Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis.
BACKGROUND
Paleolithic nutrition, which has attracted substantial public attention lately because of its putative health benefits, differs radically from dietary patterns currently recommended in guidelines, particularly in terms of its recommendation to exclude grains, dairy, and nutritional products of industry.


OBJECTIVE
We evaluated whether a Paleolithic nutritional pattern improves risk factors for chronic disease more than do other dietary interventions.


METHODS
We conducted a systematic review of randomized controlled trials (RCTs) that compared the Paleolithic nutritional pattern with any other dietary pattern in participants with one or more of the 5 components of metabolic syndrome. Two reviewers independently extracted study data and assessed risk of bias. Outcome data were extracted from the first measurement time point (≤6 mo). A random-effects model was used to estimate the average intervention effect. The quality of the evidence was rated with the use of the Grading of Recommendations Assessment, Development and Evaluation approach.


RESULTS
Four RCTs that involved 159 participants were included. The 4 control diets were based on distinct national nutrition guidelines but were broadly similar. Paleolithic nutrition resulted in greater short-term improvements than did the control diets (random-effects model) for waist circumference (mean difference: -2.38 cm; 95% CI: -4.73, -0.04 cm), triglycerides (-0.40 mmol/L; 95% CI: -0.76, -0.04 mmol/L), systolic blood pressure (-3.64 mm Hg; 95% CI: -7.36, 0.08 mm Hg), diastolic blood pressure (-2.48 mm Hg; 95% CI: -4.98, 0.02 mm Hg), HDL cholesterol (0.12 mmol/L; 95% CI: -0.03, 0.28 mmol/L), and fasting blood sugar (-0.16 mmol/L; 95% CI: -0.44, 0.11 mmol/L). The quality of the evidence for each of the 5 metabolic components was moderate. The home-delivery (n = 1) and dietary recommendation (n = 3) RCTs showed similar effects with the exception of greater improvements in triglycerides relative to the control with the home delivery. None of the RCTs evaluated an improvement in quality of life.


CONCLUSIONS
The Paleolithic diet resulted in greater short-term improvements in metabolic syndrome components than did guideline-based control diets. The available data warrant additional evaluations of the health benefits of Paleolithic nutrition. This systematic review was registered at PROSPERO (www.crd.york.ac.uk/PROSPERO) as CRD42014015119.
Bahrain Branch of Cochrane, Awali, Bahrain; and emanheimer@ebsco.com.
Eric W
EW
Manheimer
Departments of Dermatology and.
Esther J
http://orcid.org/0000-0002-4780-0182
EJ
van Zuuren
Bahrain Branch of Cochrane, Awali, Bahrain; and.
Zbys
Z
Fedorowicz
Internal Medicine, Section Endocrinology, Leiden University Medical Centre, Leiden, Netherlands.
Hanno
http://orcid.org/0000-0002-3076-1551
H
Pijl
D001794:Blood Pressure; D008076:Cholesterol, HDL / Q000097:blood; D002908:Chronic Disease; D016208:Databases, Factual; D066046:Diet, Paleolithic; D006801:Humans; D024821:Metabolic Syndrome / Q000178:diet therapy*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference
D008076:Cholesterol, HDL; D014280:Triglycerides
GRADE; Paleolithic diet; cardiovascular risk; meta-analysis; metabolic syndrome; randomized controlled trials; systematic review