www.ThePaleoDiet.com Loren Cordain, Ph.D. Issue: # 2009 – 36 / September 4, 2009
The following is extracted from The Paleo Diet Update, which “look(s) at new scientific research into the relationship between what we eat and how well our bodies function. We search for nutritional guides to provide optimum health, including how to prevent and reverse disease, how to increase mental focus and memory, how to improve athletic performance, and how to increase daily energy and stamina.
“Different diets have been followed in attempts to improve health and prevent and/or treat disease, including the Paleo Diet. This diet is based on available evidence of what our species evolved to eat over millions of years. For almost all of our evolutionary history, humans and human ancestors survived on hunter-gatherer diets. This included lean meats, seafood, vegetables, fruits and nuts. In this issue, we take a look at how well the Paleo Diet protects you from disease compared to other diets”.
“Paleolithic Diet Is Best Bet for Diabetes and Other Diseases by Loren Cordain, Ph.D.
A newly published study in Cardiovascular Diabetology compared the effects of a Paleolithic diet to the current guidelines for a diabetes diet, and looked at cardiovascular risk factors for type 2 diabetes patients.
The participating three women and ten men, who had type 2 diabetes that was not treated with insulin, were instructed to follow each diet for three-months. The Paleolithic diet used was lower in cereals and dairy products, and higher in fruits, vegetables, meat and eggs. It was also higher in unsaturated fatty acids, dietary cholesterol and several vitamins. It was lower in total energy, energy density, carbohydrate, dietary glycemic load (GL) and glycemic index (GI), saturated fatty acids and calcium.
Paleolithic diet compared to current diabetes diet
The study concluded that a Paleolithic diet improved glycemic control and several cardiovascular risk factors as compared to a diabetes diet.
The Paleolithic diet produced lower A1c, triglycerides, and diastolic blood pressure. An A1c test (also known as glycated hemoglobin or HbA1c) gives you a picture of your average blood glucose control for the past 2 to 3 months. Triglycerides are a type of fat found in your blood. Excess triglycerides in plasma are linked to coronary artery disease in some people. Elevated triglycerides may be a result of untreated diabetes mellitus or another disease. Diastolic blood pressure measures the pressure in your blood vessels between heartbeats when your heart is resting, and it’s the bottom number in a blood pressure reading. Below 60 is considered low, and higher than 90 is considered high. The Paleolithic diet also produced lower weight, body mass index (BMI), waist circumference and higher high-density lipoprotein (HDL) cholesterol. “Good” HDL cholesterol seems to scour the walls of blood vessels, and clean out excess cholesterol.
The authors of this study also compared the effects of a Paleolithic diet to those of several other diets:
Paleolithic diet compared to Mediterranean-like diet
This 12-week randomized controlled study involved 29 men with ischemic heart disease and impaired glucose tolerance or type 2 diabetes.
The study concluded that a Paleolithic diet improved glucose tolerance independent of weight-loss when compared to a Mediterranean-like diet1. Impaired glucose tolerance is considered to be a pre-diabetic state of dysglycemia that is associated with insulin resistance, and increased risk of cardiovascular pathology. Paleolithic diet studies with overweight individuals In a non-controlled study with nine overweight people who were otherwise healthy, intervention food was supplied and weight was kept steady. Researchers concluded that a Paleolithic diet consumed for just ten days improved diastolic blood pressure, glucose tolerance, insulin sensitivity and lipid profiles2.
Insulin sensitivity is one measure of the risk for heart disease. In general, the more sensitive one is, the lower the risk for heart problems.
Lipid profiles include tests that are often ordered together to determine the risk of coronary heart disease. These tests that have been shown to be good indicators of the risk for heart attack or stroke caused by blockage of blood vessels or hardening of the arteries, also known as atherosclerois. Lipid profiles typically include total cholesterol, high density lipoprotein cholesterol (HDL-C) — “good” cholesterol, low density lipoprotein cholesterol (LDL-C) — “bad” cholesterol, and triglycerides.
A second non-controlled study of 14 healthy people found that three weeks on a Paleolithic diet significantly reduced weight, BMI, waist circumference, systolic blood pressure, and the plasminogen activator inhibitor-1 (PAI-1)3. Systolic blood pressure is the top number in a blood pressure reading, and it represents the maximum pressure exerted when the heart contracts. PAI-1 is mainly produced by the cells lining the blood vessels, but is also secreted by other tissue types. PAI-1 is an inhibitor of the physiological process that degrades blood clots. Elevated PAI-1 concentrations are associated with cardiovascular disease.
Hunter-gatherer diet studies with Australian Aborigines
One non-controlled study involved ten Australian Aborigines with diabetes, and a mean BMI of 27 kg/m2. Researchers concluded that reverting to a hunter–gatherer lifestyle for just seven weeks led to a 10% weight loss, and reductions in fasting and 2-hour glucose and fasting insulin levels4.
The same authors also conducted a second study with healthy Australian Aborigines. In this latter study, they found the insulin response to 70 g of starch from white bread was reduced, while the glucose response was not, following a reversion to a traditional lifestyle for 10- to 12-weeks5.
Epidemiological study with Pacific Islanders
This study looked at traditional Pacific Island inhabitants of Kitava, Papua New Guinea. These people, who practiced a hunter-gatherer lifestyle, had no signs of ischemic heart disease, stroke or markers of metabolic syndrome, which may result from their traditional lifestyle6-8. Metabolic syndrome refers to a group of symptoms that occur together, and promote the development of coronary artery disease, stroke, and type 2 diabetes.
Comparison of findings
The researchers concluded that all the improvements in markers of the metabolic syndrome on a Paleolithic diet are in line with findings from epidemiological studies in non-Western populations6-8. Improvements in A1c1, weight1, 4, 9, BMI9, waist circumference1, 9, diastolic blood pressure2, and triglycerides2 on a Paleolithic diet have been observed in intervention studies. A lower reported energy intake and energy density of food, despite food intake ad libitum, also agrees with earlier findings that a Paleolithic diet facilitates reduced caloric intake1, 10, 11.
Next time, we’ll take a look at theories regarding what our Paleolithic ancestors really ate, and weigh that against existing evidence. We’ll also show you how to make Mexican dining “Paleo”. “
References:
1. 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.
2. 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.
3. 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.
4. 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.
5. O’Dea K, Spargo RM, Akerman K: The effect of transition from traditional to urban life-style on the insulin secretory response in Australian Aborigines. Diabetes Care 1980, 3(1):31-37.
6. Lindeberg S, Lundh B: Apparent absence of stroke and ischaemic heart disease in a traditional Melanesian island: a clinical study in Kitava. J Intern Med 1993, 233(3):269-275.
7. Lindeberg S, Nilsson-Ehle P, Terént A, Vessby B, Scherstén B: Cardiovascular risk factors in a Melanesian population apparently free from stroke and ischaemic heart disease — the Kitava study. J Intern Med 1994, 236:331-340.
8. Lindeberg S, Eliasson M, Lindahl B, Ahrén B: Low serum insulin in traditional Pacific Islanders–the Kitava Study. Metabolism 1999, 48(10):1216-1219.
9. 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 2007.
10. Jonsson T, Ahren B, Pacini G, Sundler F, Wierup N, Steen S, Sjoberg T, Ugander M, Frostegard J, Goransson 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, 3:39.
11. Jönsson T: Healthy Satiety Effects of Paleolithic diet on Satiety and Risk factors for Cardiovascular disease PhD Thesis. Lund: Lund University; 2007.
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