Maximilian Andreas Storz

University Medical Center Freiburg · Department of Internal Medicine II

Within the last decades, plant-based diets have received increasing interest for their potential benefits to human and environmental health. The concept of plant-based diet, however, varies widely in its definition. Current definitions range from the exclusion of all animal products to diets that include meat, fish, and dairy in varying quantities....

The percentage of U.S. adults following low-carbohydrate diets (LCD) doubled in the last decade. Some researchers observed this trend with concern, and highlighted the potential for nutritional deficiencies and impaired overall diet quality with LCD. The present study investigated nutrient intake in a nationally-representative sample of 307 U.S. ad...

Objective: Adherence to vegetarian diets has been associated with physical health benefits, whereas vegetarian mental health is less well documented. We sought to investigate whether adherence to a vegetarian diet was associated with depression in a nationally-representative sample of US adults. Methods: We used population-based data from the US Na...

Dietary acid load (DAL) is an important determinant of the acid-base balance in humans and has been associated with several chronic non-communicable diseases. Plant-based diets, including vegetarian and vegan diets, decrease DAL-although their alkalizing potential varies substantially. Their net effect on common DAL scores, including potential rena...

Background/Objective Plant-based diets reduce the risk of cardiovascular disease but also increase the risk of certain micronutrient deficiencies, particularly, of vitamin B12 (B12). The extent to which the unsupervised use of oral nutrient supplements is sufficient to prevent these deficiencies is not well established. We analyzed nutrient intake,...

Background Although national food guides are designed, ostensibly, to translate scientific evidence with respect to food, dietary patterns, and health, their development has increasingly become a corporate/political process as well as scientific one; often with corporate/political influences overriding science. Our aim was to construct an unbiased,...

Background International medical electives (IMEs) are considered high-impact practice in global health education. Nevertheless, international medical elective (IME) research remains scarce, with only a few new publications appearing each year. The discrepancy between the many unanswered questions regarding IMEs and the lack of opportunities to perf...

There are currently more than 3.3 million prostate cancer (PC) survivors in the United States. Conformance with national dietary guidelines and a good diet quality may lower the risk for Gleason grade progression in PC patients. Assessing the nutritional status of PC survivors is thus of paramount importance from a public health nutrition perspecti...

Background: With advancing age, the worsening of cognitive and physical disabilities may lead older adults to seek help in their daily living activities. Community/senior centers support older adults during aging, offering a wide variety of services, including meal programs. Using data from the National Health and Nutrition Examination Surveys (200...

Given animal research is challenged with inadequacies, e.g., animal-to-human knowledge translation, ethical considerations, and cost:benefit, new approach methodologies (NAMs) have been proposed as a replacement. With reference to the field of nutrition and dietetics, our aim was to examine the policies of its leading journals regarding human-based...

Plant-based diets are increasingly popular worldwide. A well-planned plant-based diet lowers the risk of cardiovascular disease, type 2 diabetes and certain cancers. In contrast, a poorly planned plant-based diet increases the risk of certain micronutrient deficiencies, chiefly, vitamin B12 (B12). Because B12 is not present in plants or in unfortif...

Food literacy reflects personal behaviours around healthy eating and is an important skill for individuals to make healthy dietary choices. The present cross-sectional study investigated food literacy and the ability to identify n = 43 foods of plant origin in n = 1322 Venezuelan adolescents aged 15–17 years in the city of Puerto La Cruz, Venezuela...

Background Fruits and vegetables are abundant in alkali precursors and effectively reduce the Potential Renal Acid Load (PRAL) from diet. Oral alkali supplements are supposed to exert comparable alkalizing effects on the human body, and have been shown to beneficially affect bone and kidney health. A comparative analysis of the available dietary al...

A growing interest in more sustainable and alternative food sources has brought seaweed and macroalgae to the spotlight for the general worldwide cuisine. Algae are often praised for their high nutritional value and are rich in potassium, calcium, and magnesium. Abundant in base precursors, algae are particularly interesting from an acid-base persp...

Background: Healthy plant-based diets, such as the lacto-ovo-vegetarian and the vegan diet, offer numerous benefits to human health. Poorly designed plant-based diets, however, bear the risk for vitamin- and micronutrient deficiencies. Vitamin B12 (B12, cobalamin) is a nutrient of particular concern in both diets, and should be readily supplemented...

Plant-based meat alternatives (PBMAs) are food products derived from plants and designed to mimic the preparation methods, nutritional profile, and sensorial qualities of meat. PBMAs are currently subject to a controversial debate concerning their health value. Here, we reviewed PBMAs’ potential renal acid load (PRAL). The PRAL is an estimate for t...

The capability of any food to alter net endogenous acid or base production can be estimated using the potential renal acid load (PRAL) estimation method. The PRAL of edible mushrooms has been rarely examined; thus a quantification study of n = 37 edible mushroom species was performed. Results revealed a heterogeneous picture: although the most comm...

Background Doege–Potter syndrome is defined as paraneoplastic hypoinsulinemic hypoglycemia associated with a benign or malignant solitary fibrous tumor frequently located in pleural, but also extrapleural sites. Hypoglycemia can be attributed to paraneoplastic secretion of “Big‐IGF‐II,” a precursor of Insulin‐like growth factor‐II. This prohormone...

Background Abroad medical electives are recognized as high-impact practice and considered a necessity to provide global health training. As of recently, the COVID-19 pandemic and its related travel restrictions prohibited most international elective activities. Another important barrier to abroad electives that received comparably little attention...

Background The beneficial effects of a plant-based diet on gut microbiota diversity are well documented, however, its impact on clinical bowel health and defecation patterns are less well understood. Vegetarian diets have been associated with a higher bowel movement (BM) frequency as well as softer stools in cross-sectional studies. The effects of...

The potential renal acid load (PRAL) describes the capacity of a food to produce acid or base in the human body. The long-term consumption of high-PRAL diets induces a chronic low-grade metabolic acidosis state that has been associated with inflammation and impaired kidney function. PRAL tables are available to help individuals in selecting low-PRA...

Background: The American College of Lifestyle Medicine proposed 6 evidenced-based pillars to tackle the increasing burden from chronic non-communicable diseases, including regular physical activity, 7+ hours of restorative sleep, a whole-food plant-based diet, stress management, avoidance of risky substances and positive social connections. Methods...

Background: Fiber, potassium and calcium are nutrients of public health concern and their intakes in the United States are alarmingly low. The usage of nutrition facts labels has been reported to increase the odds for dietary reference intake of fiber in some studies. The overall evidence, however, is mixed, as some studies suggested that nutritio...

Recently, there has been a renewed interest in Cannabis sativa and its uses. The recreational use of inflorescences as a source of THC has led to the legal restriction of C. sativa cultivation to limit the detrimental effects of psychotropic substance abuse on health. However, this has also limited the cultivation of textile/industrial varieties wi...

The market for plant-based milk alternatives has been growing continuously within the last years, and numerous new food items including almond, oat, and soy milk are nowadays commercially available. The impact of said foods on the acid-base balance in humans has been rarely assessed but is of great importance for individuals who adopt an alkaline d...

Background Dietary acid load (DAL) has been associated with frailty and hip fractures in older adults, who often have a reduced kidney function and thus compromised buffering capacities. Studies to quantify DAL in older adults are scarce and controversies persist as to whether DAL in- or decreases with age. Aim To enhance the understanding of DAL...

Dietary acid load (DAL) is recognized as a risk factor for several chronic disorders, including obesity, diabetes, and osteoporosis. Recent evidence suggests that an elevated DAL, as measured by the validated potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores, could also increase the risk for several cancers. This nar...

The dietary acid load (DAL) is a novel marker of overall diet quality, which has been associated with overweight, type 2 diabetes and altered glucocorticoid secretion. A potential association with sex hormones is thus not inconceivable. We investigated whether DAL was associated with serum total testosterone concentrations of men in the National He...

Chronic low-grade metabolic acidosis is now a common phenomenon in the Western world. The high dietary intake of sulfur-containing amino acids in the form of processed meats results in an excessive release of acid in the form of protons and non-metabolizable acidic anions. The kidneys produce increasing amounts of ammonia to excrete this acid. This...

A reliable diet quality (DQ) assessment is critical to empower individuals to improve their dietary choices. Controversies persist as to whether self-perceived DQ is accurate and correlated with actual DQ as assessed by validated nutrient intake indexes. We used National Health and Nutrition Examination Surveys data to examine whether a higher self...

With the increasing adoption of plant-based diets in the United States, more and more individuals replace cow milk with plant-based milk alternatives. Soy milk is a commonly used cow milk substitute, which is characterized by a higher content of polyunsaturated fatty acids and fibers. Despite these favorable characteristics, little is known about t...

Objective: Dietary acid load can contribute to metabolic acidosis, which is closely linked to cancer development through inflammation and cell transformation mechanisms. However, limited epidemiologic evidence is still linking diet-dependent acid load and cancer risk. Since we published nine studies specifically focusing on dietary acid load and th...

Unlabelled: We present the case series of two women aged 35 and 60 years who presented to our emergency department with severe vomiting, nausea, and malaise. Their symptoms started approximately 2 h after the ingestion of home-made mixed vegetables with freshly picked vegetables and leaves from the patients' garden, of which one was supposed to be...

Background: In 1995, Remer and Manz reported potential renal acid load (PRAL) values of various foods, quantifying their estimated impact on acid-base balance. Their estimation considered ionic dissociation, sulphur metabolism and intestinal absorption rates for several micronutrients and proteins. Notably, PRAL values are based on food content dat...

Purpose Changes in eating habits and food preferences caused by circadian rhythm disruptions in shift workers increase the risk for chronic diseases. Several studies demonstrated that shift work exerts adverse effects on various risk factors for cardiometabolic disease and cancer. Moreover, shift work leads to altered eating patterns, including die...

The regular consumption of net acid-producing diets can produce "acid stress" detrimental to human health. Alkalizing diets characterized by a negative potential renal acid load (also called low-PRAL diets (LPD)) enjoy uninterrupted popularity. However, the nutritional adequacy of said diets has rarely been assessed in large populations. Using data...

The state of nutrition education in medicine is inadequate, with nutrition-related topics being poorly integrated into lectures. Most medical students receive only a few contact hours of nutrition instruction during their entire time at medical school. Identifying potential barriers that may explain the paucity of nutritional knowledge in medical s...

Plant-based diets are associated with numerous health benefits but also bear risks of micronutrient deficiencies if inadequately planned. The risk of nutrient deficiencies can be reliably reduced by supplementation but requires risk-awareness. We distributed a paper-and-pencil questionnaire to n = 902 healthcare professionals attending a congress o...

Background Cardiovascular disease and obesity affect racial and ethnic minorities disproportionally. Public health research suggests that suboptimal diet is an important contributor to health disparities. Limited evidence points at an increased dietary acid load (DAL) in certain ethnic groups. DAL is determined by the balance of acidifying foods an...

In recent decades, China has quickly transformed itself into a modern, urban, technological and economic powerhouse. China’s medical education system is internationalizing and attracting a considerable number of foreign students seeking medical degrees and other clinical experience, such as observerships, in China. Although the majority of internat...

A plant-based diet (PBD) can provide numerous health benefits for patients with cardiovascular risk factors. However, an inadequately planned PBD also bear the potential for deficiencies in certain macro- and micronutrients. The present study analyzed nutrient profiles of individuals who adopted a PBD as part of the CardioVeg study. Participants wi...

Contemporary diets in Western countries are largely acid-inducing and deficient in potassium alkali salts, resulting in low-grade metabolic acidosis. The chronic consumption of acidogenic diets abundant in animal-based foods (meats, dairy, cheese and eggs) poses a substantial challenge to the human body's buffering capacities and chronic retention...

Background: The safety profile of low-carbohydrate diets is controversial and poorly understood. We investigated the effects of low-moderate carbohydrate intake on dietary acid load (DAL), an emerging health risk factor and novel clinical marker associated with numerous adverse clinical outcomes. Methods: We used data from the National Health and N...

Objective: The dietary acid load can contribute to metabolic acidosis, which is closely linked to cancer development through mechanisms of inflammation and cell transformation. However, very limited epidemiologic evidence is linking diet-dependent acid load and cancer risk. Since no published studies focused on dietary acid load and gastric cancer (...

Home cooking is an important obesity prevention strategy and associated with benefits for diet and health. Although cooking may be a joyful act of mindfulness, it also requires planning, preparation and time. Historically, women have been more likely to fulfill the role of food shopping and cooking. More recent studies suggested a transition in tra...

Adiponectin and leptin are important mediators of metabolic homeostasis. The actions of these adipokines extend beyond adipocytes and include systemic modulation of lipid and glucose metabolism, nutrient flux, and the immune response to changes in nutrition. Herein, we hypothesized that short-term intervention with a vegan diet might result in an i...

Background: A high dietary acid load (DAL) can produce metabolic acidosis, which is linked to cancer development through mechanisms of inflammation and cell transformation. There is limited epidemiological evidence linking DAL and cancer risk; however, none of the published studies focused on DAL and esophageal cancer (EC) risk in particular. Ther...

The gluten-free diet (GFD) ensures improvement of clinical symptoms in the vast majority of celiac disease (CD) patients. Despite stable CD rates in many countries, an increasing number of healthy individuals are adopting gluten-free diets, believing that this diet is an inherently healthier choice. The health effects of gluten-free diets are contr...

Cognitive decline is a common problem in older individuals, often exacerbated by neurocognitive conditions, such as vascular dementia and Alzheimer’s disease, which heavily affect people’s lives and exert a substantial toll on healthcare systems. Currently, no cure is available, and commonly used treatments are aimed at limiting the progressive los...

Aim Metabolic acidosis subsequent to a high dietary acid load (DAL) leads to inflammation and cell transformation, which are common features of cancer development. Because the epidemiologic evidence associating DAL and cancer risk is still limited, we sought to explore the potential role of DAL as a risk factor for head and neck and oral cavity tum...

Metabolic Syndrome (MetS) is a cluster of metabolic alterations mostly related to visceral adiposity, which in turn promotes glucose intolerance and a chronic systemic inflammatory state, characterized by immune cell infiltration. Such immune system activation increases the risk of severe disease subsequent to viral infections. Strong correlations...

Recent research suggests an impact of psychological distress on postoperative outcomes in orthopedic and neurosurgery. It is widely unknown whether patients’ mood might affect the postoperative outcome and complication rate in colorectal surgery. Over a period of 22 months, a monocentric, observational study among patients undergoing elective color...

Western diets are characterized by a high dietary acid load (DAL), which has been associated with adverse clinical outcomes, including type-2-diabetes and metabolic syndrome. Effective dietary strategies to lower DAL are urgently warranted. Plant-based diets (PBD), including vegetarian and vegan diets, are an effective measure to reduce DAL. Notabl...

Background Diet is an important determinant of systemic pH and acid–base regulation. A frequent consumption of acid-inducing foods (including processed meats and cheese) combined with a low intake of base-inducing foods (such as fruits, legumes and vegetables) increases Dietary Acid Load (DAL), which has been associated with an increased risk for c...

Background Immune thrombocytopenia (ITP) is a rare autoimmune disorder characterized by low platelet counts and increased bleeding risk. The disease may be induced by other disorders, including malignancies, autoimmune diseases, infectious agents or drugs. However, ITP has also been described following vaccinations, such as the measles–mumps–rubell...

Introduction: Dietary acid load contributes to metabolic acidosis, closely linked to cancer development through inflammation and cell transformation. There is very limited epidemiologic evidence; linking diet-dependent acid load and cancer risk. Since there are few published studies specifically on urinary pH and bladder cancer (BC) risk, we sought...

Background International medical electives are an important and popular component of the academic curriculum in many medical schools and universities worldwide. The purpose of abroad electives is to provide medical students with an opportunity to gain a better understanding of education and healthcare in an international context. The COVID-19 pande...

Dietary acid load (DAL) is an important determinant of systemic pH and acid–base homeostasis. Diets abundant in acidogenic foods, such as meat and meat products, induce a low-grade metabolic acidosis state that has been associated with cardiovascular disease, type-2-diabetes, and an increased cancer risk. Fruits and vegetables have alkalizing prope...

Working outside of regular daytime hours is increasingly common in current societies and poses a substantial challenge to an individual’s biological rhythm. Disruptions of the gastrointestinal tract’s circadian rhythm and poor dietary choices subsequent to shiftwork may predispose the shift workforce to an increased risk of gastrointestinal disorde...

Soy is a key food in human nutrition. It is widely used in eastern traditional cuisine and it has recently diffused among self-conscious and vegetarian diets. The success of soy mainly depends on versatility and supposed healthy properties of soy foods and soy components. Meanwhile, the possible influence on endocrine system, in particular by isofl...

The number of shift workers has increased substantially within the last decades to keep pace with the increasingly complex societal need for 24 h services. Shift work has been associated with unhealthy lifestyles and a lower overall diet quality. Little is known, however, with regard to food security and consumer behavior in shift workers. The pres...

Dietary fiber is of paramount importance in the prevention of large-bowel diseases, yet fiber intake in many high income countries is well below daily recommendations. Vegetarian diets high in fiber-rich plant-foods have been associated with a higher frequency of bowel movements and softer stools. Thus, vegetarians appear to suffer less frequently...

Background International medical electives are one the highlights of medical training. Literature about international electives is scarce, and understanding what made a student choose one destination over another is unclear. Many medical students based in Europe travel to Africa each year for their elective, however, students’ expectations and moti...

An increasing number of individuals adopt plant-based diets for their potential health benefits. Understanding vegetarians’ dietary behavior in the context of their socioeconomic background is essential for pro-vegetarian messaging and to influence public beliefs about plant food consumption. Thus, this study sought to investigate diet and consumer...

The introduction of lockdowns and other containment measures during the COVID-19 pandemic substantially altered people’s lifestyle and dietary behavior. Several studies evaluated the short-term effects of these measures; yet reports on long-term consequences are scarce. We sought to address this gap in the literature by analyzing dietary and lifest...

Purpose of Review The SARS-CoV-2-pandemic has caused mortality and morbidity at an unprecedented global scale. Many patients infected with SARS-CoV-2 continue to experience symptoms after the acute phase of infection and report fatigue, sleep difficulties, anxiety, and depression as well as arthralgia and muscle weakness. Summarized under the umbre...

Objective: Dietary acid load contributes to metabolic acidosis, which leads to inflammation and cell transformation, closely linked to cancer development. The epidemiologic evidence associating diet-dependent acid load and cancer risk, particularly for prostate cancer, is severely limited , based on a single study. Therefore, we sought to explore t...

Background The results of recent surveys indicate that more than 50% of the German population has experience with complementary and alternative medicine (CAM) or uses CAM regularly. This study investigated the CAM usage and CAM-related needs of hospitalized patients at university medical centres in the state of Baden-Württemberg, Germany. Methods...

Dear Editor, It is with great interest that we read the recently published review entitled “Stroke and Diets” in the Tzu Chi Medical Journal [1]. The authors provide a concise and up‑to‑date discussion on the role of different dietary patterns in the prevention of stroke. Lin et al. concluded that “vegetarian (meatless) diets have a significant imp...

Objective: Recent research studies linked the intake of processed meat and fatty foods to an increased risk of renal cell carcinoma. Fruits and vegetables, on the other hand, may convey protective effects. Dietary acid load (DAL) has been proposed as a potential risk factor for various cancer types within the last years. The present study sought to...