We have all heard that for long life you need to avoid smoking and drinking excessive alcohol, eat a healthy mix of fruit and vegetable, exercise regularly and be sociable. It also helps to be born with good genes.
It may also help to take a few pills.
In recent years, the science of anti-ageing has moved from science-fiction into evidence-based science.
“There are a lot of people out there who sell you snake oil and tell you that you’ll live forever, and then when you die, nobody sues them,” Dr Nir Barzilai, director of the Institute for Ageing at the Albert Einstein College of Medicine in New York told Science Focus.
Instead, it’s about increasing the number of years that people live well without disease. Therefore, scientists are striving to increase our healthspan – the time we remain fit enough and able to enjoy life. Extending the lifespan could be a lucky side effect. It could also save the economy billions.
How long could humans live?
In the 16th century life expectation in Europe was around 35 years, but this statistic is skewed by childhood deaths from infectious diseases. People who escaped them and lived a moderately affluent life lived longer.
The first person to become a centenarian, whose age could be validated was a Norwegian, Eilif Philipsen in 1782. Norway.
It is possible to estimate the maximum lifespan of a mammal by measuring epigenetic changes to its DNA. Epigenetic markers are chemical labels that determine what gene are active without altering the underlying sequence. Epigenetic change usually consists of adding a small molecule called a methyl group to the DNA letter C, in a process known as methylation.
Scientists, led by Professor Steve Horvath at the University of California Los Angeles, looked at methylation patterns in 60 different tissue types in 348 different mammals. From this they were able to estimate the age of individual animals. They then used machine learning to find methylation patterns linked with the approximate maximum lifespan of the species.
This method is least accurate for people, predicting a maximum of around 98 years, whereas Jeanne Calment, thought to be the world’s longest lived person, made it to 122 years. Calment’s age has been disputed, but others are verified as living up to 119 years.
So, we can reasonably expect science, eventually, to be able to extend our lifespan to 120 years.
Investigating ageing
It is difficult to test the effect of treatments on human aging because it takes a long time to conduct double blind trials, the gold standard for human research. Imagine getting teogether a group of volunteers in (say) their 50s, half take a pill daily while the others take a placebo and continuing doing so for the rest of their lives. The trial would take 50 years or more.
Therefore, scientists use mice as a model. Mice live only two years and are much easier to experiment on than people. But it is a long step from mice to people. Mice are not humans, although they share much of our biology.
Clinical trials on humans are currently taking place, but it will be many years before results are known, so for current advice about life extension we need to rely on data from animal trials.
David Sinclair, an Australian biologist, is professor of genetics at Harvard Medical School and co-director of the Paul F. Glenn Center for Biology of Aging Research. He is well known for his research on aging and epigenetics.
Since the publication of his seminal book Why we age and why we don’t have to interventions to try to extend longevity have become popular. Some of the compounds being tried follow.
Drugs to delay ageing
Resveratrol
Resveratrol is found mainly in peanuts and the skins of berry fruits including grapes and hence in red wine. It is anti-inflammatory and it protects cells in your body, especially brain and heart, by providing your blood vessels with a protective lining.
Resveratrol decreases LDL (bad cholesterol) in animals and helps lower blood pressure by increasing the production of nitric oxide. It also protect brain cells from damage, increases sensitivity to insulin and has shown cancer-blocking activity in test tube and animal studies.
It appears to activate genes that ward off the diseases of ageing and it increases the lifespan of 60 per cent of organisms studied, but the effect is strongest in organisms that are more distantly related to humans, such as worms and fish.
There is no conclusive recommended dosage for resveratrol, but consuming large amounts may lead to gastrointestinal upset and interfere with medications. A maximum of one gram per day is suggested.
Nicotinamide mono nucleotide (NMN)
NMN is found naturally in broccoli, cabbage, cucumber and avocados.
When swallowed NMN is converted within cells into another molecule known as NAD+ (nicotinamide adenine dinucleotide). All the cells in your body use NAD+ to function properly; it helps cells regulate a number of essential functions that keep your cells running smoothly, including energy metabolism and DNA repair.
By middle age, our NAD+ levels have plummeted to half that of our youth. Boosting NAD+ levels increases insulin sensitivity, reverses mitochondrial dysfunction, and extends lifespan in mice.
NMN helps muscle building by preventing age-related protein imbalance, enhances cardiovascular health by restoring blood vessels and helps increasing energy by increasing mitochondrial function. It also reduces DNA damage by preserving the length of telomeres which protect the ends of chromosomes and shorten at each cell division.
Most consumers take one 500mg capsule daily although up to one gram has been suggested.
Are these drugs safe to take?
Associate professor Ryu Takechi, director of Health Innovation Research at Curtin University said NMN is an anti-inflammatory.
“There are no known side effects. It does not appear to be harmful, but research has not established a safe upper limit. Excessive amounts could be toxic,” he warned.
Conclusions
There is considerable evidence of the efficacy of these drugs on expanding the lifespan of mice, fruit flies, yeast cells and some worms, but there is a dearth of evidence from studies in humans. Younger people can afford to wait for long term trial results; older people cannot. The upside is possibly improved health and longer life, the downside is the small risk of taking these supplement and the not inconsiderable cost.
Where to get these supplements
Neither NMN nor Resveratrol are restricted, some pharmacies stock Resveratrol
Alpha-Cell Enterprises sells both NMN and Resveratrol
There are other sources on the Internet
Next month we will look at senolytics, drugs that remove zombie, senescent cells.
