by Greg McKenzie © Copyright 2016
Greg's articles

OF Mice And Men… And Women…And Long Life

I know I meant to follow up Polypharmacy with a review of non-prescription substances, like St John’s Wort and aspirin that impact on the prescribed medications you may be taking but an event has taken place that is highly worthy of mention.

In April this year (2016) 130 Australian and international experts on ageing in fields from metabolism, to epigenetics, to neurobiology, to nutrition, to genomics and evolution gathered at the University Of NSW to discuss the latest research aimed at prolonging life, maintaining health and slowing the ageing process.

I became pretty excited when I read about the inaugural Australian Biology Of Ageing Conference although a bit chagrined that it was buried on page 19 of a major newspaper.

If you’re still scratching your head about epigenetics and genomics, I’ll divert with a quick explanation. Epigenetics is concerned with the heritable changes in gene function that cannot be explained by changes in DNA sequence. Something is going on outside the way genes normally work to affect how cells read genes.

Both the environment and individual lifestyle can directly interact with the genome to influence epigenetic change. Human epidemiological studies provide evidence that prenatal and early postnatal environmental factors influence the adult risk of developing chronic diseases and behavioural disorders.

For example, studies show children born during the Dutch famine of 1944-45 have increased rates of cardiac heart disease and obesity in life when their mothers were exposed to famine during early pregnancy compared to those not exposed to famine.

I took an interest in epigenetics recently when researchers posited that emotional trauma can be passed on from generation to generation. It seems certain genes switched on during a parent or parents’ history may imprint upon their children.

Within genetics, genomics concerns the sequencing and analysis of an organism’s genome. The genome is the entire DNA content of a single cell. Basically genetics deals with the role and function of single genes while genomics tries to explain the complex interaction of the biological system of genes and their interaction with cells and beyond.

Now that is clear as mud, back to the conference.

The keynote speaker was Dr Darren Baker who is Associate Professor of Biochemistry and Molecular Biology at the Mayo Clinic in the US. He and his co-researcher studied senescent cells that accumulate at sites of age-related disease. Senescent cells are cells that are “worn out” and no longer divide. The study’s aim was to look at the results of removing cells from mice that had been engineered so that these specific cells could be killed off by a drug they injected.

Mice received the drug at age 12 which is 40 in human years. Compared to a control group whose senescent cells were allowed to accumulate the results were remarkable:

* Heart and kidney function improved
* Mice looked healthier, seemed less anxious and explored their cages more
* They developed tumours and cataracts at a later age
* They lived longer, with a median lifespan boosted by 17-35%
* These spectacular results were not accompanied by any adverse effects

Dr Baker predicts that further research will link senescent cells to age-related diseases like Alzheimer’s, Parkinson’s, diabetes, osteoarthritis and macular degeneration.

Conference chair Lindsay Wu from the UNSW Lab For Ageing Research summed up the emphasis on genetics in ageing research. He said genes tell our body to start degrading and that most non-communicable human diseases can be attributed to the ageing process taking place in all our cells. Switching off this process is the Holy Grail for researchers.

Given the impact of epigenetics, environment and lifestyle still play a strong role in healthy ageing.
Another study discussed at the conference and published in “Cell Metabolism” was conducted by Professor David Le Couteur of the University Of Sydney and Dr Samantha Solon-Biet of the Charles Perkins Centre.

If you have followed the Atkins Diet or “gone Paleo” you’ll want to re-think that strategy as you get older and take more interest in living a longer, healthier life. The three-year study put 900 mice on 25 different diets. The basis of the study was a challenge to the long-held theory that animals have to trade off longevity against fertility when resources are limited.

The study concluded that while a high-protein, low-carbohydrate diet favoured increased fertility, a low-protein, high-carbohydrate favoured lifespan. Professor Le Couteur summed up; “If you’re interested in a longer lifespan and late life health, then a diet that is low in protein, high in carbohydrate and low in fat is preferable.”

The healthiest mice (based on cardio and metabolic health indicators like blood pressure, LDL cholesterol, glucose tolerance and rate of diabetes) ate 5-15% protein, 60-70% carbohydrate and less than 20% fat. These mice also had the highest dietary energy content. The researchers found that restricted calories caused mice to die more quickly. The healthiest mice had no calorie restriction. That flies in the face of animal studies that show extended life from 25% calorie restriction.

Dr Solon-Biet added that “high-protein diets lead to weight loss and greater muscle bulk but are associated with worse outcomes.” She was referring to blood pressure, diabetes and lifespan.

I found this very interesting because over the last two years I have gone back to my bodybuilding roots and trained hard and fanatically. I have gained a lot of muscle and lost lots of body fat. I did change my diet, bumping up protein with lean meat, chicken and fish displacing much of the vegetarian fare I normally eat. Carbohydrate in the form of fruit, vegetables and grains are still prominent and my fat intake is low.

I think many people, particularly Atkins and Paleo adherents boost protein but fail to keep fat intake low. I’ve had several blood tests over the transformation period and my lipids and readings in general remain very good. I have also dropped alcohol.

We shall see.

Happy, healthy ageing to you.