The Paleo Diet might be bad for your heart, research finds

Edith Cowan University compared 44 people on the Paleo Diet with 47 following a traditional Australian diet. Scientists were looking for levels of TMAO, a compound produced in the gut. This compound is associated with an increased risk of heart disease. Published in the European Journal of Nutrition, this study measured the levels of TMAO in participants' blood. People on the Paleo Diet had twice the level of TMAO in their blood, when compared to those following the standard diet.

The impact of Paleo on your gut

Dr. Angela Genoni was the lead researcher behind the study. She is keen to stress the risks of this diet, especially given its increasing popularity. "Many Paleo diet proponents claim the diet is beneficial to gut health, but this research suggests that when it comes to the production of TMAO in the gut, the Paleo diet could be having an adverse impact in terms of heart health," she said. "We also found that populations of beneficial bacterial species were lower in the Paleolithic groups, associated with the reduced carbohydrate intake, which may have consequences for other chronic diseases over the long term."

Why does Paleo get it wrong?

In those going full Paleo, Dr. Genoni said a lack of whole grains in the diet could explain why levels of TMAO were so high. "We found the lack of whole grains were associated with TMAO levels, which may provide a link between the reduced risks of cardiovascular disease we see in populations with high intakes of whole grains," she said. Scientists also found a higher level of the bacteria that produces TMAO in the Paleo Diet group. "The Paleo diet excludes all grains and we know that whole grains are a fantastic source of resistant starch and many other fermentable fibres that are vital to the health of your gut microbiome," Dr Genoni said. "Because TMAO is produced in the gut, a lack of whole grains might change the populations of bacteria enough to enable higher production of this compound. "Additionally, the Paleo diet includes greater servings per day of red meat, which provides the precursor compounds to produce TMAO, and Paleo followers consumed twice the recommended level of saturated fats, which is cause for concern."