Tuesday, December 23, 2014

Health Benefits of a Mediterranean Diet: Heart Attack and Stroke Benefits

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Mediterranean diet associated with lower risk of death in cardiovascular disease patients

Mediterranean diet cuts heart disease risk by nearly half



Adults who closely followed the Mediterranean diet were 47 percent less likely to develop heart disease over a 10-year period compared to similar adults who did not closely follow the diet, according to a study to be presented at the American College of Cardiology's 64th Annual Scientific Session in San Diego.



Among the study's participants, adherence to the Mediterranean diet was more protective than physical activity. The study, conducted in Greece, bolsters evidence from earlier studies pointing to the diet's health benefits and is the first to track 10-year heart disease risk in a general population. Most previous studies have focused on middle-aged people.



"Our study shows that the Mediterranean diet is a beneficial intervention for all types of people--in both genders, in all age groups, and in both healthy people and those with health conditions," said Ekavi Georgousopoulou, a Ph.D. candidate at Harokopio University in Athens, Greece, who conducted the study along with Demosthenes B. Panagiotakos, Ph.D., professor at Harokopio University. "It also reveals that the Mediterranean diet has direct benefits for heart health, in addition to its indirect benefits in managing diabetes, hypertension and inflammation."



The study is based on data from a representative sample of more than 2,500 Greek adults, ages 18 to 89, who provided researchers with their health information each year from 2001 to 2012. Participants also completed in-depth surveys about their medical records, lifestyle and dietary habits at the start of the study, after five years and after 10 years.



Overall, nearly 20 percent of the men and 12 percent of the women who participated in the study developed or died from heart disease, a suite of conditions that includes stroke, coronary heart disease caused by the buildup of plaque in the heart's arteries, acute coronary syndromes such as heart attack, and other diseases. Other studies have shown Greeks and Americans have similar rates of heart disease and its risk factors.



The researchers scored participants' diets on a scale from 1 to 55 based on their self-reported frequency and level of intake for 11 food groups. Those who scored in the top-third in terms of adherence to the Mediterranean diet, indicating they closely followed the diet, were 47 percent less likely to develop heart disease over the 10-year follow-up period as compared to participants who scored in the bottom-third, indicating they did not closely follow the diet. Each one-point increase in the dietary score was associated with a 3 percent drop in heart disease risk.



This difference was independent of other heart disease risk factors including age, gender, family history, education level, body mass index, smoking habits, hypertension, diabetes and high cholesterol, all of which the researchers adjusted for in their analysis.



The analysis also confirmed results of previous studies indicating that male gender, older age, diabetes and high C-reactive protein levels, a measure of inflammation, are associated with an increased risk for heart disease.



While there is no set Mediterranean diet, it commonly emphasizes fresh fruits and vegetables, whole grains, beans, nuts, fish, olive oil and even a glass of red wine. Earlier research has shown that following the traditional Mediterranean diet is linked to weight loss, reduced risk of diabetes, lower blood pressure and lower blood cholesterol levels, in addition to reduced risk of heart disease.



"Because the Mediterranean diet is based on food groups that are quite common or easy to find, people around the world could easily adopt this dietary pattern and help protect themselves against heart disease with very little cost," Georgousopoulou said.



Among study participants, women tended to follow the Mediterranean diet more closely than did men. Despite the fact that Greece is the cradle of the Mediterranean diet, urbanization has led many Greeks to adopt a more Western diet over the past four decades, he said.



The study was limited to participants living in and around Athens, Greece, so the sample does not necessarily reflect the health conditions or dietary patterns of people in more rural areas or the rest of the world. However, previous studies have also linked the Mediterranean diet with reduced cardiovascular risks, including the Nurses' Health Study, which included nearly 75,000 American nurses who were tracked over a 30-year period. Additional studies in other adult populations would further advance understanding of the diet's influence on heart disease risk.

“Prudent” diet (higher intake of fruits and vegetables; associated with a lower heart attack risk

The typical Western diet — fried foods, salty snacks and meat — accounts for about 30 percent of heart attack risk across the world, according to a study of dietary patterns in 52 countries reported in Circulation: Journal of the American Heart Association.

Researchers identified three dietary patterns in the world:
• Oriental: higher intake of tofu, soy and other sauces;
• Prudent: higher intake of fruits and vegetables; and
• Western: higher intake of fried foods, salty snacks, eggs and meat.

The Prudent diet was associated with a lower heart attack risk than the Oriental, researchers said.

“The objective of this study was to understand the modifiable risk factors of heart attacks at a global level,” said Salim Yusuf, D.Phil., the study’s senior author.

Previous studies have reached similar conclusions about the Prudent and Western diet in the United States and Europe. This study broadens those findings and identifies a unique dietary pattern that researchers labeled “Oriental” (because of a higher content of food items typical of an Oriental diet.) The dietary pattern recommended by the American Heart Association is similar to the Prudent diet described in this study.

“This study indicates that the same relationships that are observed in Western countries exist in different regions of the world,” said Yusuf, professor of medicine at McMaster University and director of the Population Health Research Institute at Hamilton Health Sciences in Ontario, Canada.

Researchers analyzed the INTERHEART study, which documents the association of various risk factors and the risk of heart attack in about 16,000 participants in 52 countries. Here, they analyzed 5,761 heart attack cases and compared them to 10,646 people without known heart disease (controls).

The researchers created a dietary risk score questionnaire for heart attacks patients, based on 19 food groups and adjusted it for dietary preferences for each country. Trained medical personnel interviewed the heart attack patients and the control group. The questionnaires included healthy food items (such as fruits and vegetables) and unhealthy food items (such as fried foods and salty snacks).

“A simple dietary score, which included both good and bad foods with the higher score indicating a worse diet, showed that 30 percent of the risk of heart disease in a population could be related to poor diet,” said Romania Iqbal, Ph.D., lead author of the study.

After adjusting for known risk factors, researchers found:
• People who consumed the Prudent diet of more fruits and vegetables had a 30 percent lower risk of heart attack compared to people who ate little or no fruits and vegetables.
• People who consumed the Western diet had a 35 percent greater risk of having a heart attack compared to people who consumed little or no fried foods and meat.
• The Oriental pattern showed no relationship with heart attack risk.

Researchers said that while some components of the Oriental pattern may be protective, others such as the higher sodium content of soy sauces, may increase cardiovascular risk, neutralizing any relationship.

It’s expensive and time-consuming to establish a large and long-term study examining the relationship of diet and heart attack in every region of the world. So the approach of this study is the only feasible way to examine the relationship to diet and heart disease from multiple populations in a relatively short time at an affordable cost, Yusuf said.

Data from this study helped confirm that changes in dietary intake, including the consumption of more fruits and vegetables, can help reduce the risk of having a heart attack in populations worldwide, he said.

“At the same time, an unhealthy dietary intake, assessed by a simple dietary risk score, accounts for nearly one-third of the world population’s attributable risk,” Yusuf said.


Mediterranean diet linked to improved CV function in erectile dysfunction patients

Erectile dysfunction patients with poor diets have more vascular and cardiac damage

The Mediterranean diet is linked to improved cardiovascular performance in patients with erectile dysfunction, according to research presented at EuroEcho-Imaging 2014 by Dr Athanasios Angelis from Greece. Patients with erectile dysfunction who had poor adherence to the Mediterranean diet had more vascular and cardiac damage.

EuroEcho-Imaging is the annual meeting of the European Association of Cardiovascular Imaging (EACVI), a branch of the European Society of Cardiology (ESC), and is held 3-6 December in Vienna, Austria.

Dr Angelis said: "Erectile dysfunction is not a symptom of ageing, it is a bad sign from the body that something is wrong with the vasculature. In 80% of cases erectile dysfunction is caused by vascular problems and is a warning that patients are at increased risk of a heart attack or stroke."

He added: "The Mediterranean diet is associated with lower cardiovascular events and could be a way to help erectile dysfunction patients lower their risk. We wanted to investigate whether patients with erectile dysfunction who follow this diet have less vascular and cardiac damage."
The study included 75 men with erectile dysfunction, aged 56 years on average, who attended the Department of Cardiology at Hippokration Hospital in Athens, Greece. Adherence to the Mediterranean diet was assessed with the Med-Diet Score1 which ranks patients as high (30-55), intermediate (21-29) or low (0-20) according to consumption of cereals, fruit, vegetables, meat, fish, dairy products, wine and olive oil.


Vascular function was assessed by measuring two aspects of atherosclerosis, namely atheromatosis and arteriosclerosis. Atheromatosis refers to the development of atheroma (plaque), a fatty deposit in the intima (inner lining) of the artery, and was measured by the intima-media thickness (IMT) of the common carotid artery. Arteriosclerosis refers to the stiffening of the arteries and was evaluated with carotid-femoral pulse wave velocity (PWV). Heart involvement was based on diastolic function and left ventricular mass.


The researchers found that a lower Med-Diet Score correlated with significantly worse vascular and heart function. These patients had greater IMT and aortic stiffness as well as higher left ventricular mass and more profound diastolic dysfunction.


Dr Angelis said: "Patients with erectile dysfunction who had unhealthy diets had more vascular and cardiac damage than those who followed the Mediterranean diet. Previous studies have shown that patients with erectile dysfunction have vascular damage but we found that the heart is also damaged. This may help to further explain why these patients are more prone to cardiovascular events. The formation of atheroma, the stiffening of the arteries, and the poor functioning of the heart can eventually lead to a cardiac event."


He added: "Our findings suggest that adopting the Mediterranean diet can improve the cardiovascular risk profile of patients with erectile dysfunction and may reduce their chances of having a heart attack or stroke. This needs to be tested in a larger study."


The Mediterranean diet is characterised by daily consumption of fruit, vegetables, unrefined cereals and pasta, olive oil and nuts. Dairy products are eaten in modest amounts, in the form of yogurt and cheese. Consumption of meat is low, with red meat once a week and poultry once a week considered a healthy level. A modest amount of wine can be consumed, and refined sugar should be avoided in favour of natural desserts like fruit.


Dr Angelis said: "Really simple changes in our diet may help a lot, for example using olive oil which contains monounsaturated fat. If someone doesn't have the money to buy some of the foods they can substitute them with others, for example nuts are a good source of monounsaturated fat. Sometimes it's difficult to adopt something if you consider that it's part of a prescription, but the Mediterranean diet is not a prescription, it's a lifestyle. It's about having an awareness of what foods are healthy or unhealthy."


He concluded: "Patients who have erectile dysfunction and don't adhere to the Mediterranean diet have vascular and cardiac damage and are at increased risk of heart attack and stroke. Our findings suggest that adopting a healthy diet can reduce that risk. We also advise patients to stop smoking, exercise and ensure that they have healthy levels of blood pressure and lipids."

Diets high in fruit, vegetables, whole grains and nuts among factors to lower first-time stroke risk



American Heart Association/American Stroke Association guideline
 
Eating Mediterranean or DASH-style diets, regularly engaging in physical activity and keeping your blood pressure under control can lower your risk of a first-time stroke, according to updated AHA/ASA guideline published in the American Heart Association's journal Stroke.

"We have a huge opportunity to improve how we prevent new strokes, because risk factors that can be changed or controlled — especially high blood pressure — account for 90 percent of strokes," said James Meschia, M.D., lead author of the study and professor and chairman of neurology at the Mayo Clinic in Jacksonville, Florida.

The updated guidelines recommend these tips to lower risk:

  • Eat a Mediterranean or DASH-style diet, supplemented with nuts.
  • Monitor high blood pressure at home with a cuff device.
  • Keep pre-hypertension from becoming high blood pressure by making lifestyle changes such as getting more physical activity, eating a healthy diet and managing your weight.
  • Reduce the amount of sodium in your diet; sodium is found mostly in salt.
  • Visit your healthcare provider annually for blood pressure evaluation.
  • If your medication to lower blood pressure doesn't work or has bad side effects, talk to your healthcare provider about finding a combination of drugs that work for you.
  • Don't smoke. Smoking and taking oral birth control pills can significantly increase your stroke risk. If you're a woman who experiences migraines with aura, smoking raises your risk of stroke even more than in the general population.
  • Mediterranean-style or DASH-style diets are similar in their emphasis on fruits, vegetables, whole grains, legumes, nuts, seeds, poultry and fish. Both are limited in red meat and foods containing saturated fats, which are mostly found in animal-based products such as meat, butter, cheese and full-fat dairy.
  • Mediterranean-style diets are generally low in dairy products and DASH-style diets emphasize low-fat dairy products.
  • Avoiding secondhand smoke also lowers stroke and heart attack risks, according to the guidelines.

The writing committee reviewed existing guidelines, randomized clinical trials and some observational studies.

"Talking about stroke prevention is worthwhile," Meschia said. "In many instances, stroke isn't fatal, but it leads to years of physical, emotional and mental impairment that could be avoided."

Mediterranean-style diets most successful in lowering CV risk


A study published in The American Journal of Medicine reveals that a whole diet approach, which focuses on increased intake of fruits, vegetables, nuts, and fish, has more evidence for reducing cardiovascular risk than strategies that focus exclusively on reduced dietary fat. This new study explains that while strictly low-fat diets have the ability to lower cholesterol, they are not as conclusive in reducing cardiac deaths. By analyzing major diet and heart disease studies conducted over the last several decades, investigators found that participants directed to adopt a whole diet approach instead of limiting fat intake had a greater reduction in cardiovascular death and non-fatal myocardial infarction.

Early investigations of the relationship between food and heart disease linked high levels of serum cholesterol to increased intake of saturated fat, and subsequently, an increased rate of coronary heart disease. This led to the American Heart Association's recommendation to limit fat intake to less than 30% of daily calories, saturated fat to 10%, and cholesterol to less than 300 mg per day.

"Nearly all clinical trials in the 1960s, 70s and 80s compared usual diets to those characterized by low total fat, low saturated fat, low dietary cholesterol, and increased polyunsaturated fats," says study co-author James E. Dalen, MD, MPH, Weil Foundation, and University of Arizona College of Medicine. "These diets did reduce cholesterol levels. However they did not reduce the incidence of myocardial infarction or coronary heart disease deaths."

Carefully analyzing studies and trials from 1957 to the present, investigators found that the whole diet approach, and specifically Mediterranean-style diets, are effective in preventing heart disease, even though they may not lower total serum or LDL cholesterol. The Mediterranean-style diet is low in animal products and saturated fat, and encourages intake of monounsaturated fats found in nuts and olive oil. In particular, the diet emphasizes consumption of vegetables, fruit, legumes, whole grains, and fish.

"The potency of combining individual cardioprotective foods is substantial – and perhaps even stronger than many of the medications and procedures that have been the focus of modern cardiology," explains co-author Stephen Devries, MD, FACC, Gaples Institute for Integrative Cardiology (Deerfield, IL) and Division of Cardiology, Northwestern University (Chicago, IL). "Results from trials emphasizing dietary fat reduction were a disappointment, prompting subsequent studies incorporating a whole diet approach with a more nuanced recommendation for fat intake."

Based on the data from several influential studies, which are reviewed in the article, Dalen and Devries concluded that emphasizing certain food groups, while encouraging people to decrease others, is more cardioprotective and overall better at preventing heart disease than a blanket low-fat diet. Encouraging the consumption of olive oil over butter and cream, while increasing the amount of vegetables, fruits, whole grains, nuts, and fish promises to be more effective.

"The last fifty years of epidemiology and clinical trials have established a clear link between diet, atherosclerosis, and cardiovascular events," concludes Dr. Dalen. "Nutritional interventions have proven that a 'whole diet' approach with equal attention to what is consumed as well as what is excluded is more effective in preventing cardiovascular disease than low fat, low cholesterol diets."

Mediterranean Diet Helps Cut Risk of Heart Attack, Stroke

Results of the PREDIMED study, aimed at assessing the efficacy of the Mediterranean diet in the primary prevention of cardiovascular diseases, have been published in The New England Journal of Medicine. They show that the Mediterranean diet supplemented with extra-virgin olive oil or tree nuts reduces by 30 percent the risk of suffering a cardiovascular death, a myocardial infarction or a stroke.

The study has been coordinated by the researcher Ramon Estruch, from the Faculty of Medicine of the UB and the Hospital Clínic -- affiliated centres with the health campus of the UB, HUBc -- and has had the collaboration of the professor Rosa M. Lamuela and her team from the Natural Antioxidant Research Group of the Faculty of Pharmacy -- located at the campus of international excellence BKC -- which determined the biomarkers of Mediterranean diet consumption.

The research is part of the project PREDIMED, a multicentre trial carried out between 2003 and 2011 to study the effects of the Mediterranean diet on the primary prevention of cardiovascular diseases. The study was funded by the Carlos III Health Institute by means of the cooperative research thematic network (RETIC RD06/0045) and the CIBER of Physiopathology of Obesity and Nutrition (CIBERobn).

A total of 7,447 people with major cardiovascular risk factors participated in the study. They were divided into three dietary intervention groups: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with nuts (walnuts, almonds, hazelnuts), and a low-fat diet (animal and vegetable). A dietician visited the patients every three months and they attended dietary training group sessions, in which they received detailed information about the Mediterranean and the low-fat diet, and the food included in each one. Moreover, they were provided with shopping lists, menus and recipes adapted to each type of diet and each season of the year.

During the study, those participants who followed any of the two types of Mediterranean diet received freely extra-virgin olive oil (one litre per week), and nuts (30 grams per day; 15 grams of walnuts, 7.5 grams of almonds and 7.5 grams of hazelnuts).

After five years, it has been proved that participants who followed any of the two types of Mediterranean diet showed a substantial reduction in the risk of suffering a cardiovascular death, a myocardial infarction or a stroke.

According to the researchers, the results of PREDIMED study are relevant as they prove that a high-vegetable fat diet is healthier at a cardiovascular level than a low-fat diet. The authors state that the study has been controversial as it provides new data to reject the idea that it is necessary to reduce fats in order to improve cardiovascular health.


Mediterranean Diet: Ingredients for a Heart-Healthy Eating Approach

In countries bordering the Mediterranean Sea, heart disease is less common than in the United States. Researchers believe that foods common to the area are a major reason for this difference.

Eating generous amounts of fruits and vegetables and whole grains. In most Mediterranean countries, fruits and vegetables are part of every meal. They are naturally low in fat and sodium and have no cholesterol. Many are loaded with antioxidants, which may help prevent cholesterol buildup in the arteries.

Breads, pastas and rice are typically made from whole grains instead of grains that have been refined and lost some nutritional value. Whole grains provide an excellent source of fiber and contain a variety of vitamins and minerals. Certain types of dietary fiber also can help reduce blood cholesterol levels and may lower the overall risk of heart disease.

Getting most fats from healthy sources. Olive oil is the primary fat used in Mediterranean cooking. This type of monounsaturated fat can help reduce low-density lipoprotein (LDL, or “bad”) cholesterol levels when used in place of unhealthy saturated fats or trans fats. Other healthy fats in the Mediterranean diet include polyunsaturated fats and omega-3 fatty acids, which can be found in vegetable oils, nuts and fish. Omega-3 fatty acids are considered especially beneficial because they can lower triglycerides, a type of blood fat; improve the health of blood vessels; and protect against death from sudden heart attack.

Consuming very little red meat and eating generous amounts of legumes. Red meat isn’t a big part of the Mediterranean diet. Legumes, a class of vegetables that includes beans, peas and lentils -- offer a source of protein that’s typically low in fat and contains no cholesterol.

Drink wine, in moderation. Some research has shown that a light intake of alcohol is associated with a reduced risk of heart disease. In the Mediterranean, the alcoholic beverage consumed most is wine, which may offer slightly greater heart health benefits than other forms of alcohol. For women (and men over age 65), the recommendation is no more than one glass, or 5 ounces, of wine daily. For men under age 65, it’s no more than two glasses, or 10 ounces, daily.

Other aspects of the Mediterranean diet include dining on fish or shellfish as least twice a week; lesser amounts of dairy products, such as cheese and yogurt; incorporating small portions of nuts and seeds daily; eating sweets only on occasion; using herbs and spices instead of salt to flavor food; getting plenty of physical activity; and eating meals with family and friends.

The Mediterranean diet may be best known as a heart-healthy eating plan, but some studies suggest that it may also reduce the risk of diabetes, certain cancers, obesity and Alzheimer’s disease.

Mediterranean diet helps men lower bad cholesterol


A heart-healthy diet helped men at high risk for heart disease reduce their bad cholesterol, regardless of whether they lost weight, in a study presented at the American Heart Association’s Arteriosclerosis, Thrombosis and Vascular Biology 2013 Scientific Sessions.

The 19 24- to 62-year-old men in the study had metabolic syndrome, which refers to three or more significant risk factors for heart disease and stroke. The risk factors included in this study were high waist circumference, high blood pressure, high levels of triglycerides and fasting glucose and low levels of high density lipoprotein or HDL “good” cholesterol.

For five weeks, the men followed a standard North American diet which is high in fats, carbohydrates, refined sugar and red meat. For a second five weeks, they ate a Mediterranean-style diet, which is high in fruits, vegetables and whole grains, and low in red meat. It also includes olive oil and moderate wine drinking.

The men then went on a 20-week weight-loss regime, then another five weeks of Mediterranean eating.

Regardless of whether patients lost weight, following the Mediterranean-style diet resulted in a 9 percent decrease in levels of low density lipoprotein (LDL) known as “bad” cholesterol. Similarly, blood concentrations of the protein part of the lipoprotein, called apolipoproteinB, dropped 9 percent after eating Mediterranean-style. Apolipoprotein plays an important role in lipid transport and metabolism.

“The Mediterranean-style diet, or MedDiet, may be recommended for effective management of the metabolic syndrome and its related risk of cardiovascular disease,” said Caroline Richard, M.Sc., study lead author and a registered dietician and Ph.D. candidate in nutrition.

Healthy diet may help prevent recurrent heart attacks, strokes


If you have cardiovascular disease, a heart-healthy diet may help protect you from recurrent heart attacks and strokes, according to new research (December, 2012) in the American Heart Association journal Circulation.

"At times, patients don't think they need to follow a healthy diet since their medications have already lowered their blood pressure and cholesterol — that is wrong," said Mahshid Dehghan, Ph.D., study author and a nutritionist at the Population Health Research Institute, McMaster University in Hamilton, Ontario, Canada. "Dietary modification has benefits in addition to those seen with aspirin, angiotensin modulators, lipid-lowering agents and beta blockers."

For the study, 31,546 adults (average age 66.5) with cardiovascular disease or end organ damage were asked how often they consumed milk, vegetables, fruits, grains, fish, meat and poultry in the past 12 months. They were also asked about lifestyle choices such as alcohol consumption, smoking and exercise. Total scores were determined by daily fruits, vegetables, grains and milk consumed and the ratio of fish to meats consumed.

During a follow-up of nearly five years, participants experienced 5,190 cardiovascular events.

Researchers found those who ate a heart-healthy diet had a:

35 percent reduction in risk for cardiovascular death;
14 percent reduction in risk for new heart attacks;
28 percent reduction in risk for congestive heart failure; and
19 percent reduction in risk for stroke.
Food habits in different regions of the world varied considerably; however, a healthy diet was associated with prevention of recurrent cardiovascular disease throughout the world in countries with different economic levels, Dehghan said.

A diet rich in vegetables and fruits with a higher ratio of fish to meats appeared to be more beneficial for preventing heart disease than for preventing cancer, fractures or injury.

"Physicians should advise their high-risk patients to improve their diet and eat more vegetables, fruits, grains and fish," Dehghan said. "This could substantially reduce cardiovascular recurrence beyond drug therapy alone and save lives globally."

Study Affirms ‘Mediterranean Diet’ Improves Heart Health


A team of Johns Hopkins researchers has uncovered further evidence of the benefits of a balanced diet that replaces white bread and pasta carbohydrates with unsaturated fat from avocados, olive oil and nuts — foods typical of the so-called “Mediterranean diet.”

In a report prepared for the American Heart Association’s scientific sessions in Orlando (November, 2011) , the Johns Hopkins investigators say swapping out certain foods can improve heart health in those at risk for cardiovascular disease, even if the dietary changes aren’t coupled with weight loss.

“The introduction of the right kind of fat into a healthy diet is another tool to reduce the risk of future heart disease,” says Meghana Gadgil, M.D., M.P.H., a postdoctoral fellow in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine who presented the research.

Gadgil and her colleagues analyzed data from the OmniHeart Trial, which studied the cardiovascular effects of three different balanced diets on 164 people with mild hypertension but no diabetes. The researchers compared the body’s ability to regulate blood sugar and maintain healthy insulin levels while on a carbohydrate-rich diet, a protein-rich diet and a diet rich in unsaturated fats. People whose bodies fail to effectively use insulin usually develop type 2 diabetes, which is a major risk factor for heart disease.

The researchers found that a generally balanced diet higher in unsaturated fats such as those in avocados, olive oil and nuts improves insulin use significantly more than a diet high in carbohydrates, particularly such refined carbs as white bread and pasta. The preferred diet is very similar to the Mediterranean diet, inspired by the foods of southern Italy and Greece and emphasizing healthy fats, fruits and vegetables.

Each participant in the study was fed each of the three diets for six weeks in a row, with two to four weeks off in between. Blood samples were collected after fasting periods in weeks four and six of each diet, and used to monitor insulin and glucose levels. The study was designed to keep participants at their starting weights. “A lot of studies have looked at how the body becomes better at using insulin when you lose weight,” Gadgil says. “We kept the weight stable so we could isolate the effects of the macronutrients. What we found is that you can begin to see a beneficial impact on heart health even before weight loss.”


Mediterranean Diet: Ingredients for a Heart-Healthy Eating Approach

In countries bordering the Mediterranean Sea, heart disease is less common than in the United States. Researchers believe that foods common to Greece and southern Italy are a major reason for this difference.

The February, 2010 issue of Mayo Clinic Women’s HealthSource covers key components of the Mediterranean diet as well as reasons why this approach is beneficial to heart health. Key components include:

Eating generous amounts of fruits and vegetables and whole grains. In most Mediterranean countries, fruits and vegetables are part of every meal. They are naturally low in fat and sodium and have no cholesterol. Many are loaded with antioxidants, which may help prevent cholesterol buildup in the arteries.

Breads, pastas and rice are typically made from whole grains instead of grains that have been refined and lost some nutritional value. Whole grains provide an excellent source of fiber and contain a variety of vitamins and minerals. Certain types of dietary fiber also can help reduce blood cholesterol levels and may lower the overall risk of heart disease.

Getting most fats from healthy sources. Olive oil is the primary fat used in Mediterranean cooking. This type of monounsaturated fat can help reduce low-density lipoprotein (LDL, or “bad”) cholesterol levels when used in place of unhealthy saturated fats or trans fats. Other healthy fats in the Mediterranean diet include polyunsaturated fats and omega-3 fatty acids, which can be found in vegetable oils, nuts and fish. Omega-3 fatty acids are considered especially beneficial because they can lower triglycerides, a type of blood fat; improve the health of blood vessels; and protect against death from sudden heart attack.

Consuming very little red meat and eating generous amounts of legumes. Red meat isn’t a big part of the Mediterranean diet. Legumes, a class of vegetables that includes beans, peas and lentils -- offer a source of protein that’s typically low in fat and contains no cholesterol.

Drink wine, in moderation. Some research has shown that a light intake of alcohol is associated with a reduced risk of heart disease. In the Mediterranean, the alcoholic beverage consumed most is wine, which may offer slightly greater heart health benefits than other forms of alcohol. For women (and men over age 65), the recommendation is no more than one glass, or 5 ounces, of wine daily. For men under age 65, it’s no more than two glasses, or 10 ounces, daily.

Other aspects of the Mediterranean diet include dining on fish or shellfish as least twice a week; lesser amounts of dairy products, such as cheese and yogurt; incorporating small portions of nuts and seeds daily; eating sweets only on occasion; using herbs and spices instead of salt to flavor food; getting plenty of physical activity; and eating meals with family and friends.

The Mediterranean diet may be best known as a heart-healthy eating plan, but some studies suggest that it may also reduce the risk of diabetes, certain cancers, obesity and Alzheimer’s disease.
  

Mediterranean-style diet improves heart function


A study of twins shows that even with genes that put them at higher risk of cardiovascular disease, eating a Mediterranean-style diet can improve heart function, according to research reported in Circulation: Cardiovascular Quality and Outcomes, an American Heart Association journal.

Using data from the Emory Twins Heart Study, researchers found that men eating a Mediterranean-style diet had greater heart rate variability (HRV) than those eating a Western-type diet. Heart rate variability refers to variation in the time interval between heart beats during everyday life – reduced HRV is a risk factor for coronary artery disease and sudden death.

“This means that the autonomic system controlling someone’s heart rate works better in people who eat a diet similar to a Mediterranean diet,” said Jun Dai, M.D., Ph.D., study author and assistant professor of nutrition and epidemiology at Indiana University in Bloomington.

Eating a Mediterranean-style diet — one characterized by low saturated fats and high in fish, fruits, vegetables, legumes, nuts, olive oil, cereals and moderate alcohol consumption — reduces a person’s heart disease risk. But until now, the way the diet helps reduce the risk of coronary disease remains unknown.

Dai and her colleagues analyzed dietary data obtained from a food frequency questionnaire and cardiac data results from 276 identical and fraternal male twins. They scored each participant on how closely his food intake correlated with the Mediterranean diet; the higher the score, the greater the similarity to a Mediterranean-style diet.

To measure HRV, participants had their heart’s electrical activity continuously measured and recorded with a Holter Monitor, a portable, battery operated electrocardiogram device.

Using twins allowed team members to assess the influence of the diet on HRV while controlling for genetic and other familial influence.

Among the study’s key findings:

- Measurements of HRV showed that the higher a person’s diet score, the more variable the heart beat-to-beat time interval — 10 percent to 58 percent (depending on the HRV measure considered) for men in the top Mediterranean diet score quarter compared to those in the lowest quarter; this equates to a 9 percent to 14 percent reduction in heart-related death.
- Genetic influence on HRV frequency ranged from 20 percent – 95 percent, depending on the HRV measure considered.
-       The study cannot be generalized to women or other ethnic groups because 94 percent of participants were non-Hispanic white males.

Mediterranean diet = lower heart disease


A review of previously published studies suggests that vegetable and nut intake and a Mediterranean dietary pattern appear to be associated with a lower risk for heart disease, according to a report published in the April 13, 2009 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. However, intake of trans-fatty acids and foods with a high glycemic index may be harmful to heart health.

"The relationship between dietary factors and coronary heart disease has been a major focus of health research for almost half a century," the authors write as background information in the article. Although "a wealth of literature" has been published on the topic, "the strength of the evidence supporting valid associations has not been evaluated systematically in a single investigation."

Andrew Mente, Ph.D., of the Population Health Research Institute, and colleagues conducted a systematic search for articles investigating dietary factors in relation to heart disease published between 1950 and June 2007. A total of 146 prospective cohort studies (looking back on the habits of a particular group of individuals) and 43 randomized controlled trials (where participants are randomly assigned to a dietary intervention or a control group) were identified and included in the systematic review.

When the researchers pooled the study results and applied a predefined algorithm, "we identified strong evidence of a causal relationship for protective factors, including intake of vegetables, nuts and monounsaturated fatty acids and Mediterranean, prudent and high-quality dietary patterns, and harmful factors, including intake of trans–fatty acids and foods with a high glycemic index or load and a western dietary pattern," they write. "Among these dietary exposures, however, only a Mediterranean dietary pattern has been studied in randomized controlled trials and significantly associated with coronary heart disease."

In addition, modest relationships were found supporting a causal relationship between intake of several other foods and vitamins and heart disease risk, including fish, omega-3 fatty acids from marine sources, folate, whole grains, alcohol, fruits, fiber and dietary vitamins E and C and beta carotene. Weak evidence also supported causal relationships between vitamin E and ascorbic acid supplements, saturated and polyunsaturated fatty acids and total fats, alpha-linoleic acid, meat, eggs and milk.

"The modest or weak evidence of these dietary exposures is mostly consistent with the findings of randomized controlled trials, although randomized controlled trials have yet to be conducted for several factors," the authors write. "Taken together, these findings support a causal relationship between only a few dietary exposures and coronary heart disease, whereas the evidence for most individual nutrients or foods is too modest to be conclusive."

"Although investigations of dietary components may help to shed light on mechanisms behind the benefits of dietary patterns, it is unlikely that modifying the intake of a few nutrients or foods would substantially influence coronary outcomes," they conclude. "Our findings support the strategy of investigating dietary patterns in cohort studies and randomized controlled trials for common and complex chronic diseases such as coronary heart disease."


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