Two remarkable aspects of human longevity.

OK, a change to the theme of the last few days, to a topic that must cross the minds of practically every single human being at some point; what is our lifespan going to be?  Who doesn’t want to live a long and healthy life, and I don’t wish to be insensitive to those who labour under mental and physical troubles, of course.

So a recent couple of fascinating stories have given an insight into just how to live that longer and healthier life.

The first one is easy – be a woman!

OK, a bit of an issue if you are a man like me but did you realise, because I didn’t, that being the female of many species offers a significant advantage.  This came from a BBC item published on the 2nd August, from which I quote,

Scientists believe they have discovered a clue to why women tend to live longer than men – by studying fruit flies.

Writing in Current Biology, they focus on mutations in mitochondrial DNA – the power source of cells.

Mitochondria are inherited only from mothers, never from fathers, so there is no way to weed out mutations that damage a male’s prospects.

Then came an extraordinary fact [my italics below],

By the age of 85, there are approximately six women for every four men in the UK, and by 100 the ratio is more than two to one.

And females outlive males in many other species.

If you are of the scientific bent and/or a woman! you can read a fuller account of the research findings on the Science Daily website.  As well as that link you can also read the  Monash University press release on those research findings.

As a fella’ I think I’m moving on!

The second one is almost as easy – Fasting

Again, this news came from the BBC website, the news about the power of fasting.  In an article promoting the showing of a BBC Horizon programme, Michael Mosley wrote this,

Scientists are uncovering evidence that short periods of fasting, if properly controlled, could achieve a number of health benefits, as well as potentially helping the overweight, as Michael Mosley discovered.

I’d always thought of fasting as something unpleasant, with no obvious long term benefits. So when I was asked to make a documentary that would involve me going without food, I was not keen as I was sure I would not enjoy it.

But the Horizon editor assured me there was great new science and that I might see some dramatic improvements to my body. So, of course, I said, “yes”.

I am not strong-willed enough to diet over the long term, but I am extremely interested in the reasons why eating less might lead to increased life span, particularly as scientists think it may be possible to get the benefits without the pain.

For obvious reasons I can’t republish the full BBC article but I encourage you to read it here.  And stay with me for some more research links that are most interesting.

But I will just include this part from the BBC item,

The IGF-1 hormone (insulin-like growth factor) is one of the drivers which keep our bodies in go-go mode, with cells driven to reproduce. This is fine when you are growing, but not so good later in life.

There is now evidence suggesting that IGF-1 levels can be lowered by what you eat. Studies on calorie restrictors suggest that eating less helps, but it is not enough.

As well as cutting calories you have to cut your protein intake. Not entirely – that would be a very bad idea. It’s about sticking to recommended guidelines, something most of us fail to do.

The reason seems to be that when our bodies no longer have access to food they switch from “growth mode” to “repair mode”.

As levels of the IGF-1 hormone drop, a number of repair genes appear to get switched on according to ongoing research by Professor Valter Longo of the University of Southern California.

Intermittent fasting

One area of current research into diet is Alternate Day fasting (ADF), involving eating what you want one day, then a very restricted diet (fewer than 600 calories) the next, and most surprisingly, it does not seem to matter that much what you eat on non-fast days.

Dr Krista Varady of the University of Illinois at Chicago carried out an eight-week trial comparing two groups of overweight patients on ADF.

“If you were sticking to your fast days, then in terms of cardiovascular disease risk, it didn’t seem to matter if you were eating a high-fat or low-fat diet on your feed (non-fast) days,” she said.

Michael Mosley explains how he couldn’t manage Alternate Day Fasting and found it was just too impractical.

Instead I did an easier version, the so-called 5:2 diet. As the name implies you eat normally 5 days a week, then two days a week you eat 500 calories if you are a woman, or 600 calories, if you are a man.

The BBC Horizon programme  was screened on the 6th August but is available on the BBC iPlayer for UK viewers.  Here’s how it was promoted on the BBC website,

Michael Mosley has set himself a truly ambitious goal: he wants to live longer, stay younger and lose weight in the bargain. And he wants to make as few changes to his life as possible along the way. He discovers the powerful new science behind the ancient idea of fasting, and he thinks he’s found a way of doing it that still allows him to enjoy his food. Michael tests out the science of fasting on himself – with life-changing results.

This programme clip will also attract your attention, trust me!

and if you would prefer a more inspiring antidote then here’s another clip from the programme,

Tomorrow, I’m going to link to the scientists behind these new findings because this is very significant research that could revolutionize the future health for millions.

Finally, I’m here to tell you that Jean and I have ‘signed up’ to the 5:2 pattern and had our fast days last Thursday and Friday.  They were much easier than I expected and, frankly, will be fun to maintain.  Leave a comment if you would like details of the food and calorific values of what Jean served those two days.