Research

A Paleolithic diet confers higher insulin sensitivity, lower C-reactive protein and lower blood pressure than a cereal-based diet in domestic pigs

Tommy Jönsson¹ , Bo Ahrén¹ , Giovanni Pacini² , Frank Sundler³ , Nils Wierup⁴ , Stig Steen⁵ , Trygve Sjöberg⁵ , Martin Ugander⁶ , Johan Frostegård⁷ , Leif Göransson⁸ and Staffan Lindeberg¹

¹Department of Clinical Sciences, Lund University, Box 117, 221 00 Lund, Sweden

²Metabolic Unit, Institute of Biomedical Engineering, National Research Council, Corso Stati Uniti, 4, 35127 Padova, Italy

³Department of Experimental Medical Science, Lund University, Box 117, 221 00 Lund, Sweden

⁴Department of Physiological Sciences, Lund University, Box 117, 221 00 Lund, Sweden

⁵Department of Cardiothoracic Surgery, Heart-Lung Division, Lund University, Box 117, 221 00 Lund, Sweden

⁶Department of Clinical Physiology, Lund University, Box 117, 221 00 Lund, Sweden

⁷Department of Medicine, CIM, Karolinska University Hospital, Huddinge, 141 86 Stockholm, Sweden

⁸The Swedish Farmers Supply and Crop Marketing Association, Box 30192, 104 25 Stockholm, Sweden

author email corresponding author email

Nutrition & Metabolism 2006, 3:39doi:10.1186/1743-7075-3-39

Published:	2 November 2006

Abstract

Background

A Paleolithic diet has been suggested to be more in concordance with human evolutionary legacy than a cereal based diet. This might explain the lower incidence among hunter-gatherers of diseases of affluence such as type 2 diabetes, obesity and cardiovascular disease. The aim of this study was to experimentally study the long-term effect of a Paleolithic diet on risk factors for these diseases in domestic pigs. We examined glucose tolerance, post-challenge insulin response, plasma C-reactive protein and blood pressure after 15 months on Paleolithic diet in comparison with a cereal based swine feed.

Methods

Upon weaning twenty-four piglets were randomly allocated either to cereal based swine feed (Cereal group) or cereal free Paleolithic diet consisting of vegetables, fruit, meat and a small amount of tubers (Paleolithic group). At 17 months of age an intravenous glucose tolerance test was performed and pancreas specimens were collected for immunohistochemistry. Group comparisons of continuous variables were made by use of the t-test. P < 0.05 was chosen for statistical significance. Simple and multivariate correlations were evaluated by use of linear regression analysis.

Results

At the end of the study the Paleolithic group weighed 22% less and had 43% lower subcutaneous fat thickness at mid sternum. No significant difference was seen in fasting glucose between groups. Dynamic insulin sensitivity was significantly higher (p = 0.004) and the insulin response was significantly lower in the Paleolithic group (p = 0.001). The geometric mean of C-reactive protein was 82% lower (p = 0.0007) and intra-arterial diastolic blood pressure was 13% lower in the Paleolithic group (p = 0.007). In evaluations of multivariate correlations, diet emerged as the strongest explanatory variable for the variations in dynamic insulin sensitivity, insulin response, C-reactive protein and diastolic blood pressure when compared to other relevant variables such as weight and subcutaneous fat thickness at mid sternum. There was no obvious immunohistochemical difference in pancreatic islets between the groups, but leukocytes were clearly more frequent in sampled pancreas from the Cereal group.

Conclusion

This study in domestic pigs suggests that a Paleolithic diet conferred higher insulin sensitivity, lower C-reactive protein and lower blood pressure when compared to a cereal based diet.