In the most general sense Homo Sapien Sapiens have already slowed down the ageing process remarkably compared with other creatures, and notably their closest DNA relatives - Chimps, Gorillas and Baboons. This was done by neoteny - a process of extending the immature stage of development. Somehow the Human species pulled off a remarkable set of neoteny characteristics which gave us the longest period of development of any species on Earth. It takes a Human male brain 27 years to reach its full adult form. Almost all this time from conception to maturity is spent growing and developing the Human brain. Science still hasn’t worked out how Humanity did this. It might be an evolutionary fluke resulting from some form of epigenetics, but there is so much that’s special about homo sapien sapiens that it leaves one wondering if there was a little help in there somewhere from some external intelligent source too.
Anyhow - the first thing to notice is that by using neoteny to slow down development into adults, the human species also slowed down the development of ageing as a whole. This is why Human’s live longer than any other mammal.
There are two known effective ways to slow down ageing within Humans.
First - anti-oxidants. Anti-oxidants do capture free radicals and this does stop them causing damage.
Second - Slow down the metabolic rate.
It has been noted that there is a direct correlation between the rate of heart beat and the length of life of an enormous number of species.
Slowing down the Human metabolism extends life. Slow down the rate of breathing, the rate of heart beats, and the rate of cell replacement, and you extend life. You may not have any more heartbeats in your life, but a slower heart rate means you will live longer.
How does one do that? Well start by doing the opposite of that recommended by western culture. Do NOT go to the gym and pump iron. Do NOT put in hours on treadmills boosting cardio-vascular activity.
Follow the Buddhist approach. Do Tai Chi. Do Buddhist breathing - which slows down breathing. In Buddhist breathing you don’t breath in, you only breath out. You allow the diaphragm to expand and refill again naturally, but you never draw in a deep breath.
Eat less. Those skinny little Asian Buddhist gurus know what they are doing.
Meditate and maintain inner peace. Anxiety increases the heart rate. Tension and stress kill you - slowly, but literally.
Learn to live life in the slow lane.
These are currently the only two techniques known to extend human life.
There are about a dozen parts to the ageing process.
One is cell replication using up telomeres. So logically, slowing your metabolism down slows down the rate of cell replication, which reduce the rate at which telomeres are used up.
Of course, nothing is quite that simple either.
Being aerobically fit increases efficiency, reduces oxygenation, and lowers ones resting heart rate.
So, one wants to achieve aerobic efficiency without increasing metabolic rate. Tai Chi can do this.
Best advice I can give at present.
That said technologists are working very hard on the problems of ageing and are making progress. It’s not hard, for example to replicate cells without using up telomeres, or to add telomeres. The problems are coping with the resulting problems, particularly cancer.
What we would do with a whole lot more people living a lot longer is a sociological problem that’s distinctly non-trivial.
And how we would cope psychologically with living to 160 years of age is another issue. With attendant medical problems. Anyone want a genuine ‘life sentence’ of one hundred and forty years in jail? How about being married to the same partner for a hundred and forty years? Caught up with the great-great-great-great-great-grandchildren lately?
But the other thing to bear in mind is that while slowing down the ageing process takes takes dedicated effort, we know how to speed it up very easily.
Have children. Drink and smoke. Overeat and don’t exercise. Do drugs.
Or do exercise in the fast lane. Do gym. Run marathons. Do dangerous sports, like Grid Iron or Boxing.
Lead a high stress, high burn life. Rage at night. Study hard and pull all-nighters. Drink Coca Cola and live life to the Max.
These things will take years off your life and health.
So - there’s a price. How much do you really want to live longer, and how much are you willing to give up to do so?
Hope this helps.