The Oldest Living People in the World are All Women

At the end of a narrow road accessible only by foot or motorbike, I meet Nguyen's caretaker and daughter-in-law, 76-year-old Ba Thi Nguyen. When she takes me inside the family home, instead of family pictures, plaques announcing Nguyen's age adorn the green walls. Nguyen is a woman of petite stature, normally draped in a ba ba—the traditional clothing of choice for women from central and southern Vietnam. A slight and silent woman, Nguyen extends her palms in greeting. With silver hair pulled back into a tight bun, Nguyen beams at the rare visitor with a youthful mirth belying her long years. Her short, wiry legs are bent underneath her body, and she watches visitors wordlessly.

According to the World Record Association, 122-year-old Nguyen is the oldest person in the world. Her age, verified by the association this past April, places her among the globe's supercentenarians, a small group which lives beyond the age of 110. Although the Guinness World Records recognizes 116-year-old Susannah Mushatt Jones of Brooklyn, New York as the oldest living person on Earth, Nguyen's family in southeastern Vietnam is waiting for the organization to validate Nguyen's identity documents, which state she was born in 1893.

Besides the mere task of staying alive, it's certainly not easy to jump through the bureaucratic hoops required to appear on a list of supercentenarians. The number of fabricated claims skyrockets after the age of 110. In fact, "99 percent of claims of 115 years and older are incorrect," says Dr. Thomas Perls, the founder of Boston University's New England Centenarian Study. The validation process has researchers reviewing ages of family members relative to a supercentenarian's claimed age. Birth certificates are also verified for authenticity, as many cases emerge of a living individual using a deceased person's birth certificate. Whenever possible, researchers crosscheck multiple documents to ensure ages are consistent across marriage, school, or other documents.

In a country such as Vietnam, these challenges are only compounded when the person in question predates the creation of the country itself. From 1858 to 1954, before it became a modern nation-state, Vietnam was ruled by a French colonial administration that levied taxes partly based on population figures collected through birth and death documents. However, problems of under-registration of female infants and inaccurate reports of mortality trends were rife. Thus, while the oldest people in the world appear to come most frequently from high-income, industrialized countries like Japan, Italy, or the United States, the absence of people from developing nations may owe as much to unreliable or absent birth certificates, poor record-keeping, and other age-verification issues in these countries.

Indeed, Nguyen's life straddles three centuries of history and change, including both World Wars and occupation by numerous foreign powers. She has seen her country ruled by the Japanese, French and Americans, as well as split and subsequently reunified as a modern nation-state. During the Vietnam War, Nguyen's family survived without death or injuries, but the family was forced to relocate in 1974 after the area around her home became a site of battle. The property suffered damages during wartime and the family fled from the fields, parts of which were seized illegally, or sold to the government as part of a construction plan. Nguyen and her family were also forced to walk out to the fields clutching a Republic of Vietnam flag (a yellow flag featuring three red stripes) to avoid being shot by soldiers.

Yet for Nguyen, the most significant milestones have been personal, not political. She has outlived her husband and all but two of her ten children. Nguyen was 82 when her husband died in 1975 at the age of 85. The death of a spouse is a near-universal trend for heterosexual female supercentenarians, according to Robert D. Young, the Director of the GRG Supercentenarian Research and Database Division: "With the very elderly (105+), men often have a higher mortality even if they are in better shape because the males tend to "drop dead," while women tend to overcome challenges, or at least extend them before succumbing," he explains. For example, one of the most common causes of death for men in the U.S. is coronary heart disease — at least 50% of male deaths from this disease show no symptoms and simply "drop dead."

Female longevity is one of the few uncontested truths in research about aging. According to Dr. Tom Kirkwood, Associate Dean for Ageing at Newcastle University, women boast an approximately five-six year advantage over men. "By age 85 there are roughly six women to every four men," he writes in Scientific American. "At age 100 the ratio is more than two to one. And by age 122—the current world record for human longevity—the score stands at one-nil in favor of women."

Indeed, females not only exceed males in terms of their longevity but also their survivability: "Once we understand that the female sex outlives the male sex even in the womb, then we realize that environmental effects can only be secondary effects," Young says.

Even among the youngest population group—premature infants—females still outlive males. A staggering 90 percent of premature infants weighing under two pounds that survive are female, Young says. And from Asia to Africa, women are living much longer than men on every continent. According to the World Health Organization (WHO) women typically live nearly a full decade longer than men in Vietnam. The World Bank's statistics indicate that Vietnamese women's life expectancies far exceed that of their neighboring countries. In 2013 (the year of the most recently available data), Vietnam had a life expectancy at birth for women of 80 years—slightly higher than neighboring Laos (70), Cambodia (75), or China (77)--a set of countries where average ages for women range from 70 to 77. Total life expectancy at birth for both sexes outpaced that of most other lower middle income countries, hovering around 76 for the general Vietnamese population, compared to the global average of 66 among countries of this income bracket.

Moreover, in the United States, most women live five years longer than their male counterparts—averaging 81 years versus the male life expectancy of 76. The situation is no different in the United Kingdom, where women can expect to live to 83 while men will often top out at 79. And in Japan, which has the highest female life expectancy rate in the world, women frequently live a full seven years longer than men—reaching an expected age of 87 compared to the expected male age of 80, according to WHO data.

The longevity gap is not simply limited to humans. Even among other species, females regularly outperform males in terms of life expectancy. Female flies outlive male flies during periods of intense mating pressure. While the majority of male lemurs face death as teenagers, most female lemurs will reach their 30s--despite the fact that both sexes have comparable testosterone levels, growth rates and predator capture rates. And while captive male chimpanzees normally live up to 31 years, female chimpanzees may reach 38 years.

In humans, the life expectancy gap between men and women is a relatively new phenomenon, dating back to 1870, when the world saw decreases in infant mortality and infectious disease alongside advances in modern medicine, sanitation, and healthcare, thereby lengthening the average human lifespan. By 1972, females in the U.K. outlived males by 6.25 years, and by 1950, elderly mortality improvements were already witnessing a strong transformation.

"[W]omen today still outlive men by about as much as their stay-at-home mothers outlived their office-going fathers a generation ago," writes Dr. Kirkwood.

However, while all of this might suggest a biological explanation for the superiority of female survivability and longevity, there in fact seems to be little consensus on the root cause of either this fact or the causes of extraordinary longevity generally, both of which remain clouded in mystery, speculation, and contrasting theories. Indeed, more often than not it seems that examining the lives of the small sample of supercentenarians is a lot like reading tealeaves — you find the explanation you want to see. Finding a set of common characteristics among the globe's supercentenarians is difficult; Young says everything from good sleep to a belief in a higher power appear on the list.

As is the case for the majority of women in rural Vietnam, most of Nguyen's life has been spent in agriculture. Vietnam's elderly population is not composed of sedentary retirees; over 40 percent still participate in the labor force, with most involved in self-employment in the precarious agricultural sector, according to the United Nations Population Fund. With 3.5 times more elderly people in rural than urban areas, older rural Vietnamese women are also more likely to work than elderly rural men. Nguyen is no anomaly here; she only stopped working in the field at the age of 70, despite belonging to a family that could afford to pay for extra farmhands. In Nguyen's life, the feminization of manual labor—including agriculture—has led her to spend much of her employed life on the field.

In one way, Nguyen's labor has been a health boon, enabling Nguyen to pick fresh produce and fruits from privately tended grassland. Yet it is also a perfect counterpoint to the prevailing notion that men die younger from a larger stress burden. Chronic stress has been linked to everything from cardiovascular disease to Alzheimer's disease, and men disproportionately face cardiovascular disease earlier than women— in some instances, even developing it seven to ten years before a female might. Experts speculate that the higher presence of oestrogen in women's bodies before menopause seemingly acts as a buffer against cardiovascular disease, strengthening female longevity outcomes.

"A graph of mortality rates by gender show that women outlive men at every age, except when girls are going through puberty—then it's even," Young says.

"The hypothesis that I prefer is the Double X hypothesis," explains Young. "Women have two XX chromosomes, and men have only one. A woman has a "backup copy" of every gene, but men have only one. This means that a man has a much greater chance of getting a defective genetic expression (such as color-blindness). For a woman to be color-blind, both X chromosomes must have the same defect at the same location."

"The female body is a matrix with support systems that try to keep it going," Young adds.

A woman's immune system may also slow the pace of aging, as male immune systems generally age faster. In a 2013 Immunity & Ageing study, scientists examined the blood of Japanese citizens ranging from 20 to 90 years in age. Although white blood cells plummeted for both sexes as a result of age, the speed of T and B cell loss was faster for men than women, indicating that female bodies underwent a slower deterioration as the body aged, signifying it might be better-equipped for survival over the long haul.

In line with this, Kirkwood's "disposable soma" theory appeared in 1977 as one answer to why longevity favors female organisms and grants them less 'disposable' bodies. At its heart, Kirkwood articulated a theory that the body's energy budget was constrained by two different aims: one, a need to reproduce, and second, and a need for maintenance. The body—by its very design—has limitations, and its end-goal was never to live eternally, but temporarily. Survival has long been the aim, not immortality.

"Mother Nature has a higher regard for the female," echoes Dr. Walter Brotz, author of Dare to be 100. "It is essential to be needed. Nature abhors uselessness." To that end, females have always boasted a clear reproductive advantage. As Kirkwood explains, successful offspring production has inevitably been linked to the condition of female health, given that the fetus cannot inhabit a mother's womb if her body is in a state of damage. This may be one factor accounting for women's longevity over men, as a female soma (body) may be—by default—less "disposable" under Mother Nature's decree.

Kirkwood's research also shows that animals that live long possess a superior repair system, in addition to higher intelligence or other biological 'golden eggs' like superior flight capabilities, bigger size in relation to predators, or better concealment opportunities from hunters. He argues that the body prioritizes its energy budget on repair based on the value it assigns to the body's performance: "If you can avoid the hazards of the environment for a bit longer by flying away from danger or being cleverer or bigger, then the body is correspondingly a bit less disposable, and it pays to spend more energy on repair," Kirkwood explains.

However, while studies such as these provide a strong case for the general argument that behavior, cultural, and social factors cannot be overlooked in explanations of longevity, it is far less certain whether the near obsessive attention paid to the details of supercentenarian lives yields any real insights into this dimension of the aging process.

The supercentenarian's diet, in particular, is a frequent source of fascination for societies searching for a supermarket elixir. While most of us will never achieve extreme longevity simply through scrupulous study or imitation, the very knowledge that a human can eat four bacon strips and eggs a day, as 116-year-old Susannah Mushatt Jones does, and still outlive a steadfast vegetarian is enough of a reassurance to the diet-averse. Young says the group of oldest women in the world is "not afraid to eat what it wants."

Around 7AM each morning, Nguyen's caretaker, Ba, sets a bowl of hu tieu (Vietnamese vermicelli), chao (porridge) or pho in front of the smiling supercentenarian. Lunch, served at 11 am or 12 pm, sees Nguyen nibbling on a soft baguette, which she normally washes down with a glass of water. Dinner is fixed at an early hour to account for Nguyen's nightly repose at 5PM.

Aside from these regular meals, however, Nguyen has an intense sweet tooth. Specifically, she craves palm sugar, ground into a thin powder, or stirred into a thick banana soup. Sometimes a cup of jasmine or green tea sprinkled with the palm sugar will sate her sweet tooth. For a woman who has never imbibed alcohol and rarely consumes meat, ?'ường th?'t n?'t, as palm sugar is called in Vietnamese, remains Nguyen's vice of choice. Shrimp or fish meet Nguyen's protein needs, but sugar is the chief joy in the elderly woman's life.

Of course, the social and cultural environment in which Nguyen exists sustains all of this. Nguyen's day begins around 4:30AM, when her eyes sweep the low-lit hut in wait of her devoted daughter-in-law and primary caretaker, Ba. Nguyen's early dinner at 4PM features an array of dishes, starting with white rice set against small bowls of vegetables or fish. Daytime snacking is still permitted by Nguyen's family members, so she may eat fruits, rice, meat or vegetables from the farm. After dinner, Tru is brought back to bed to sleep. "She doesn't have a long sleep. She wakes up and sleeps unpredictably many times at night and always stays in bed," Ba says to me.

Ba is responsible for dressing and washing her mother-in-law, two tasks she does not take up lightly. "It's my duty to take care of her," Ba explains. "I'm happy she's loved," she says. Although Nguyen lives with her family, her need for tranquillity required some readjustment. The family home has been overcrowded with her son's children, prompting her to pitch a hammock in the hut behind the house. She prefers to live inside the hut because the temperatures are cooler than inside the family home, and the noise levels much calmer away from her grandchildren.

Over the years, Nguyen has cultivated a reputation for her magnanimous spirit, offering food to neighbors even when her own supply was low. She frequented local pagodas, where she came as a supplicant praying for both herself and her fellow townsfolk, even donating clothes or money to the them whenever necessary. "Everybody in the neighborhood loves her," her caretaker says. Nguyen's outlook over the late period has remained upbeat and positive, and she enjoys warm relations with her daughter-in-law and caretaker, a rare feat in a culture where friction between mother and daughter-in-law can be a common wedge in a marriage.

"She is a funny, kind, and nice mother-in-law," Ba says, as if explaining why she remained in the caretaker role for so long. When Nguyen's son, Ba's husband, passed away earlier this March at the age of 85, it was a difficult moment for the entire family. But Ba stuck around, washing and dressing her mother-in-law as if it were any other day.

Nguyen's close but separate living situation with her family suggests a delicately balanced social life. Indeed, despite studies stressing the importance of social networks in human health, living alone may not be entirely fatal for the very old. In fact, it may be a common feature of supercentenarian life, Young says, reflecting on the list: "[Most of the supercentenarians] were physically active at 105 and often lived on their own at 100."

Solitary living for the elderly, however, is not a norm in Vietnam. When 28-year-old Vietnamese teacher Thuy Tong Thi Thu addresses her 87-year-old grandmother in Thái Nguyên province, she uses the affectionate greeting "con chào bà ạ," which roughly translates to "Hello, granny." All across Vietnam, respect for the elderly is still woven into the cultural fabric, but social protection schemes for the elderly are waning. In 2010, the Vietnamese government only spent 0.52% of its GDP on social safety net programs. Despite rapid economic growth and a sharp decline in poverty, approximately half of Vietnam's nearly ten million people aged 60 or older today live without social security programs like a pension, reports the Thanh Nien Daily. With retirement currently set at 60 for men—and 55 for women—discussion is underway about increasing the retirement age by two years for men and five years for women, making a social safety net all the more difficult to reach.

Smoking, in particular, is one behavior with dramatic impact on longevity rates. Although male smoking rates are in decline, the historical record confirms that smoking has a gendered dimension, particularly when focusing on mortality rates. After 1890, for example, 30 percent of the mortality gap between men and women could be imputed to smoking.

Controversially, there are also behavioral trends in male adolescence—during a period known as a "testosterone storm"—that may increase fatality rates, ranging from high alcohol consumption to higher access to violent weapons. While females can also drink alcohol and purchase firearms, during their lifetime they are more likely than men to possess health insurance, seek healthcare services and check their cholesterol, vital actions that render it possible to detect and address any looming health problems.

There is, of course, one problem with female longevity. Women—and people generally—do not always age well. According to Dr. Brotz, climbing past the age of 110 may not be advisable. "Don't live that long. It is grim. See Tithonus," he says. According to Greek mythology, old age left Tithonus enfeebled, babbling like an infant and lacking "supple limbs"—entirely enervated in body and in mind. The prospect of a diminished quality of life is always a gamble beyond one's healthy years. Even for Nguyen, who nature has thus far spared from cancer, dementia, or cardiovascular disease, life still appears to be on the decline. Her family reports that she largely remains restricted to the hammock and easily loses consciousness, forgetting where she is or what she needs. The once-sprightly woman no longer stands upright or takes leisurely strolls. While guard dogs bark in circles around her, Nguyen's thin frame displays a frailty from old age, her limber arms hanging loosely by her side. Most nights, she lies supine on the hammock, enmeshed in a mosquito net while her daughter-in-law watches carefully over her, fetching water or victuals when Nguyen enjoins her for help.

And the saccharine treats Nguyen indulges in with great relish are gradually becoming off-limits. Nguyen's family, worried about impending mortality, have restricted the supercentenarian's daily intake of sugar. For a woman afflicted with a perennial sweet tooth, this may be a death sentence of its own.

All photos provided by Giang Pham.