A read from Cordain:
This year, the European Journal of Clinical Nutrition published a study that demonstrated that Paleo-like diets produced rapid and dramatic reductions in blood pressure, plasma insulin, total cholesterol, low-density lipoproteins (LDL) and triglycerides all in just 10 days.1 These researchers concluded that remarkably short-term consumption of Paleo-like diets provided these benefits, all without losing weight, increasing activity levels or taking any medication.1
Previous studies analyzing all of the components of the Paleo Diet (fresh fruits, veggies, lean meat, seafood, fish, nuts and certain oils that try to mimic the fatty acid profile of our ancestor's diets) had shown similar results both in healthy people2 and in individuals with ischaemic heart disease3
Although there are only three human intervention trials and one animal model study4 with a Paleo-type diet, evidence gathered from tissue, animal, epidemiological and human metabolic studies analyzing certain dietary characteristics that also exist in the Paleo Diet has led several authors to argue that Paleo-like diets reduced the risk of atherosclerotic cardiovascular disease, insulin resistance and type 2 diabetes, metabolic syndrome hypertension, age-related sarcopenia and osteoporosis, certain cancers, and, perhaps, auto-immune diseases.5
Indeed there are literally hundreds, if not thousands, of well-controlled scientific experiments that show how certain characteristics of the Paleo Diet improve human health.
For instance, just this year, the Journal of Nutrition published a study comparing reduced carbohydrate diets, like the Paleo Diet, to conventional high-carbohydrate diets for weight loss. The reduced carbohydrate diet was more effective in promoting fat mass loss and improved body composition, as well as in reducing serum triacylglycerol and increasing HDL cholesterol.6 While both diets resulted in similar weight loss, more of the reduced carbohydrates diet participants completed the year-long study.6 The researchers also noted that higher protein diets, like the Paleo Diet, appeared to increase satiety7-9 and energy expenditure,10-12 while maintaining lea n tissue with higher metabolic activity.13-15
Furthermore, Paleo-like low salt diets have been shown to improve blood pressure and reduce the risk for stroke and kidney disease.16,17 Low glycemic-load diets, like the Paleo Diet, have improved blood chemistry, insulin sensitivity, diabetic symptoms, obesity, blood pressure, risk of cardiovascular disease, certain cancers16,17 and acne.18 Paleo-like diets high in long-chain omega-3 fatty acids have reduced the risk of heart attacks, stroke, certain cancers, and improved symptoms of many inflammatory and autoimmune diseases.16,17,19 Many chronic diseases are related to low intake of vitamins, minerals and phytochemicals16,17 and the Paleo Diet reduces the risk for these illnesses because it is rich in trace nutrients compared to the typical Western diet.20
Other aspects of Paleo-like diets, such as being high in soluble fiber, potassium, and monounsaturated fats, being very low in industrially-produced trans fats, and yielding a net base load, also have a long trail of scientific support documenting their health benefits.16 These studies represent only an inkling of the dramatic effect we can expect when people get serious about this lifelong way of eating.
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 Feb 11.
2. Osterdahl M, Kocturk T, Koochek A, Wändell PE. Effects of a short-term intervention with a paleolithic diet in healthy volunteers. Eur J Clin Nutr. 2008 May;62(5):682-5.
3. Lindeberg S, Jönsson T, Granfeldt Y, Borgstrand E, Soffman J, Sjöström K, Ahrén B. A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia. 2007 Sep;50(9):1795-807.
4. Jönsson T, Ahrén B, Pacini G, Sundler F, Wierup N, Steen S, Sjöberg T, Ugander M, Frostegård J, Göransson L, Lindeberg S. A Paleolithic diet confers higher insulin sensitivity, lower C-reactive protein and lower blood pressure than a cereal-based diet in domestic pigs. Nutr Metab (Lond). 2006 Nov 2;3:39.
5. Eaton et al., 1988; Cohen, 1989; Jansson, 1990; Eaton and Cordain, 1997; Cordain, 1999; Neel, 1999; Simopoulos, 1999; Eaton and Eaton, 2000; Cordain et al., 2000, Sebastian et al., 2002, 2006; Lindeberg et al., 2003b, 2007; Mann, 2004; O'Keefe and Cordain, 2004; Cordain et al., 2005.
6. Layman DK, Evans EM, Erickson D, Seyler J, Weber J, Bagshaw D, Griel A, Psota T, Kris-Etherton P. A Moderate-Protein Diet Produces Sustained Weight Loss and Long-Term Changes in Body Composition and Blood Lipids in Obese Adults. J. Nutr. 139: 514-521, 2009.
7. Skov AR, Toubro S, Ronn B, Holm L, Astrup A. Randomized trial on protein versus carbohydrate in ad libitum fat reduced diet for the treatment of obesity. Int J Obes Relat Metab Disord. 1999;23:528-36.
8. Weigle DS, Breen PA, Matthys CC, Callahan HS, Meeuws KE, Burden VR, Purnell JG. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr. 2005;82:41-8.
9. Adam-Perrot A, Clifton P, Brouns F. Low-carbohydrate diets: nutritional and physiological aspects. Obes Rev. 2006;7:49-58.
10. Westerterp-Plantenga MS, Rolland V, Wilson SAJ, Westerterp KR. Satiety related to 24-h diet-induced thermogenesis during high protein/carbohydrate vs high fat diets measured in a respiratory chamber. Eur J Clin Nutr. 1999;53:495-502.
11. Mikkelsen PB, Toubro S, Astrup A. The effect of fat-reduced diets on 24-h energy expenditure: comparisons between animal protein, vegetable protein, and carbohydrate. Am J Clin Nutr. 2000;72:1135-41.
12. Feinman RD, Fine EJ. Thermodynamics and metabolic advantage of weight loss diets. Metab Syndr Relat Disord. 2003;1:209-19.
13. Layman DK, Boileau RA, Erickson DJ, Painter JE, Shiue H, Sather C, Christou DD. A reduced ratio of dietary carbohydrate to protein improves body composition and blood lipid profiles during weight loss in adult women. J Nutr. 2003;133:411-7.
14. Layman DK, Evans E, Baum JI, Seyler J, Erickson DJ, Boileau RA. Dietary protein and exercise have additive effects on body composition during weight loss in adult women. J Nutr. 2005;135:1903-10.
15. Westerterp-Plantenga MS, Lejeune MPGM, Nigs I, van Ooijen M, Kovacs EMR. High protein intake sustains weight maintenance after body weight loss in humans. Int J Obes Relat Metab Disord. 2004;28:57-64.
16. 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 Feb;81(2):341-54.
17. O'Keefe JH Jr, Cordain L. Cardiovascular disease resulting from a diet and lifestyle at odds with our Paleolithic genome: how to become a 21st-century hunter-gatherer. Mayo Clin Proc. 2004 Jan;79(1):101-8.
18. Smith RN, Mann NJ, Braue A, Mäkeläinen H, Varigos GA. A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Am J Clin Nutr. 2007 Jul;86(1):107-158.
19. Simopoulos AP. Evolutionary aspects of omega-3 fatty acids in the food supply. Prostaglandins Leukot Essent Fatty Acids. 1999 May-Jun;60(5-6):421-9.
20. Cordain L. The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Nutraceut Assoc 2002; 5:15-24.