For most of human history we have conceived age as rigid — and ageing as inevitable. Now, a fresh understanding of the biological processes associated with ageing calls for us to challenge these assumptions.

Eis três áreas de investigação que poderão mudar a forma como pensamos o envelhecimento.

O tempo de vida saudável é influenciado por factores interligados, incluindo a genética, a doença, o ambiente e o estilo de vida. O tempo de vida saudável é influenciado por factores interligados, incluindo a genética, a doença, o ambiente e o estilo de vida.

Many lifestyle interventions to extend healthspan are well understood (an article in Frontiers illustrates the improvements to healthspan), such as not smoking and taking regular exercise.

But there is also a growing body of research into what happens in our cells as we age, presenting new opportunities to alter our healthspan. There's lots of excitement around maintaining levels of NAD+, a molecule that plays a critical role in cell metabolism and which dramatically declines with age. A 2018 study found that subjects whose diet was supplemented with a NAD precursor saw increased healthspan, while older subjects showed improved cognitive function when given the supplement for just two weeks. Harvard University geneticist and longevity expert Professor David Sinclair believes NAD supplements may also slow ageing in humans, as noted in an anti-ageing article in Harvard Magazine.

Researchers continue to identify molecules associated with ageing, and explore whether they could be targeted to extend lifespan and healthspan. For instance, supplements like glutathione or glyNAC — antioxidants found in cells, which decline with age — have been shown to increase the lifespan in research studies.

A replicação destes efeitos em seres humanos poderia pôr em causa as nossas ideias há muito estabelecidas sobre a inevitabilidade do declínio físico e mental.

SENOLÍTICOS

A major biological process associated with ageing is cellular senescence: when cells can no longer perform cellular functions or replicate, but also do not die. This is an important process for protecting against cancer and organ failure, but these ‘zombie’ cells can also emit a toxic chemical cocktail which causes damage to surrounding healthy cells. Increased cellular senescence is a biomarker of ageing.

Investigadores estão a estudar a possibilidade de combater este processo reservando ou suprimindo a senescência, ou matando as células senescentes para que possam ser recicladas em segurança pelo organismo.

A senescência é desencadeada numa célula quando os seus telómeros - que encurtam ligeiramente em cada divisão celular - descem abaixo de um determinado tamanho.

Therefore, there is considerable interest in whether telomere extension could combat cellular senescence. This has been demonstrated at Stanford Medical University with cultured human cells.

Another approach to combating cellular senescence is senolytics — developing molecules that kill senescent cells. Senolytics tested so far include the cancer drug dasatinib and the flavonoids quercetin and fisetin, and studies have shown increased lifespan and healthspan in subjects treated with senolytics.

As primeiras evidências sugerem que os senolíticos podem também reduzir o número de células senescentes nos seres humanos, um passo importante para compreender se e como os senolíticos podem funcionar no futuro.

Ageing is a wildly complex process — a process we have only just begun to comprehend. These are just three of the many areas researchers are pursuing in their bid to help us age slower and more healthily.

Join us in Part 2 where we will further examine what determines life expectancy.

FAQS

What is NAD in medical terms?

Nicotinamide Adenine Dinucleotide, or NAD, was discovered in 1906 and is a coenzyme found in all living cells. NAD exists in two forms: NADH which helps improve brain functions such as concentration, memory, and alertness and NAD+ which maintains our neurological system and healthy internal organs.

O que é a quercetina?

A quercetina é um flavonoide vegetal que se encontra nas cebolas, maçãs, couves, brócolos, chá verde e café. Como o nosso organismo não a produz naturalmente, podemos garantir que obtemos uma quantidade adequada tomando um suplemento.

Para que é utilizada a quercetina?

A quercetina é um potente antioxidante, que desempenha um papel fundamental na eliminação das células senescentes que contribuem para o envelhecimento e as doenças relacionadas com a idade.