But it seems that the real headline should be: Stop Eating Meat and Slow Your Aging.
Telomeres are little cap-like structures on the ends of the chromosomes in your cells. As cells age, the telomeres grow shorter and shorter. Eventually when the telomeres in a cell grow short enough, the cell stops dividing, which results in cell death. The more of this cell death that occurs, the faster you age.
Chromosomes (gray) and telomeres (white)
A vegan diet is one that includes no meat, fish, or animal products such as cheese or milk. But we don't know exactly what causal factors played a part in the results. It might have been that the results would have been as good if the participants had merely followed a vegetarian diet, one which excludes meat but does not exclude fish, eggs, or cheese.
There was a previous study that compared diet and telomere length. Published in the American Journal of Clinical Nutrition, this study involved 840 people, many times more than the small group studied by the study published in Lancet Oncology. The study analyzed a large variety of foods and drinks consumed by the 840 people, and found only one type of food that tended to shorten people's telomeres.
That type of food was processed meat.
In other words, the study found that sausages, hot dogs, salami, and similar food is making you age faster.
No one should be surprised that sausages and similar food makes you age faster. You never really know what is in a sausage. I'm reminded of a line from the song Master of the House in the musical Les Miserables, in which the inn keeper confesses that his sausages are made with the livers of horses and the kidneys of rats.
You should give up processed meat, and your best best for slowing your aging is to give up all red meat. If you do so, you will not merely be helping yourself, but our planet as well.
Meat consumption is one of the largest causes of global warming. Five years ago the United Nations produced a report called Livestock's Long Shadow, which estimated that raising livestock for food is causing 18 percent of global warming. Two environmental specialists for the World Bank produced a report arguing that raising livestock for food is causing 51 percent of the world's global warming. The exact percentage is a matter of debate, but there can be no doubt that a large amount of global warming could be prevented if we stopped eating meat, or greatly reduced our meat consumption, particularly the consumption of beef. Beef consumption is a particularly large factor in global warming, because cows abundantly produce methane, which speeds up global warming much more dramatically than carbon dioxide.
There is also the moral issue that if more gave up meat eating, there would be more food available. To make a pound of meat available, you have to feed an animal as much as 13 pounds of grain. If the world ate much less meat, there would be much more grain available, and we would not have a world where up to a billion people suffer from hunger.
Let me end this post by simply considering what is best for helping you slow your aging rate. I will list three options: an easy option, a more challenging option, and a most challenging option.
The easy option is for you to simply stop eating processed meat such as sausages. That will eliminate from your diet the one and only food product that the previously cited AJCN study found to be a telomere shortener (a food that accelerates your aging).
The more challenging option is to give up all red meat, or all meat. That might well help slow your aging rate, and will help reduce global warming and help increase the world food supply.
The most challenging option is to go vegan, and give up consumption of all animal products. While it might seem to be justified by the study recently published in Lancet Oncology (which showed the big telomere improvement for vegans), you might wait for a follow-up study before taking this most difficult step (as that study used only a small sample size).