Eating too much red meat could increase the body's "biological age" and contribute to health problems, new research suggests.
Scientists found that a moderate increase in levels of serum phosphate in the body caused by red meat consumption, combined with a poor overall diet, can make a person age.
But the research has come under criticism by experts from the Meat Advisory Panel.
Dr Carrie Ruxton told The Huffington Post UK: "The elementary theory that red meat is to blame is simply speculation and is not based on solid evidence."
She added that red meat is a valuable source of iron, selenium, B vitamins and vitamin D, "all of which would be expected to support normal health".
The new study, led by a team at the University of Glasgow, analysed people from the most deprived to the least deprived areas covered by NHS Greater Glasgow.
The researchers found that those in the most deprived areas ate more red meat compared to those in more affluent locations.
Researchers believe excess red meat consumption particularly affects this group because of their poor diet and "sub-optimal fruit and vegetable intake".
The results suggested accelerated biological ageing and diet-related phosphate levels among the most deprived males were directly related to how much red meat they ate.
High phosphate levels in deprived men were also found to be linked to reduced kidney function and even underlying mild to moderate chronic kidney disease.
Professor Paul Shiels, of the Institute of Cancer Sciences at University of Glasgow, said: "Our observations indicate that elevated red meat consumption has adverse effects amongst deprived males, who already have a poor diet and eat less fruit and vegetables than recommended.
"We think in this group the effects of high serum phosphate intake may be exacerbated.
"Indeed, it's notable that these effects are not apparent among less deprived males, or in females, especially in the context of a more balanced diet."
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Phosphate is naturally present in basic foodstuffs, including meats, fish, eggs, dairy products and vegetables.
But high phosphate levels, as a consequence of dietary intake, have previously been linked to higher mortality risk, premature vascular ageing and kidney disease.
Professor Shiels added: "Strikingly, many of the subjects had kidney function indicative of incipient or early onset chronic kidney disease.
"It has also not escaped our attention that red meat product quality and preservation may have an impact upon the diets of the most deprived and their associated health."
The study, which was published in the journal Ageing, has since come under fire.
Dr Carrie Ruxton from the Meat Advisory Panel said the study's conclusion that eating red meat is to blame for faster ageing "bears no relation to the evidence the researchers actually collected".
"Dietary phosphate comes from a wide variety of sources...as noted by the authors themselves in the paper. Therefore, using a cross-sectional ‘snapshot’ of diet and blood samples as was the case in this study, it is impossible to say which individual dietary component was responsible for people’s raised blood phosphate levels," she said.
"The dietary assessment only asked participants to record how often they ate a food – no data were collected on the amounts eaten. Again, this hampers any chance of linking diet with phosphate levels.
"To do this, you would need a controlled clinical trial which varied the amounts of phosphate-containing foods in the diet."
She continued: "Looking at the authors’ theory that a higher meat intake in lower socio-economic groups contributed to faster ageing, national diet data actually showed lower or similar intakes of red meat in less well-off groups of people.
"The National Diet and Nutrition Survey which has data on more than 6,000 individuals reported that men in the two lowest socio-economic groups ate 84-85g of red and processed meat daily, while men in the two highest socio-economic groups ate 83-93g daily.
"For women the differences were 53-57g daily in the lowest two groups and 56-59g in the highest two groups."
She added: "In conclusion, all this study can say is that higher blood phosphate levels are linked with faster cell ageing, and that red meat and blood phosphate are statistically correlated.
"It tells us nothing about the cause of high phosphate levels, or the cause of faster ageing. The elementary theory that red meat is to blame is simply speculation and is not based on solid evidence.
"Red meat is a valuable source of iron, selenium, B vitamins and vitamin D – all of which would be expected to support normal health."
