As the global population continues to age at an disturbing rate, elders (65 years and older) will comprise a large share of the total population. The factors that encourage longevity gain must be identified and their affect on health status must be explored. As a result, there is a growing need to explore the effect of diet and lifestyle on cardiovascular disease risk factors (such as hypertension, hypercholesterolemia, diabetes, and obesity) that are increasingly pronounced in older populations. Recommendations for the healthy ageing of elders must be strong and applicable to varying demographic groups. The Mediterranean Island Study (MEDIS) is a health and nutrition survey wherein demographic, behavioral, clinical and dietary data were collected from 1812 participants from twelve Mediterranean islands (10 Greek islands, the Republic of Cyprus and Malta). The purpose of this work is to explore various lifestyle and dietary characteristics of a healthy (without a history of cardiovascular disease or cancer) long-lived population residing on the Mediterranean islands. Furthermore, as a smaller part of the present work, a case study from the northern villages of Karpathos was conducted in order to determine the core diet of a population that has been minimally eroded by industrialization and tourism, and to examine factors that may contribute or delay dietary change. Analysis of MEDIS data suggests that physical activity, smoking cessation, mid-day naps and adherence to the Mediterranean diet are modifiable characteristics that may encourage healthy ageing, and that dietary modification is occurring at varying rates throughout the Mediterranean islands. Data from the case study completed on the island of Karpathos, in the northern isolated villages of Olympos and Avlona suggests that the absence of mechanized farming, the social role of women and customs of inheritance are factors that can contribute to the preservation of traditional food-related practices. As older Mediterranean populations modify their dietary behaviors, they also lose the health benefits associated with the traditional Mediterranean diet. There is a growing need to identify and understand the role of various characteristics, such as diet on longevity gain and health.