Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02641834 |
| Other study ID # |
CAR-123-VEG |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 2016 |
| Est. completion date |
December 2016 |
Study information
| Verified date |
August 2021 |
| Source |
Azienda Ospedaliero-Universitaria Careggi |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The study is a randomized, open, cross-over trial designed to test whether a vegetarian diet
would benefit the cardiovascular risk profile of the participants, compared with a
Mediterranean diet.
Description:
Nutrition is able to substantially alter the health status of the general population. In
industrialized countries such as Italy the most important association between diet and health
is certainly the relationship with cardiovascular disease, the leading cause of death and
disability. The ability to identify with certainty, therefore, the relationship between diet
and cardiovascular disease appears to be a key element in the implementation of specific
primary prevention strategies.
Cardiovascular diseases would be the result of interactions between genetics and
environmental factors. Many studies have evaluated the associations between food groups,
foods, or nutrients and chronic diseases, and a consensus about the role of nutritional
factors in the etiology of common diseases, such as cardiovascular and neoplastic diseases,
has gradually emerged. Recent studies have been focused on examining the impact of a whole
dietary approach rather than on isolating single nutrients; it is recognized that analyses of
single nutrients ignore the important and complex interactions between components of a diet
and, more importantly, because people do not eat isolated nutrients.
The optimal dietary strategy for the prevention of chronic degenerative diseases remains a
challenging and a highly relevant preventive health issue. Over the last years, numerous
evidence on the existing relationship between nutrition and chronic degenerative diseases
have led investigators to search for the optimal dietary pattern to maintain a good health
status. Several models of diet have been imposed on public attention, but those that got the
most interest are certainly Mediterranean and vegetarian diets. These dietary patterns seem
to exert protective effects on blood pressure, lipid profiles, cardiovascular diseases and
metabolic parameters.
The term Mediterranean diet has been widely used to describe the traditional dietary habits
of people in Crete, South Italy, and other Mediterranean countries during the decade of the
1960s. Since the first data from the Seven Countries Study, several studies in different
populations have established a beneficial role for the main components of the Mediterranean
diet on the occurrence of cardiovascular diseases and chronic degenerative diseases. This
dietary pattern is characterized by plentiful plant foods (fruits, vegetables, breads, other
forms of cereals, beans, nuts, and seeds), olive oil as the principal source of fat, moderate
amounts of dairy products (mainly cheese and yogurt), low to moderate amounts of fish and
poultry, red meat in low amounts and wine consumed in low to moderate quantities, usually
with meals.
The vegetarian diet is a diet that excludes the use of animal foods (meat, fish) in its
fresh, preserved and/or processed. The increase in the number of vegetarians is attributable
to health, ethical, environmental, and social concerns.
Recently, meta-analysis conducted by our group have revealed, in a population of over than 2
million of people, that a strict adherence to a Mediterranean dietary pattern is associated
with a significant improvement in health status, as seen by a significant reduction in
overall mortality (10%) and incidence and/or mortality from cardiovascular diseases (9%).
During the past few decades, there has been a gradual abandonment of this dietary pattern by
the inhabitants of the Mediterranean basin, especially by the younger generations. Several
factors have contributed to this nutrition transition, such as the enhanced commercial
availability of food, the urbanization of life, and the overall improvement in socioeconomic
conditions in Europe, which has increased the food and energy supply and made food
(especially of animal origin) more affordable. Consumption of milk, meat and animal fat
products increased in all Mediterranean countries. Moreover, a stressful lifestyle, less time
spent on cooking, and the enhanced variety and availability of household appliances have also
been proposed as determinants of nutrition transition.
Because of the growing evidence in favor of link between red and processed meat and
cardiovascular disease risk, cancer and diabetes, the interest towards vegetarian diets has
increased. In the last years, the number of subjects who began to adopt a vegetarian dietary
pattern has enormously increased with respect to the past, when the population of vegetarians
was limited only to few and selected cohorts. Such increase has been mainly attributed to the
supposed beneficial effect of this dietary pattern versus the occurrence of diseases.
Health benefits of Mediterranean and vegetarian diets have been widely described in
case-control and prospective cohort studies during the last 50 years. There are several
beneficial nutrients that are abundant in these diets, such as monounsaturated fatty acids,
high amounts of fiber and antioxidants and low intake of total and saturated fats. However,
it is unclear whether established health benefits for vegetarians are attributable to the
absence of meat in the diet, the increased consumption of particular food component(s) the
pattern of foods eaten within the vegetarian diet or other healthy lifestyle components often
associated with vegetarianism.
In a recent systematic review with meta-analysis carried out on over than 130,000
vegetarians, plant-based diet was associated with many health benefits. Main findings were
that vegetarian diet determines, among case-control studies, lower levels of the most
important risk factor for chronic disease, along with a reduced risk of occurrence for
ischemic heart disease (-25%) when cohort prospective studies were taken into account.
Currently there are no randomized controlled trials to compare, in a high-risk group of
patients with risk factors for cardiovascular disease, the efficacy of nutritional
interventions based on Mediterranean and vegetarian dietary patterns. From this comparison it
would may be possible to obtain interesting results in order to identify the optimal diet for
prevention of cardiovascular diseases.
OBJECTIVES:
The primary aim of the study is to compare the effects of vegetarian diet on risk markers
(anthropometric and biochemical measures) associated with cardio-metabolic diseases (CMD)
after a 3-month dietary-intervention phase, compared with a Mediterranean diet.
Secondary objectives of the study are:
- To improve knowledge about the pathophysiological role of vegetarian and Mediterranean
diets in cardiovascular prevention
- To evaluate the feasibility and degree of adherence to a dietary substitution with
vegetarian diet in a omnivorous population
- To evaluate the ability of a nutrition education intervention to reduce fresh and
processed meat consumption in subjects at high cardiovascular risk, in order to enhance
health and quality of life
- To explore the impact of food prices on consumption and to evaluate the overall cost of
buying food products in different dietary patterns
STUDY DESIGN The study is a randomized, open, cross-over trial designed to test whether a
vegetarian diet would benefit the cardiovascular risk profile of the participants, compared
with a Mediterranean diet.
The eligible participants are randomly divided into two groups, each assigned to either the
experimental group (Group 1), which receives a vegetarian diet, or the control group (Group
2), which receives a Mediterranean diet. Following the first intervention phase, the subjects
are crossed over in order to obtain the second intervention phase. Both diets are isocaloric
and lasting three months each. The whole trial includes five clinical visits.
STUDY POPULATION Subjects in primary prevention with low-middle cardiovascular risk (1-5%
according to the guidelines of the European Society of Cardiology), determined by the
presence of BMI >o=25 kg/m2 and no more than other 2 concomitant metabolic risk factors.
