Telomeres and the science of ikigai
An examination of the Japanese concept of ikigai (worth of life), and how it can improve well-being and longevity.
THE Japanese concept of ‘ikigai’ (translated as ‘worth of life’) can be approximated to the French ‘raison d’être’ or a valid purpose for a human to continue living. And there is actually no science in ikigai, although there is a curiously large body of science supporting it.
Ikigai differs somewhat from raison d’être in that ikigai involves less of sense of duty to observing rules or conventions. For example, the raison d’être of a bookkeeper is to manage company accounts, but the simplest meaning of ikigai is to be at peace with doing what makes one happiest. So, for some people ikigai may really mean being a good, diligent bookkeeper, but it would be done for personal joy, rather than as a wage-earning obligation.
I came across ikigai from a book given by my daughter, and from the first pages about the longevity of people in Okinawa, it became clear that ikigai is connected to various research papers about human stresses caused by diets, environmental factors, and societal choices.
The connection is an inverse relationship: zero or less ikigai in people is associated with higher degrees of negative health outcomes, including shorter lifespans. This is not to say that ikigai is the solution to all human health issues; for example, happily enjoying working in a toxic chemical plant will not improve health or lifespan, but studies have indicated plausible benefits of ikigai for most ordinary people.
Telomeres
Telomeres are sequences of repetitive or “spare” DNA blocks at the ends of chromosomes and they are one of the reasons why ikigai can improve the well-being and longevity of people. Telomeres prevent chromosomes (sequences of reproductive DNA) from damage during cell division, which happens when the body is replacing dead cells or restoring the function of an organ.
An analogy is telomeres act like the end tabs of the zips on our clothes. Once the zip ends are badly damaged or lost, the zips cannot function properly to seal the two sides together properly. So, the loss of too many telomeres results in ‘senescence’, the condition when cells lose the ability to divide properly during normal cell replenishment processes, resulting in deformed or failed (non-viable) cells. Such abnormal cells can cause various diseases and/or reduced lifespans.
The number of telomeres in humans varies significantly, between 5,000 to 15,000 base pairs at birth. The initial numbers are determined genetically and the count of telomeres in humans is small compared to other mammals, such as mice, which can have 50,000 base pairs at birth. But despite having far fewer telomeres, humans live much longer than mice, and this curious fact helped to establish the theory of how telomeres affect longevity.
Humans lose a much smaller number of telomere base pairs over time while mice can lose around 7,000 base pairs a year, and it is this rapid loss that limits their lifespans to a maximum of around 4 years. However, humans have been recorded living to an age of over 120 years. Hence the data indicates that lifespans of various species are determined by the rate of telomere loss rather than the numbers of telomeres at birth.
The rate of human loss of telomeres changes with age, and various organs also have different rates of telomere erosion. From birth to around age four, humans can lose over 1,000 telomeres per year. The rate of loss decreases markedly from age four to early adulthood (losing between 20-35 base pairs a year) before increasing again from around age 25 onwards until death (between 40-70 base pairs a year in healthy humans).
Skin cells tend to lose more telomeres, probably due to environmental exposures. Organs that filter toxins such as lungs, kidneys, and liver also lose telomeres more quickly, again likely due to constant exposure to smoke/fumes and dietary toxins. Stress can also cause the heart to pump harder, increasing the risk of heart disease while damaging telomeres in heart tissue at the same time.
Note the annual rates of telomere loss are not fixed as they can vary significantly due to various factors. Ikigai may be one such factor.
Ikigai
Although some might dismiss ikigai as some lifestyle mumbo-jumbo, there is evidence a deeper awareness of ikigai can cause physical changes in human microflows, which are defined as tiny instinctual changes in behaviour resulting from various stimuli.
For example, watching an advert for burgers can start microflows of subconscious greed/desire which can finally lead to ordering a takeaway dinner. An awareness of ikigai can also start as small, almost unnoticeable adjustments in human microflows which can eventually have a positive effect on health.
These new microflows arise from changes in self-perception, which in turn can cause changes in the emotional and physiological outcomes from interactions with other people, society, the environment, and the food eaten.
There are several credible connections between ikigai and telomeres, and it is entirely plausible that ikigai mainly affects telomeres by reducing stress levels. Stress is one of the main drivers of much of human behaviour in modern times, such as anxieties related to work, social interactions, family obligations, money, addictions, etc.
Regardless of the cause(s) of stress, research shows that emotional/mental tensions cause changes in microflows which can result in negative physiological adaptations to the stressful stimuli. It starts with stress causing the activation of a series of glands called the “hypothalamic-pituitary-adrenal (HPA) axis”.
How the HPA axis works is too detailed for this column, but the end result is the secretion of compounds such as corticotropin-releasing hormone, catecholamines, cortisol, etc. A major issue would be the persistent and excessive expression of cortisol, a hormone heavily associated with weight gain, hypertension, diabetes, heart disease, depression, sleep problems, weakened immune system, and loss of telomeres.
Cortisol is often linked with another stress hormone called adrenaline, which accelerates heart rate, induces sweating, and releases glucose into the bloodstream, along with other side effects such as reduced immune function, anxiety attacks, and depression.
There are secondary effects of an overactive HPA axis, such as an instinctive desire for sugary or other high-energy foods, tensed muscles, sleeplessness, etc, as the body prepares for a fight-or-flight response to a physically stressful situation, which is what the HPA axis was evolved to handle.
However, in modern times, stress is usually provoked in the mind rather than an existential physical threat, so the hormonal response of the HPA axis is a severe overreaction to mental anxieties, with the observable symptoms listed above. What is not usually observed is the impact of cortisol on cell telomeres, and studies have indicated this effect can be significant, with telomere loss occurring at up to several times the normal rate (without stress).
Ikigai and bad diets
Bad diets also damage telomeres, and one opinion is that a person without ikigai would have less respect for the food eaten due to less respect for the body and mind. To make matters worse, modern processed foods have made it very easy for people to confuse nutrition with eating, and eating non-nutritious calorific foods is usually how people develop metabolic syndrome.
There is also a link between cortisol and food, as lousy diets often cause issues such as inflammation. The body then attempts to suppress this food-induced inflammation by expressing cortisol, which is used in this instance as an anti-inflammatory compound. Free radicals in foods and other sources (e.g., cigarette smoke) can also directly damage telomeres because such free radicals react easily with guanine, a DNA component of telomeres.
For more information on metabolic syndrome, please review my previous article, titled ‘TOFI, FOFI and metabolic syndrome’ on The Star Online.
A curious ikigai rule is never to fill the stomach completely at mealtimes, maybe 80% full or so. This is claimed to reduce oxidative stress from too much food, though the science is unclear about this.
Blue zones and ikigai
There are 5 “Blue Zones” in the world, which are places where the inhabitants have significantly longer lifespans than average. They are (1) Okinawa, Japan, (2) Sardinia, Italy, (3) Nicoya Peninsula, Costa Rica, (4) Ikaria, Greece, and (5) Loma Linda, California.
Needless to say, people in the blue zones eat very little processed foods, if at all, and generally they consume only real foods such as fruits, vegetables, and whole grains, with limited amounts of meat. They also tend to exercise regularly and have good social connections with their communities.
In terms of ikigai, people in the blue zones usually claim to have a purpose in their lives, a sense of making a meaningful contribution to the world, which they approach with a positive attitude and a focus on the good things in their lives. These observations are of course derived from surveys rather than laboratory tests, but studies of telomeres in the older populations of Okinawa and Sardinia have established that they are characteristically longer than similarly aged populations in the USA.