Study Examines Risks of the Paleo Diet on Heart Health

Overview of the Paleo Diet

The paleo diet is frequently advocated for its potential benefits to gut health. This dietary approach emphasizes the intake of meats, eggs, fish, nuts, vegetables, and fruits while excluding dairy, grains, and processed foods. However, the high levels of animal-based proteins in this diet might elevate the concentrations of trimethylamine-N-oxide (TMAO), a gut-derived compound linked to cardiovascular disease. While short-term studies have not indicated significant changes in TMAO levels associated with the paleo diet, the long-term effects remain unexamined.

Research Findings from Australia

A recent study published in the European Journal of Nutrition aimed to explore the long-term health implications of the paleo diet, particularly concerning heart disease risk. Conducted in Australia, the research involved participants aged 18 to 70 who reported following a paleo diet for a minimum of one year. Participants were required to maintain three-day weighted food records and provide blood, urine, and stool samples for analysis.

The participants adhering to the paleo diet were categorized into two groups: the Strict Paleolithic group, which consumed less than one serving of grains and dairy daily, and the Pseudo-Paleolithic group, which consumed more than one serving. Additionally, a control group comprised individuals following a balanced diet that included grains and dairy.

Dietary Intake and TMAO Levels

The study revealed that the Strict Paleolithic group had a total dietary fiber intake comparable to that of the control group, while the Pseudo-Paleolithic group exhibited a lower fiber intake. Protein consumption was notably higher in the Strict Paleolithic group compared to both other groups, and fat intake was significantly elevated in both paleo groups relative to the control.

Importantly, TMAO concentrations were found to be significantly higher in the Strict Paleolithic group compared to the control group. Furthermore, the bacteria responsible for TMAO production were also present in greater amounts among participants following the paleo diet.

Implications of Dietary Composition

The absence of whole grains in the paleo diet, which are crucial for providing resistant starch and fermentable fibers beneficial for gut health, may explain the increased TMAO levels. A diet rich in vegetables and whole grains supports a more favorable gut microbiota composition, promoting health benefits. In contrast, the gut bacteria associated with higher fat intake have been shown to be detrimental to health. Additionally, diets with elevated fat content are linked to obesity, a known risk factor for heart disease.

Conclusions and Recommendations

Given the paleo diet’s high fat consumption and the elevated TMAO levels found among its participants, the researchers concluded that the paleo diet may not support claims of enhancing gut health or reducing heart disease risk. Instead, the study suggests that long-term adherence to this dietary approach could increase the likelihood of developing heart disease.

References

Genoni, A., Christophersen, C. T., Lo, J., Coghlan, M., Boyce, M. C., Bird, A. R., . . . Devine, A. (2019). Long-term Paleolithic diet is associated with lower resistant starch intake, different gut microbiota composition and increased serum TMAO concentrations. European Journal of Nutrition. doi:10.1007/s00394-019-02036-y

EurekAlert. (2019, July 22). Heart disease biomarker linked to paleo diet. Retrieved from https://www.eurekalert.org/pub_releases/2019-07/ecu-hdb072219.php