Scientists may have finally discovered the secret to a long life – and it’s in our blood.
Swedish researchers examined blood samples from more than 40,000 people over 60.
They found that centenarians, people who lived to their 100th birthday, had lower blood sugar levels and healthier kidney and liver function starting in their 60s.
However, contrary to health advice, those who lived the longest also had higher total cholesterol levels in their blood.
The team suspected that lifestyle factors – such as diet and alcohol consumption – accounted for some of the differences in blood biomarkers and recommended that people keep a close eye on results related to kidney and liver health as they age.
They found that centenarians, people who live to at least their 100th birthday, had lower glucose, creatinine and uric acid levels starting at age 60. However, contrary to health advice, they also had higher total cholesterol levels in their blood
Some 13,924 people in England and Wales had reached the age of 100 at the time of the 2021 census, a staggering increase from just 110 when the survey was conducted in 1921
The centenarians had exceeded their expected life expectancy by three or four decades and experienced significant events such as women’s suffrage, the Second World War, the introduction of the NHS and the introduction of television
They compared 12 biomarkers – biological measurements – between those who lived to 100 years and those who didn’t. All have been linked to mortality in previous studies.
These included total cholesterol and blood sugar, markers of metabolism; uric acid, an inflammatory marker; creatinine, a measure of kidney function; iron, which is linked to anemia; and albumin, a protein that may indicate liver or kidney disease.
Writing in the diary GeroScienceResearchers claimed it was the largest study of its kind to date comparing the concentrations of different molecules in the blood.
The results showed that higher iron and total cholesterol levels were associated with a higher likelihood of living to centenarians, the researchers noted.
Although this contradicts clinical guidelines on cholesterol levels, it reflects results of previous studies suggesting that high total cholesterol levels generally promote mortality in very old age.
NHS guidelines state that a healthy total cholesterol level should be 5 millimoles per liter (mmol/L) or less. However, the results showed that only two percent of people whose total cholesterol was 5.2 mmol/L or less lived to 100 years, compared to 3 percent of those whose level was 7.2 mmol/L or more.
Lower levels of glucose, creatinine, uric acid and liver enzymes signaled a higher likelihood of living past 100, the team said.
Those in the group with the lowest uric acid levels had a four percent chance of living to 100, while only 1.5 percent of those with the highest levels made it to 100.
The results showed that there was no association between albumin and the likelihood of living to a centenarian, contradicting a previous study that suggested higher albumin levels were associated with higher chances of survival at older ages.
The researchers acknowledged that their results did not examine lifestyle or genetic factors responsible for biomarker levels.
In the journal they wrote: “While chance likely plays a role in reaching age 100, the differences in biomarker levels more than a decade before death suggest that there are genetic and/or lifestyle factors reflected in these biomarker levels , could also play a role in exceptional longevity.’
They added: “However, it is reasonable to assume that factors such as diet and alcohol consumption play a role.”
“It’s probably not a bad idea to keep an eye on your kidney and liver values, as well as glucose and uric acid levels, as you get older.”
Globally, the number of centenarians has roughly doubled every decade since 1950 and is expected to increase fivefold between 2022 and 2050.
But despite the uncertainty over how this milestone will be reached, there are record numbers of centenarians in England and Wales, data from the Office for National Statistics also revealed last month.
In 2021, there were almost 14,000 people per 100 living in England and Wales – an increase of more than a quarter in just a decade.
In April, a study by US scientists found that the only key to life over 100 years is ample experience fighting infections.
Researchers told DailyMail.com that immune profiles of centenarians show “a long history of exposure to infections and the ability to recover from them.”
Scientists at Karolinska Institutet found that long life is the result of a “complex interaction” of a number of factors, such as genetic and lifestyle factors.
Although many believe it’s a matter of luck, studies have shown that those who live the longest have fewer underlying medical conditions, hospitalizations, and better brain health than those who live shorter lives.
To understand whether the signals that someone will live a long life are visible earlier in their life, they examined blood samples from more than 44,600 Swedes aged 64 to 99.
The team monitored these patients through their medical records for up to 35 years, until 2020.
The results show that 1,224 (2.7 percent) lived to 100 years. Almost nine out of ten of this group (85 percent) were women.