Secret no.49 Good genes

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Mary Belle Roach and Mae Belle Powell (known as the ‘Wallace sisters’ because of their maiden names) are identical twins. Throughout their lives they’ve rarely been apart. They live together in the Kentucky house in which they grew up. They dress alike and do most things together. They’ve both outlived their husbands. And in May 2016 they became centenarians together.

Why do they think they’ve both reached 100?

“Good genes. Our mother lived to be 97,” says Mae Belle. But she adds: “We didn’t smoke cigarettes. We didn’t smoke that pot. We never drank beer.”

Let’s take that first answer (we’ll get to the tobacco, drugs and alcohol later). Is the Wallace sisters’ longevity down to their genes?

Plausibility rating: 10 out of 10.  Genes play a big role in our longevity and it appears to become even more important the older we getLet’s try and tease out the facts.

The first place to turn are studies of identical twins like the Wallaces. Twins share identical genetic make-ups so if genes were to determine everything about our longevity we’d expect both twins to have the same length of life.

But they don’t: some die much earlier than their twin, some much later. In fact, this major study of twins estimated that just 20%-30% of longevity is inherited. The rest, it said, is down to their environment.

However those studies weren’t looking just at centenarian twins but at twins who died at all ages. Could it be that those who make it to 100 share a different genetic make-up to those that don’t, perhaps with a higher amount of heritability?

Almost certainly yes. One strong piece of evidence for this is a major study of over 2,000 family members of centenarians. It found that, compared to the population as a whole, male children of 100-year-olds were at least 17 times as likely to get to 100 themselves, while females were at least eight times as likely.

This suggests that genes are playing a much larger role than the 20-30% in the population as a whole. It helps to explain why extreme longevity often clusters in families (the Guinness Book of Records award for the highest combined total for nine siblings is an incredible 818 years, awarded to the Melis family of Sardinia in 2012). And certainly centenarian twins turn up much more frequently than you might expect if genetics played a limited role.

Why might that be? Gerontologists talk about something called the ‘compression of morbidity’ hypothesis. Basically, this is the tendency for some people to stave off illness and disability until much later in their lives than most people.

Some achieve it because they look after themselves. This study of Seventh Day Adventists in the United States suggests that diet, exercise and other factors can help get the ‘average’ person well into their 80s, adding up to 10 years to longevity.

However not only do centenarians get this benefit for longer, many of them seem to have it granted them naturally: it’s in their genes. This research in Japan for example found that at 92% of people who went onto become centenarians were still living independently at 92. That genetic tendency may even include some degree of protection from habits that are usually pretty disastrous for health, like smoking. This research for example claims to have identified a gene that makes smokers less likely to die from their habit than the rest of the population (though it’s by no means definitive: we cover the subject in a bit more depth here). And we’ve previously seen that very long-lived people like centenarians are less likely to die of conditions like cancer.

So it’s fairly clear that genetics does play a large role in whether you’ll live to 100. However there plenty of reasons why we should be wary of assuming that genes completely determine our lifespan. For a start, despite intense efforts, scientists have struggled to find a gene or even a set of genes that correlate closely with longevity. And even if we can identify the genes that aid longevity, we may find that they are shared by quite a large number of people.

Secondly, our environment influences how our genes express themselves, including turning individual genes on and off. So despite having identical genomes, even identical twins like the Wallace Sisters may differ across a range of factors such as susceptibility to illness.

And finally, lots of other factors can also influence how long we live. As we’ve seen in the previous 48 ways of living to 100, these include what we eat and drink, how much exercise we take and the strength of our social networks. Changing these factors alone can make a significant difference to our longevity. Which reminds us that the Wallace sisters wisely ascribed their longevity not just to their genes but also to not drinking and not smoking (especially ‘that pot’).

Overall, our genetic make-up is perhaps best seen as strongly shaping our ‘potential’ longevity, with our environment and own behaviours then influencing how much of that potential we actually achieve. But the honest truth is that we really don’t know for sure.

photo credit: Chromosomes and DNA double helix via photopin (license)

 

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Secret no.43 A big family

When Edna Owen turned 100 on Hawaii recently she celebrated it with five generations of relatives – three children, eight grandchildren, 16 great grand children, and 11 great, great grandchildren.

And she credits that large family with her longevity: “My secret to a long life is a big family, and mine is all with me today,” said Edna.

We’ve (too briefly) discussed the importance of a loving family but is family more important than other relationships?

Plausibility rating: 7 out of 10

This one is going to defeat us. There’s plenty of evidence that social relationships matter. But it’s far more difficult to tease out whether family is more important than other relationships or in fact whether the number of social relationships matters as well as their quality.

To start at the beginning: there’s little doubt that social relationships matter in later life. A huge meta-analysis of 148 studies involving well over 3oo,ooo people found that people were 50% more likely to be alive if they had strong social relations. Being lonely was as much of a risk factor as smoking and more of a risk than obesity.

That study didn’t compare the relative (sic) importance of family and friends. But this analysis of studies involving over 100,000 people did and concluded that family had more of an impact than other relationships. It quotes the Spanish proverb: ‘An ounce of blood is worth more than an pound of friendship’.

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This is five generations of my own family at a recent reunion. 

But it’s far from undisputed. This study in Australia found that close contact with children and relatives had little impact on survival over a 10 year period but a strong network of friends and confidants did improve the chances of survival.

It’s also unclear whether the number of social contacts matters. This big study in the United States found that size did matter whereas this one – there’s a pretty clear trend towards inconsistency here, isn’t there? – didn’t.

But perhaps that isn’t so surprising. Our social relationships are extremely complex and unpicking their relationship over time is going to be tough. Perhaps the most likely answer to our questions of whether family and family size matters is – ‘it depends’.

So let’s go back to Edna Owen, who seems to have been ahead of us in this debate. She said a big family was the key to her longevity but she then qualifies that and says: “Have a good family who loves you very much and will do anything for you.”

That echoes the research about why social contacts might matter to our health. One explanation is that they act as a ‘buffer’ between us and the big, bad world – when something goes wrong we have someone to talk to and make ourselves feel better. But the other explanation is that social relationships give us a role in our life and so bring meaning and fulfillment to it.

So when Edna says that she’s loved and that her family would do anything for her perhaps she’s also saying that that she has an importance and status as head of her family. And it’s not hard to see why that might matter very much.

Duck photo credit: “Make Way for Ducklings” via photopin (license)

Secret no.27 Chilli peppers

1796297804_1d9622673e_oDaisy McGhee lives in Ohio and at 100 years old remains a keen gardener, growing garlic, potatoes, parsley, onions – and jalapeno peppers. It’s to these that she credits her long life, according to local paper the Star Beacon.

Born in Cleveland, Daisy skipped school because her mother couldn’t afford the textbooks and started work as a maid. She married twice but lost both of her husbands, the second in 1977. She has one son – who she lives next door to – and four grandchildren, five great-grandchildren and three great-great-grandchildren. A rich life then – but surely her fondness for chilli peppers isn’t responsible for the length of it?

Plausibility rating: 6 out of 10. Don’t be so sure. The fiery taste of chilli peppers comes from capsaicin, which is also found in cayenne pepper. Its strength is measured on the Scoville scale – pure capsaicin scores 16 million on the scale and the hottest pepper – the alarmingly named Carolina Reaper – scores around two million units. Daisy’s jalapenos are much, much milder – perhaps 20,000 units at most- but enough to pack a bit of a punch.

Capsaicin doesn’t just give peppers their taste though. It has well-established pain relief properties and is used to treat conditions such as arthritis. It may also aid longevity: one study – admittedly on mice – suggests that the pain-relieving qualities of capsaicin can also extend lifespan by 14 percent. A more recent study points to benefits for humans too. The study used extensive questionnaire data on half a million Chinese and found that those who ate spicy food once or twice a week had a 10 percent reduced chance of death (eating it daily further increased the health benefit but only marginally). NHS Choices, which takes pride in sober analysis of sometimes hysterical health news, gave this one a cautious thumbs up, saying it ‘adds to emerging evidence that capsaicin in chilli pepper may have a positive effect’ on health.

How appropriate then that Daisy celebrates her birthday on October 12th, the day that Columbus landed in the Americas and – among many other things – introduced Europe to the chilli pepper.

STORY SO FAR: top-rated ways to live to 100

Twenty entries in to our ‘101 ways to live to 100′ and already one or two trends are emerging. Alcohol and religion both turn up in quite a few of our centenarians’ secrets to longevity, as does chocolate. So far, no one has mentioned genetics (though a few have mentioned ‘family’). And our surprise leader is mountaineering.

Our league table below is surely the only time these words have ever appeared in a list together:

9/10: Mountaineering
8/10: A loving family; Be happy and enjoy life;
7/10: A good doctor; praising God
6/10: One meal a day; sleep; hard work
5/10: ChocolateMonogamy; Guinness; Yoga; a lot of booze
4/10: Two raw eggs;
3/10: Work less overtime;
2/10: Bacon
1/10: Water from a wishing well
0/10: Pearls
No score: Good food; stem cells

Back soon with: Does a sense of humour help you live longer?

Secret no.20 Chocolate

Blogger Penny Walford recently wrote a touching piece about her great aunt Marie, who had died aged 106. Marie sounds a remarkable woman, who travelled the world in her youth by hitching rides on cargo ships. Penny first met her later in life, when she would follow her favourite ice hockey team, the Ottowa Senators on TV and, when her eyesight failed, on the radio.

Penny describes how Marie was a strong and active woman who swam every day when she was younger and walked every day as she got older. Even at 106 she was still taking a turn around her nursing home. So surely this explains her long life?

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Well not according to Marie. She and Penny had a shared love – chocolate. And it is to this that Marie gave credit for her long life. Penny describes how Marie ate it every day, with half-hidden stashes of it near her bed and usually a couple of bar wrappers in or around the wastepaper bin. (In the interests of accuracy, I should also say that Penny thinks Marie’s love of chatting and storytelling also helped her live longer and we’ll return to this theme in a later post).

So is this possible? Could Cadbury and Hershey be manufacturing the key to a longer life?

Plausibility rating: 5 out of 10. While at first the idea of chocolate as a superfood seems outlandish, it turns out Marie is not the only centenarian to give it credence. Bernard LaPallo is 110 and he too says, chocolate (along with four other ‘superfoods’) is the reason while 105-year-old Edna Sandys also thought it had played a part. And perhaps we were wrong to focus on the two raw eggs that Emma Morano eats (No. 12 of our 101 ways) and should instead have followed the evidence of the chocolate that goes missing in the night.

So what about the science part? Well, there is some reported evidence to support chocolate’s credentials. It is high in polyphenols, which may protect against heart disease (along with lots of other, healthier-sounding, foods like blueberries, cereal bran and green tea). It may also help lower blood pressure and some studies suggest a reduction in heart attack, stroke and diabetes. Certainly the internet is full of articles with titles like ‘the 9 health benefits of chocolate’ and ‘7 reasons why chocolate is healthy’.

However, on closer examination the benefits of chocolate do tend to dissolve, a little like cocoa powder in hot milk. Many of the studies are small and still need confirmation. And they tend to focus on either cocoa or strong dark chocolate, not the mass-produced stuff that most of us eat and which is made up mainly of milk fat and sugar. Alison Hornby of the British Dietetic Association brings us down to earth: “Chocolate is an energy-dense food that could contribute to weight gain and a higher risk of disease. As an occasional treat, chocolate can be part of a healthy diet. Eaten too frequently, it is an unhealthy choice.”

I fear this is good, sensible advice  – even if Marie, Bernard, Edna and Emma were all able to ignore it and still make their way to 100. Kit Kat, anyone?

photo credit: Geknöppel via photopin (license)

Secret no.18 Monogamy

Linah Mmola was born in Limpopo and apparently turned 117 years old recently in Tembisa, South Africa. I say ‘apparently’ because there is some debate about Linah’s birthday: her family believe it was January 2nd 1898 but there are (perhaps understandably) no documents to prove it. Whether Linah is 117 or a little younger, though, there is little reason to doubt she’s lived a very long life. Her secret? Well, she told the local Eyewitness News that her longevity was down to ‘staying true to one good man for many years‘, as well as a diet of spinach and corn meal porridge.

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At least we think she did’: it’s not clear from the reports whether Linah gave this reason or one of her family.

But let’s assume she did say it: could it be true?

Plausibility rating: 5 out of 10We know (see Ways to Live to 100 no. 12) that loneliness and isolation can be bad for us but it’s a big stretch from there to concluding that monogamy is good for us. There is some academic research to suggest that marriage might be beneficial. One 1995 US study called, perhaps inevitably, ‘Til death do us part‘ found that married people had longer lives than single people. However that in itself does not mean that monogamy leads to a longer life. For one thing, married people are not necessarily monogamous, as the data leak from the AshleyMadison website this month reminds us. Nor can marital status at time of death – which many of the studies use – distinguish between lifelong pairings and deathbed dalliances. Finally, it’s also possible that those in good health are more likely to get married in the first place, rather than it being wedlock that leads to healthiness. There is an entertaining run-through of other possible health benefits of marriage here. However when a link about married women takes us not to an academic text but at a Beyonce video we know that we are on shaky ground.

For the opposition, one lovely  piece of research by the University of Sheffield bangs the drum for polygamy. It found that men aged 60+ from countries that practice polygamy lived on average 12% longer than men from mostly monogamous nations. ‘Want to live longer? Get a second wife’ said the New Scientist while the Daily Mail found an expert to say that men in polygamous marriages ‘benefit from having a fuss made over them by a gaggle of women’ as well as being better cared for into old age.

While that may not be conclusive proof (not least because it tells us nothing about the longevity of women in polygamous marriages – or the longevity of men and women in polyandrous marriages, for that matter) it is enough to conclude that the case for monogamy and long life is, at best, not proved.

photo credit: Wedding rings via photopin (license)

Secret no.12 A loving family’

Nazar Singh, who died last month in India where he was visiting family, was believed to be Europe’s oldest man. He was though to be 111, though he had no birth certificate.

He told media after his 110th birthday that his longevity was due to good food, good family and happiness. However his fondness for a tot of whisky every night – and perhaps the fact that he was pictured on his birthday with a pint of lager and a whisky chaser – led understandably to the whisky also being cited (we’ve covered whisky in another post).

Nazar was born in the Punjab, India. He navigated two world wars and the independence and partition of India before moving to the UK in 1965. He worked in a foundry in the West Midlands and then moved to Sunderland on retirement. He returned to India in January this year and was being cared for by his two eldest sons.

Plausibility rating: 8 out of 10. We don’t know exactly what food Nazar ate (though we know he drank milk and almond oil}. There is evidence about the beneficial effect of alcohol in moderation but also some that questions it. And he is surely right to emphasise the importance of a loving family to longevity: the absence of strong relationships – whether family or friends – is linked to early death. One study, cited by the Campaign to End Loneliness, says it is the equivalent of smoking 15 cigarettes a day. Nazar believed that ‘family need to look after elders’, a view that would be popular with the Health Secretary, Jeremy Hunt, who recently worried in public about the number of ‘lonely funerals’. The latter need not have concerned Nazar: he had 34 grandchildren and 63 great-grandchildren.