Scoping review of Paleolithic dietary patterns: a definition proposal

Adherence to Healthy Dietary Patterns and Glioma: A Matched Case-Control Study

Recent studies have revealed a putative relationship between diet and glioma development and prognosis, but few studies have examined the association between overall diet and glioma risk. This study, conducted in China, employed a hospital-based case-control approach. The researchers utilized an a priori method based on dietary data to evaluate compliance scores for five healthy dietary patterns (the Mediterranean diet, the Dietary Approaches to Stop Hypertension (DASH) diet, the Mediterranean-DASH diet Intervention for Neurodegenerative Delay (MIND) diet, the Paleolithic diet, and the Planetary Health Diet) in 1012 participants. At the same time, data-driven methods were used to explore the association between dietary patterns and glioma via principal component analysis (PCA). In the multivariate model, adhering to the Mediterranean diet (odds ratio (OR) = 0.29; 95% confidence interval (95% CI): 0.17-0.52), the DASH diet (OR = 0.09; 95% CI: 0.04-0.18), the MIND diet (OR = 0.25; 95% CI: 0.14-0.44), and the Paleolithic diet (OR = 0.13; 95% CI: 0.06-0.25) was associated with a reduced glioma risk. The results of PCA suggested that increasing the intake of plant-based foods and fish and limiting foods rich in carbohydrates, fats, and salts were associated with a reduced glioma risk. There was a substantial nonlinear dose-response association between glioma and the Mediterranean diet score. However, the DASH diet score, the MIND diet score, and the Paleolithic diet score exhibited linear dose-response relationships. Therefore, this study finds that dietary patterns may be an influencing factor for glioma risk.

The Effects of the Paleo Diet on Autoimmune Thyroid Disease: A Mixed Methods Review

The aim of this systematic review was to examine the characteristics of Paleolithic diet (PD) interventions designed for adult patients with autoimmune thyroid disease (AITD) in order to determine if diet elements have the potential to successfully reduce thyroid antibodies (Ab) such as thyroglobulin (Tg), thyroid peroxidase (TPO), and thyroid stimulating hormone receptor (TSHR), and improve thyroid hormones (thyroxine (T4), triiodothyronine (T3) and thyroid stimulating hormone (TSH)) or resolve AITD pathogenesis. Randomized controlled trials (RCTs) with an adult population of 18 years and older, diagnosed with Hashimoto's thyroiditis (HT) or Graves' disease (GD) (Basedow's), who were placed on a diet of Paleolithic or ancestral nature, and achieved reduction of AITD Abs, improvement of thyroid hormones, and, or resolution of AITD were searched. Various electronic databases were used. Bias was assessed using critical appraisal tools from the Scottish Intercollegiate Guidelines Network (SIGN) and Joanna Briggs Institute (JBI). Studies were excluded according to exclusion criteria and results analyzed. One randomized controlled trial (RCT), a pilot study, and six case studies were found. In total, eight AITD studies focusing on Paleolithic or ancestral interventions were located. In highlight, females were the predominant gender. Case studies solely focused on AITD with protocols ranging from 8-60 weeks. All studies showed clinical improvements, one had significant improvement, two showed AITD resolution. After structured evaluation of nutritional interventions utilizing the PD on the effects of AITD, it was concluded foods of ancestral nature along with the addition of specific supplements, food components, exercise and mindfulness meditation, and exclusion of modern day foods have a considerable impact on thyroid Ab and hormones. The relevant studies suggest while this dietary protocol can be useful in clinical practice, larger-scale studies need to be conducted. Key teaching pointsThere are currently no dietary interventions recommended for the treatment of autoimmune thyroid disease. The Paleo diet has been documented to improve AITD antibodies and thyroid hormones in both Hashimoto's thyroiditis and Graves' disease.The Paleo diet can provide a natural source of nutrients similar to supplemental nutrients that have shown positive results on AITD.The paleo diet provides specific macronutrient percentages that may be beneficial in reducing AITD antibodies, while improving thyroid hormones.Methylation supplementation may be useful in AITD cases.

Circadian Oscillations of Minimal Erythema Dose (MED) are Also Influenced by Diet in Patients with Psoriasis: A Chronomedical Study

INTRODUCTION

Minimal erythema dose (MED) remains a parameter of paramount importance to orient narrow-band (NB)-UVB phototherapy in psoriatic (PsO) patients. Recently, circadian rhythm and diet were recognized as potential MED modulators, but their mutual interaction remains understudied. Thus, we aimed to evaluate the potential diet modulation of MED circadian oscillations.

METHODS

In the first phase, a cohort study was performed comparing potential MED oscillations (morning, afternoon, and evening) among omnivorous psoriatic patients before and after a phototherapy cycle and omnivorous healthy controls. The two groups were age-, gender-, skin-type-, MED-, and diet-matched. Then, in the second phase, another cohort study was carried out comparing MED oscillations 24 h after the last phototherapeutic session only in psoriatic patients cleared with NB-UVB and undergoing different diets (vegan, vegetarian, paleo , ketogenic, intermittent circadian fasting, and omnivore). Patients with different diets were age-, gender-, and skin-type matched.

RESULTS

In the first phase, we enrolled only omnivores, specifically 54 PsO patients and 54 healthy individuals. Their MED before and after NB-UVB therapy changed significantly among the three different time-points (morning, afternoon, and evening) (p < 0.001). The time effect was statistically significant in both groups before and after phototherapy. In the second phase, we enrolled 144 PsO patients (vegan, vegetarian, paleo, ketogenic, intermittent circadian fasting, and omnivore). MED circadian oscillations preserved a significant difference also after clearance and were influenced by diet type and time of day (p < 0.001). In particular, vegans displayed the lowest MED values, whilst Ramadan fasting showed the highest values in morning, afternoon, and evening.

CONCLUSIONS

Diet, like other ongoing therapies, should be reported in the medical records of patients with psoriasis undergoing NB-UVB and patients with lower MEDs should be preferentially treated in the morning when the MED is higher.

Dietary Patterns and Non-Communicable Disease Biomarkers: A Network Meta-Analysis and Nutritional Geometry Approach

Quantitative rankings of multiple dietary patterns for their effects on non-communicable disease (NCD) biomarkers is lacking and would inform primary prevention strategies. Accordingly, a network meta-analysis (NMA) was conducted to compare and rank the effects of different dietary patterns on NCD biomarkers, and associations of dietary patterns’ underlying macronutrient composition with NCD biomarkers were determined by a nutritional geometry approach. Randomised controlled trials (RCTs) were eligible for inclusion if they enrolled healthy participants, employed food-based dietary pattern interventions without energy restriction, and reported NCD biomarker outcomes. NCD biomarkers were included as an outcome if ≥10 trials were available. A systematic search of five electronic databases identified 4008 records. Sixty-eight articles from 59 RCTs reporting lipids, glycemic, and inflammatory biomarkers were included for quantitative syntheses. Risk-of-bias was predominantly categorized as low or having some concerns, and confidence-of-evidence low. Relative to western habitual diet, the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), dietary guidelines-based, plant-based, and low-fat diets reduced low-density lipoprotein cholesterol (mean difference range: −0.29 to −0.17 mmol/L), total cholesterol (−0.36 to −0.24 mmol/L), and apolipoprotein B (−0.11 to −0.07 g/L) (all p < 0.05); the Paleo, plant-based and dietary guidelines-based diets reduced homeostasis model assessment of insulin resistance (−0.95 to −0.35, all p < 0.05). No dietary pattern ranked consistently highest. The Paleo diet received the highest all-outcomes-combined average Surface Under the Cumulative Ranking Curve value (67%), followed by DASH (62%) and Mediterranean diets (57%), whereas western habitual diet was lowest (36%). Our findings were independent of macronutrient composition, highlighting the significance of dietary pattern-level analysis.

Feeding the Brain: Effect of Nutrients on Cognition, Synaptic Function, and AMPA Receptors

In recent decades, traditional eating habits have been replaced by a more globalized diet, rich in saturated fatty acids and simple sugars. Extensive evidence shows that these dietary factors contribute to cognitive health impairment as well as increase the incidence of metabolic diseases such as obesity and diabetes. However, how these nutrients modulate synaptic function and neuroplasticity is poorly understood. We review the Western, ketogenic, and paleolithic diets for their effects on cognition and correlations with synaptic changes, focusing mainly (but not exclusively) on animal model studies aimed at tracing molecular alterations that may contribute to impaired human cognition. We observe that memory and learning deficits mediated by high-fat/high-sugar diets, even over short exposure times, are associated with reduced arborization, widened synaptic cleft, narrowed post-synaptic zone, and decreased activity-dependent synaptic plasticity in the hippocampus, and also observe that these alterations correlate with deregulation of the AMPA-type glutamate ionotropic receptors (AMPARs) that are crucial to neuroplasticity. Furthermore, we explored which diet-mediated mechanisms modulate synaptic AMPARs and whether certain supplements or nutritional interventions could reverse deleterious effects, contributing to improved learning and memory in older people and patients with Alzheimer’s disease.

Associations of the Paleolithic Diet Pattern Scores and the Risk of Breast Cancer among Adults: A Case-Control Study

Evidence suggests the role of changing traditional lifestyle patterns such as Paleolithic to modern lifestyle in the incidence and epidemic of chronic diseases. Thus, this study aimed to investigate the association between Paleolithic diet (PD) and risk of Breast Cancer (BC) in adult Iranian women. This matched case-control study included 253 women with BC and 267 healthy women aged >18 years. PD score was evaluated using a validated 168-item quantitative food frequency questionnaire. Conditional logistic regression model was used to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs), and dose-response was investigated. Mean of PD score was 39.00 ± 6.39. Among the food groups of the PD components, BC patients significantly had lower consumption of healthy food groups as vegetables, fruits, fish, and nuts, higher intakes of sugar-sweetened beverages as well as grains and starches. After adjustment for potential confounders, comparing the highest quartile of PD scores with the lowest quartile, a decrease in the risk of BC was observed for all women (OR: 0.26; 95% CI: 0.13-0.53), as well as those premenopausal (OR: 0.29; 95% CI: 0.11), and postmenopausal (OR: 0.17; 95% CI: 0.05 - 0.56). Our findings show that adherence to the PD pattern significantly reduces the risk of BC in the population studied. However, prospective studies are needed to further investigate this association.

Adherence to a Paleolithic Diet in Combination With Lifestyle Factors Reduces the Risk for the Presence of Non-Alcoholic Fatty Liver Disease: A Case-Control Study

Background

Evidence suggests the role of changing traditional lifestyle patterns, such as Paleolithic, to the modern lifestyle in the incidence and epidemic of chronic diseases. The purpose of this study was to investigate the associations between the Paleolithic diet (PD) and the Paleolithic-like lifestyle and the risk of non-alcoholic fatty liver disease (NAFLD) among an adult population.

Materials and Methods

This case-control study was carried out among 206 patients with NAFLD and 306 healthy subjects aged >18 years. PD score was evaluated using a validated 168-item quantitative food frequency questionnaire. In addition, to calculate the Paleolithic-like lifestyle score, the components of physical activity, body mass index (BMI), and smoking status of the participants were combined with the score of the PD.

Results

The mean PD and Paleolithic-like lifestyle scores were 38.11 ± 5.63 and 48.92 ± 6.45, respectively. After adjustment for potential confounders, higher scores of adherence to the PD diet conferred a protection for the presence of NAFLD [odds ratio (OR): 0.53; 95% confidence interval (CI): 0.28–0.98; P for trend = 0.021]. Furthermore, PD and healthy lifestyle habits were negatively associated with NAFLD (OR = 0.42, 95% CI 0.23–0.78; P for trend = 0.007).

Conclusion

Our data suggest that the PD alone and in combination with lifestyle factors was associated with decreased risk of NAFLD in a significant manner in the overall population. However, prospective studies are needed to further investigate this association.

A score appraising Paleolithic diet and the risk of cardiovascular disease in a Mediterranean prospective cohort

Purpose

To assess the association between a score appraising adherence to the PaleoDiet and the risk of cardiovascular disease (CVD) in a Mediterranean cohort.

Methods

We included 18,210 participants from the Seguimiento Universidad de Navarra (SUN) cohort study. The PaleoDiet score comprised six food groups promoted within this diet (fruit, nuts, vegetables, eggs, meat and fish) and five food groups whose consumption is discouraged (cereals and grains, dairy products, legumes, culinary ingredients, and processed/ultra-processed foods). CVD was defined as acute myocardial infarction with or without ST elevation, non-fatal stroke and cardiovascular death. Cox proportional hazards models adjusted for potential confounders were fitted to assess the association between the PaleoDiet score and CVD risk, and the PaleoDiet and MedDiet indices to explore differences between both diets.

Results

During 12.2 years of follow-up, 165 incident CVD cases were confirmed. A significant inverse association was found between the PaleoDiet score and CVD (HR Q5 vs. Q1: 0.45, 95% CI 0.27–0.76, P for trend = 0.007). A weaker association that became non-significant was observed when the item for low consumption of ultra-processed foods was removed from the score. Joint analysis of PaleoDiet and MedDiet Trichopoulou scores suggested that the inverse association between PaleoDiet and CVD was mainly present when adherence to the MedDiet was also high (HR for high adherence vs low adherence to both diet scores: 0.22, 95% CI 0.08–0.64).

Conclusions

Our findings suggest that the PaleoDiet may have cardiovascular benefits in participants from a Mediterranean country. Avoidance of ultra-processed foods seems to play a key role in this inverse association.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02696-9.

Mediterranean Diet to Prevent the Development of Colon Diseases: A Meta-Analysis of Gut Microbiota Studies

Gut microbiota dysbiosis is a common feature in colorectal cancer (CRC) and inflammatory bowel diseases (IBD). Adoption of the Mediterranean diet (MD) has been proposed as a therapeutic approach for the prevention of multiple diseases, and one of its mechanisms of action is the modulation of the microbiota. We aimed to determine whether MD can be used as a preventive measure against cancer and inflammation-related diseases of the gut, based on its capacity to modulate the local microbiota. A joint meta-analysis of publicly available 16S data derived from subjects following MD or other diets and from patients with CRC, IBD, or other gut-related diseases was conducted. We observed that the microbiota associated with MD was enriched in bacteria that promote an anti-inflammatory environment but low in taxa with pro-inflammatory properties capable of altering intestinal barrier functions. We found an opposite trend in patients with intestinal diseases, including cancer. Some of these differences were maintained even when MD was compared to healthy controls without a defined diet. Our findings highlight the unique effects of MD on the gut microbiota and suggest that integrating MD principles into a person’s lifestyle may serve as a preventive method against cancer and other gut-related diseases.

Short-term effects of a Paleolithic lifestyle intervention in breast cancer patients undergoing radiotherapy: a pilot and feasibility study

Evolutionary principles are rarely considered in clinical oncology. We here aimed to test the feasibility and effects of a dietary and physical activity intervention based on evolutionary considerations in an oncological setting. A total of 13 breast cancer patients referred to our clinic for curative radiotherapy were recruited for this pilot study. The women were supposed to undertake a "Paleolithic lifestyle" (PL) intervention consisting of a Paleolithic diet and daily outdoor activity of at least 30 min duration while undergoing radiotherapy. Body composition was measured weekly by bioimpedance analysis. Blood parameters were assessed before, during, and at the end of radiotherapy. A control group on an unspecified standard diet (SD) was assigned by propensity score matching. A total of eleven patients completed the study. The majority of patients (64%) reported feeling good or very good during the intervention. The intervention group experienced an average decrease of 0.4 kg body weight (p < 0.001) and 0.34 kg (p < 0.001) fat mass per week, but fat-free and skeletal muscle mass were not significantly affected. Vitamin D levels increased slightly from 23.8 (11-37.3) ng/ml to 25.1 (22.6-41.6) ng/ml (p = 0.053). β-hydroxybutyrate levels were significantly increased and triglycerides and free T3 hormone levels significantly reduced by the PL intervention. This pilot study shows that adoption of a PL intervention during curative radiotherapy of breast cancer patients is feasible and able to reduce fat mass. Daily outdoor activity could eliminate vitamin D deficiency (vitamin D < 20 ng/ml). Future studies are needed to confirm these findings.