What’s it all About?
Humans evolved during the Paleolithic era between 2.6million and 100,000 years ago and in accordance with Pritchard (2010), the changes that has come about related to human DNA since then is minimal. What has undergone a dramatic change however is how we live our day to day lives and the foods upon which we indulge as a result of agricultural and technological advances (Metzgar 2011). These dietary changes see a reduction in the consumption of fiber, micronutrients, protein alongside an overconsumption of carbohydrates, foods with a high Na/K ratio and a high n-3/n-6 ratio (Eaton et al 2010). The Paleolithic diet is based on the principle of evolutionary health and consists of modern equivalents to ancient paleo foods which predominantly consist of lean meat, seafood, fruit and vegetables and nuts (Cordain 2002). Compared to the traditional food pyramid, the paleo diet consists of no grains and no dairy products. The purpose of this article is to explore the topic of the paleo diet by evaluating its misconceptions which can often confuse people looking for an eating regime to go by for weight management, healthy living or sports performance.
The most common misconception relates to that of life expectancy when the paleo diet is discussed. According to Eaton et al (2002), judgement of whether or not the paleo lifestyle is any more beneficial than that of the current era should be judged on parameters such as weight, body composition, strength and endurance and not on life expectancy. It is inevitable that with longer life expectancy the risk of disease onset increases. Where a life expectancy of 40 (the estimated forager life expectancy) prevails, mortality from cancer and other chronic diseases is not so prevalent and so, it is difficult to compare this generation to a similar westernised 40 year old population. However, while the prevalence of chronic disease leads to mortality at a later stage in Western society, the onset of these diseases can occur much earlier, often in childhood (Eaton et al 2002). This allows comparison of age-matched individuals from both societies. According to Eaton et al (1998) biomarkers that included those of increased obesity incidence, rising blood pressure, and poor insulin resistance were greater among those living in industrial societies along with discrepancies where performance measures were concerned such as muscular strength and muscular power in comparison to their industrially primitive counterparts (Shephard and Rode 1996). It is estimated that 20% of hunter-gatherers make it to 60 years of age and even still these individuals appear free of degenerative disease implying that it is our Westernised lifestyle that imposes these degenerative diseases rather than age. Reasons for us westerns living longer include the greater availability of energy to assist in the repair post trauma, for the purpose of child-bearing and the body’s ability to combating certain microbes that were at one point in time; life threatening. Public health advancements such as immunizations, safer food, improved sanitation and effective systems of quarantine all impact on today’s life expectancy (Szreter 2000). The way we live these years though must be given further thought in light of the evidence presented here.
I can’t survive without my Carbs!
So the paleo regime rules out cereals, wheat, grains and gluten; so surely that’s not sustainable? In thinking carbohydrate, the first thought would be bread, pasta and rice, foodstuffs that we consume too much of. Strohle and Hahn (2011) conducted a study examining the various carbohydrate (CHO) intake of hunter gatherers across the globe and reported that CHO intake ranged from 3-50%. This variation differed with varying latitude. According to Leturque et al (2012) CHO accounts for 50% of overall energy requirements in a typical Western diet. However it is the quality of carbohydrate that remains the important consideration and not the quantity. Ludwig and Jenkins (2004) concur with this concept stating that “humans can probably do well over the long term consuming diets that vary widely in macronutrients as long as adequate attention is paid to nutrient quality.” Good sources of natural CHO include vegetables particularly root vegetables and fruit. These foods which have not undergone a state of processing will provide nutrients in its natural state resembling the diet of the hunter gatherer.
But that’s too much protein, Right?
With obesity on the rise, the use of diets high in protein such as the paleo diet has increased in popularity for weight loss and weight management. Current guidelines recommend a consumption of 0.8g/kg/d of protein as being sufficient to reach the needs of the majority of people nutritionally (Friedman 2004). Currently there is no upper limit defining a high protein diet. Western diets typically constitutes of 1.2g/kg/d of protein (15% total energy). High protein diets can usually see protein intake between 28-64%of total energy while CHO ranges between 3-16% compared to the recommended 40-50% (Agaston 2003). In brief, high protein diets increase glomerular filtration rate (GFR) and renal blood flow as much as 100% from baseline (Friedman 2004). Protein-induced haemodynamic changes permit the kidney to excrete greater amounts of protein-derived nitrogenous which in the long term can have deleterious consequences. However, these long term effects are not understood and many studies conducted investigating this issue have used animals. Concern has been presented however for those using high protein diets in individuals with existing kidney disease and so caution must be taken adhering to such a regime. For the healthy individual, no evidence presents a high protein diet as being dangerous to one’s health however one must not ignore the theoretical risks such as chronic glomerular hyperfiltration and hyperaemia, increased proteinuria and an elevated risk of nephrolithiasis. Further longitudinal in vivo studies are required to confirm such theories.
Many forums, blog discussions and fellow paleolithic abiders often report this particular regime as being expensive. A negative relationship exists between low-income consumers and diet quality (Lee et al 2009; Beaglehole et al 2011). With that it is easy to assume that the paleo way is too expensive to abide by. Metzgar et al (2011) investigated the feasibility of the paleolithic diet for low income consumers. According to this study, the first of its’ kind, reports that a paleo diet is feasible for a low income population. This is based on a female population of 20-50 years. While it appears feasible, it does present a shortage of both iron and fibre in order to meet the daily recommended intakes (DRIs). According to Metzgar et al (2011) an increase in income of 9.3% would see consumers meet all dietary needs when adhering to a paleo diet. Considering men require more calories, this income may require a further increase. This theory requires further research to confirm.
To conclude, the paleolithic diet has been presented as a nutritionally dense eating lifestyle with its positive attributes outweighing the negatives that prevail the western society of today whereby obesity and its associated chronic diseases that are widespread. Many people reject the concept of abiding by a paleolithic lifestyle due to some misconceptions that are presented here. It is important to understand the mechanism of these and what the science illustrates. In addition, it is always important to see a ‘diet’ as a lifestyle change where physical activity should also be considered to maintain and improve health. Also consider a client’s food preference so a particular plan is suitable both economically and in terms of accessibility to cooking and food preparation mechanisms, ensuring that one’s diet meets all nutritional requirements.