Legumes May Lower Risk of Type 2 Diabetes

Type 2 diabetes is a serious health concern in the United States and across the globe. New research shows that a high consumption of legumes significantly reduces the risk of developing the disease.
[various types of legumes]
A new study suggests that a high consumption of legumes can reduce the risk of type 2 diabetes by 35 percent.

The legume family consists of plants such as alfalfa, clover, peas, peanuts, soybeans, chickpeas, lentils, and various types of beans.

As a food group, they are believed to be particularly nutritious and healthful. One of the reasons for this is that they contain a high level of B vitamins, which help the body to make energy and regulate its metabolism.

Additionally, legumes are high in fiber and contain minerals such as calcium, magnesium, and potassium. They also comprise a variety of so-called phytochemicals – bioactive compounds that further improve the body’s metabolism and have been suggested to protect against heart disease and diabetes.

Finally, legumes are also considered to be a “low glycemic index food,” which means that blood sugar levels increase very slowly after they are consumed.

To make people aware of the many health benefits of legumes, the year 2016 has been declared the International Year of Pulses by the Food and Agriculture Organization of the United Nations. Pulses are a subgroup of legumes.

Because of their various health benefits, it has been suggested that legumes protect against the onset of type 2 diabetes – a serious illness that affects around 29 million people in the U.S. and more than 400 million adults worldwide. However, little research has been carried out to test this hypothesis.

Therefore, researchers from the Unit of Human Nutrition at the Universitat Rovira i Virgili in Tarragona, Spain, together with other investigators from the Prevención con Dieta Mediterránea (PREDIMED) study, set out to investigate the association between legume consumption and the risk of developing type 2 diabetes in people at an increased risk of cardiovascular disease.

The study also analyzes the effects of substituting legumes with other foods rich in proteins and carbohydrates, and the findings were published in the journal Clinical Nutrition.

High intake of lentils lowers risk of type 2 diabetes by 33 percent

The team investigated 3,349 participants in the PREDIMED study who did not have type 2 diabetes at the beginning of the study. The researchers collected information on their diets at the start of the study and every year throughout the median follow-up period of 4.3 years.

Individuals with a lower cumulative consumption of legumes had approximately 1.5 weekly servings of 60 grams of raw legumes, or 12.73 grams per day. A higher legume consumption was defined as 28.75 daily grams of legumes, or the equivalent of 3.35 servings per week.

Using Cox regression models, the researchers analyzed the association between the incidence of type 2 diabetes and the average consumption of legumes such as lentils, chickpeas, dry beans, and fresh peas.

Overall, during the follow-up period, the team identified 266 new cases of type 2 diabetes.

The study revealed that those with a higher intake of legumes were 35 percent less likely to develop type 2 diabetes than their counterparts who consumed a smaller amount of legumes. Of all the legumes studied, lentils had the strongest association with a low risk of type 2 diabetes.

In fact, individuals with a high consumption of lentils (defined as almost one weekly serving) were 33 percent less likely to develop diabetes compared with their low-consumption counterparts – that is, the participants who had less than half a serving per week.

Additionally, the researchers found that replacing half a serving per day of legumes with an equivalent portion of protein- and carbohydrate-rich foods including bread, eggs, rice, or potatoes also correlated with a reduced risk of diabetes.

The authors conclude that:

“A frequent consumption of legumes, particularly lentils, in the context of a Mediterranean diet, may provide benefits on type 2 diabetes prevention in older adults at high cardiovascular risk.”

Mediterranean Diet Enriched with Virgin Olive Oil May Protect the Heart

Forget chocolates and roses this Valentine’s day. Instead, cook up a Mediterranean-inspired meal with lashings of virgin olive oil to win and protect your lover’s, heart. New research reports that a Mediterranean diet rich in virgin olive oil may boost the cardioprotective effects of “good” cholesterol.
[Sandwich with mozzarella, sun-dried tomatoes and arugula]
Consuming a Mediterranean diet rich in virgin olive oil may protect the heart.

Montserrat Fitó, Ph.D., was the senior author of the new research and coordinator of the Cardiovascular Risk and Nutrition Research Group at the Hospital del Mar Medical Research Institute in Barcelona, Spain, as well as the Ciber of Physiopathology of Obesity and Nutrition, also in Spain. Fitó and team’s findings were published in the American Heart Association’s journal Circulation.

There are two types of molecules called lipoproteins that carry cholesterol in the blood: low-density lipoprotein (LDL) and high-density lipoprotein (HDL).

LDL is known as “bad” cholesterol, since having high levels of LDL can bring about plaque buildup in the arteries, which can result in heart disease and stroke. HDL is known as “good” cholesterol; HDL absorbs cholesterol and carries it to the liver where it is flushed from the body. Having high levels of HDL reduces heart disease and stroke.

Mediterranean diets compared with healthy control diet

A growing body of evidence supports the theory that the Mediterranean diet protects against the development of heart disease. Studies have also shown that the Mediterranean diet improves the lipid profile of HDLs.

“However, studies have shown that HDL doesn’t work as well in people at high risk for heart attacks, strokes, and other cardiovascular diseases and that the functional ability of HDL matters as much as its quantity,” explains Fitó. “At the same time, small-scale trials have shown that consuming antioxidant-rich foods like virgin olive oil, tomatoes, and berries improved HDL function in humans. We wanted to test those findings in a larger, controlled study,” she adds.

The research team aimed to determine whether eating a Mediterranean diet enriched with virgin olive oil or nuts over a long period of time would improve the beneficial properties of HDL in humans.

Fitó and collaborators randomly selected a total of 296 individuals who had a high risk of heart disease and were participating in the Prevención con Dieta Mediterránea study. The participants had an average age of 66 and were assigned to one of three diets for a year.

The first diet was a traditional Mediterranean diet enriched with around 4 tablespoons of virgin olive oil per day. The second, a traditional Mediterranean diet supplemented with a fistful of nuts each day. The third diet was a healthful “control” diet that contained a reduced amount of red meat, high-fat dairy products, processed foods, and sweets.

Both Mediterranean diets emphasized the inclusion of fruit, vegetables, legumes (such as beans, chickpeas, lentils, and whole grains), and moderate amounts of fish and poultry.

Blood tests were conducted at the start and end of the study to measure LDL and HDL levels.

Virgin olive oil-enriched Mediterranean diet enhanced HDL function

The researchers found that total and LDL cholesterol levels were only reduced in the healthful control diet. While none of the three diets significantly increased HDL levels, the two Mediterranean diets improved HDL function, and the improvement was more pronounced in the group enriched with virgin olive oil.

The Mediterranean diet enriched with virgin olive oil improved HDL functions, such as reversing cholesterol transport, providing antioxidant protection, and enabling vasodilation.

Reverse cholesterol transport is the process in which HDL removes cholesterol from plaque in the arteries and takes it to the liver. Antioxidant protection is the ability of HDL to counteract the oxidation of LDL. Oxidation of LDL triggers the development of plaque in the arteries.

Lastly, vasodilator capacity – which relaxes the blood vessels, keeps them open, and keeps the blood flowing – is improved by the Mediterranean diet with virgin olive oil.

Although the control diet was rich in fruits and vegetables like the two Mediterranean diets, the diet was shown to have an adverse impact on HDL’s anti-inflammatory properties. This negative impact was not observed in the Mediterranean diets. A reduction in HDL’s anti-inflammatory capacity is linked with a greater risk of heart disease.

As expected, the researchers only found slight differences in results between the diets, because the variation between the two Mediterranean diets was modest, and the control diet was healthful.

“Following a Mediterranean diet rich in virgin olive oil could protect our cardiovascular health in several ways, including making our ‘good cholesterol’ work in a more complete way.”

Montserrat Fitó

This research could contribute to the development of novel therapeutic targets, such as new antioxidant-rich foods, nutraceuticals, or new drug families that may improve HDL function, conclude the study authors.

Mediterranean Diet Prevents Brain Atrophy, Study Finds

Mounting evidence emphasizes the health benefits of a Mediterranean diet. New research suggests that the healthful diet helps to preserve brain volume in elderly adults.
[mediterranean diet foods]
A new study suggests that a Mediterranean diet could protect against certain changes to the brain in older age.

More and more studies seem to suggest that components of the Mediterranean diet, either in isolation or taken together, can have a beneficial effect on various aspects of human health.

The “traditional” Mediterranean diet – consisting of large amounts of fruits and vegetables, whole grains, olive oil, a moderate amount of fish, dairy, and wine, as well as a limited intake of red meat – has been shown to improve cardiometabolic health.

Research ranging from observational studies to randomized trials has shown the diet to reduce the risk of type 2 diabetes and obesity, aid weight loss, and contribute to the prevention of cardiovascular disease.

Other studies have suggested that the diet helps to keep mental and physical health well into old age and can reduce the risk of premature death.

New research published in Neurology, the medical journal of the American Academy of Neurology, looks specifically at the benefits of the Mediterranean diet on brain health in elderly adults.

Examining link between diet and brain volume in elderly people

Researchers led by Michelle Luciano, Ph.D. – from the University of Edinburgh in Scotland – looked at the effects of the Mediterranean diet (MeDi) on total brain volume, gray matter volume, and the thickness of the cortex.

The authors explain that, with age, the human brain shrinks, and more and more of its cells die. This may cause problems with learning and memory.

The study followed 967 people aged between 73 and 76 years, who lived in Scotland and who did not have dementia, over a period of 3 years.

The 967 participants were asked to complete food questionnaires when they were 70 years old – 3 years prior to collecting data on their brain volume.

Then, 562 of these people had a magnetic resonance imaging brain scan at the age of 73, in order to measure total brain volume, gray matter volume, and cortical thickness. Of these, 401 people had a second brain scan at age 76.

People’s dietary habits were calculated using a food frequency questionnaire. The brain measurements were compared with how well the participants adhered to the MeDi during the 3-year period.

Mediterranean diet accounts for 0.5 percent of total brain volume change

The scientists found an association between MeDi adherence and brain volume.

Participants who did not follow the diet closely were likely to develop brain atrophy over the 3-year interval.

More specifically, poor adherence to the diet was associated with a 0.5 percent greater reduction in total brain volume than those who had followed the diet closely.

A 0.5 percent decrease in brain volume is half the size of what is considered a normal decrease due to the natural aging process.

Researchers adjusted for variables that might have influenced the changes in brain volume, including age, education, and health conditions such as diabetes or hypertension.

The study found no association between the diet and gray matter volume or thickness of the cortex.

Contrary to previous studies, this research did not find a relationship between fish and meat consumption and changes in brain volume. This suggests that other individual components of the diet – or all of its components taken in combination – might be responsible for the association.

Additionally, unlike previous research – which measured the brain at one point in time – this study examined changes in brain volume over time.

“In our study, eating habits were measured before brain volume was, which suggests that the diet may be able to provide long-term protection to the brain. Still, larger studies are needed to confirm these results.”

Michelle Luciano, Ph.D.