Loren Cordain

The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic

Objective: Field studies of twentieth century hunter-gathers (HG) showed them to be generally free of the signs and symptoms of cardiovascular disease (CVD). Consequently, the characterization of HG diets may have important implications in designing therapeutic diets that reduce the risk for CVD in Westernized societies. Based upon limited ethnographic data (n=58 HG societies) and a single quantitative dietary study, it has been commonly inferred that gathered plant foods provided the dominant energy source in HG diets.Method and Results: In this review we have analyzed the 13 known quantitative dietary studies of HG and demonstrate that animal food actually provided the dominant (65%) energy source, while gathered plant foods comprised the remainder (35%). This data is consistent with a more recent, comprehensive review of the entire ethnographic data (n=229 HG societies) that showed the mean subsistence dependence upon gathered plant foods was 32%, whereas it was 68% for animal foods. Other evidence, including isotopic analyses of Paleolithic hominid collagen tissue, reductions in hominid gut size, low activity levels of certain enzymes, and optimal foraging data all point toward a long history of meat-based diets in our species. Because increasing meat consumption in Western diets is frequently associated with increased risk for CVD mortality, it is seemingly paradoxical that HG societies, who consume the majority of their energy from animal food, have been shown to be relatively free of the signs and symptoms of CVD.Conclusion: The high reliance upon animal-based foods would not have necessarily elicited unfavorable blood lipid profiles because of the hypolipidemic effects of high dietary protein (19–35% energy) and the relatively low level of dietary carbohydrate (22–40% energy). Although fat intake (28–58% energy) would have been similar to or higher than that found in Western diets, it is likely that important qualitative differences in fat intake, including relatively high levels of MUFA and PUFA and a lower ω-6/ω-3 fatty acid ratio, would have served to inhibit the development of CVD. Other dietary characteristics including high intakes of antioxidants, fiber, vitamins and phytochemicals along with a low salt intake may have operated synergistically with lifestyle characteristics (more exercise, less stress and no smoking) to further deter the development of CVD.

Cardiovascular disease resulting from a diet and lifestyle at odds with our Paleolithic genome: how to become a 21st-century hunter-gatherer.

Our genetic make-up, shaped through millions of years of evolution, determines our nutritional and activity needs. Although the human genome has remained primarily unchanged since the agricultural revolution 10,000 years ago, our diet and lifestyle have become progressively more divergent from those of our ancient ancestors. Accumulating evidence suggests that this mismatch between our modern diet and lifestyle and our Paleolithic genome is playing a substantial role in the ongoing epidemics of obesity, hypertension, diabetes, and atherosclerotic cardiovascular disease. Until 500 generations ago, all humans consumed only wild and unprocessed food foraged and hunted from their environment. These circumstances provided a diet high in lean protein, polyunsaturated fats (especially omega-3 [omega-3] fatty acids), monounsaturated fats, fiber, vitamins, minerals, antioxidants, and other beneficial phytochemicals. Historical and anthropological studies show hunter-gatherers generally to be healthy, fit, and largely free of the degenerative cardiovascular diseases common in modern societies. This review outlines the essence of our hunter-gatherer genetic legacy and suggests practical steps to re-align our modern milieu with our ancient genome in an effort to improve cardiovascular health.

Hyperinsulinemic diseases of civilization: more than just Syndrome X

Compensatory hyperinsulinemia stemming from peripheral insulin resistance is a well-recognized metabolic disturbance that is at the root cause of diseases and maladies of Syndrome X (hypertension, type 2 diabetes, dyslipidemia, coronary artery disease, obesity, abnormal glucose tolerance). Abnormalities of fibrinolysis and hyperuricemia also appear to be members of the cluster of illnesses comprising Syndrome X. Insulin is a well-established growth-promoting hormone, and recent evidence indicates that hyperinsulinemia causes a shift in a number of endocrine pathways that may favor unregulated tissue growth leading to additional illnesses. Specifically, hyperinsulinemia elevates serum concentrations of free insulin-like growth factor-1 (IGF-1) and androgens, while simultaneously reducing insulin-like growth factor-binding protein 3 (IGFBP-3) and sex hormone-binding globulin (SHBG). Since IGFBP-3 is a ligand for the nuclear retinoid X receptor alpha, insulin-mediated reductions in IGFBP-3 may also influence transcription of anti-proliferative genes normally activated by the bodys endogenous retinoids. These endocrine shifts alter cellular proliferation and growth in a variety of tissues, the clinical course of which may promote acne, early menarche, certain epithelial cell carcinomas, increased stature, myopia, cutaneous papillomas (skin tags), acanthosis nigricans, polycystic ovary syndrome (PCOS) and male vertex balding. Consequently, these illnesses and conditions may, in part, have hyperinsulinemia at their root cause and therefore should be classified among the diseases of Syndrome X.

The western diet and lifestyle and diseases of civilization

Correspondence: Pedro Carrera-Bastos R. Gorgel do Amaral, No. 5, 1 e; Lisbon 1250-119, Portugal Tel +351 967 088 799 email pedro.carrera_bastos@med.lu.se Abstract: It is increasingly recognized that certain fundamental changes in diet and lifestyle that occurred after the Neolithic Revolution, and especially after the Industrial Revolution and the Modern Age, are too recent, on an evolutionary time scale, for the human genome to have completely adapted. This mismatch between our ancient physiology and the western diet and lifestyle underlies many so-called diseases of civilization, including coronary heart disease, obesity, hypertension, type 2 diabetes, epithelial cell cancers, autoimmune disease, and osteoporosis, which are rare or virtually absent in hunter–gatherers and other non-westernized populations. It is therefore proposed that the adoption of diet and lifestyle that mimic the beneficial characteristics of the preagricultural environment is an effective strategy to reduce the risk of chronic degenerative diseases.

Estimated macronutrient and fatty acid intakes from an East African Paleolithic diet

Our genome adapts slowly to changing conditions of existence. Many diseases of civilisation result from mismatches between our Paleolithic genome and the rapidly changing environment, including our diet. The objective of the present study was to reconstruct multiple Paleolithic diets to estimate the ranges of nutrient intakes upon which humanity evolved. A database of, predominantly East African, plant and animal foods (meat/fish) was used to model multiple Paleolithic diets, using two pathophysiological constraints (i.e. protein < 35 energy % (en%) and linoleic acid (LA) >1.0 en%), at known hunter-gatherer plant/animal food intake ratios (range 70/30-30/70 en%/en%). We investigated selective and non-selective savannah, savannah/aquatic and aquatic hunter-gatherer/scavenger foraging strategies. We found (range of medians in en%) intakes of moderate-to-high protein (25-29), moderate-to-high fat (30-39) and moderate carbohydrates (39-40). The fatty acid composition was SFA (11.4-12.0), MUFA (5.6-18.5) and PUFA (8.6-15.2). The latter was high in α-linolenic acid (ALA) (3.7-4.7 en%), low in LA (2.3-3.6 en%), and high in long-chain PUFA (LCP; 4.75-25.8 g/d), LCP n-3 (2.26-17.0 g/d), LCP n-6 (2.54-8.84 g/d), ALA/LA ratio (1.12-1.64 g/g) and LCP n-3/LCP n-6 ratio (0.84-1.92 g/g). Consistent with the wide range of employed variables, nutrient intakes showed wide ranges. We conclude that compared with Western diets, Paleolithic diets contained consistently higher protein and LCP, and lower LA. These are likely to contribute to the known beneficial effects of Paleolithic-like diets, e.g. through increased satiety/satiation. Disparities between Paleolithic, contemporary and recommended intakes might be important factors underlying the aetiology of common Western diseases. Data on Paleolithic diets and lifestyle, rather than the investigation of single nutrients, might be useful for the rational design of clinical trials.

Dissociation of the glycaemic and insulinaemic responses to whole and skimmed milk

In most carbohydrate-containing foods, the blood insulin response is predictable and is closely linked to the foods glycaemic index (GI). A single study, examining whole milk and fermented milk products made from whole milk, recently reported a large dissociation between the GI and insulinaemic index (II) in healthy normal adults. Because the fat component of a food may influence the GI and II, it is unclear if a similar dissociation may exist for skimmed milk in normal adults. We determined the GI and II of both skimmed and whole milk in nine healthy, male (n 6) and female (n 3) subjects (23.6 (sd 1.4) years). No significant (P>0.05) differences existed between GI and II for skimmed and whole milks. Significant (P<0.05) differences were observed between the actual and predicted areas under the insulin curves for both skimmed milk (predicted 1405 (sd 289) pmol x min/l; actual 6152 (sd 1177) pmol x min/l) and whole milk (predicted 1564 (sd 339) pmol x min/l; actual 5939 (sd 1095) pmol x min/l). Consequently, a large and similar dissociation of the GI and II existed for both whole milk (42 (sd 5) and 148 (sd 14)) and skimmed milk (37 (sd 9) and 140 (sd 13)). It is concluded that the dissociation of the GI and II in milk is not related to its fat content.

Influence of moderate daily wine consumption on body weight regulation and metabolism in healthy free-living males.

OBJECTIVE Although previous studies have clearly demonstrated that energy from alcohol may not be efficiently utilized to maintain body weight when it comprises 20% or more of the daily caloric intake, there is considerable debate regarding the influence of moderate alcohol consumption (< or = 5% of the total daily caloric intake) upon metabolism, substrate utilization and body weight regulation. Consequently, the objectives of this study were to determine whether moderate alcohol consumption could influence body weight via changes in substrate utilization, oxygen consumption or alterations in dietary macronutrient content. METHODS Fourteen male subjects (mean age = 32.1 years) participated in a 12-week, free-living, crossover trial in which they either drank red wine (270 ml; 13% v/v ethanol) daily for 6 weeks and then abstained for the next 6 weeks or vice-versa. RESULTS Whether wine was imbibed or not, no significant differences (p > 0.05) were demonstrated for any of the following variables: body weight, body fat percentage, skinfold thickness, resting metabolic rate, respiratory quotient, caloric intake, dietary macronutrient content, or fasting insulin or glucose concentrations. CONCLUSIONS In free-living subjects over a 6-week period, the addition of two glasses of red wine to the evening meal does not appear to influence any measured variable which may adversely affect body weight or promote the development of obesity during this time period.

Modulation of immune function by dietary lectins in rheumatoid arthritis.

Despite the almost universal clinical observation that inflammation of the gut is frequently associated with inflammation of the joints and vice versa, the nature of this relationship remains elusive. In the present review, we provide evidence for how the interaction of dietary lectins with enterocytes and lymphocytes may facilitate the translocation of both dietary and gut-derived pathogenic antigens to peripheral tissues, which in turn causes persistent peripheral antigenic stimulation. In genetically susceptible individuals, this antigenic stimulation may ultimately result in the expression of overt rheumatoid arthritis (RA) via molecular mimicry, a process whereby foreign peptides, similar in structure to endogenous peptides, may cause antibodies or T-lymphocytes to cross-react with both foreign and endogenous peptides and thereby break immunological tolerance. By eliminating dietary elements, particularly lectins, which adversely influence both enterocyte and lymphocyte structure and function, it is proposed that the peripheral antigenic stimulus (both pathogenic and dietary) will be reduced and thereby result in a diminution of disease symptoms in certain patients with RA.

Exercise Like a Hunter-Gatherer: A Prescription for Organic Physical Fitness

A large proportion of the health woes beleaguering modern cultures are because of daily physical activity patterns that are profoundly different from those for which we are genetically adapted. The ancestral natural environment in which our current genome was forged via natural selection called for a large amount of daily energy expenditure on a variety of physical movements. Our genes that were selected for in this arduous and demanding natural milieu enabled our ancestors to survive and thrive, leading to a very vigorous lifestyle. This abrupt (by evolutionary time frames) change from a very physically demanding lifestyle in natural outdoor settings to an inactive indoor lifestyle is at the origin of many of the widespread chronic diseases that are endemic in our modern society. The logical answer is to replicate the native human activity pattern to the extent that this is achievable and practical. Recommendations for exercise mode, duration, intensity, and frequency are outlined with a focus on simulating the routine physical activities of our ancient hunter-gatherer ancestors whose genome we still largely share today. In a typical inactive person, this type of daily physical activity will optimize gene expression and help to confer the robust health that was enjoyed by hunter-gatherers in the wild.

Biological and Clinical Potential of a Palaeolithic Diet

Purpose: To explore the possibility that a Palaeolithic diet, i.e. one that corresponds to what was available in any of the ecological niches of pre‐agricultural humans (1.5 million–10,000 years bp), is optimal in the prevention of age‐related degenerative disease.Design: Literature review.Materials and Methods: Between 1985 and December 2002, more than 200 scientific journals in medicine, nutrition, biology and anthropology were systematically screened for relevant papers. Computer‐based searches and studies of reference lists in journals and books provided a vast number of additional papers.Results: Increasing evidence suggests that a Palaeolithic diet based on lean meat, fish, vegetables and fruit may be effective in the prevention and treatment of common Western diseases. Avoiding dairy products, margarine, oils, refined sugar and cereals, which provide 70% or more of the dietary intake in northern European populations, may be advisable. Atherosclerosis is highly dependent on dietary manipulation in a...