“If I’d known I was going to live this long, I’d have taken better care of myself” - Mae West
Growing old has always been one of life’s inevitabilities.
We have all seen or felt age slowly and insidiously creeping into the faces, the bones and the minds of those around us. Or our own. For generations, this gradual fading into ‘old age’ has been begrudgingly accepted and while our life spans over this time have in general improved, these extra years have not necessarily been kept in perfect health.
Over the last few decades however, scientists have begun to understand the specific cellular and molecular processes that cause the deteriorations of old age. Researchers from the Mayo Clinic have identified 4 main cellular processes that contribute to ageing: chronic inflammation; cell dysfunction; changes in stem cells that make them fail to regenerate tissue; and finally cellular senescence, the accumulation in tissue of ageing cells that accompanies the disease.
As these ageing cells accumulate in parts of the body, they can result in chronic inflammation and even cancer. Healthy young people have fewer of these cells but as we reach our 50s and 60s they significantly increase. Research has begun to look at ways that these old cells can be cleared, either through medication or lifestyle interventions.
So does that mean that age should be seen, at least in part, as a condition with a cure? Last year, the World Health Organisation took a step in that direction by declaring ‘ageing’ as a condition that is treatable. With this change in thinking, has come the idea that diseases associated with ageing, such as heart disease, cancer and dementia can be delayed and in some cases reversed.
A number of compounds and drugs have already shown promising results in clinical trials. Some drugs already approved for other purposes are being tested as “senolytics,” as the drugs that kill old cells are now called.
Dr. Nir Barzilai, a professor of medicine at the Albert Einstein School of Medicine, is planning a study of metformin, a drug that has been used for 60 years to treat diabetes and has been shown to be effective against several age-related diseases.
If drugs can treat ageing, is ageing itself a disease? “No”, Dr. Barzilai says.
“Neither I nor the FDA is interested in calling ageing a disease. Our study is to show that we can prevent a composite of age-related diseases — cardiovascular, cancer, cognitive — and ultimately affect mortality.”
Another drug candidate involves a coenzyme called nicotinamide adenine dinucleotide, or NAD. It functions in cell respiration, moving electrons into the mitochondria where energy is produced. As people age, levels of NAD. decline to the point where it is undetectable in the blood of the elderly.
David A. Sinclair, a professor of genetics at Harvard, is working on methods of replenishing those levels. In studies of yeast, worms, flies and mice, he has shown “that replenishing (NAD) rapidly reverses some aspects of ageing,” he said. “And now there are trials underway in humans.”
But it’s not just a simple magic pill that will hold all the secrets to a longer life. A recent Finnish study published in JAMA looked at sauna use in over 2000 men aged 40-60yrs. They showed a reduction in heart disease and all-cause mortality of up to 50% in men that used the sauna 4 or more times per week when compared to those that used it once or less.
Exposure to heat stress causes the body to activate proteins which in turn protects the bodies cells through a number of mechanisms. Repeated heat exposure also results in a number of cardiovascular benefits including reduced resting heart rate, improved skeletal muscle blood flow hence reducing cardiac strain.
Doctors and modern medicine have traditionally tried to tackle one disease at a time. Treating ageing at its source, however, has a potentially much greater impact on health and lifespan than drugs that target a single disease. While a longer lifespan has been in part due to the many advances in health and medicine, we are also seeing an increasing rate of age-related diseases such as Alzheimer's dementia, heart disease, joint and muscle disease.
Lifestyle interventions must continue to play a part in maintaining good health as we age. Through advances in genetic profiling, we can gain a more exact understanding of the nutritional, exercise and metabolic interventions that will benefit us the most. This unique blueprint of our health and wellness allows us to modulate the effects of our environment, giving us the best chance we have ever had, to live a long and healthy life.
Dr Brett Gerrard MD