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Paleolithic Diet Found to Be Healthful

By Dr. John Briffa

Last May a study was published that tested the effects of a so-called Paleolithic diet—a diet based on the foods eaten prior to about 10,000 years ago, when it’s believed some of our ancestors converted from hunter-gatherers to agriculturalists.

The Paleolithic diet is one that contains “primal”

foods such as meat, vegetables, fruits, and nuts, but is devoid of dietary newcomers like refined sugar, grain-based foods, dairy products, and legumes (beans and lentils) [1].

In this study, for three weeks, individuals ate an average of 900 fewer calories per day than they had been eating. Not surprisingly, they lost weight (an average of 5 pounds). The study subjects experienced other benefits as well: reduced blood pressure and a considerable reduction in the levels of plasminogen activator inhibitor-1. (This would be expected to reduce the clotting tendency of the blood, which might translate into a reduced risk of heart attack and stroke.)

The effects of the Paleolithic diet were once again assessed in a recent study published online in the European Journal of Clinical Nutrition [2]. This study subjected nine men and women to a Paleolithic diet for just 10 days. In the preceding seven days, their usual diet was morphed into the Paleolithic diet in the form of three diets that contained increasingly more potassium and fiber.

The Paleolithic diet that the subjects ate for 10 days was made up of meat (chicken, pork, and turkey), vegetables (lettuce, spinach, broccoli, salad, and parsnips), fruit (pineapple and melon), honey, and nuts (almonds). The diet emphasized lean meat (while the true Paleolithic diet was unlikely to be particularly lean) and also included foods that you can’

t imagine our early ancestors eating (tomato soup, guacamole, carrot juice, and mayonnaise), but the basic make-up of the diet was, overall, reflective of the foods we ate prior to the agricultural age.

While weight loss is often experienced on a Paleolithic-type diet, the authors of this study were not interested in this. If someone in the study was found to be losing weight, they were instructed to eat more to counteract the weight loss. The aim was to see if such a diet might produce physiological and metabolic benefits even in the absence of weight loss.

The subjects experienced significant changes in a number of parameters. These included:

• Reduced blood pressure
• Lower fasting insulin levels (levels fell from an average of 11.5 to 3.6 µU/ml)
• Lower insulin secretion after ingestion of glucose
• Lower levels of total cholesterol
• Lower levels of LDL-cholesterol

Lower triglyceride levels

These changes, if sustained, would be expected to translate into a reduced risk of type 2 diabetes and cardiovascular disease.

While the number of individuals in this study was relatively small, one perhaps notable finding is that the results were very consistent: eight or nine members of the group (remember, the group only contained nine people) were found to experience each of the changes listed above. The suggestion here is that such a diet may have broad benefits for a population, though larger studies would be required to confirm this.

What is also striking about the results is just how quickly the changes came. There was a run-in of a week, but the full-blown Paleolithic diet lasted a mere 10 days. It does seem that returning to the diet of our past can bring about very rapid benefits in terms of our physiology and biochemistry.


1. Österdahl M, et al. Effects of a short-term intervention with a Paleolithic diet in healthy volunteers. European Journal of Clinical Nutrition 2008; 62:682–


2. Frassetto LA, et al. Metabolic and physiologic improvements from consuming a Paleolithic, hunter-gatherer type diet. European Journal of Clinical Nutrition Feb. 11, 2009 [Epub ahead of print]

Dr. John Briffa is a London-based physician and health writer with an interest in nutrition and natural medicine. His Web site is