The study doesn't say vegan diets actively alter your DNA. The study says that people who are descended from different populations have different DNA. You could just as easily say that people descended from populations that ate a lot of meat have different DNA, that's equally true.
We all have different DNA, but we have the same biology. In the same way that all Koalas have different DNA from each other, but they all have the same biology so they all eat eucalyptus leaves despite their different DNA. People overstate the significance of DNA differences, and understate the significance of our shared biology.
This study is interesting, but the conclusions in the Telegraph article you linked to don't entirely agree with the studies they mention (if you read the actual studies, rather than media reports on them). And the study is looking at vegetable oils. Vegetable oil is junk food, so I don't add vegetable oils to my food any more than I eat Oreo cookies or smoke cigarettes. The study might as well conclude that processed meat or heroin is bad for you. We all know that vegetable oils, processed meats, etc., are bad for you, and studies concluding that are not surprising to me. I'm no more a fan of eating refined carbohydrates or vegetables oils than I am meat, dairy, or eggs. I eat whole foods. The fact that vegetarians are more susceptible to the problems of vegetable oils, and meat eaters are more susceptible to the problems of processed meats (because of what eating meat does to their gut bacteria), is not exactly a strong argument either way. And that's what this study is looking at.
The article suggests that there can be problems with fertility for vegans, hilariously because of high levels of pesticides. Again, the news story has drawn a conclusion that the researchers themselves did not appear to conclude (from what I can tell, as the study doesn't appear to link to a single study meaning some guess work is required). The studies I found don't conclude that vegetarians/vegans are at risk, they conclude that people with lots of pesticides in their diet are at risk. People eating organic produce are at low risk for that, and I eat almost exclusively organic food. However, people who eat lots of non-organic meat often have extremely high levels of pesticides in their systems. Pesticides bio-accumulate up the food chain. A cow might eat 500 times as much food energy as we get from eating the cow, for example. If you are buying meat at the grocery store, then you often get meat from animals that have eaten hundreds of times as much pesticide and herbicide-laden plant foods as you would if you were eating plants yourself.
One American study increased the amount of vitamin C for people that were having problems with fertility and there was a huge jump in fertility (most participants in the study were able to conceive a child), so the evidence suggests that fertility is best enhanced by eating organic plant foods (organic to avoid pesticides, and plants to increase the amount of natural vitamin C consumed).
The study then goes on to point out three common nutrient deficiencies with vegetarians... without bothering to point out that the same studies concludet hat meat eaters are typically deficient in seven essential nutrients. So that's not exactly good journalism on the telegraph's part. And most studies on nutrient deficiencies look at ovo-lacto vegetarians, but people sometimes then attribute those conclusions to vegans. But since vegans don't eat dairy and eggs (which are foods that have low nutrients-per-calorie ratios), there is evidence that vegans tend to suffer fewer nutrient deficiencies. I know my bloodwork shows I'm not low in any of the above (not the three nutrients that vegetarians are typically low in, nor the seven nutrients that meat eaters are typically low in... anecdotal of course, but enough for me to want to stay the course since I'm enjoying success). And that makes sense since meat/dairy/eggs have very low levels of nutrition per calorie compared to the foods I eat, so people eating whole food plant-based diets will eat more total food, get more nutrition, and if you're eating the rainbow you'll get a wider variety of nutrition.
Anyway, your conclusion is that it's impossible to be healthy without eating meat. Pretty much every government health body on the planet disagrees with that conclusion. There's no "recommended daily amount" for meat. Animals get their nutrition from eating plants. Nutrition comes from the ground after all, from plants and bacteria. I'm particularly amused at the conclusion of the article you link to that vegetarians are at greater risk of heart disease. Heart disease was essentially unknown in the world amongst populations that were mostly plant-based. It's only by introducing animal products or processed foods to one's diet that populations see any significant risk of heart disease. The article you linked to was interesting, but appears to have fallen prey to journalists (AKA non-scientists) drawing conclusions from the headlines of studies rather than from reading the studies themselves.
