Vitamin D plays a crucial role in the regulation of the immune system, with immunomodulatory effects that are key in the prevention of colorectal cancer (CRC). Over the past decades, research has shown that this steroid hormone impacts much more than bone health, significantly influencing immune responses. Vitamin D enhances immune organ functions such as the spleen and lymph nodes, and boosts T-cell activity, which is essential in defending the body against tumors. Additionally, vitamin D mitigates inflammatory responses closely linked to cancer development, reducing the inflammation that contributes to CRC. It acts via vitamin D receptors (VDRs) expressed on immune cells, modulating immune responses. Adequate vitamin D levels influence gene expression related to inflammation and cell proliferation, inhibiting tumor development. Vitamin D also activates mechanisms that suppress cancer cell survival, proliferation, migration, and metastasis. Low levels of vitamin D have been associated with an increased risk of CRC, with deficiency correlating with higher disease incidence. Lifestyle factors, such as a diet high in red meat and calories but low in fiber, fruits, and vegetables, as well as physical inactivity, contribute significantly to CRC risk. Insufficient calcium and vitamin D intake are also linked to disease occurrence and poorer clinical outcomes. Maintaining optimal vitamin D levels and adequate dietary intake is crucial in preventing CRC and improving patient prognosis. This review explores the role of vitamin D in immune regulation and summarizes findings from randomized clinical trials assessing the effects of vitamin D supplementation on CRC outcomes.

Background: Accelerated demographic aging in Hungary and across Europe presents significant public health and socioeconomic challenges, particularly in preserving cognitive function and preventing neurodegenerative diseases. Modifiable lifestyle factors—especially dietary habits—play a critical role in brain aging and cognitive decline. Objective: This narrative review explores the mechanisms by which Western dietary patterns contribute to cognitive impairment and neurovascular aging, with specific attention to their relevance in the Hungarian context. It also outlines the rationale and design of the Semmelweis Study and its workplace-based health promotion program targeting lifestyle-related risk factors. Methods: A review of peer-reviewed literature was conducted focusing on Western diet, cognitive decline, cerebrovascular health, and dietary interventions. Emphasis was placed on mechanistic pathways involving systemic inflammation, oxidative stress, endothelial dysfunction, and decreased neurotrophic support. Key findings: Western dietary patterns—characterized by high intakes of saturated fats, refined sugars, ultra-processed foods, and linoleic acid—are associated with elevated levels of 4-hydroxynonenal (4-HNE), a lipid peroxidation product linked to neuronal injury and accelerated cognitive aging. In contrast, adherence to Mediterranean dietary patterns—particularly those rich in polyphenols from extra virgin olive oil and moderate red wine consumption—supports neurovascular integrity and promotes brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) activity. The concept of “cognitive frailty” is introduced as a modifiable, intermediate state between healthy aging and dementia. Application: The Semmelweis Study is a prospective cohort study involving employees of Semmelweis University aged ≥25 years, collecting longitudinal data on dietary, psychosocial, and metabolic determinants of aging. The Semmelweis–EUniWell Workplace Health Promotion Model translates these findings into practical interventions targeting diet, physical activity, and cardiovascular risk factors in the workplace setting. Conclusions: Improving our understanding of the diet–brain health relationship through population-specific longitudinal research is crucial for developing culturally tailored preventive strategies. The Semmelweis Study offers a scalable, evidence-based model for reducing cognitive decline and supporting healthy aging across diverse populations.

Background: Considerable changes in health policy in the area of publicly funded primary dental care in Hungary over the past 25 years have shaped primary care dentists’ financing, training and working conditions and the forms of association between dental providers. This study aims to describe the advancement of primary care dentistry in Hungary and the progress of the dental cluster model since the 2021 legislation.Methods: A mixed method study was designed that included a scoping review of the literature in December 2023 to collect information on the health policy developments of Hungary’s publicly funded primary dental care system; (b) secondary data analysis was carried out to assess the development of primary care dentistry and the formation and operation of dental cluster practices in Hungary.Results: Primary care dental clusters in Hungary were established to allow active professional cooperation within the dental clusters to improve the population’s access to preventive dental services and the quality of services. From its legislative base until December 31, 2023, 74 primary dental clusters were formed nationwide, representing 30% of dental practices. On average, the primary dental clusters contain nine practices. There is an uneven geographical distribution of primary dental clusters by counties. Up to the date of this research, primary care dental clusters were set up exclusively in the form of consortia. Adult and mixed dental practices, practices from county towns, county capitals and the capital city, as well as practices from districts with more dentists in the proportion of the population were more likely to join a dental group practice.Conclusion: Monitoring and evaluating of the operation, performance and impact of primary care dental clusters in the future will provide important information about the Hungarian model.

Background: Ketogenic dietary therapies (KDTs), characterized by substantial carbohydrate restriction and increased dietary fat intake, were originally developed for the treatment of drug-resistant epilepsy but have recently attracted broader scientific interest. In the context of population aging and the increasing prevalence of cognitive impairment and dementia, their potential relevance for brain health has received growing attention. Experimental and emerging clinical evidence suggests that ketogenic metabolism may influence biological processes involved in brain aging, including cerebrovascular regulation, neuroinflammatory signaling, and cerebral energy metabolism. Objective: This narrative review aims to synthesize current evidence on the relationship between ketogenic dietary therapies and brain health, with particular emphasis on cerebrovascular mechanisms, neuroinflammatory pathways, and neuroprotective processes relevant to aging. The review also briefly introduces the Semmelweis Study as an example of a translational research framework for evaluating nutrition-related interventions in real-world preventive settings. Methods: A narrative literature review was conducted using structured searches of major scientific databases to identify experimental and human studies investigating ketogenic dietary interventions, cerebrovascular mechanisms, and neuroprotective outcomes. Publications related to the Semmelweis Study were included solely to illustrate implementation-oriented research approaches and not as evidence supporting dietary efficacy. Results: Available evidence indicates that ketogenic dietary interventions may modulate several biological pathways relevant to brain health, including cerebral energy metabolism, mitochondrial function, oxidative stress regulation, and inflammatory signaling. However, the current evidence base is dominated by preclinical studies and short-term human investigations, and direct evidence linking ketogenic dietary therapies to long-term cerebrovascular or cognitive outcomes remains limited. Conclusions: Ketogenic dietary therapies represent metabolically distinct dietary strategies with potential relevance for cerebrovascular and neuroprotective mechanisms. Nevertheless, human evidence remains heterogeneous and insufficient to support broad clinical recommendations. Future research should prioritize well-designed long-term human studies with clearly defined metabolic, cerebrovascular, and cognitive endpoints. Translational research frameworks may facilitate the evaluation of feasibility, safety, and implementation of ketogenic interventions in aging populations.