Introduction
The secret to a long life has always been a fascinating topic and an appealing scientific inquiry. People are interested with the elixir of life. This is because everyone wants to die old and extend their stay on earth. The whole of humanity embraces youthfulness and life, in general. The manner by which people live is also paramount. Most people anywhere in the world are interested with health and wellness. Public health has also become a necessity while modern medicines and several technologies are trying to slow down the natural processes of ageing (Manning, et. al., 2012).
Most popular longevity factors include lifestyles, genetics, environment, exercise, diet, spirituality, among others. The geneticist, Dr. Nir Barzilai, affirmed that genetics is a major factor in human longevity (Goldring, 2008). However, this was contradicted by a Swedish study of twins which showed that genetics is not the principal factor. The Swedish study favored lifestyle as a major factor (Goldring, 2008).
People are fascinated by the Seventh Day Adventists who seem to live longer than others. They do not smoke, drink and eat red meat. They are active and they socialize. People wonder how they live a long life and they attribute such factors for living longer. Hence, studies on centenarians abound. The most famous of which is the series of studies of the Okinawans, the people with an average lifespan of 81.2 years (Craig, et. al., 2008). There are several centenarian studies in Italy, Denmark and Sweden.
Who are the Centenarians?
People who live longer than the average life span or those who live to be one hundred years old or older are called “centenarians.” They are called “the oldest of the old” (Goldring & Ercilla, 2008). The etymology of the word "centenarian" implies that these people have live “one century” or one hundred years, hence, they are called centenarians (Okinawa Centenarian Study, 2012). Centenarians are often the subject of studies on human longevity and aging because they have lived and aged successfully.
According to Barrow (2010), the “current centenarians are older than the crossword puzzles, the Titanic ship and even Mickey Mouse.” They have outlived 18 presidents and two World Wars. They experienced the start of radio and movies then the invention of telvision.” These centenarians are envied since they have celebrated the fullness of their lives - having experienced their golden wedding anniversaries, saw their great-grandchildren and great-great-grandchildren, traveled to different parts of the world or just lived their lives entirely in one small place. Presently, these one hundred year olds are very much delighted to be dancing, walking, driving around, or simply living their lives out. However, some of them are also just lingering and they think that they are now burdens to their families (MacDonald, et. al., 2009). Their longevity is usually attributed to both genetics and lifestyle factors (Willcox, et. al., 2008).
According to the Okinawa Centenarian Study (2012), the current estimates of the centenarian population is about 80,000. This is in the United States alone. There are about 10 to 20 centenarians per 100,000 population. However, this is just a rough estimate because there is no national registration system in the country until the 1940’s. Meanwhile, the U.S. Census Bureau figures indicate that there are over 84,000 centenarians in the country at present. This figure is expected to grow to 580,000 in 28 years (Manning, et. al., 2012). In a publication of Science, the experiments concerning 801 centenarians in the New England Centenarian Study, the largest study of centenarians worldwide, centenarian live exceptionally long and they rarely develop age associated diseases like heart diseases, dementia and cancer. They also bound back from illnesses (Manning, et. al., 2012).
Interestingly, the centenarians are the rapidly increasing demographic group in several First World contries such as the United States and Japan (The Okinawa Centenarian Study, 2012). In the United Kingdom, the population has grown by a factor of 60 since the start of the 20th century. It is estimated that by 2030, there will be about one million centenarians worldwide. The increasing number of centenarians globally is due to the following factors: healthier births, better medical care, public health system, better housing, greater income, and more nutrition than the previous populations (Okinawa Centenarian Study, 2012).
Factors Attributed to Human Longevity
Genetics
Genetics is the number one factor which research has pointed out to be the main reason for longevity. As also mentioned by the New York geneticist, Dr. Nir Barzilai of the Albert Einstein College of Medicine, centenarians are 20 times as likely to have long-lived relatives compared to the average individuals (Goldring, 2008). Dr. Perls, the famous doctor who studies human longevity also stressed that “the genetic influence is very, very strong” (Manning, et. al., 2012).
Craig, et. al. (2008) also affirms this by saying that those Americans who were born in 1900, brothers of centenarians were 17 times as likely to reach 100 years. Meanwhile, the sisters of centenarians were 8 times as likely to reach their hundredth birthday. Likewise, the New England study shows that compared with the other people, the daughters and sons of centenarians are less than one-sixth as likely to die of heart ailments. They are also less than one-sixth as likely to die of heart disease (Craig, et. al., 2008).
According to Willcox, et. al. (2008), genetic differences somehow explain why long-lived people group together in families. Researches comparing life expectancy in twins and other family members illustrate that up to 25% of the differences in human lifespan is attributed to genetics while the rest is attributed to environmental exposures, chance, accidents and injuries. The genetic base of centenarians appears to be stronger and they reach a very long life, between 90 to 100 years old. In contrast, various clinical syndromes of “accelerated aging” and death at an early age have a known genetic basis (Koch, 2010).
In the longevity hotspots or where many centenarians live such as in Okinawa, Japan, Sardinia, Italy and Iceland, studies show genetic variants which predispose people to longevity. Studies also show that as people age, the influence of environmental factors such as education or wealth become less significant (MacDonald, et. al., 2009).
In a study conducted by Christensen comparing 10,000 sets of Scandinavian twins, the gentologist revealed that genes initially exert a strong influence on a human lifespan after the age of 60. Prior to that, both identical and non-identical twins have greatly independent chances of reaching a given age. After 60, however, the chances of one twin reaching a given age are largely increased if their co-twin has done so, more so, if they are identical twins (Craig, et. al., 2008). The outcomes of these studies lead to the "centenarian genome," a principal resource for determining "longevity genes" (MacDonald, et. al., 2009). The researchers considered this as a very important process underlying longevity. These genes are also found out to be present in other living organisms such as worms.
A gene variant called FOXO3A is an example of a particular gene form which is three times as likely to make it to 100 than those of other gene formations. This type of gene is most likely to age better with lower levels of stroke, heart disease and cancer. FOXO3A is part of the signifying pathways which are conserved across animal species (Wehrwien, n.d.). It manages the insulin/IGF-1 pathway that affects how the body process food. It also controls genes which shield cells from very reactive oxygen radicals or those elements which damage the DNA. FOXO3A is even said to protect the body against cancer by encouraging apoptosis. In this special cell defense mechanisms, the abnormal or compromised cells commit suicide. The variant of FOXO3A related with longevity is much more prevalent in centenarians. This evidences the value of the centenarian genome (Wehrwein, n.d.).
Environmental Factors
Environmental factors are attributed with 75% of the overall factors influencing long life. The other 25% is given to the genetic factor. This is a welcome note to those who want to live longer because it implies that people have a good hold of their health and longevity compared to the chances of its genetic predisposition (Manning, et. al., 2012).
The researchers at the New England Centenarian Study also support this claim by also generalizing that 70 percent of longevity is attributed to environmental factors. These researchers also cite genetic factor for the other 30 percent (Koch, 2010).
Manning, et. al. (2012) refers to the social networks such as families and relatives as a major environmental factor for human longevity. Dr. Sonya Vasto of the Department of Molecular and Biomolecular Science at Palermo University showed that living in a healthy social environment which is basically composed of relatives lead to staying alive longer. This is attributed to the notion that these individuals feel that they are not alone or bored and they always have other people to look after them and care for them.
The study also exemplified the ancient Sicilians who live long. They are between 100 and 107 years old. They lead active lives and are free from heart disease, serious cognitive and physical degeneration, clinically evident cancer or renal failure (Manning, et. al., 2012).
The environmental factors generally include active lifestyle, (which will be discussed in length in the latter part of the paper), weight and diet, avoiding smoking, spirituality, and social networking. Active lifestyle and exercises include being busy and doing light activities such as walking or gardening. Diet more or less means lean weight and moderate eating. This also means avoiding meat and dairy products and eating mostly grains, fish and vegetables. Social networks refer to one’s social contacts such as their relatives and friends and the local community. Spirituality means less stressful living and being involved with meditation and praying. Lastly, avoiding cigarettes is a given and self explanatory factor for healthy and longer living.
Lifestyle
The New England Centenarian Study (NECS), a research of centenarians living in Boston, Massachusetts, indicates that specific lifestyles tend to be popular among centenarians (Werhwein, n.d.). These include:
- Smoke free living – these Bostonian centenarians rarely smoke even when they grew up not knowing the perils of smoking.
- Maintaining an ideal body weight – most of these centenarians are lean and only a very few are obese.
- Regular exercise – researches among the Okinawan centenarians show that they regularly exercise throughout their lives.
- Healthy diet - the Okinawan centenarians eat a healthy diet. This consists of low caloric intake, more fruits and vegetables, fiber, and good fats such as omega-3 fatty acids.
These lifestyles are supported by varied studies and researches on good health, healthy living and human longevity. Experts confounded the positive effects of regular exercises. Dr. Deepak Chopra, a mind body expert, mentioned in his book, Ageless Body Timeless Mind, that a constant, low level physical activity i.e. walking half an hour every day can benefit an individual the same way as a rigorous activity benefits the human body. Other fitness experts advise certain exercises to help people live longer and stay in shape (Koch, 2010).
Fackelmann (2004) also supports the lifestyle factor. His research indicated that lifestyle habits are a vital part of keeping the body and mind in good shape best into the eightieth and ninetieth years of a person. Other scholar also believe that lifestyle is very important aside from the genetic factor in staying up to one hundred years old. In a study done by the Albert Einstein College, results show that even those individuals with the good genes predisposed to longer life also need to apply a good lifestyles (Fackelman, 2004). They must avoid smoking, watch their diet and exercise regularly. All of these lifestyle factors lead to human longevity.
This is supported bya study of the Okinawans who moved to the Western countries such as the U.S. and have adopted the new country’s lifestyles. Study shows that when these Okinawans adopted a western diet and lifestyle, their longevity probability dropped to a significant decrease (Okinawa Centenarian Study, 2012). This proves that a genetic predisposition is only the initial point in staying old. Lifestyles can be a very determining factor to longevity.
Nutrition and Diet
One of the most durable theories of human longevity is the theory on free radicals (Okinawa Centenarian Study, 2012). This theory means that the human body is shielded from free radicals (unstable cells) as it is metabolozing food less in caloric content into energy. Thus, there is less damages to the important body molecules (such as DNA, tissue, among others). This damage is cumulative and once older, the human body will fall apart due to these damaged cells. Hence, the low caloric intake is one of the main factors pointed by several studies. Direct evidence shows that the traditional diet of Okinawans lead to healthier bodies and low blood levels of free radicals (Okinawa Centenarian Study, 2012).
Aside from the above mentioned active lifestyle and less stress, natural diet is seen as a significant factor to longevity (Manning, et. al., 2012). The centenarian hotspots such as the Costa Rica’s coastal regions, Panama’s Shangri-La valley, Italy’s Sardinia, and Japan’s Okinawa, USA’s California, and New Zealand’s Kiwi all indicated good diet as part of the people’s lifestyle. For instance, in Okinawa, seeweed are a major part of the people’s diet. This is very low in calorie. In California, the Seventh Day Adventists do not eat junk foods (Manning, et. al., 2012).
Diet can also prevent cell damages. For instance, Fackelmann (2004) mentioned that a minimum of 10 fruit and vegetable servings daily help prevent age-related cell damages. These foods contain protective substances that help defend the body against cancer and heart disease. Most longevity experts also recommend reducing one diet of fatty and salty foods (Fackelmann, 2004). Centenarians usually eat lean meats, poultry and fish and different varieties of fresh fruits, vegetables and whole grain foods.
Centenarians also eat little amounts of food. According to Dr. Vasto, Sicilian centenarians only consume an average of 1,200 calories daily. They eat modest meals such as those consisting of bread and a little milk for breakfast, small portions of pasta and vegetables for lunch and a light dinner of eggs and fresh cow’s or goat’s cheese, small meat (often chicken), legumes (i.e. peas, beans and lentils) or fish occasionally. They also usually eat plenty of vegetables that are locally produced (MacDonald, et. al., 2009). Dr. Vasto also said that the Sicilian centenarians eat foods according to their seasons. For instance, they would eat two or three types of vegetables which are in season for one long month. This is the same way with their fruit intakes. They do not usually eat apple in June.
Aside from fruits, they also eat a lot of olive oil, healthy mono-unsaturated fats. These oils have vitamin E, polyphenols and coenzyme-Q which are all anti oxidants and protect the body from diseases. Water is also a major element in theri diet. Their meals are occasionally accompanied by red wine (MacDonald, et. al., 2009). Finally, their diets are low in blood-sugar igniting carbohydrates. It is low in glycemic index since the refined carbohydrates are low. They eat no sweet breads, cakes and cookies. They also do not eat in between meals.
Exercise
Research shows that regular exercise can help prevent or delay various ailments and diseases such as heart disease, colon cancer, diabetes and even Alzheimer’s disease (Fackelmann, 2004). According to experts, a minimum 30 minutes of moderately intense exercises for five days a week or more promote good health. Exercising include simple activities such as walking, dancing, swimming, even gardening and housework. These can help people stay in shape. Aerobic exercises such as walking, swimming and jogging for at least 30 to 40 minutes a day weekly is also helpful.
According Robert Butler, director of the International Longevity Center-USA in New York, exercise is important because additional body weight puts a strain on our heart and other crucial body systems (Fackelmann, 2004). These make people prone to heart attacks, cancer, diabetes, and other diseases which can reduce the life span.
Attitude
Personality traits such as being receptive to the uncommon may plainly explain why life for some centenarians is still as free and delightful as it was when they were younger. By having rich experiences, these centenarians have varied skills to adapt to new challenges (Koch, 2010).
Optimistic people are also seen to be more adoptive and to make changes, which are factors contributing to good health. This is according to John Santrock, a longevity researcher at the University of Texas. The individuals with sunnier personality types believe success can happen to them (Koch, 2010).
Centenarians are also observed to be more conscientious (Koch, 2010). They are more orderly, less impulsive and more careful. These attitudes are considered to be better for health. Being cautious is always associated with better health since drastic moves like picking up on cigarettes when down are riskier than those who choose to stay healthier and caution themselves with a good attitude. Social support is also another factor which helps in the general outlook and attitude of centenarians. Relationships aid us, according to experts. Maintaining social ties really help.
References:
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Craig, D., Willcox, Bradley J., Willcox, Qimei He. et. al. (April, 2008). They really are that old: a validation study of centenarian prevalence in Okinawa. Journals of Gerontology: Series A, Biological Sciences and Medical Sciences, 63A (4), p. 338-349.
Fackelmann, K. (2004). The Secrets to Longetivity. USA Today: Health and Behavior. Retrieved on June 12, 2013 from, http://www.usatoday.com/news/health/2004-02-22-longevity-usat_x.htm.
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Okinawa Centenarian Study. (2012). “Centenarians.” Retrieved on June 13, 2013 from, http://www.okicent.org/cent.html.
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