Most of us are aware that a healthy lifestyle is good for us – it can reduce our risk of developing cancer and other diseases and even help us live longer.
There are several reasons for this. For a start, healthy living reduces our exposure to damaging chemicals such as those in tobacco smoke. But an interesting article published this week in the prestigious journal The Lancet Oncology suggests another route – our lifestyle choices could directly affect a key protein that controls the ageing process. Let’s take a closer look…
What they did
The study was carried out by Dean Ornish and his team of researchers at the University of California. They recruited a group of 24 men with early-stage prostate cancer that didn’t need immediate treatment and asked them to make extensive lifestyle changes over a 3-month period.
The men all adopted a diet low in fat and high in fruit and vegetables, with added soy, fish oil and vitamin supplements. They were encouraged to exercise regularly (6 days per week) and went through a stress management programme consisting of yoga and meditation techniques.
The team measured the levels of a protein called telomerase in the men’s white blood cells at the beginning and end of the 3 months. On average, telomerase levels were found to increase by 29% and this coincided with falling levels of ‘bad cholesterol’ and psychological stress.
Why is this so important?
Although this is a small study, the link between lifestyle and telomerase is interesting because telomerase plays a central role in both ageing and cancer. Just over two weeks ago, scientists published the molecular structure of a part of telomerase and we wrote about the importance of this discovery. To recap briefly…
Every time a cell divides in two, telomerase helps to re-build telomeres – the protective structures at the ends of chromosomes. Without telomerase, telomeres progressively shorten, acting as a ‘molecular timer’ ticking away as the cell ages. When telomeres shorten beyond a certain length, the cell enters a ‘shut-down’ mode.
However, at this critical time, the cell has no more telomeres protecting the ends of its chromosomes, leading to cancer-causing damage. Previous work has suggested that people with shorter telomeres in their cells have a higher risk of developing certain types of cancer such as lung, kidney and bladder cancer. Shortened telomeres have also been linked to a worse outcome for people with cancers such as breast and bowel cancers.
What’s more, shorter telomeres are associated with an increased risk of developing other conditions such as coronary heart disease and dying at a younger age.
Because the telomerase enzyme lengthens the telomeres in our cells, scientists think it has the ability to slow the ageing process and help protect us from diseases such as cancer.
This study reinforces the idea that we can influence our own ‘countdown timer’ through our behaviour, as it suggests our lifestyle can affect the levels of telomerase in the cells that make up our bodies.
Kat’s recent post about telomerase painted a portrait of the molecule as a cancer promoter – when cancer cells reactivate telomerase, they bypass their molecular clock and become immortal.
This may seem counterintuitive – longer telomeres are a good thing in healthy cells, as they seems to protect us against ageing and DNA damage. But in cancer cells, telomerase is a bad thing.
Clearly there’s a lot we don’t know about telomeres and telomerase – we need to do a lot more research before we understand how we can tip the telomerase balance in favour of healthy cells, while preventing its activity in cancers.
As acknowledged by the study’s authors, their work is still at a very early stage, only looked at a relatively small number of men, and needs to be replicated in much larger trials involving proper control groups.
What’s more, the very short time-frame of this study meant that it was only possible to study telomerase levels, not actual telomere length. The researchers haven’t investigated whether increased levels of telomerase protein actually lead to longer telomeres – a crucial step in finding out how this research impacts on the risk of cancer and overall life span.
However, if the results ARE found to hold true generally, it will be interesting to discover whether certain elements of our lifestyle out of all the ones tested in this pilot study have the different effects on telomerase levels.
In the meantime, our advice for people looking to reduce their risk of cancer and to promote general wellbeing remains unchanged – first and foremost, don’t smoke; eat a healthy balanced diet; stay active; limit alcohol consumption; and avoid heavy sun exposure.
Jo September 18, 2008
We totally agree that this is very preliminary work and limited by the large number of factors studied in relation to telomerase levels. And obviously, the conclusions that can be drawn are limited by the design of the study.
But with all scientific research, you have to start somewhere – and there’s credible evidence to suggest that things like obesity, inflammation and ‘cell stress’ are linked to shortened telomeres, such as this paper and this one. So it’s definitely worthwhile to conduct a small study like this to see if lifestyle impacts on telomerase levels. Given the encouraging results of this pilot study, the next step is to certainly carry out much larger trials to examine the effects of each of the lifestyle factors thrown into the mix in this study.
Don Cox September 17, 2008
What’s the use of an experiment where you change ten variables at once? Maybe it was just the yoga that did all the good? Or, the fruit and veg may have helped but the excess vitamins reduced the improvement.
Given also the small sample size, I don’t think this trial tells us anything.