Effect of a 21 day Daniel Fast on metabolic and cardiovascular disease risk factors in men and women

The effect of observing religious or faith-based fasting on cardiovascular disease risk factors: A systematic review and meta-analysis

AIMS

Cardiovascular diseases (CVD) are the leading cause of death worldwide. Fasting is common in many religions and is associated with health benefits. This systematic review to compares the impact of different religious fasting practices, on risk of cardiometabolic diseases.

DATA SYNTHESIS

The search covered five databases following PRISMA guidelines to identify papers published in English from inception to March 2023 (updated January 2024). Inclusion criteria were healthy adults in observational studies, who engaged in religious fasting practices, studies were included where data on matched non-fasting individuals was available. Outcomes were systolic and diastolic blood pressure, body mass index (BMI), triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDLc), high-density lipoprotein cholesterol (HDLc), and fasting plasma glucose levels. A meta-analysis was conducted, and the review was registered (CRD42022352197). Fourteen studies were met the inclusion criteria with ten studies data being suitable for meta-analysis, reporting on 755 adults participating in fasting practices and 661 non-fasting controls. Religious fasting was associated with a reduction in BMI (-0.40 kg/m2, 95% CI [-0.70, -0.10], p < 0.01). Observance of Ramadan fasting was associated with decreased systolic blood pressure (-3.83  mmHg, 95% CI [-7.44, -0.23], p = 0.04). The observance of Orthodox Christian fasting was associated with a reduction in TC (-0.52 mmoL/l, 95%CI [-0.64, -0.39], p < 0.01). No difference was found for the other outcomes.

CONCLUSION

This review found religious fasting practices which were associated with a reduction in some biomarkers of cardiometabolic diseases risk. Further research on other fasting practices is needed due to limited data.

Religious fasting and its impacts on individual, public, and planetary health: Fasting as a "religious health asset" for a healthier, more equitable, and sustainable society

Religious fasting is practiced by people of all faiths, including Christianity, Islam, Buddhism, Jainism, as well as Hinduism, Judaism, and Taoism. Individual/clinical, public, global, and planetary health has traditionally been studied as separate entities. Nevertheless, religious fasting, in conjunction with other religious health assets, can provide several opportunities, ranging from the individual to the population, environmental, and planetary levels, by facilitating and supporting societal transformations and changes, such as the adoption of healthier, more equitable, and sustainable lifestyles, therein preserving the Earth's systems and addressing major interconnected, cascading, and compound challenges. In this review, we will summarize the most recent evidence on the effects of religious fasting, particularly Orthodox and Ramadan Islamic fasting, on human and public health. Further, we will explore the potential effects of religious fasting on tackling current environmental issues, with a special focus on nutrition/food restriction and planetary health. Finally, specific recommendations, particularly around dietary intake during the fasting rituals, will be provided to ensure a sustainable healthy planet.

Fasting: How to Guide

Fasting potentials are the most interesting topics in the Nutritional Era. Fasting consists of the catabolism of lipids, proteins, and carbohydrates to maintain blood glucose levels in a normal range. The action mechanisms of fasting were firstly understood in minor organisms and later in humans. Nutritional interventions of caloric restriction could attenuate age-associated epigenetic alterations and could have a protective effect against cellular alterations, promoting longevity and health span. While most fasting studies point out the weight and fat mass decreases, it is important to define specific guidelines for fasting and non-fasting days to enhance adherence, minimize the dropout rates of the interventions, and maximize body composition improvement. Although the panorama of evidence on fasting and caloric restriction is wide, there is a lack of a safe fasting protocol to guide physicians in its prescription. The main goal is to identify a how to use guide, a major posology of fasting, inserted within a huge dietetic personalized strategy leading to an optimal and healthy nutritional status.

Spiritually motivated restrictions on animal products have a limited impact on consumption of healthy plant-based foods

Plant-based diets are considered healthier than many omnivorous diets. However, it is unclear that restriction of animal products necessarily motivates increased consumption of nutrient- and fibre-rich plant-based foods as opposed to energy-dense but nutrient-poor plant-based foods containing refined grains and added sugars and fats. The present study examined FFQ and food record data from ninety-nine individuals in the USA with varying degrees of adherence to the Orthodox Christian tradition of restricting meat, dairy and egg (MDE) products for 48 d prior to Easter to investigate whether restricting MDE products in the absence of explicit nutritional guidance would lead to increased consumption of healthy plant-based foods and greater likelihood of meeting dietary recommendations. Multiple linear regression models assessed changes in major food groups, energy and nutrients in relation to the degree of reduction in MDE consumption. Logistic regression analyses tested the odds of meeting 2015-2020 Dietary Guidelines for Americans on plant-based foods in relation to MDE restriction. Each serving reduction in MDE products was associated with small (approximately 0·1-0·7 serving) increases in legumes, soya products and nuts/seeds (all P values < 0·005). MDE restriction was not associated with higher odds of meeting recommendations on vegetable, fruit or whole-grain intake. Consumption of refined grains and added sugars did not change in relation to MDE restriction but remained above recommended thresholds, on average. These findings demonstrate that a reduction of MDE products for spiritual purposes may result in increases in some nutrient-rich plant-based foods but may not uniformly lead to a healthier dietary composition.

A Comparison of Dietary and Caloric Restriction Models on Body Composition, Physical Performance, and Metabolic Health in Young Mice

Time-restricted feeding (TRF), alternate day fasting (ADF), and the dietary restriction model known as the Daniel Fast (DF; a vegan/non-processed food diet plan) have garnered attention recently as nutritional interventions to combat obesity. We compared the effects of various dietary models on body composition, physical performance, and metabolic health in C57BL/6 mice. Sixty young C57BL/6 male mice were assigned a diet of TRF, ADF, DF, caloric restriction (CR), a high-fat Western diet (HF) fed ad libitum, or standard rodent chow for eight weeks. Their body composition, run time to exhaustion, fasting glucose, insulin, and glucose tolerance test area under the glucose curve (AUC) were determined. Compared to the HF group, all groups displayed significantly less weight and fat mass gain, as well as non-significant changes in fat-free mass. Additionally, although not statistically significant, all groups displayed greater run time to exhaustion relative to the HF group. Compared to the HF group, all groups demonstrated significantly lower fasting glucose, insulin, and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), as well as improved glucose tolerance, and the ADF group displayed the best fasting glucose and glucose tolerance results, with DF having the best HOMA-IR. All investigated fasting protocols may improve body composition, measures of insulin sensitivity, and physical performance compared to a high-fat Western diet. The DF and ADF protocols are most favorable with regards to insulin sensitivity and glucose tolerance. Since our selected dietary protocols have also been investigated in humans with success, it is plausible to consider that these dietary models could prove beneficial to men and women seeking improved body composition and metabolic health.

Nutrient Intake and Physical Exercise Significantly Impact Physical Performance, Body Composition, Blood Lipids, Oxidative Stress, and Inflammation in Male Rats

BACKGROUND

Humans consuming a purified vegan diet known as the "Daniel Fast" realize favorable changes in blood lipids, oxidative stress, and inflammatory biomarkers, with subjective reports of improved physical capacity.

OBJECTIVE

We sought to determine if this purified vegan diet was synergistic with exercise in male rats.

METHODS

Long⁻Evans rats (n = 56) were assigned to be exercise trained (+E) by running on a treadmill three days per week at a moderate intensity or to act as sedentary controls with normal activity. After the baseline physical performance was evaluated by recording run time to exhaustion, half of the animals in each group were fed ad libitum for three months a purified diet formulated to mimic the Daniel Fast (DF) or a Western Diet (WD). Physical performance was evaluated again at the end of month 3, and body composition was assessed using dual-energy x-ray absorptiometry. Blood was collected for measurements of lipids, oxidative stress, and inflammatory biomarkers.

RESULTS

Physical performance at the end of month 3 was higher compared to baseline for both exercise groups (p < 0.05), with a greater percent increase in the DF + E group (99%) than in the WD + E group (51%). Body fat was lower in DF than in WD groups at the end of month 3 (p < 0.05). Blood triglycerides, cholesterol, malondialdehyde, and advanced oxidation protein products were significantly lower in the DF groups than in the WD groups (p < 0.05). No significant differences were noted in cytokines levels between the groups (p > 0.05), although IL-1β and IL-10 were elevated three-fold and two-fold in the rats fed the WD compared to the DF rats, respectively.

CONCLUSIONS

Compared to a WD, a purified diet that mimics the vegan Daniel Fast provides significant anthropometric and metabolic benefits to rats, while possibly acting synergistically with exercise training to improve physical performance. These findings highlight the importance of macronutrient composition and quality in the presence of ad libitum food intake.

From Religion to Secularism: the Benefits of Fasting

PURPOSE OF REVIEW

Since the early development of human societies, religious beliefs, and practices has been integral to their identity, culture, and social structure, traditions are influenced by the area, era, and culture wherein they developed. Some religions offer advice on behavioral and diet modifications as strategies to fortify the body, purify the spirit, and elevate consciousness. This review is an attempt to compare different practices, describe the health benefits and risks of fasting, and reconcile these age-old recommendations with practical modern life.

RECENT FINDINGS

Research to clarify and quantify the impact of these dietary modifications is challenging due to the variability in recommendations among various religions and in day-to-day practices. Most religions share common goals of well-being, body-mind integration, and spiritual attainment. Historically, the transformational power of fasting periods has been appreciated, but there is still much to discover about the underlying beneficial physiologic mechanisms of fasting in preventing and treating metabolic diseases.

A defined, plant-based diet utilized in an outpatient cardiovascular clinic effectively treats hypercholesterolemia and hypertension and reduces medications

BACKGROUND

Cardiovascular disease (CVD) is a major economic burden in the United States. CVD risk factors, particularly hypertension and hypercholesterolemia, are typically treated with drug therapy. Five-year efficacy of such drugs to prevent CVD is estimated to be 5%. Plant-based diets have emerged as effective mitigators of these risk factors.

HYPOTHESIS

The implementation of a defined, plant-based diet for 4 weeks in an outpatient clinical setting may mitigate CVD risk factors and reduce patient drug burden.

METHODS

Participants consumed a plant-based diet consisting of foods prepared in a defined method in accordance with a food-classification system. Participants consumed raw fruits, vegetables, seeds, and avocado. All animal products were excluded from the diet. Participant anthropometric and hemodynamic data were obtained weekly for 4 weeks. Laboratory biomarkers were collected at baseline and at 4 weeks. Medication needs were assessed weekly. Data were analyzed using paired-samples t tests and 1-way repeated-measures ANOVA.

RESULTS

Significant reductions were observed for systolic (-16.6 mmHg) and diastolic (-9.1 mmHg) blood pressure (P < 0.0005), serum lipids (P ≤ 0.008), and total medication usage (P < 0.0005). Other CVD risk factors, including weight (P < 0.0005), waist circumference (P < 0.0005), heart rate (P = 0.018), insulin (P < 0.0005), glycated hemoglobin (P = 0.002), and high-sensitivity C-reactive protein (P = 0.001) were also reduced.

CONCLUSION

A defined, plant-based diet can be used as an effective therapeutic strategy in the clinical setting to mitigate cardiovascular risk factors and reduce patient drug burden.

A 40-Day Journey to Better Health: Utilizing the DanielFast to Improve Health Outcomes in Urban Church-Based Settings

Background: As the costs associated with obesity increase, it is vital to evaluate the effectiveness of chronic disease prevention among underserved groups, particularly in urban settings. This research study evaluated Philadelphia area Keystone First members and church participants enrolled in a group health education program to determine the impact of the Daniel Fast on physical health and the adoption of healthy behaviors. Methods: Participants attended six-weekly health education sessions in two participating churches, and were provided with a digital healthy eating platform. Results: There was a statistically significant decrease from baseline to post assessment for weight, waist circumference and cholesterol. Participants reported a significant improvement in their overall well-being, social and physical functioning, vitality and mental health. Conclusion: Results of this study demonstrate that dietary recommendations and comprehensive group health education delivered in churches and reinforced on a digital platform can improve physical health, knowledge and psychosocial outcomes.

Linking dietary patterns with gut microbial composition and function

Emerging insights have implicated the gut microbiota as an important factor in the maintenance of human health. Although nutrition research has focused on how direct interactions between dietary components and host systems influence human health, it is becoming increasingly important to consider nutrient effects on the gut microbiome for a more complete picture. Understanding nutrient-host-microbiome interactions promises to reveal novel mechanisms of disease etiology and progression, offers new disease prevention strategies and therapeutic possibilities, and may mandate alternative criteria to evaluate the safety of food ingredients. Here we review the current literature on diet effects on the microbiome and the generation of microbial metabolites of dietary constituents that may influence human health. We conclude with a discussion of the relevance of these studies to nutrition and public health and summarize further research needs required to realize the potential of exploiting diet-microbiota interactions for improved health.

Intestinal adaptations to a combination of different diets with and without endurance exercise

Background

Endurance athletes search for diet regimens that will improve performance and decrease gastrointestinal disturbances during training and events. Although the intestine can adapt to changes in the amount and composition of dietary inputs, the responses to the combination of endurance exercise and diet are poorly understood.

Methods

We evaluated small intestinal dimensions and mucosal architecture and calculated the capacities of the entire small intestine to digest maltose and maltodextrin and absorb glucose in response to two different diet types; a western human diet and the Daniel Fast, a vegan style diet, and with moderate intensity endurance training or a no-exercise sedentary lifestyle for a 13 week period (n = 7 per group). The influences of diet and exercise, alone and in combination, were analyzed by analysis of variation.

Results

Rats fed the western diet gained more weight (P < 0.05) due to more fat mass (P < 0.05), with a similar response for the sedentary compared with the exercised rats in each diet group (P < 0.05). The Daniel Fast rats had longer and heavier intestines with deeper crypts with villi that were wider (P < 0.05), but not taller. Despite increased energetic demands, the exercised rats had shorter and lighter intestines with shorter villi (P < 0.05). Yet, the percentage of mucosa did not differ among groups. Total small intestinal activities for maltase and α-glucoamylase, and capacities for glucose absorption were similar regardless of diet or exercise.

Conclusions

These findings indicate the structural responses of the small intestine to a vegan style diet are modified by exercise, but without altering the capacities of the brush border membrane to digest and absorb carbohydrates.

Electronic supplementary material

The online version of this article (doi:10.1186/s12970-016-0147-6) contains supplementary material, which is available to authorized users.

The moderate essential amino acid restriction entailed by low-protein vegan diets may promote vascular health by stimulating FGF21 secretion

The serum total and LDL cholesterol levels of long-term vegans tend to be very low. The characteristically low ratio of saturated to unsaturated fat in vegan diets, and the absence of cholesterol in such diets, clearly contribute to this effect. But there is reason to suspect that the quantity and composition of dietary protein also play a role in this regard. Vegan diets of moderate protein intake tend to be relatively low in certain essential amino acids, and as a result may increase hepatic activity of the kinase GCN2, which functions as a gauge of amino acid status. GCN2 activation boosts the liver's production of fibroblast growth factor 21 (FGF21), a factor which favorably affects serum lipids and metabolic syndrome. The ability of FGF21 to decrease LDL cholesterol has now been traced to at least two mechanisms: a suppression of hepatocyte expression of sterol response element-binding protein-2 (SREBP-2), which in turn leads to a reduction in cholesterol synthesis; and up-regulated expression of hepatocyte LDL receptors, reflecting inhibition of a mechanism that promotes proteasomal degradation of these receptors. In mice, the vascular benefits of FGF21 are also mediated by favorable effects on adipocyte function - most notably, increased adipocyte secretion of adiponectin, which directly exerts anti-inflammatory effects on the vasculature which complement the concurrent reduction in LDL particles in preventing or reversing atherosclerosis. If, as has been proposed, plant proteins preferentially stimulate glucagon secretion owing to their amino acid composition, this would represent an additional mechanism whereby plant protein promotes FGF21 activity, as glucagon acts on the liver to boost transcription of the FGF21 gene.

Comparison of a Restricted and Unrestricted Vegan Diet Plan with a Restricted Omnivorous Diet Plan on Health-Specific Measures

Background: We have previously noted beneficial health outcomes when individuals follow a dietary restriction plan in accordance with the Daniel Fast (DF). This is true whether individuals eliminate all animal products or include small amounts of meat and dairy in their plan. The present study sought to compare anthropometric and biochemical measures of health in individuals following a traditional DF (i.e., restricted vegan) or modified DF (i.e., restricted omnivorous; inclusive of ad libitum meat and skim milk consumption), with those following an unrestricted vegan diet plan. Methods: 35 subjects (six men; 29 women; 33 ± 2 years; range: 18–67 years) completed a 21-day diet plan. Subjects reported to the lab for pre- (day 1) and post-intervention testing (day 22) in a 10 h fasted state. Blood samples were collected and assayed for complete blood count, metabolic panel, lipid panel, insulin, HOMA-IR, C-reactive protein, and oxidative stress biomarkers (malondialdehyde, advanced oxidation protein products, and nitrate/nitrite). Heart rate and blood pressure were measured and body composition was determined via dual energy X-ray absorptiometry. Subjects’ self-reported compliance, mental and physical health, and satiety in relation to the dietary modification were recorded. Results: No interaction effects were noted for our outcome measures (p > 0.05). However, subjects in the traditional DF group reported an approximate 10% increase in perceived mental and physical health, with a 25% reduction in malondialdehyde and a 33% reduction in blood insulin. Systolic BP was reduced approximately 7 mmHg in subjects assigned to the traditional DF, with an approximate 5 mmHg reduction in subjects assigned to the modified DF and the unrestricted vegan plan. A small (2 mmHg) reduction in diastolic BP was noted for subjects in both DF groups; a slight increase in diastolic BP was noted for subjects assigned to the unrestricted vegan group. An approximate 20% reduction was noted in total and LDL cholesterol for subjects in the traditional DF group, with an approximate 10% decrease for subjects in the modified DF group. No decrease in total or LDL cholesterol was noted for subjects in the unrestricted vegan group. Conclusion: These data indicate that both a traditional or modified DF may improve blood pressure and blood lipids in a clinically meaningful manner if these results are sustained over the long term. A traditional DF also results in a significant reduction in blood insulin and oxidative stress. An unrestricted vegan diet may improve systolic blood pressure, but in the absence of measures to strictly monitor adherence, it does not favorably impact other markers of health measured in the present study.

Medicinal chemistry of the epigenetic diet and caloric restriction

The pronounced effects of the epigenetic diet (ED) and caloric restriction (CR) have on epigenetic gene regulation have been documented in many pre-clinical and clinical studies. Understanding epigenetics is of high importance because of the concept that external factors such as nutrition and diet may possess the ability to alter gene expression without modifying the DNA sequence. The ED introduces bioactive medicinal chemistry compounds such as sulforaphane (SFN), curcumin (CCM), epigallocatechin gallate (EGCG) and resveratrol (RSV) that are thought to aid in extending the human lifespan. CR, although similar to ED in the target of longevity, mildly reduces the total daily calorie intake while concurrently providing all beneficial nutrients. Both CR and ED may act as epigenetic modifiers to slow the aging process through histone modification, DNA methylation, and by modulating microRNA expression. CR and ED have been proposed as two important mechanisms that modulate and potentially slow the progression of age-related diseases such as cardiovascular disease (CVD), cancer, obesity, Alzheimer's and osteoporosis to name a few. While many investigators have examined CR and ED as separate entities, this review will primarily focus on both as they relate to age-related diseases, their epigenetic effects and their medicinal chemistry.

Do Ramadan fasting restrictions alter eating behaviours in obese women?

Ramadan fasting can be considered as a kind of dietary restriction. Eating restriction is a risk factor for later development of eating disorders. The purpose of this study is to evaluate whether Ramadan fasting changes the eating behaviours of obese women. Our sample consisted of 34 obese women who fasted during the Ramadan month. The data were collected by using Questionnaire Form, Eating Attitude Test (EAT) and Bulimic Investigatory Test, Edinburgh (BITE). No statistically significant differences were found between the scores of EAT, BITE, BMI, which were administered within the weeks before and after Ramadan. According to our results, Ramadan fasting restrictions do not seem to change the eating behaviours of obese women.

Both a traditional and modified Daniel Fast improve the cardio-metabolic profile in men and women

BACKGROUND

The Daniel Fast involves dietary modification similar to a purified vegan diet. Although improvements in several health-specific biomarkers have been noted with this plan, the removal of animal products results in a significant reduction in both dietary protein and saturated fatty acid intake, which results in a loss of lean body mass and a reduction in HDL-cholesterol.

METHODS

We assigned 29 men and women to either a traditional or modified Daniel Fast for 21 days and measured anthropometric and biochemical markers of health pre and post intervention. The modified Daniel Fast was otherwise identical to the traditional plan but included one serving per day of lean meat and dairy (skim milk), providing approximately 30 grams per day of additional protein.

RESULTS

Compared to baseline, both plans resulted in similar and significant improvements in blood lipids, as well as a reduction in inflammation.

CONCLUSIONS

Modification of dietary intake in accordance with either a traditional or modified Daniel Fast may improve risk factors for cardiovascular and metabolic disease.

Alternate day fasting and endurance exercise combine to reduce body weight and favorably alter plasma lipids in obese humans

OBJECTIVE

This study examined whether the combination of alternate day fasting (ADF) plus exercise produces superior changes in body composition and plasma lipid levels when compared to each intervention alone.

DESIGN AND METHODS

Obese subjects (n = 64) were randomized to 1 of 4 groups for 12 weeks: 1) combination (ADF plus endurance exercise), 2) ADF, 3) exercise, or 4) control.

RESULTS

Body weight was reduced (P < 0.05) by 6 ± 4 kg, 3 ± 1 kg, and 1 ± 0 kg in the combination, ADF, and exercise groups, respectively. Fat mass and waist circumference decreased (P < 0.001), while lean mass was retained in the combination group. Low-density lipoprotein (LDL) cholesterol decreased (12 ± 5%, P < 0.05) and high-density lipoprotein (HDL) cholesterol increased (18 ± 9%, P < 0.05) in the combination group only. LDL particle size increased (P < 0.001) by 4 ± 1 Å and 5 ± 1 Å in the combination and ADF groups, respectively. The proportion of small HDL particles decreased (P < 0.01) in the combination group only.

CONCLUSIONS

These findings suggest that the combination produces superior changes in body weight, body composition, and lipid indicators of heart disease risk, when compared to individual treatments.

A 21-day Daniel fast with or without krill oil supplementation improves anthropometric parameters and the cardiometabolic profile in men and women

BACKGROUND

The Daniel Fast is a vegan diet that prohibits the consumption of animal products, refined foods, white flour, preservatives, additives, sweeteners, flavorings, caffeine, and alcohol. Following this dietary plan for 21 days has been demonstrated to improve blood pressure, LDL-C, and certain markers of oxidative stress, but it has also been shown to lower HDL-C. Krill oil supplementation has been shown to increase HDL-C.

METHODS

We investigated the effects of following a Daniel Fast dietary plan with either krill oil supplementation (2 g/day) or placebo supplementation (coconut oil; 2 g/day) for 21 days. The subjects in this study (12 men and 27 women) were heterogeneous with respect to body mass index (BMI) (normal weight, overweight, and obese), blood lipids (normolipidemic and hyperlipidemic), blood glucose (normal fasting glucose, impaired fasting glucose, and type 2 diabetic), and blood pressure (normotensive and hypertensive).

RESULTS

Krill oil supplementation had no effect on any outcome measure (all p > 0.05), and so the data from the krill oil group and the placebo group were collapsed and analyzed to examine the effects of following a 21-day Daniel Fast. Significant reductions were observed in LDL-C (100.6 ± 4.3 mg/dL vs. 80.0 ± 3.7 mg/dL), the LDL:HDL ratio (2.0 ± 0.1 vs. 1.7 ± 0.1), fasting blood glucose (101.4 ± 7.5 mg/dL vs. 91.7 ± 3.4 mg/dL), fasting blood insulin (7.92 ± 0.80 μU/mL vs. 5.76 ± 0.59 μU/mL), homeostasis model assessment of insulin resistance (HOMA-IR) (2.06 ± 0.30 vs. 1.40 ± 0.21), systolic BP (110.7 ± 2.2 mm Hg vs. 105.5 ± 1.7 mm Hg), and body weight (74.1 ± 2.4 kg vs. 71.5 ± 2.3 kg) (all p < 0.05).

CONCLUSION

Following a Daniel Fast dietary plan improves a variety of cardiometabolic parameters in a wide range of individuals in as little as 21 days, and these improvements are unaffected by krill oil supplementation.

TRIAL REGISTRATION

Clinicaltrial.govNCT01378767.

Impact of short-term dietary modification on postprandial oxidative stress

Background

We have recently reported that short-term (21-day) dietary modification in accordance with a stringent vegan diet (i.e., a Daniel Fast) lowers blood lipids as well as biomarkers of oxidative stress. However, this work only involved measurements obtained in a fasted state. In the present study, we determined the postprandial response to a high-fat milkshake with regards to blood triglycerides (TAG), biomarkers of oxidative stress, and hemodynamic variables before and following a 21-day Daniel Fast.

Methods

Twenty-two subjects (10 men and 12 women; aged 35 ± 3 years) completed a 21-day Daniel Fast. To induce oxidative stress, a milkshake (fat = 0.8 g·kg^-1; carbohydrate = 1.0 g·kg^-1; protein = 0.25 g·kg^-1) was consumed by subjects on day one and day 22 in a rested and 12-hour fasted state. Before and at 2 and 4 h after consumption of the milkshake, heart rate (HR) and blood pressure were measured. Blood samples were also collected at these times and analyzed for TAG, malondialdehyde (MDA), hydrogen peroxide (H₂O₂), advanced oxidation protein products (AOPP), nitrate/nitrite (NOx), and Trolox Equivalent Antioxidant Capacity (TEAC).

Results

A time effect was noted for HR (p = 0.006), with values higher at 2 hr post intake of the milkshake as compared to pre intake (p < 0.05). Diastolic blood pressure was lower post fast as compared to pre fast (p = 0.02), and a trend for lower systolic blood pressure was noted (p = 0.07). Time effects were noted for TAG (p = 0.001), MDA (p < 0.0001), H₂O₂ (p < 0.0001), AOPP (p < 0.0001), and TEAC (p < 0.0001); all concentrations were higher at 2 h and 4 h post intake compared to pre intake, except for TEAC, which was lower at these times (p < 0.05). A condition effect was noted for NOx (p = 0.02), which was higher post fast as compared to pre fast. No pre/post fast × time interactions were noted (p > 0.05), with the area under the curve from pre to post fast reduced only slightly for TAG (11%), MDA (11%), H₂O₂ (8%), and AOPP (12%), with a 37% increase noted for NOx.

Conclusion

Partaking in a 21-day Daniel Fast does not result in a statistically significant reduction in postprandial oxidative stress. It is possible that a longer time course of adherence to the Daniel Fast eating plan may be needed to observe significant findings.

Can we live longer by eating less? A review of caloric restriction and longevity

Caloric restriction, decreasing caloric intake by 20-30%, was first shown to extend life in rats nearly 80 years ago. Since that time, limiting food intake for longevity has been investigated in species from yeast to humans. In yeast and lower animals, caloric restriction has repeatedly been demonstrated to lengthen the life span. Studies of caloric restriction in non-human primates and in humans are ongoing and initial results suggest prolongation of life as well as prevention of age-related disease. There is also data in rodents suggesting that short term caloric restriction has beneficial effects on fertility. Although caloric restriction has many positive effects on health and longevity, quality of life on a restricted diet as well as the ability to maintain that diet long term are concerns that must be considered in humans.

Biochemical and anthropometric effects of a weight loss dietary supplement in healthy men and women

Background:

We have recently noted an acute increase in circulating free fatty acids and glycerol, as well as resting metabolic rate, when men and women ingested the dietary supplement OxyELITE Pro™ in a single dose. We have also noted a reduction in appetite when subjects were treated with this supplement for 14 consecutive days. It is possible that such findings may favor body weight and fat loss over time. Therefore, the purpose of the present study was to determine the effects of this dietary supplement on weight loss and associated markers using an eight week intervention.

Methods:

Exercise-trained subjects were randomly assigned in double blind manner to ingest either the dietary supplement (n = 16; aged 22.8 ± 0.7) or a placebo (n = 16; 22.5 ± 0.5) every day for eight weeks. Body weight, body composition, skinfold thickness, serum lipids, and appetite were measured as the primary outcome variables. As measures of supplement safety, a complete blood count and comprehensive metabolic panel were performed, and resting heart rate and blood pressure were measured (pre and post intervention).

Results:

No interactions or main effects were noted for our primary outcome measures (P > 0.05). However, when comparing pre and post intervention values for the supplement, significant decreases were noted in appetite, body weight, body fat percentage, and skinfold thickness (P < 0.05), while increases were noted for total and HDL-C, as well as for resting heart rate (P < 0.05). No changes were noted for placebo from pre to post intervention (P > 0.05), with the exception of an increase in HDL-C (P < 0.05). Blood pressure and bloodborne safety variables were not differently impacted by supplement or placebo (P > 0.05), with the exception of monocytes, for which an interaction effect was noted (P = 0.04).

Conclusion:

These data indicate that the dietary supplement OxyELITE Pro™ may assist in weight and body fat loss in a sample of exercise-trained men and women. The supplement does not result in any adverse effects pertaining to resting blood pressure or bloodborne markers of safety; however a small increase in resting heart rate is observed.

Impact of caloric and dietary restriction regimens on markers of health and longevity in humans and animals: a summary of available findings

Considerable interest has been shown in the ability of caloric restriction (CR) to improve multiple parameters of health and to extend lifespan. CR is the reduction of caloric intake - typically by 20 - 40% of ad libitum consumption - while maintaining adequate nutrient intake. Several alternatives to CR exist. CR combined with exercise (CE) consists of both decreased caloric intake and increased caloric expenditure. Alternate-day fasting (ADF) consists of two interchanging days; one day, subjects may consume food ad libitum (sometimes equaling twice the normal intake); on the other day, food is reduced or withheld altogether. Dietary restriction (DR) - restriction of one or more components of intake (typically macronutrients) with minimal to no reduction in total caloric intake - is another alternative to CR. Many religions incorporate one or more forms of food restriction. The following religious fasting periods are featured in this review: 1) Islamic Ramadan; 2) the three principal fasting periods of Greek Orthodox Christianity (Nativity, Lent, and the Assumption); and 3) the Biblical-based Daniel Fast. This review provides a summary of the current state of knowledge related to CR and DR. A specific section is provided that illustrates related work pertaining to religious forms of food restriction. Where available, studies involving both humans and animals are presented. The review includes suggestions for future research pertaining to the topics of discussion.

A 21 day Daniel Fast improves selected biomarkers of antioxidant status and oxidative stress in men and women

BACKGROUND

Dietary modification via both caloric and nutrient restriction is associated with multiple health benefits, some of which are related to an improvement in antioxidant status and a decrease in the production of reactive oxygen species. The Daniel Fast is based on the Biblical book of Daniel, is commonly partaken for 21 days, and involves food intake in accordance with a stringent vegan diet. The purpose of the present study was to determine the effect of a 21 day Daniel Fast on biomarkers of antioxidant status and oxidative stress.

METHODS

43 subjects (13 men; 30 women; 35 ± 1 yrs; range: 20-62 yrs) completed a 21 day Daniel Fast following the guidelines provided by investigators. Subjects reported to the lab in a 12 hour post-absorptive state both pre fast (day 1) and post fast (day 22). At each visit, blood was collected for determination of malondialdehyde (MDA), hydrogen peroxide (H2O2), nitrate/nitrite (NOx), Trolox Equivalent Antioxidant Capacity (TEAC), and Oxygen Radical Absorbance Capacity (ORAC). Subjects recorded dietary intake during the 7 day period immediately prior to the fast and during the final 7 days of the fast.

RESULTS

A decrease was noted in MDA (0.66 ± 0.0.03 vs. 0.56 ± 0.02 μmol L-1; p = 0.004), while H2O2 demonstrated a trend for lowering (4.42 ± 0.32 vs. 3.78 ± 0.21 μmol L-1; p = 0.074). Both NOx (18.79 ± 1.92 vs. 26.97 ± 2.40 μmol L-1; p = 0.003) and TEAC (0.47 ± 0.01 vs. 0.51 ± 0.01 mmol L-1; p = 0.001) increased from pre to post fast, while ORAC was unchanged (5243 ± 103 vs. 5249 ± 183 μmol L-1 TE; p = 0.974). As expected, multiple differences in dietary intake were noted (p < 0.05), including a reduction in total calorie intake (2185 ± 94 vs. 1722 ± 85).

CONCLUSION

Modification of dietary intake in accordance with the Daniel Fast is associated with an improvement in selected biomarkers of antioxidant status and oxidative stress, including metabolites of nitric oxide (i.e., NOx).

The impact of religious fasting on human health

The past two decades have seen a rise in the number of investigations examining the health-related effects of religiously motivated fasts. Islamic Ramadan is a 28 - 30 day fast in which food and drink are prohibited during the daylight hours. The majority of health-specific findings related to Ramadan fasting are mixed. The likely causes for these heterogeneous findings are the differences between studies in the following: 1) the amount of daily fasting time; 2) the percentage of subjects who smoke, take oral medications, and/or receive intravenous fluids; and 3) the subjects' typical food choices and eating habits. Greek Orthodox Christians fast for a total of 180 - 200 days each year, and their main fasting periods are the Nativity Fast (40 days prior to Christmas), Lent (48 days prior to Easter), and the Assumption (15 days in August). The fasting periods are more similar than dissimilar, and they can each be described as a variant of vegetarianism. Some of the more favorable effects of these fasts include the lowering of body mass, total cholesterol, LDL-C, and the LDL-C/HDL-C ratio. The Biblical-based Daniel Fast prohibits the consumption of animal products, refined carbohydrates, food additives, preservatives, sweeteners, flavorings, caffeine, and alcohol. It is most commonly partaken for 21 days, although fasts of 10 and 40 days have been observed. Our initial investigation of the Daniel Fast noted favorable effects on several health-related outcomes, including: blood pressure, blood lipids, insulin sensitivity, and biomarkers of oxidative stress. This review summarizes the health-specific effects of these fasts and provides suggestions for future research.