In our last iNform Voice blog we explained the main differences between a Paleo diet and our current Australian Guidelines. However, do we know if this way of eating is good for us or is it just another fly-by diet?
Is there actually any research to this diet and if so what does it tell us?
What I found surprised me in many ways.
Firstly, if we look at the amount of research on the Paleolithic diet it is actually quite scarce. A simple search of the medical database, Pubmed, revealed 5 Randomised Controlled Trials (RCTs are considered the gold standard) from 2009 to present. This is miniscule compared to the Mediterranean diet that brings up 324 papers with the same search. Further to this, these studies were very small, both in number of participants (ranging from 13 to 34), and in duration (the shortest being 2 weeks and the longest 3 months).
How to they compare to the Australian Dietary Guidelines?
While there are no studies that directly compare the Paleo diet to the current Australian guidelines, they do compare it to similar guidelines developed by such authorities such as the American Diabetes Association, and European Authorities. While they are not identical, all of these diets (let’s call them the controls), contain dairy, whole grains and legumes, unlike Paleo.
So what did they find?
Well, they actually found some promising results.
All of the 5 studies found significant improvements in many cardiovascular and metabolic markers. In fact in measurements such as weight, waist girth, blood sugar levels, blood pressure and triglyceride levels, the Paleo diet outperformed the control (even though they didn’t always reach a significant level). Blood pressure, glucose control and waist girth reached a significant level in three of the studies, while weight and triglyceride levels were significantly lower in two studies.
Now it is important to note here that four of these five studies were on participants with Metabolic Syndrome or Type II Diabetes, so it would be dangerous for us to make assumptions for the people without these conditions. We also should be careful when making long term health changes based on studies where three of the five studies went for three weeks or less.
However, it is still good to ask the question: Why did these health markers improve?
Firstly, blood pressure on average reduced by 4 mmHg in systolic and 3 mmHg diastolic above and beyond the control diet. Given that the paleo diet was lower in salt (sodium) and higher in potassium than the reference diets, this could well explain the greater improvement.
Changes in blood sugar control, triglyceride levels and waist girth (often associated with poor metabolic control) may be explained by a reduced sugar and carbohydrate level consumption.
So could these benefits of the Paleo diet be seen by simply reducing salt, increasing potassium (through fruit and vegetables) and decreasing carbohydrate levels to the levels of the paleo diet, without actually excluding whole grains, dairy and legumes?
I guess we won’t know until a study controls for these variables……
So it appears the Paleo way shows promise in a number of health variables, albeit limited at present. However, I’m sure we’ll see many more studies over the coming years.
What we do need to consider though, is that we may well be seeing short term gains by putting our long term health at risk.
In our final blog of the series we’ll look into the potential impact of excluding these food groups, so we can make up our mind on whether eating like we did in the past is the way of the future!
- Boers et al.(2014) Favourable effects of consuming a Palaeolithic-type diet on characteristics of the metabolic syndrome: a randomized controlled pilot-study. Lipids in Health and Disease 13:160.
- Jönsson et al. (2009). Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovasc Diabetol.;8:35
- Lindeberg et al. (2007) A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia, 50(9):1795-1807.
- Masharani et al. (2015) Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. European Journal of Clinical Nutrition, 69: 944–948.
- Osterdahl M, Kocturk T, Koochek A, Wandell PE (2008) Effects of a short-term intervention with a paleolithic diet in healthy volunteers. European Journal of Clinical Nutrition, 62(5):682-685.