Food May Kill You

Like all animals, we need food to survive. But some foods are obviously better than others, while some may be downright dangerous. A study published this week in Nature suggests that too much lean red meat, thought by some to be a good source of protein, may not be very good for your health.

Consumption of red meat has been found to increase the risk of death from heart disease, even when controlling for levels of fat and cholesterol2. To find out why, [co-author] Hazen and his colleagues gave the nutrient l-carnitine — found in red meat and dairy products — to 77 volunteers, including 26 who were vegans or vegetarians. One committed vegan even agreed to eat a 200-gram sirloin steak.

But even when they took l-carnitine supplements, vegans and vegetarians made far less TMAO than meat eaters. Faecal studies showed that meat eaters and non-meat eaters also had very different types of bacteria in their guts. Hazen says that a regular diet of meat probably encourages the growth of bacteria that can turn l-carnitine into TMAO.

The finding should give pause not only to meat lovers, but also to people who take l-carnitine supplements, which are marketed with the promise that they promote energy, weight loss and athletic performance, says Hazen. “None of those claims have been proven,” he says. “I see no reason why anyone needs to take it.”

And, of course, chickens may be harmful to our health, too, as witnessed by news this week that a new Avian flu has been discovered in China. So far it has killed two people, but too little is yet known about the disease to understand how it might spread. The evidence suggests, however, that it is spreading from domestic poultry, largely being raised for human consumption, rather than from wild birds.