Why Women Live Longer

When it comes to the ultimate battle of the sexes, women win. Scientists have, over the last few decades, uncovered many reasons why women live longer than men. There is growing evidence that men are biologically more ‘disposable’ in their genetic make-up.

Professor Tom Kirkwood of the University of Newcastle believes that women’s bodies are genetically programmed to last longer than men’s, primarily for the survival of mankind. Evidence suggests that the female body has evolved to accommodate the need to remain healthy for successful reproduction. If woman’s body is weakened, it will threaten the chances of healthy offspring. Men’s individual health is less important for survival once they have reproduced. “Under the pressure of natural selection to make the best of scarce energy supplies, our species gave higher priority to growing and reproducing than to living forever,” Prof Kirkwood writes in American Scientist.

Pro-Women Facts and Statistics

• Across the industrialised world, women on average live five to 10 years longer than men.

• Out of individuals around the world who are over 100 years old, 85% are women.

• In fact, the oldest living person is a woman, 115-year-old Besse Cooper of the United States.

• Last December, Singapore’s then oldest person, also a woman, named Teresa Hsu, died at the age of 113.

• According to Singapore’s 2010 census, among the 724 centenarians here, two-thirds or about 466 are women.

XX-rated

Singapore’s figures seem to correspond with those in other countries where centenarians make up about 0.01% of the populations. Japan takes the top spot, with 0.03% of the population made up of people over 100 years old, with women making up a staggering 84%. The extra X-factor in women seems to play a part in their longevity—women have two X chromosomes, while men have one X and one Y chromosome.

According to Dr Philip Koh from Healthway Medical Group, this means that a woman has a combination of two different X cell lines: one cell line with the X chromosome from the mother and another cell line with the X chromosome from the father. However, males have only one X cell line because they receive only one X chromosome from their mother and one Y chromosome from their father.

As such, if a certain X-linked disease—such as colour blindness—occurs in a female that is passed down by one parent, then the disorder will be masked by the other ‘healthy’ X chromosome, which acts as a back-up, hence preventing the expression of most X-linked diseases. Men have no such luxury. “In women, there can be more genetic variations that can take place in either of the X chromosomes, so if a set of variations provides a survival advantage for the cells, hence delaying aging, then this better variation is more likely to take place in women with two X chromosomes versus men with only one,” says Dr Koh.

Diseases Come Later

Dr Tom Perls, founder of the New England Centenarian Study at Boston University and creator of the website LivingTo100. com, says that one important reason why women are living longer is because of the later onset of cardiovascular diseases, such as heart attack or stroke.

Such diseases only occur in women in their late 70s and 80s, while men develop them in their 50s and 60s. He attributes this to iron deficiency in women, due to menstruation. Iron is instrumental in the creation of free radicals, which cause cell damage and ageing, leading to cardiovascular conditions such as heart disease or stroke. A study looking at the intake of red meat—the main dietary source of iron—and heart disease in Leiden in the Netherlands supports this theory. It found that populations in regions where people do not eat red meat have half the rate of heart attacks and strokes compared to populations that eat red meat.

Reach out and Touch

Geriatrician Dr Chan Kin Ming observes that women who live beyond 70 are generally happy and active, with good family and social support. Although many have common medical conditions, they are well-controlled. Most have adequate nutrition. Dr Chan, who practises at Gleneagles and Mount Alvernia Medical Centres, also notes a trend in women that may contribute to their longevity. “Women tend to seek treatment for their conditions earlier, whereas men tend to ignore them till late.” Men don’t deal with stress as well as women. They are less capable of sharing their feelings and are more prone to internalising that stress rather than letting it go. This can lead to depression. According to Dr Koh, “Depression in the elderly can be quite common. But if depression leads to attempted suicide, then the men are more likely to succeed.” Women have been found to be better at reaching out and connecting with others. They express emotions better, and reduce stress by communicating with others, which can boost their health.

Raging Hormones

The male sex hormone, testosterone, induces more high-risk behaviour among men. These include excessive drinking, engaging in violent behaviour, excessive smoking, experimenting with drugs, and driving too fast. These high-risk activities lead to higher death rates among men. Testosterone also increases harmful cholesterol, raising a male’s chances of getting heart disease and stroke.

Exercise Plays a Part

Lifestyle and diet play a part in longevity. Dr Ni Maoshing, a doctor of Chinese medicine and a longevity expert, has studied the daily activities of centenarians for two decades and found that every one of them walked for at least 30 minutes a day. Walking is an exercise that has proven benefits. According to Chinese medicine, it’s the perfect low-impact exercise for promoting digestion and encouraging cleansing of the lymphatic system. Dr Ni adds that how you breathe is also a factor. Take deep, diaphragmatic breaths instead of shallow breaths from the top of the lungs. Proper breathing is important not only to mitigate stress, but also to dispel toxins and waste.

Colour Your Way to Health

In TCM, the five elemental energies in our bodies are represented by wood, fire, earth, metal and water. Each element corresponds to certain colours: wood to green, fire to red, earth to yellow and orange, metal to white, and water to black, blue and purple. It’s believed that health and longevity depend on a balance of all five elemental energies. Dr Ni advises taking baby steps, perhaps starting with just two colours a day in all categories of fruits and vegetables, then adding one colour a day to eventually make up five. Pigments which colour the skins of fruits and vegetables are packed with powerful anti-oxidants crucial for maintaining health, preventing cancer, and protecting the body against environmental toxins. “A balanced diet is probably the way to go to ensure that one is as healthy as one can be. I tend to believe that longevity is predetermined by our genes, but our lifestyle can modify this to a certain extent.”

Anything You Can Do...

• Women have stronger immune systems Their secret weapon: oestrogen. A study done by McGill University found that oestrogen deals with a certain enzyme that often hinders the body’s first line of defence against bacteria and viruses.
   
• Women invest better A study of 100,000 portfolios shows that women outperform men, drawing an average of 18% profits to men’s 11%. This could be because women are typically more cautious and think in longer terms.
   
• Women can multi-task better than men Scientists have found that when women and men were asked to work on a number of simple tasks at the same time, the women significantly outperformed the men. Women are better able to reflect upon a problem, while continuing to juggle their other commitments.
   
• Women continue to evolve in looks; men don’t A study showed that attractive women tend to have 16% more children than average-looking ones, and that beautiful people are 36% more likely to have a girl as their firstborn. If you do the maths, this means that there are more gorgeous women now than in previous generations.

 

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Photo courtesy of Thinkstock. This article first appeared in NATURA magazine issue No.1. Find NATURA at Eu Yan Sang retail outlets, newsstands and major bookstores in Singapore.