Human lifespan “could continue to increase far into the foreseeable future”

Scientists researching human lifespan have concluded that it has no detectable limit, and that with advances in technology and medicine it could continue to climb for the foreseeable future.

“We just don’t know what the age limit might be,” said study co-author Siegfried Hekimi, a biologist from McGill University.

“In fact, by extending trend lines, we can show that maximum and average lifespans could continue to increase far into the foreseeable future.”

The study, which is published today in the journal Nature, analysed the lifespan of the longest-surviving people from Japan, France, the UK and the US every year from 1968 to the present day.

The scientists found that there was no evidence that a limit on lifespan exists, and concluded that if it does, we certainly have not yet reached it or even identified what it could be.

The research flies in the face of previous studies that concluded that not only was there a limit of 115 years, but that we were beginning to reach it. However Hekemi and his colleague Bryan G Hughes do not believe this is the case, and are unable to even hazard a guess as to what such a limit could be.

“It’s hard to guess,” Hekimi said. “Three hundred years ago, many people lived only short lives.

“If we would have told them that one day most humans might live up to 100, they would have said we were crazy.”

Images courtesy of Jonathan Kos-Read

Average lifespans have jumped significantly over the past century. In 1920, Canadians had an average expectancy of 60 years, but by 1980 it had climbed to 76 years. Now it is 82 years, and is likely to climb further.

These jumps have been down to the revolution in medical science over the last hundred years, however advances in medical technologies could cause a significant further jump in our lifetimes.

In particular, work by organisations such as the SENS Research Foundation, led by noted gerontologist Aubrey de Grey, is focused on treating ageing as something that can be cured, and has seen growing support from the mainstream scientific community.

However, if such medical treatments do become available, they may only be available to those that can afford them, particularly in countries that do not have a single-payer healthcare system, such as the US. In these instances, there are fears that such treatments could divide humanity, with the rich gaining far longer lifespans than the poor.

Beyond vaccines: Microneedle patch set to consign flu shots to history

A self-administered patch that contains hundreds of microscopic dissolvable needles could in the future replace the yearly flu shot, after highly promising early-stage trials.

Applied like a plaster, the tiny patch was found to be just as effective in protecting patients from the flu, and was greatly preferred by study participants to the traditional flu shot. It is hoped, therefore, that it would significantly increase the number of people opting to immunising themselves each year.

“Despite the recommendation of universal flu vaccination, influenza continues to be a major cause of illness leading to significant morbidity and mortality,” said study first author Dr Nadine Rouphael, associate professor of medicine (infectious diseases) at Emory University School of.

“Having the option of a flu vaccine that can be easily and painlessly self-administered could increase coverage and protection by this important vaccine.”

A close-up of the coin-sized patch. Above: an extreme close-up of the patch’s microneedles, which eliminate the need for a traditional vaccine. Images courtesy of Georgia Tech

It would also be cheaper than the current vaccine, as it would be applied by the user rather than requiring a specialist to administer, and would not need to disposed of through sharps waste: biomedical waste that has to be carefully disposed of by specialists due to its ability to puncture the skin.

“One of the main goals of developing the microneedle patch technology was to make vaccines accessible to more people,” said senior co-author Dr Mark Prausnitz, Georgia Tech Regents professor of chemical and biomolecular engineering.

“Traditionally, if you get an influenza vaccine you need to visit a health care professional who will administer the vaccine using a hypodermic needle. The vaccine is stored in the refrigerator, and the used needle must be disposed of in a safe manner.”

As a result, once the patch is approved it could be easily picked up at pharmacies to apply at home, or even be ordered online and mailed to the recipient.

“With the microneedle patch, you could pick it up at the store and take it home, put it on your skin for a few minutes, peel it off and dispose of it safely, because the microneedles have dissolved away,” added Prausnitz. “The patches can also be stored outside the refrigerator, so you could even mail them to people.”

Study lead author Dr Nadine Rouphael administers the patch to a study participant. Image courtesy of Rob Felt, Georgia Tech

The phase I clinical trial, which was published today in the leading medical journal The Lancet, ran from June 2015 and involved 100 participants who had not had any form of flu vaccine the previous year.

They were divided into four groups, one which got the patch applied by a healthcare professional; one that applied the patch at home; one that got a placebo patch applied by a healthcare professional and one that got the traditional vaccine.

No major issues were found with the patches, with the worst issues being mild skin itching that lasted a couple of days, and no notable difference was found between patches applied by healthcare workers and those put on by the study participants themselves.

The patch will now undergo further trials with a view to getting it approved as quickly as possible for use in patients. Research is also being conducted on the use of the patch to replace other vaccines such as measles, polio and rubella, which are normally given to young children.