A new blood test could tell us how fast our bodies are ageing

Forget the year you were born. Do you have the body and brain of a 30-year-old or a 70-year-old?

Here's the strange thing - the actual answer might be a mixture.

An in-depth study of how proteins - the body's building blocks - change over time in different organs suggests that different organs age at different rates. And a blood test might be able to tell you how 'old' each part of you is.

What's more, when people hit 50, ageing seems to accelerate markedly.

The research backs up the view that ageing is not a smooth, linear process and certain molecules can speed it up.

Some tissues, particularly blood vessels, may also age faster than others, a new study published in the journal Cell shows.

Researchers compiled a list of proteins found in organs from people of different ages and found that there was an age-related increase in the expression of 48 proteins associated with disease. Early changes from the age of about 30 were also noted in the adrenal gland, which is responsible for the production of various hormones.

Between the ages of 45 and 55 there was a marked change in protein levels, most notably in the aorta, which is the main vessel carrying blood from the heart.

Separate research from Stanford University suggests a simple blood test could be used to determine the relative age of your brain and organs, and in turn whether you are likely to live a long and healthy life.

Based on samples from over 45,000 people from the UK Biobank, scientists have shown that lifestyle factors and medication have an impact on organ ageing, and were associated with the future onset of a number of diseases. These include heart failure, chronic obstructive pulmonary disease, type 2 diabetes and Alzheimer’s disease. Most notably, having an aged brain was strongly correlated with Alzheimer's disease.

The more organs aged, the more mortality is affected, and conversely, youthful brains and immune systems were associated with longevity. This means that plasma proteins identified through a blood test could be used to monitor organ health.

Given that the global cost of brain disorders is projected to cost $16 trillion annually by 2030, safeguarding our brains is not just a health priority but an economic one too.

The World Economic Forum's Brain Economy Action Forum convenes stakeholders to ensure that brain health and skills are invested in and prioritised in order to support a more resilient and inclusive future.

Over the course of the 20th century, richer nations saw a massive leap in life expectancy, growing by approximately 30 years because of better public health and medicine.

But since 1990, these improvements have decelerated. Scientists predict that the proportion of people who live to 100 is unlikely to exceed 15% for women and 5% for men. Unless we can make major changes to the process of ageing then we are not going to radically shift human life expectancy.

There are periods of our life where we age more quickly than others though. Stanford researchers think we go through two periods of radical change in our lives - one around 44 and one around 60. These are characterised by shifts in molecules associated with cardiovascular disease, as well as those related to immune function.

The research also showed significant changes in the number of molecules related to the metabolism of alcohol, caffeine and lipids when people hit their 40s. When people reach 60, there are likely also changes relating to the metabolism of carbohydrate and caffeine. However, some of these changes could be tied to lifestyle or behavioural factors, the researchers say - for example, an uptick in alcohol consumption in people's mid-40s - often a stressful period of life - could lead to a dysfunction in alcohol metabolism.

The good news is that you're not just a passenger on this journey. Your lifestyle choices have a direct impact on how quickly your organs age. Taking control today means focusing on key factors that protect your body while avoiding those that speed up the clock:

Protective factors: Vigorous exercise, eating fish (rich in omega-3s) and higher levels of education.

Accelerating factors: Smoking, drinking too much alcohol, eating lots of processed foods, particularly meat, and poor sleep.

Making these positive choices is crucial as we enter an era where a routine blood test could provide a full report on your organ health, paving the way for more proactive and personalized medicine.