New research: Why you should never eat food past its best before date

Make sure to check the best-before date before you eat. Photo / Getty

We've all been there: you know exactly what you want to eat, it's right there in your fridge - but it's one day past the sell-by date.

Do you take the plunge?

According to a new study, there is no question: absolutely not - because old ingredients could shorten lifespan.

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Though it sounds dramatic, researchers at Harvard University insist they have concrete evidence old food accelerates ageing at a cellular level, reported The Daily Mail.

Our youthfulness fades as our cells get damaged: wear and tear to DNA protein interaction, lack of aerobic respiration, or slowing enzyme function start to grind everything down. Eventually the body becomes so weak that we die.

Now, scientists claim old food is one of the factors that adds to the damage.

The team, led by Vadim Gladyshev, was looking primarily at the age of meat when it is farmed - for example, three-year-old deer meat versus 25-year-old deer meat.

Over its lifetime, that deer has accumulated so much damage that its meat is far less nutritious than that of its young.

Experts suggest this could also translate to food that has been left too long after being farmed, allowing for the nutrients to deteriorate.

For the study, Gladyshev and colleagues examined three different organisms - yeast, mice and fruit flies - and how they reacted to different aged foods over a period of years.
They found those that were fed 'younger food' - i.e., fresh produce - consistently suffered less cellular damage.

'That shows us that these age-related changes that accumulate are truly deleterious,' Gladyshev said. 'And that provides a fundamental insight into the aging process.'
For the yeast, they grew two batches of yeast - one on young yeast cells, one on old yeast cells.

The fruit flies were fed either young dead flies or old dead flies. To achieve this, the team collected 5,000 dead fruit flies who had lived around 45 days. They also killed 5,000 young fruit flies.

They then split a batch of living fruit flies in half, feeding one group the old flies and feeding the other group the young flies.

The mice were fed deer meat, either three-year-old deer or 25-year-old deer, instead of the worms and insects they would usually eat.

Fruit flies on an old diet had a 13 per cent shorter lifespan than those on a young diet.
In mice, the damage was most acutely witnessed in females compared to males - though the researchers warn this could boil down to sample size.

Female mice on an old diet had a 13 percent shorter lifespan than their female peers eating younger food. Males saw barely any different.

Glayshev said the study surprised him; he expected the damage to be more acute.
But the data suggests he is on the right track.

'So the question is, how do we slow down this process? How do we restructure cellular metabolism so that this damage accumulates at a slower rate?'

He insists the study cannot yet be applied to humans, since it was only a study in animals.

However, this is something he will explore in further research.