Experts have slammed claims that a popular diet trend endorsed by celebs could raise the risk of deadly motor neurone (MND) disease.
The 5:2 method, made famous by much-loved TV diet guru and Daily Mail columnist Dr Michael Mosley, has long been lauded for improving blood sugar control and boosting brain function.
But one molecular biologist this week said that following the regime interfered with the energy metabolism in her nerve cells, triggering amyotrophic lateral sclerosis (ALS) — the most common form of MND.
Dr Vivienne Cox, 65, said her old diet, rich in sugar and carbs, compensated for these energy shortfalls.
Scientists, however, have warned there is little evidence behind the claims and research currently suggests no such link.
One molecular biologist this week said that following the regime interfered with the energy metabolism in her nerve cells, triggering the condition. Dr Vivienne Cox, 65, said her old diet, rich in sugar and carbs, compensated for these energy shortfalls
ALS or ‘locked in’ syndrome can lead to paralysis and eventually death.
It claimed the life of Sandra Bullocks’ partner Bryan Randall last year and was famously suffered by the acclaimed scientist Stephen Hawking.
Dr Cox told The Telegraph: ‘I led a carefree and indulgent life up to my late 50s and enjoyed good food, booze and sweet treats.
‘I was pretty fit, from an outdoorsy life with gardening and country walks my main pastimes.
‘Then Michael Mosley’s intermittent fasting idea became the fad diet of the period. I had gained a little weight, so signed up to the 5:2 diet with great enthusiasm.
‘I lost a stone immediately and felt pretty good. I cut out refined sugar and limited carbohydrates.’
Followers of the 5:2 diet restrict their calories to 500–to-600 a day for two days a week and then eat as normal for the remaining five days.
But within two years of the starting the diet she claimed she developed a ‘lop-sided walk’ and ‘broke a few bones, always tripping over my right foot’.
ALS or ‘locked in’ syndrome can lead to paralysis and eventually death. It was famously suffered by the acclaimed scientist Stephen Hawking
ALS also claimed the life of Sandra Bullocks’ partner Bryan Randall (pictured with Sandra Bullock in 2018) last year
Dr Cox, who worked at two leading pharmaceutical companies, said her MND may have been triggered quicker as restricting food intake could interfere with energy metabolism in cells.
She added: ‘Fast forward to now, aged 64, and I am in a wheelchair with a diagnosis of motor neurone disease.
‘As a scientist, I have delved deep to see what might have been the trigger for the onset of disease, when I have been carrying this mutation since birth. I strongly suspect intermittent fasting to be the culprit.’
However Prof Sir John Hardy, a professor of neuroscience at University College London, refuted Dr Cox’s claim, telling MailOnline: ‘Anecdotal reports like this do not constitute evidence.’
The Motor Neurone Disease Association does not acknowledge any links between diet and the onset of MND.
However the body does state that studies have found possible links between MND and high levels of exercise, exposure to agricultural chemicals, and a variety of heavy metals.
But this evidence ‘has often been conflicting and clear conclusions cannot be given’.
With these limits, ‘it is not yet possible to provide guidance on how to reduce the risk of developing MND’, the charity says.
Very limited research on animals, meanwhile, has suggested there may be a link between intermittent fasting and the onset of MND.
One 2004 study on 14 mice found those on a calorie restricted diet ‘reached the clinical onset’ of the disease earlier than those following no diet plan.
Writing in the journal Muscle and Nerve, researchers said: ‘These results suggest that a calorie restricted diet is not a protective strategy for patients with ALS [the most common form of MDN] and hence is contraindicated.’
But no human studies on the effects of intermittent fasting on MND currently exist.
Dr Mosley was first introduced to the 5:2 diet through a 2011 study and it became the backbone of his 2013 book The Fast Diet.
On the diet’s website, Dr Mosley said those following it can expect to lose around 0.5kg a week and enjoy health benefits from improvements to blood pressure and cholesterol levels to better insulin sensitivity.
The health guru even found personal success with the 5:2 diet when he reversed his type 2 diabetes.
Studies in animals have also suggested it may boost the regenerative abilities of stem cells, fight cancer and even improve lifespan.
But, despite swathes of studies suggesting it works, experts remain divided over the effectiveness of intermittent fasting and the potential long term health impacts.
Jennifer Aniston , Chris Pratt and Kourtney Kardashian are among the Hollywood A-listers to have jumped on the trend since it shot to prominence in the early 2010s. But, despite swathes of studies suggesting it works, experts have remained divided over its effectiveness and the potential long term health impacts
Some argue that fasters usually end up consuming a relatively large amount of food in one go, meaning they don’t cut back on their calories — a known way of beating the bulge.
They even warn that it may raise the risk of strokes or heart attacks.
ALS is a rare condition that progressively damages parts of the nervous system.
It occurs when specialist nerve cells in the brain and spinal cord called motor neurones stop working properly — known as neurodegeneration.
Life expectancy for about half of those with the condition is between just two and five years from the onset of symptoms.
However, some people may live for up to 10 years, and, in rarer circumstances, even longer.
Around 5,000 people in the UK and 30,000 in the US have the condition.
Locked-in syndrome (LIS) is a rare neurological disorder that can also occur in some progressive cases of ALS.