New study reveals: Women Really are Better Survivors

Women survive crises better than men Newborn girls are hardier than newborn boys during famines, epidemics
Women today tend to live longer than men almost everywhere worldwide — in some countries by more than a decade. Now, three centuries of historical records show that women don’t just outlive men in normal times: They’re also more likely to survive even in the worst of circumstances, such as famines and epidemics.
Women today tend to live longer than men almost everywhere worldwide — in some countries by more than a decade.

Now, three centuries of historical records show that women don’t just outlive men in normal times: They’re more likely to survive even in the worst of circumstances, such as famines and epidemics, researchers report.

Most of the life expectancy gender gap was due to a female survival advantage in infancy rather than adulthood, the researchers found. In times of adversity, newborn girls are more likely to survive.

The fact that women have an edge in infancy, when behavioral differences between the sexes are minimal, supports the idea that explanation is at least partly biological, the researchers say.

Led by Virginia Zarulli, an assistant professor at the University of Southern Denmark, and James Vaupel, a research professor at Duke University, the team analyzed mortality data going back roughly 250 years for people whose lives were cut short by famine, disease or other misfortunes.

The data spanned seven populations in which the life expectancy for one or both sexes was a dismal 20 years or less. Among them were working and former slaves in Trinidad and the United States in the early 1800s, famine victims in Sweden, Ireland and the Ukraine in the 18th, 19th and 20th centuries, and Icelanders affected by the 1846 and 1882 measles epidemics.

In Liberia, for example, freed American slaves who relocated to the West African country in the 1800s experienced the highest mortality rates ever recorded. More than 40 percent died during their first year, presumably wiped out by tropical diseases they had little resistance to. Babies born during that time rarely made it past their second birthday.

Another group of people living in Ireland in the 1840s famously starved when a potato blight caused widespread crop failure. Life expectancy plummeted by more than 15 years.

Overall the researchers discovered that, even when mortality was very high for both sexes, women still lived longer than men by six months to almost four years on average.

Girls born during the famine that struck Ukraine in 1933, for example, lived to 10.85, and boys to 7.3 — a 50 percent difference.

When the researchers broke the results down by age group, they found that most of the female survival advantage comes from differences in infant mortality. Newborn girls are hardier than newborn boys.

The results suggest that the life expectancy gender gap can’t be fully explained by behavioral and social differences between the sexes, such as risk-taking or violence.

Instead, the female advantage in times of crisis may be largely due to biological factors such as genetics or hormones. Estrogens, for example, have been shown to enhance the body’s immune defenses against infectious disease.

“Our results add another piece to the puzzle of gender differences in survival,” the researchers said.

The findings were published Jan. 8, 2018, in the early online edition of Proceedings of the National Academy of Sciences.


Read this article on Science Daily:

Duke University. “Women survive crises better than men: Newborn girls are hardier than newborn boys during famines, epidemics.” ScienceDaily. ScienceDaily, 9 January 2018. <www.sciencedaily.com/releases/2018/01/180109105941.htm>.

Sunscreen use now implicated in widespread vitamin D deficiency

Results from a clinical review find nearly 1 billion people worldwide may have deficient or insufficient levels of vitamin D due to chronic disease and inadequate sun exposure related to sunscreen use.

Results from a clinical review published in The Journal of the American Osteopathic Association find nearly 1 billion people worldwide may have deficient or insufficient levels of vitamin D due to chronic disease and inadequate sun exposure related to sunscreen use.

The study also found that 95 percent of African American adults may have vitamin D deficiency or insufficiency. Vitamin D variations among races are attributed to differences in skin pigmentation.

“People are spending less time outside and, when they do go out, they’re typically wearing sunscreen, which essentially nullifies the body’s ability to produce vitamin D,” said Kim Pfotenhauer, DO, assistant professor at Touro University and a researcher on this study. “While we want people to protect themselves against skin cancer, there are healthy, moderate levels of unprotected sun exposure that can be very helpful in boosting vitamin D.”

Dr. Pfotenhauer also said chronic diseases like Type 2 Diabetes and those related to malabsorption, including kidney disease, Crohn’s and celiac disease greatly inhibit the body’s ability to metabolize vitamin D from food sources.

Considered a hormone rather than a vitamin, vitamin D is produced when skin is exposed to sunlight. Vitamin D receptors are found in virtually every cell in the human body. As a result, it plays a wide role in the body’s functions, including cell growth modulation, neuromuscular and immune function and inflammation reduction.

Symptoms for insufficient or deficient vitamin D include muscle weakness and bone fractures. People exhibiting these symptoms or who have chronic diseases known to decrease vitamin D, should have their levels checked and, if found to be low, discuss treatment options. However, universal screening is likely neither necessary nor prudent absent significant symptoms or chronic disease.

Increasing and maintaining healthy vitamin D levels can be as easy as spending 5-30 minutes in midday sun twice per week. The appropriate time depends on a person’s geographic location and skin pigmentation — lighter skin synthesizes more vitamin D than darker skin. It is important to forgo sunscreen during these sessions because SPF 15 or greater decreases vitamin D3 production by 99 percent.

“You don’t need to go sunbathing at the beach to get the benefits,” said Dr. Pfotenhauer. “A simple walk with arms and legs exposed is enough for most people.”

Food sources such as milk, breakfast cereals, and Portobello mushrooms are also fortified with vitamin D. Dr. Pfotenhauer said supplements are a good option, as they are effective and pose few risks, provided they are taken as directed and a physician is consulted beforehand.

Research is ongoing to determine whether vitamin D deficiency has a role in multiple sclerosis, autoimmune disorders, infections, respiratory disease, cardiometabolic disease, cancer, and fracture risk.

“Science has been trying to find a one-to-one correspondence between vitamin D levels and specific diseases,” said Dr. Pfotenhauer. “Given vitamin D’s ubiquitous role in the body, I believe sufficient vitamin D is more about overall health. Our job as osteopathic physicians is to recognize those patients that need to be tested and treat them accordingly.”

Currently, insufficiency is defined as between 21 and 30 ng/ml and deficiency is considered below 20ng/ml by the Endocrine Society.


Story Source: Materials provided by American Osteopathic Association. Note: Content may be edited for style and length.

Read this article on Science Daily:¬†American Osteopathic Association. “Widespread vitamin D deficiency likely due to sunscreen use, increase of chronic diseases, review finds.” ScienceDaily. ScienceDaily, 1 May 2017. www.sciencedaily.com/releases/2017/05/170501102258.htm.