What is the Mediterranean diet?
An
examination of the existing scientific literature on the health benefits of the
Mediterranean diet, conducted by Dr. Perez-Lopez and his team from the University of
Zaragoza, Spain, found that following a traditional Mediterranean diet is associated with
a longer life [1]. Their peer-reviewed study reported on a number of these health
benefits, some of which are presented below.
The area around the Mediterranean Sea is known as the birthplace of modern civilization,
and the diet of our Greek and Roman ancestors formed the basis for centuries of culinary
principles that continue to influence today's nutrition and diet. Olive oil, a staple of
present day kitchens, was used by Ancient Greeks as a main source of dietary fat – in
contrast to the practice of using fat from animal meat, consumption of which the Ancient
Greeks considered barbaric and unhealthy.
In more modern times, it has become apparent that a Mediterranean diet (MD) is associated
with significant benefits for health and longevity. Researchers initially noticed that
people living in the Mediterranean region of the world had a decreased risk of heart
disease, leading to a 30-year research study on the dietary habits of people in seven
countries – Greece, Italy, Yugoslavia, Holland, Finland, the USA, and Japan. The
study, sponsored by the World Health Organization, found that the death rate from heart
disease for men from the Greek island of Crete – where a traditional Mediterranean
diet was followed – was exceptionally low.
Other research studies have found that the MD, a nutritional model based on traditional
diets of countries of the Mediterranean basin, is associated with a number of health
benefits. These benefits include lower rates of cardiovascular disease, cancer, and
cognitive decline associated with age. Although the MD is based primarily on the diets of
Greece, southern Italy, Portugal, Cyprus, Spain, and Turkey, its health benefits have made
it an increasingly popular diet around the world.
Mediterranean Diet Increases Longevity
There have been a number of studies looking at the association between the MD and
longevity, and the results have shown that lifespan is generally longer in people who
follow the traditional MD. The European Prospective Investigation into Cancer and
Nutrition (EPIC) Elderly study assessed the diet of nine European countries in terms of
how closely the diet adhered to the MD. The EPIC study found that a 60-year-old man who
closely follows the MD will have an expected lifespan of an additional year when compared
to a 60-year-old man who does not adhere to the MD [2]. Additional analysis of the EPIC
cohort found that those people who most closely adhered to the MD had a significantly
reduced risk of death during the five years following the initial surveys [3]. Another
study of Europeans, examining a group of elderly subjects, found that adherence to the MD
was associated with a 23% lower annual mortality risk [4].
Mediterranean Diet Reduces Risk of Metabolic Syndrome
The metabolic syndrome (METS) is associated with a number of risks, including
cardiovascular risk, atherosclerosis, type 2 diabetes, and cardiovascular mortality. The
METS is defined by the US National Institute of Health to occur when 3 of the following 5
conditions (risk determinants) are met:
1. Abdominal obesity, defined as waist circumference >88 cm
2. Increased level of serum triglycerides, greater or equal to 150 mg/dL
3. Decreased level of high density lipoprotein cholesterol, where the good cholesterol HDL
is lower than 50 mg/dL
4. High fasting glucose level, equal to or greater than 110 mg/dL
5. Increased blood pressure, of 130/85 mmHg or higher
The Spanish SUN (Seguimiento Universidad de Navarra) Study found that adherence to the MD
was inversely associated with incidence of the METS, meaning that closer adherence to the
MD was related to lower incidence of the METS [5]. It is also known that adherence to the
MD has a protective effect when it comes to a risk of diabetes, one of the conditions
associated with the METS. This is related to the MD's high intake of vegetable fat and
abundant virgin olive oil; a low intake of trans fat; and a moderate alcohol intake [6].
Mediterranean Diet Helps Control Hypertension
It is known that nutritional factors play a large role in the control of hypertension
(high blood pressure). Steps such as increasing fruit and vegetable intake and decreasing
fat and cholesterol can result in a remarkable decrease in blood pressure, as well as
reduction in weight – also associated with a reduce in blood pressure.
The EPIC study found that the MD showed benefits for hypertension. The Greek segment of
the EPIC study found that both adherence to the MD and olive oil intake were significantly
associated with lower systolic and diastolic blood pressure [7]. The Italian EPIC group
found that consumption of vegetables, particularly leafy vegetables, was associated with
decreased systolic and diastolic blood pressure; consumption of olive oil was found to be
inversely associated with diastolic pressure [8].
Mediterranean Diet Reduces Cardiovascular Risk
An aspect examined in the EPIC study was the effect of adherence to the MD on
cardiovascular risk. For elderly people who had previously experienced a myocardial
infarction, increased adherence to the MD was associated with an overall mortality rate
that was 18% lower [9].
Another study looked at 11,323 Italian individuals to determine whether following the MD
had an effect on mortality after a myocardial infarction [10]. The individuals in the
study received instruction to increase their consumption of fish, fruit, raw and cooked
vegetables, and olive oil – all aspects of the MD. A comparison of the quartile of
participants who adhered least to the diet with the quartile that adhered best showed a
significant difference in the risk of early death.
Mediterranean Diet Encourages Healthy Body Weight
Obesity has become a troubling epidemic in industrialized countries, with 30-50% of the
general population considered obese. As overweight and obesity are linked to a number of
health problems, maintaining a healthy body weight is a key component to living a long and
healthy life. Adherence to the MD has been found to be helpful in this regard. A survey in
Spain found that those who followed the MD diet most closely had a lower BMI (Body Mass
Index) and less chance of obesity [11]. Another large study of Spanish individuals,
composed of 17,238 women and 10,589 men, found that strict adherence to the MD was also
associated with a lower risk of gaining weight [12].
Final remarks
With all the health benefits associated with the traditional Mediterranean diet,
it is not surprising that the MD has a positive impact on life expectancy. Researchers
have not determined the exact mechanism that relates to longevity, and it appears that
many components of the MD have health benefits, making it likely that there is no one
particular food that is responsible for increased longevity. Simply adding olive oil to an
unhealthy diet will not provide the health benefits received by adopting the dietary
pattern as a whole.
And the health benefits are significant: when compared to individuals not following a MD,
those who adhered to the MD were found to have a 20% lower risk of death over a period of
one decade [4]. Although based on the dietary patterns of people living around the
Mediterranean basin, the MD is not exclusive to that area and its components can be found
in countries all over the world.
References
1. Faustino R. PÈrez-LÛpeza, Peter Chedraui, Javier Haya, JosÈ L.
Cuadros. Effects of the Mediterranean diet on longevity and age-related morbid conditions.
Maturitas 2009;64; 67–79.
2. Trichopoulou A, Orfanos P, Norat T, et al. Modi?ed Mediterranean diet
and survival: EPIC-elderly prospective cohort study. BMJ2005; 330: 991.
3. Bamia C,Trichopoulos D,Ferrari P, et al. Dietary patterns and
survival of older Europeans: the EPIC-Elderly Study (European Prospective Investigation
into Cancer and Nutrition). Public Health Nutr 2007; 10: 590–8.
4. Knoops KT, de Groot LC, Kromhout D, et al. Mediterranean diet,
lifestyle factors, and 10-year mortality in elderly European men and women: the HALE
project. JAMA 2004; 292: 1433–9.
5. Tortosa A, Bes-Rastrollo M, Sanchez-Villegas A, Basterra-Gortari FJ,
Nunez-Cordoba JM, Martinez-Gonzalez MA. Mediterranean diet inversely associated with the
incidence of metabolic syndrome: the SUN prospective cohort. Diabetes Care 2007; 30:
2957–9.
6. MartÌnez-Gonz·lez MA, dela Fuente-Arrillaga C, Nunez-Cordoba JM, et
al. Adherence to Mediterranean diet and risk of developing diabetes: prospective cohort
study. BMJ 2008; 336(14): 1348–51.
7. Psaltopoulou T, Naska A, Orfanos P, Trichopoulos D, Mountokalakis T,
Trichopoulou A. Olive oil, the Mediterranean diet, and arterial blood pressure: the Greek
European Prospective Investigation into Cancer and Nutrition (EPIC) study. Am J Clin Nutr
2004; 80: 1012–8.
8. Masala G, Bendinelli B, Versari D, et al. Anthropometric and dietary
determinants of blood pressure in over 7000 Mediterranean women: the European Prospective
Investigation into Cancer and Nutrition – Florence cohort. Hypertens 2008; 26:
2112–20.
9. Trichopoulou A, Bamia C, Norat T, et al. Modi?ed Mediterranean diet
and survival after myocardial infarction: the EPIC-Elderly study. Eur J Epidemiol 2007;
22: 871–81.
10. Barzi F, Woodward M, Mar?si RM, et al. Mediterranean diet and
all-causes mortality after myocardial infarction: results from the GISSI-Prevenzione
trial. Eur J Clin Nutr 2003; 57: 604–11.
11. Schrˆder H, Marrugat J, Vila J, Covas MI, Elosua R. Adherence
to the traditionalMediterranean diet is inversely associated with body mass index and
obesity in a Spanish population. J Nutr 2004; 134: 3355–61.
12. Mendez MA, Popkin BM, Jakszyn P, et al. Adherence to a Mediterranean
diet is associated with reduced 3-year incidence of obesity. J Nutr 2006; 136:2934–8.
About the Author
Matthew Papa, PhD, is a medical researcher at Washington University School of Medicine in
St Louis, MO. Born and raised in Greece, Matthew knows well the benefits of the
Mediterranean diet and is pleased at the opportunity to share relevant scientific research
on the subject. In his website, Matthew writes reviews for some of the best weight loss programs. He
also offers a promotion
code for Medifast and an eDiet promo, two medically designed
diet programs in N. America.
