What is it?

The Paleo diet (PD) originates from long ago. It is based on the concept of eating “whole” foods that were consumed by hunter-gatherers from the Paleolithic era. The focus is on consumption of meats, vegetables and fruits with avoidance of dairy and grains.

What is the evidence for it?

While there are relatively few studies that have compared PD to traditional diets, research suggests the need for more clinical trials to fully understand its mechanistic benefits to human health. A reoccurring theme in research conducted thus far is that the PD has favorable outcomes on metabolic dysfunction¹.

Pros?

• Improves glycemic control
  • A study from the European Journal of Clinical Nutrition (EJCN) found that when type 2 diabetic subjects were placed in a PD or American Diabetes Association (ADA) recommended diet group there were significantly distinct results². The PD group had improved insulin sensitivity and glucose balance compared to the ADA diet². Additionally, the PD conferred more beneficial effects to participant’s lipid profiles².
  • The dietary glycemic index (GI) has been found to be consistently lower in a PD compared to others³.
  • Another study concluded the PD improves glucose tolerance more than the Mediterranean Diet in ischemic heart disease patients⁴.
• Modulates lipid profiles
  • In the EJCN study, participants on the PD had significantly greater improvements in lipid profiles than the ADA diet group¹.
  • The PD was found to exert significantly greater effects on regulating hyperlipidemia and cholesterol ratios in non-diabetic adults compared to a grain-based, “heart healthy” diet recommended by the American Heart Association⁵.
• Improves cardiovascular risk factors
  • A clinical trial analyzed diabetic patients administered a PD or diabetic diet (dictated by the dietary guidelines) treatment³. The study, which was published in Cardiovascular Diabetology, found that the PD participants had significantly lower levels of HbA1c, diastolic blood pressure (BP), and waist circumference along with significantly higher levels of HDL cholesterol³.
  • One study reviewed the effects of the PD on diabetic patients with an increased risk for cardiovascular disease (CVD). It concluded that the PD has increased beneficial effects on type 2 diabetes and hallmark cardiovascular risk factors⁶.
• Assists with weight loss
  • A two-year study with obese, post-menopausal women given a PD or Nordic Nutrition Recommendations (NNR) diet concluded that the PD group had significantly greater reductions in adiposity and waist circumference than the NNR group⁷. 
• Overall, advantageous for metabolic parameters and CVD risk
  • In a study, the PD had beneficial effects on metabolic syndrome and cardiovascular risk factors⁸. The results of the PD treatment were lower systolic BP, diastolic BP, total cholesterol, as well as higher HDL cholesterol⁸.
  • Furthermore, there was significant weight loss in the PD group⁸.
  • A research review concluded that the PD amassed significantly greater improvements in metabolic syndrome markers compared to guideline-based control diets⁹.

Cons?

• -Difficult diet for vegetarians and vegans.
• -If an extreme athlete, work harder to get adequate carb intake.

References

1. Pitt, 2016: https://www.racgp.org.au/afp/2016/januaryfebruary/cutting-through-the-paleo-hype-the-evidence-for-the-palaeolithic-diet/
2. Marsharini et al., 2015: https://www.ncbi.nlm.nih.gov/pubmed/25828624
3. Jonsson et al., 2009: https://www.ncbi.nlm.nih.gov/pubmed/19604407
4. Lindberg et al., 2007: https://www.ncbi.nlm.nih.gov/pubmed/17583796?dopt=Abstract
5. Pastore et al., 2015: https://www.ncbi.nlm.nih.gov/pubmed/26003334
6. Klonoff, 2009: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2787021/
7. Melberg et al., 2014: https://www.ncbi.nlm.nih.gov/pubmed/24473459
8. Boers et al., 2014: https://www.ncbi.nlm.nih.gov/pubmed/25304296
9. Manheimer et al., 2015: https://www.ncbi.nlm.nih.gov/pubmed/26269362