How to live longer, scientifically

It has been known for some years now that the length of our telomeres (in simplistic terms, the tips of chromosomes that keep them from fraying) are a major factor in how people age. Telomeres shorten slightly with each cell division, and when they get too short, the cells' ability to divide and renew is compromised, and the particular body tissue they are part of begins to break down, resulting in what we think of as a normal part of the ageing process. They are not the only factor in ageing - the oxidative damage caused by free radicals during the cells' normal metabolic processes are also implicated, and there may be other causal factors too - but the length and gradual shortening of telomeres, and the activity of the telomerase enzyme that replenishes them, is definitely an important causal element, and a good prediction of the ageing process.

Now, Elizabeth Blackburn, the Australian-American biologist who was a joint recipient of the 2009 Nobel Prize for her work in discovering the telomere connection, has published a book for the layman called The Telomere Effect: A Revolutionary Approach to Living Younger, Healthier, Longer. It sounds like another of those New Age-y self-help books, but it is actually science-based with copious references to research and studies. What it tells us is pretty much common-sense, though, and not revolutionary at all, but it also explains why this common-sense approach works, and how it affects our telomeres.

So, what is it we need to be doing?

• Exercise - we probably all know it, but exercise is the single best activity for almost all health problems, including ageing. However, not all exercises are born equal: resistance exercise like weightlifting apparently has little effect on our telomeres, while aerobic exercise (even just some light jogging or fast walking a few times a week) is much more effective, as is short but high intensity interval training. Gruelling marathons and ultra-marathons, on the other hand, add little benefit over much shorter regular workouts. And the more stressed we are, the more effective exercise is for telomere maintenance.
• Weight - actual absolute weight has little effect on our telomeres, although faddy diets and repeated losses and gains of weight actively shortens our telomeres. Reducing belly fat (as distinct from hip and thigh fat) can have a specifically beneficial effect on our telomeres, though, and the best way to achieve that - again, as well as know in our heart of hearts - is to reduce sugar intake.
• Diet - studies have show that the higher the blood levels of omega-3 essential fatty acids, the less telomeres shorten over the following years (fish, seaweeds and flaxseed are all particularly high in omega-3s). But a general healthy Mediterranean diet, high in whole grains, vegetables, fruits and nuts, has also been shown to maintain telomeres well, and the usual suspects of sugar, processed meats, white bread, pastries, saturated fats, and excessive alcohol, have all been shown to shorten telomeres.
• Mental health - depression, particularly chronic depression, has been shown to have a deleterious effect on cell telomeres, and the longer and more severe the depression, the shorter the telomeres. Anxiety, pessimism, hostility, mind-wandering and excessive rumination have also been shown to shorten telomeres. On the other hand, meditation, mindfulness-based stress reduction techniques, yoga and tai chi all increase telomerase activity and work to lengthen or at least maintain telomeres.
• Supplements - pills, creams and injections that purport to boost telomerase are commercially available, but their efficacy is at best debatable, and they can even prove to be dangerous (to much of the enzyme in the wrong cells at the wrong time can even trigger the kind of uncontrolled cell growth that leads to cancer). Commercial tests to track telomere length are expensive and largely unregulated, and could also lead to unhealthy anxiety and obsessiveness.

So, the best way to live a long healthy life? Keep fit, eat well and be happy. Obvious really.