Diet and the role it plays in health and disease
As a Paleo Nutritionist, I cannot overemphasise the importance of our diet to our health. What we eat is critical to how healthy we remain and how successful our exercise goals are. A good diet can help people remain free of disease, as well as having a positive influence on body composition.
While our ancestors have been on earth for about six million years, the modern form of humans only evolved approximately 200,000 years ago (1). Civilisation is only about 6,000 years old, and industrialisation, along with industrial agriculture, started properly in the 1800s. Our genes have evolved slowly with us as a species over time. Our modern diet has outpaced the capacity of our genes to evolve or change with it. Diet, along with environmental exposure, has a key role in which genes are expressed and the risk of disease developing (2).
The Paleolithic era was pre-modern day agricultural processes. Our gastrointestinal tract and digestive system have not changed much since that time so our modern day diet may put a strain on, or could even damage, our gastrointestinal tract. Some foods that we eat in plentiful amounts today were not suitable to eat in their raw, pre-processed form back then. For example, no other primates other than humans consume cereal grains. Theses now constitute 40-90% of our caloric intake, replacing fruits and vegetables in the process. (3)
The Paleo Diet
The Paleo diet is also known as the Caveman diet or Hunter-gatherer diet. First of all, even as a Paleo Nutritionist, I’d like to say that I dislike the term “Paleo”. However, it is the best term for the diet that is most in line with our ancestry, genetics and evolution. The aim of the diet is eating nutrient dense, toxin-free, whole foods. The most nutrient dense foods you can eat are:
- Meats from grass-fed, antibiotic free animals,
- Organic vegetables,
- Organic fruits,
- Wild fish and seafood,
- Wild game and
These are exactly the foods that I promote as a Paleo nutritionist. I do not see this as a fad diet; it is basically eating in line with your genes and eating what we have ate for the majority of our evolution, some 66,000 generations prior to the agricultural revolution. Basically, if it wasn’t around 10,000 years ago, do not eat it! The idea is that this diet is more in tune with the evolution of our body and how, over the millennia, we used to nourished it. To eat like our ancestors ate.
The diet can be somewhat low in carbohydrates, but abundant in plant foods and lean, healthy sources of protein. The plant foods provide an important source of vitamins, minerals, fibre and beneficial plant based chemical compounds (phytochemicals). Unlike other low carbohydrate diets, the Paleo diet doesn’t encourage the consumption of processed meats, while promoting plenty of fruits and vegetables. The diet also encourages the consumption of natural, healthy fats from grass fed animals, wild fish, seeds and nuts. Eliminating processed food, dairy, industrial seed oils, sugar, grains and legumes, means the diet will most probably to lead to some fat loss and an improvement in weight. However, some people who start on a Paleo diet do so to tackle a digestive or inflammatory health condition, not to lose weight. Described more as a “lifetime programme” and not a “quick fix” weight loss diet, the Paleo diet promotes a more natural way of eating. Weight loss is does commonly occur with the diet (4). More importantly, it has been shown to diet improves blood pressure, glucose tolerance, decreases insulin secretion, increases insulin sensitivity and improves blood lipid profiles (5).
The role of Inflammation
Many chronic diseases that are on the rise in the Western world have been linked to chronic inflammation. Molecules such as reactive oxygen species can cause something called lipid peroxidation, which is a key result and indicator of oxidative stress. Oxidative stress can directly increase inflammation and this relationship is bidirectional. Both oxidative stress and chronic inflammation and have been linked to cardiovascular disease, cancer and other chronic diseases. Chronic inflammation and the balance of oxidation have been linked with a poor diet.
Several dietary factors influence a person’s chronic inflammation level. Factors such as a higher ratio of Omega-6 to Omega-3 Fatty Acids, eating foods with a low fibre content, high content of saturated fat, sugar and refined carbohydrates, are associated with higher levels of inflammation in the body. Studies have demonstrated that diets that are more Paleolithic-like were associated with lower levels of systemic inflammation and oxidative stress in humans, when measuring inflammatory markers in the blood (10). The Paleo diet has elements that may reduce chronic inflammation or improve oxidative balance. It is high in vegetables, nuts and fish; these contain nutrients that are higher in antioxidants and lower in pro-oxidant, a better Omega-6:Omega-3 Fatty Acid ratio, a more favourable glycemic load and less calories per gram (energy density) than a “standard” Western diet, and are likely to lead to an improved energy balance. All of these factors are thought to improve systemic inflammation and oxidative balance.
The health of modern-day hunter-gatherers.
Anthropologists (people who study human biological and physiological characteristics and their evolution) Gurven and Kaplan studied the lifespan of current hunter–gatherer populations. They discovered that as long as they survive childhood, their lifespans are in the region of 68 to 78 years (6), which is approximately the same as ours in the Western world. However, what is remarkable is that they achieve this living in some very inhospitable environments. Even more impressive is that they reach these ages without acquiring the chronic diseases that are very common in industrialised societies. They are much less likely to suffer from heart disease, diabetes, Alzheimer’s, and many other chronic health conditions we suffer from. A study of the Tsimané people in Bolivia found that they have a prevalence of atherosclerosis five-fold lower than industrialised populations. Nine in 10 Tsimané adults aged 40 to 94 had completely clean arteries and no risk of heart disease. (7). The Tsimané have the lowest reported levels of coronary artery disease of any population recorded to date, despite many of them smoking heavily!
There are a few other contemporary hunter–gatherer populations still in existence, like the Tsimané above, the Maasai, Inuit, Kitavans, the Batak of Northern Palawan in Western Philippines, the Pirahã of the Maici River in the Amazon and the Kalahari Persistence Hunters. There is a relative lack of chronic diseases in these populations, that are so common in the industrialised world.
When the diets of 229 hunter–gatherer groups were studied, animal food provided a relatively high proportion of their food consumption (8) Only 14 percent of these societies got more than 50 percent of their calories from plant foods. The macronutrient ratios of protein, fat, and carbohydrates and the proportion of animals to plants food varied, but an ancestral population following a completely vegetarian or vegan diet has never been discovered. Other studies have found similar results: animal food comprised 68 percent of total calories on average, compared with 32 percent from plant foods (9). Their diet, by definition, is a “Paleo”-type diet in nature.
Nature vs nurture – Genes or Environment?
As a Paleo Nutritionist, I believe a Paleolithic-type diet can help support a healthy lifestyle. However, do your genetics mean that you will get a certain disease, no matter what? Genes may predispose you to certain conditions, but diet and environment have a key role in their development. The nature vs. nurture argument is quickly proving to be irrelevant an irrelevant one, because it’s coming to light that these two forces interact in very particular ways that alter gene behaviour.
Sometimes, genes need to be switched on for a certain change, or disease state, to be expressed. This is known as Epigenetics. It involves genetic control by factors other than an individual’s own DNA sequence and these epigenetic changes can switch genes on or off. Epigenetics is influenced by, amongst other things, the environment and lifestyle. New and ongoing research is continuously uncovering the role that epigenetics plays in a variety of human disorders and fatal diseases.
One relevant example that I can think of is the obesity epidemic that is affecting humans. Our genes have not changed much in the last 40 years, but during that time, we’ve seen a massive increase in the rates of obesity. This would suggest that genetics are not the primary driving force of obesity. However, we do know that genes exist that predispose some people to obesity more so than others. More importantly, not everyone is equally affected by exposure to the same environment. This suggests that genes do play a role, but so too does the diet and environment (perhaps to greater extent).
How I can help you – My credentials
I am a certified Paleo nutritionist with the CMA (Complementary Medical Association). As a Paleo nutritionist, I can help you easily adopt a healthy Paleo style diet by:
- Helping you understand the Paleo diet basics.
- Formulating a healthy Paleo diet plan and Paleo diet menu for you
- Help with cooking easy Paleo meals.
- Advising on healthy Paleo snacks
- Provide education on the best Paleo diet foods allowed.
- Advising on the best places to source Paleo foods
- Advising the best Paleo diet books to read.
- Paleo diet chart
- Implementing Paleo diet weight loss strategies / formulating a Paleo diet plan for weight loss
- Paleo diet rules
- Adopting a Paleo diet for athletes (especially how to avoid the common mistakes with regards to Paleo for athletes), the best Paleo pre workout supplements, providing a Paleo diet for athletes nutritionist plan.
- Adopting a Paleo lifestyle
- Obtaining the best Paleo diet results
The Paleo diet guidelines are not set in stone and do allow for some variability within the diet. In line with your current health and medical conditions, I can act as your personal Paleo nutritionist and provide you with a highly customised Paleo diet plan.
- Perform a kitchen clear out to get you started eating Paleo
- Go Supermarket shopping with you, to help you buy the correct ingredients for Paleo diet meals
I am also a qualified fitness nutritionist with the International Sports Science Association. As a certified sports and fitness nutritionist, I can provide advice with:
- Sport nutrition / general nutrition advisor
- Nutrition for athletes / nutrition for sport and exercise
- Sports nutrition supplements and nutritional supplements for athletes
- Bodybuilding nutrition
- Being a personal nutritionist
- A customised sports nutrition diet plan
- Evidence based scientific sports nutrition advice.
- Which sports nutrition products are useful, or not
1) Stringer C.B. (1994) Out of Africa — A Personal History. In: Nitecki M.H., Nitecki D.V. (eds) Origins of Anatomically Modern Humans. Interdisciplinary Contributions to Archaeology. Springer, Boston, MA
2) Olivia S.Anderson, Karilyn E.Sant, Dana C.Dolinoy. Nutrition and epigenetics: an interplay of dietary methyl donors, one-carbon metabolism and DNA methylation The Journal of Nutritional Biochemistry. Volume 23, Issue 8, August 2012, Pages .853-859.
3) Peter S. Ungar and Mark F. Teaford. Human diet : its origin and evolution. Imprint, Westport, Conn. : Bergin & Garvey, 2002. P13.
(4). M Österdahl, T Kocturk, A Koochek & P E Wändell. Effects of a short-term intervention with a Paleolithic diet in healthy volunteers. European Journal of Clinical Nutrition volume 62, pages 682–685 (2008)
(5). L A Frassetto, M Schloetter, M Mietus-Synder, R C Morris Jr & A Sebastian. Metabolic and physiologic improvements from consuming a Paleolithic, hunter-gatherer type diet. European Journal of Clinical Nutrition volume 63, pages 947–955 (2009)
(6) Gurven & Kaplan, 2007 Longevity Among Hunter‐ Gatherers: A Cross‐Cultural Examination Michael Gurven Hillard Kaplan Population and Development Review, Volume 33, Issue 2 First published: 29 May 2007.
(7).Prof Hillard Kaplan, PhD, Prof Randall C Thompson, MD, Benjamin C Trumble, PhD, L Samuel Wann, MD, Prof Adel H Allam, MD, Bret Beheim, PhD et al.
Coronary atherosclerosis in indigenous South American Tsimane: a cross-sectional cohort study. The Lancet Volume 389, Issue 10080, P1730-1739, April 29, 2017.
8). Loren Cordain Janette Brand Miller S Boyd Eaton Neil Mann Susanne HA Holt John D Speth. Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. The American Journal of Clinical Nutrition, Volume 71, Issue 3, 1 March 2000, Pages 682–692
9) L Cordain, SB Eaton, J Brand Miller, N Mann and K Hill. The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic. European Journal of Clinical Nutrition (2002) 56, Suppl 1, S42–S52.
10) Kristine A Whalen Marjorie L McCullough W Dana Flanders Terryl J Hartman Suzanne Judd Roberd M Bostick. Paleolithic and Mediterranean Diet Pattern Scores Are Inversely Associated with Biomarkers of Inflammation and Oxidative Balance in Adults. The Journal of Nutrition, Volume 146, Issue 6, 1 June 2016, Pages 1217–1226.