Frits Aj Muskiet’s research while affiliated with University of Groningen and other places

The main goal of this randomized controlled single-blinded pilot study was to study whether, independent of weight loss, a Palaeolithic-type diet alters characteristics of the metabolic syndrome. Next we searched for outcome variables that might become favourably influenced by a Paleolithic-type diet and may provide new insights in the pathophysiological mechanisms underlying the metabolic syndrome. In addition, more information on feasibility and designing an innovative dietary research program on the basis of a Palaeolithic-type diet was obtained. Thirty-four subjects, with at least two characteristics of the metabolic syndrome, were randomized to a two weeks Palaeolithic-type diet (n = 18) or an isoenergetic healthy reference diet, based on the guidelines of the Dutch Health Council (n = 14). Thirty-two subjects completed the study. Measures were taken to keep bodyweight stable. As primary outcomes oral glucose tolerance and characteristics of the metabolic syndrome (abdominal circumference, blood pressure, glucose, lipids) were measured. Secondary outcomes were intestinal permeability, inflammation and salivary cortisol. Data were collected at baseline and after the intervention. Subjects were 53.5 (SD9.7) year old men (n = 9) and women (n = 25) with mean BMI of 31.8 (SD5.7) kg/m2. The Palaeolithic-type diet resulted in lower systolic blood pressure (−9.1 mmHg; P = 0.015), diastolic blood pressure (−5.2 mmHg; P = 0.038), total cholesterol (−0.52 mmol/l; P = 0.037), triglycerides (−0.89 mmol/l; P = 0.001) and higher HDL-cholesterol (+0.15 mmol/l; P = 0.013), compared to reference. The number of characteristics of the metabolic syndrome decreased with 1.07 (P = 0.010) upon the Palaeolithic-type diet, compared to reference. Despite efforts to keep bodyweight stable, it decreased in the Palaeolithic group compared to reference (−1.32 kg; P = 0.012). However, favourable effects remained after post-hoc adjustments for this unintended weight loss. No changes were observed for intestinal permeability, inflammation and salivary cortisol. We conclude that consuming a Palaeolithic-type diet for two weeks improved several cardiovascular risk factors compared to a healthy reference diet in subjects with the metabolic syndrome. Trial registration Nederlands Trial Register NTR3002

Aim and Background: Astaxanthin is a unique carotenoid of predominantly marine origin providing the pink-red color to certain microalgae and accumul ating in various animals higher in the food chain. It is an antioxidant without pro-oxidant properties or known side-effects following oral intake. Materials and Methods: We investigated astaxanthin kinetics in plasma and erythrocytes (red blood cells [RBC]) of four healthy adults after a single oral 40 mg dose. Plasma- and RBC-astaxanthin were measured during 72 h. Subsequently, an 8 mg/day dose was given during 17 days. Plasma- and RBC-astaxanthin were measured each morning. Results: Plasma-astaxanthin reached a peak (from 79 to 315 nmol/L) after 8 h and then declined (half-life, 18 h). Within 72 h, plasma-astaxanthin had returned to baseline. RBC-astaxanthin reached a peak (from 63 to 137 nmol/L packed cells) at 12 h and subsequently disappeared (half-life, 28 h). During the daily dose, plasma-astaxanthin increased until day 10 (187 nmol/L) and then decreased to a steady concentration similar to that reached after 2 days. RBC-astaxanthin appeared to be highly variable (group median concentration, 86 nmol/L packed cells). Conclusion: We found high intra- and inter-individual variations, especially in RBC, possibly due to non-standardized time difference between astaxanthin intake and sampling, fluctuating background intake from the diet, variable bioavailability, large distribution volume, degradation or others. Oral astaxanthin is rapidly absorbed and incorporated into RBC. The subsequent rapid decline suggests that, for a higher-than-baseline status, astaxanthin should be taken daily, at least in an early phase when total body equilibrium, if any, has not been reached yet.

In their recent paper, Drs. Turner and Thompson1 question whether the assumption of a Paleolithic life as the human standard is complete because of its “relying primarily on genetic understandings of the human diet.” According to the authors, the Paleolithic assumption focuses too much on “a single model of human ancestral diets” and on “cultural evolution outpacing genetic evolution” as a “fundamental cause of disease in the modern world,” thereby “resulting in an incomplete view of the flexibility and variability in human dietary behavior and health in the past and present.” We would like to comment on several statements of Drs. Turner and Thompson as follows: 1. Despite the “incomplete view,” all interventions with a Paleolithic-type diet have shown favorable effects, as also noted by the authors, and were even superior to Mediterranean and diabetic diets with regard to cardiovascular disease risk factors, glucose tolerance, and appetite and body weight regulation.2–6 2. A basic misunderstanding may come from the following sentence: “Fetal imprinting and other epigenetic processes during development underscore the importance of the fetal environment in shaping long-term body composition and metabolic health …