I would like to report some good news for The Paleo Diet community. We now have the first long term, 2 Year Randomized Controlled Trial (RCT) to show The Paleo Diet to be superior health wise to low fat, high carbohydrate diets.11 This study, “Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial” adds to the increasing body of scientific literature to substantiate the therapeutic health effects of contemporary Paleo diets tested experimentally in humans.1-10
Past criticism of The Paleo Diet by the U.S. News and World Reports, which rated the Paleo Diet dead last among 32 popular diets, indicated that the Paleo Diet had not been adequately tested in the long term in the scientific and medical literature. This criticism is unfounded given this new study11 which corroborates the numerous experimental studies demonstrating the various therapeutic health effects of The Paleo Diet.1-10 The criticism is also hypocritical given that the majority of the popular diets listed in the USNWR rankings have never been tested in the long term, nor have they even been examined in the medical literature.
Experimental human studies have shown the Paleo Diet to be superior health-wise to diabetic diets in a randomized crossover trials2, 10 and to Mediterranean diets.4, 5 Further, The Paleo Diet is nutritionally superior to the USDA My Plate (formerly the My Pyramid) diet in the 13 nutrients most lacking in the US diet.12, 13
In this new study11 The Paleo Diet proved superior to a low fat, high carbohydrate diet for weight loss at 6, 12 and 18 months, for body fat, waist circumference and sagittal, abdominal diameter at 6 months. Further, The Paleo Diet caused greater improvements in blood triglycerides after 2 years than the low fat, high carbohydrate diet.
It should be noted that because the sample size in this study at 24 months (27 subjects in the Paleo group, 22 subjects in the low fat, high carbohydrate group) was relatively small, it lacked the statistical power to detect non-significant therapeutic changes that occurred in the Paleo Diet group relative to the low carbohydrate group. Specifically, improvements occurred in the following variables for the Paleo Diet: 1) systolic blood pressure (p=0.29), 2) blood cholesterol (p=0.23), 3) LDL cholesterol (p=0.29).
Finally, it should be noted that consumption of The Paleo Diet resulted in important dietary characteristics which improved significantly (p<0.05) after 2 years: these variables included: increases in dietary protein, reductions in dietary carbohydrate, increases in monounsaturated fat, increases in polyunsaturated fats, increases in omega 3 fatty acids, reductions in omega 6 fatty acids, and reductions in dietary cholesterol. All of these nutritional changes are known to have multiple positive health effects that reduce the risk for metabolic syndrome diseases, cancer and autoimmunity. Future studies12 will help to further establish how contemporary Paleo diets may improve health and well being.
Loren Cordain, Professor Emeritus
1. Frassetto LA, Schloetter M, Mietus-Synder M, Morris RC, Jr., Sebastian A: Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. Eur J Clin Nutr 2009.
2. Jönsson T, Granfeldt Y, Ahrén B, Branell UC, Pålsson G, Hansson A, Söderström M, Lindeberg S. 3. Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovasc Diabetol. 2009;8:35
3. Jonsson T, Granfeldt Y, Erlanson-Albertsson C, Ahren B, Lindeberg S. A Paleolithic diet is more satiating per calorie than a Mediterranean-like diet in individuals with ischemic heart disease. Nutr Metab (Lond). 2010 Nov 30;7(1):85
4. Lindeberg S, Jonsson T, Granfeldt Y, Borgstrand E, Soffman J, Sjostrom K, Ahren B: A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia 2007, 50(9):1795-1807.
5. O’Dea K: Marked improvement in carbohydrate and lipid metabolism in diabetic Australian aborigines after temporary reversion to traditional lifestyle. Diabetes 1984, 33(6):596-603.
6. Osterdahl M, Kocturk T, Koochek A, Wandell PE: Effects of a short-term intervention with a paleolithic diet in healthy volunteers. Eur J Clin Nutr 2008, 62(5):682-685.
7. Ryberg M, Sandberg S, Mellberg C, Stegle O, Lindahl B, Larsson C, Hauksson J, Olsson T. A Palaeolithic-type diet causes strong tissue-specific effects on ectopic fat deposition in obese postmenopausal women. J Intern Med. 2013 Jul;274(1):67-76
8. Frassetto LA, Shi L, Schloetter M, Sebastian A, Remer T. Established dietary estimates of net acid production do not predict measured net acid excretion in patients with Type 2 diabetes on Paleolithic-Hunter-Gatherer-type diets. Eur J Clin Nutr. 2013 Sep;67(9):899-903.
9. Jönsson T, Granfeldt Y, Lindeberg S, Hallberg AC. Subjective satiety and other experiences of a Paleolithic diet compared to a diabetes diet in patients with type 2 diabetes. Nutr J. 2013 Jul 29;12:105.
10. Mellberg, C., Sandberg, S., Ryberg, M., Eriksson, M., Brage, S., Larsson, C., et al. (2014). Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial. European Journal of Clinical Nutrition. doi:10.1038/ejcn.2013.290 http://www.ncbi.nlm.nih.gov/pubmed/24473459.
11. Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J. Origins and evolution of the western diet: Health implications for the 21st century. Am J Clin Nutr 2005;81:341-54
12. Cordain L, The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Neutraceut Assoc 2002; 5:15-24.
13. Fontes-Villalba M, Jönsson T, Granfeldt Y, Frassetto LA, Sundquist J, Sundquist K, Carrera-Bastos P, Fika-Hernándo M, Picazo O, Lindeberg S. A healthy diet with and without cereal grains and dairy products in patients with type 2 diabetes: study protocol for a random-order cross-over pilot study – Alimentation and Diabetes in Lanzarote -ADILAN. Trials. 2014 Jan 2;15(1):2