consumption. It can have positive effects over short periods of adoption in catalysing weight loss in obese adults. (7) It can also improve insulin sensitivity and help in reducing one’s waist size (a marker of metabolic health).
Protein is considered a key nutrient to alter metabolism and the muscle structure of one’s body. The nutrient consumes more energy to digest than carbohydrates or fats, hence boosting metabolism. Protein consumption also reduces appetite, increases satiety and can prevent the regaining of lost weight in adults. (38)(39) Ketosis is caused by and gets its name from an increase in presence in the blood, a sign that the body is burning fat from fuel (5). Ketones are chemicals created in your liver when there is an insufficiency of the hormone insulin for the conversion of glucose into energy. The process can be the consequence of a ‘keto’ diet containing high fats, moderate amounts of protein and low carbohydrates in its nutrient composition. (7) The moderation of weight, the use of fat and the ability to modify one’s metabolism away from risk make certain diet choices conducive to a life of longevity. Research suggests that a decline in metabolic health is synonymous with ageing. A high-calorie diet is associated with the deterioration of metabolism and speeding up of ageing, while calorie restriction is correlated with the extension of one’s lifespan (33). Studies have also suggested that calorie restriction can improve blood sugar regulation and is conducive to longevity (34).
2. The regulation of blood sugar is correlated with reduced advanced glycation end products
Glycation is a process in which excess glucose in the bloodstream latches on to fats, proteins as well as DNA. Advanced glycation end products (AGES) are created when protein or fat commingle with sugar in the bloodstream. These arrangements, once created, gather and stay in the body as we age. (9) When bound to receptors on cell surfaces, AGEs become receptors for advanced glycation end products (RAGEs)—they catalyse processes such as cell death, inflammation as well as oxidative stress, and may culminate in organ damage. (10) In a potentially damaging cycle, these RAGEs increase in prominence when blood sugar levels stay spiked for prolonged periods. AGES can lead to cell death and inflammation (34).
A visible effect of this is collagen, i.e. a protein that gives youthful skin its elastic nature. Collagen is reactive to excess glucose. (14) Collagen molecules in the skin form incorrect chemical bonds when sugar binds to them. This leads to a loss of skin elasticity. Research suggests that the regulation of blood sugar levels is associated with the decline in the levels of glycated collagen in the skin (34).In a study, four months of glycemic control coaching led to a 20 percent reduction in collagen levels that had experienced glycation. (13)
Stable blood sugar levels can prevent wrinkles and unintentional cell dysfunction caused by AGEs or the RAGEs.
3. Regular exercise can increase your lifespan
Certain exercise patterns or methods like high-intensity interval training (HIIT) and resistance training can have a significant impact on metabolic health. A study shows that even short bouts of HIIT can increase an individual’s basal metabolic rate (BMR, the rate at which energy is consumed by the body when it is at rest, for hours after). (16) It leads to the afterburn effect, or post-exercise oxygen consumption (EPOC), an increased metabolic rate even after the end of the exercise. (19) This is conducive to glycemic control, one of the factors associated with longevity. HIIT can boost lean muscle. Increased muscle mass is conducive to glycemic control, a dominant factor associated with longevity. Finally, this study also indicates that HIIT changes the body’s fuel source for metabolic processes. This kind of exercise, in short, intense bursts, makes the body switch from using carbohydrates as an energy source to fat, thereby reducing its presence in the body.
Ageing has adverse effects on glucose and fat oxidation in the mitochondria (organelles considered the powerhouse of the cell) and causes metabolic inflexibility, meaning inefficiency in switching between glucose and fat as fuel sources. Regular exercise can enhance mitochondrial capacity and defend against changes associated with ageing (34). Longevity research suggests two common pathways that influence the ways in which our bodies repair themselves on a cellular level and impact blood sugar regulation in the body, which can be shaped by nutrition and exercise. (34)
4. Glucose variability leads to oxidative stress
Extreme changes in blood glucose levels can lead to oxidative stress in the body. Free radicals are molecules present in the body that carry unpaired electrons, which makes them characteristically unstable and reactive. Since they seek electrons through the body to pair with, they can potentially cause cellular damage through a process called oxidation. (20) The biological or cellular stress from this process has been linked to a list of diseases associated with ageing, like Alzheimer’s, arthritis, cancer, cardiovascular disease, diabetes and even kidney disease. (22) Accumulated DNA damage to one’s mitochondria via free radicals is a key driver of ageing.
As free radicals occur both organically in the body and also enter it through inorganic impurities like polluted air, cigarette smoke and pesticides, among other means, it becomes essential to manage them. (23) To do so, one must consume antioxidants—these can be optimized in the body through the intake of certain foods—like berries, spices, leafy greens and green tea. (24)(25) Antioxidants work by binding themselves to electrons that can neutralize free radicals before they damage other molecules. Oxidative stress translates into cancer, inflammation and cognitive decline in the body (34).
5. Chronic inflammation can cause insulin resistance
Inflammation is a biological response to the body’s discovery of a foreign intruder. It combats the harmful elements present in our body, be it dietary or metabolic toxins, infections in our bloodstream, injuries on the skin surface or psychological stressors. This natural process is consistently responsible for helping the body heal. (26) Without it, wounds and infections would be likely to cause us more harm since the body would be without its natural defence. However, a feature of most metabolic disorders is also inflammation.
Inflammation can also become chronic, which sets the stage for conditions like insulin resistance. (40) To prevent, monitor and manage inflammation, one can inculcate a healthier diet with good cholesterol, lower levels of sugar and a balance of protein and anti-inflammatory foods. This, in turn, reduces insulin resistance, galvanizing a variety of functions and enabling liver effectiveness, blood sugar levels and cells efficiently metabolizing or processing glucose or fat for energy.
6. Lower heart rate variability is related to a shorter lifespan
Heart rate variability (HRV) refers to the time interval between consecutive heartbeats, measured in milliseconds (35). However, a reduction in this gap has wide-ranging detrimental consequences. Lower HRV is considered to be a predictor of cardiovascular mortality and is also linked to a 3x increase in the risk of mortality. It is also correlated with an increase in the diabetic mortality rate and inflammation. Research indicates that reduced HRV is also associated with lower life expectancy (36). Higher HRV is also synonymous with a healthy heart, a marker of metabolic health.
Conclusion
There are many ways in which metabolic health can impact longevity. The biomarkers of metabolic health include blood glucose levels, cardiovascular health and healthy lipid levels and body composition, amongst other factors. Longevity research suggests that two common pathways influence the ways in which our bodies repair themselves on a cellular level and impact blood sugar regulation in the body. They can be shaped by diet and exercise. Many diet alterations and calorie-consumption methods and schedules can positively impact longevity. A stable blood sugar level helps prevent the ill effects of ageing, including a decreased lifespan. It can also prevent unintentional cell dysfunction caused by AGES. Glucose variability leads to oxidative stress and inflammation associated with life-threatening diseases like cancer. Higher HRV, a marker of cardiac health, is also positively correlated with longevity.
Disclaimer: The contents of this article are for general information and educational purposes only. It neither provides any medical advice nor intends to substitute professional medical opinion on the treatment, diagnosis, prevention or alleviation of any disease, disorder or disability. Always consult with your doctor or qualified healthcare professional about your health condition and/or concerns and before undertaking a new healthcare regimen including making any dietary or lifestyle changes.
References
- Risk of Cause-Specific Death in Individuals With Diabetes: A Competing Risks Analysis | Diabetes Care (diabetesjournals.org)
- The preventable proportion of type 2 diabetes by ethnicity: The Multiethnic Cohort (nih.gov)
- Does A Good Metabolism Increase Longevity? — Ultrahuman
- Prevalence of Optimal Metabolic Health in American Adults: National Health and Nutrition Examination Survey 2009–2016 | Metabolic Syndrome and Related Disorders (liebertpub.com)
- https://www.healthline.com/nutrition/what-is-ketosis
