May 2017 Issue

Pulses in the Mediterranean Diet
By Sharon Palmer, RDN
Today's Dietitian
Vol. 19, No. 5, P. 22

Pulses—beans, lentils, and peas—are the backbone of the traditional Mediterranean diet, which is associated with multiple health benefits. Take a lesson or two on how these humble foods can be nutritious, as well as delicious, within this cultural eating style.

As I sat in a sun-drenched outdoor café in the charming village of Vamos, Crete, a black-and-white cat rubbing against my ankle, the restaurant owner brought out a large bowl of beans to accompany my tomato, olive, and cucumber salad. The menu did little to describe how the beans might be prepared, but when they arrived I was pleased. The large, fleshy gigantes beans were cooked to just the right texture—a bit firm on the outside, yet creamy on the inside—and they'd been simmered in a broth of tomatoes, onions, carrots, garlic, and fresh oregano. Right before the dish arrived, the chef had drizzled the beans generously with Cretan extra virgin olive oil. And he brought a basket of rustic, toasted bread for an accompaniment, which I used to sop up the savory broth. It might sound simple, yet the meal was one of the most memorable of my entire trip in Greece.

This meal serves as an example of how pulses, such as dried beans, lentils, and peas, are at the very backbone of the traditional Mediterranean diet pattern, which reflects the way of eating in 16 countries surrounding the Mediterranean Sea, including Italy, Morocco, Spain, Greece, France, Turkey, and Lebanon. The key feature of this traditional eating style is a focus on plant foods, such as vegetables, fruits, grains, nuts, seeds, herbs, spices, and, of course, pulses. The main animal food in the diet is seafood, with moderate amounts of poultry, eggs, and dairy products and low amounts of red meat.

"Pulses are the humble backbone of Mediterranean cuisine, appearing in numerous traditional Mediterranean dishes," says Kelly Toups, MLA, RD, LDN, program director at Oldways. "On the Mediterranean Diet Pyramid, pulses appear at the base, alongside fruits, vegetables, grains, olive oil, herbs, and spices, as these wholesome plant foods are the focus of daily meals."

The researcher Ancel Keys, who launched the Seven Countries Study in 1958, is credited as the first to take notice of the associations between the Mediterranean diet and health.1 At that time, the Mediterranean diet—not really a "diet" but a way of life that had evolved over the millennia in this region—was considered the "poor man's" diet. Instead of more expensive protein choices, such as red meat, which wasn't well suited for domestication in the Mediterranean, good old reliable pulses often were turned to as a primary source of protein in this traditional diet. Little did the people of this region suspect that pulses were an important facet in their celebrated vitality.

 "He walks to work daily and labors in the soft light of his Greek isle, midst the droning of crickets and the bray of distant donkeys, in the peace of his land. … His midday, main meal is of eggplant, with large livery mushrooms, crisp vegetables, and country bread dipped in the nectar that is golden Cretan olive oil. … Other meals are hot dishes of legumes seasoned with meats and condiments. The main dish is followed by a tangy salad, then by dates, Turkish sweets, nuts, or succulent fresh fruits. A sharp local wine completes this varied and savory cuisine. This living pattern, repeated six days a week, is climaxed by a happy Saturday evening. … He is handsome, rugged, kindly—and virile. His is the lowest heart-attack risk, the lowest death rate, and the greatest life expectancy in the Western world."

— Henry Blackburn, MD, describing the "low-coronary-risk male" in the Seven Countries Study

"Historically, meats and poultry were much more expensive than they are today, making animal protein harder to come by," Toups says. "In addition, Mediterranean culture before the mid-20th century drew heavily from religion, such as Greek Orthodox and Roman Catholic churches, as well as Islam and Judaism, which dictated frequent periods of religious fasting from meats and poultry. Dried pulses, such as chickpeas, lentils, or cannellini beans, offered a more affordable source of protein to Mediterranean people, and are shelf stable to boot," Toups says.

Health Benefits in Abundance
Today, we know that a body of evidence links the Mediterranean diet with multiple health benefits. According to Oldways, a nonprofit organization well-known for establishing the Mediterranean Diet Pyramid and its programs, hundreds of studies support the health advantages of the Mediterranean diet, including increased lifespan; improved brain function, rheumatoid arthritis, eye health, and fertility; better weight management; and reduced risk of certain cancers, heart disease, high blood pressure, diabetes, Alzheimer's disease, Parkinson's disease, and depression.2 In fact, in the 2015–2020 Dietary Guidelines for Americans, a Healthy Mediterranean-Style Eating Pattern is recommended as one of three eating styles that Americans should consider adopting for optimal health.3 While it's the entire eating pattern that provides benefits associated with the Mediterranean diet, pulses are truly a key characteristic of this diet. The Dietary Guidelines for Americans' Healthy Mediterranean-Style Eating Pattern recommends 11/2 cups per week of cooked beans and peas in a 2,000-kcal/day eating plan.3

Power in the Pulse
Pulses provide a rich source of nutrients in the traditional Mediterranean diet. A 1/2-cup serving contains at least 20% DV for fiber, folate, and manganese; at least 10% DV for protein, potassium, iron, magnesium, and copper; and 6% to 8% DV for selenium and zinc; as well as phytochemicals such as alkaloids, flavonoids, saponins, tannins, and phenolic compounds. The rich lysine content of pulses, when eaten in diets abundant in other plant foods, such as grains, provides a high-quality source of protein in the diet with adequate intakes of all amino acids.

John Sievenpiper, MD, PhD, FRCPC, an associate professor in the department of nutritional sciences at the University of Toronto, is an expert on pulses, having performed research on their benefits. Sievenpiper says, "Dietary pulses result in clinically meaningful improvements in glycemic control, as well as blood lipids, blood pressure, and body weight. These cardiometabolic benefits of dietary pulses translate into an important association with decreased incidence of cardiovascular disease." He explains that clinical practice guidelines have begun to recognize dietary pulses, as there has been a shift away from nutrient-based recommendations to more food and dietary pattern-based recommendations. "Traditional diets that combine the advantages of different foods result in benefits comparable to those seen with medications and provide the best opportunity for addressing the epidemics of obesity, diabetes, and cardiovascular disease," Sievenpiper adds. He recommends that including pulses can be a practical food-based strategy used to the greatest benefits within a healthful dietary pattern such as the Mediterranean diet.

Pulses Historical Roots
Pulses are the third-largest plant family, with more than 19,400 species, according to Sara Rose, vice president and director of government and industry affairs for Bush Brothers & Company. She explains that pulses are dry edible seeds with low fat content and include dried beans, peas, chickpeas, beans, lentils, fava beans/broad beans, black-eyed peas/field peas, pigeon peas, lupines, bambara beans, and bitter vetch.

Members of the pulse family were among the first cultivated plants in the Mediterranean. In many sunny regions around the Mediterranean Sea, the inhabitants turned to farming for sustenance, and pulses were easy to grow, requiring fewer agricultural inputs and resources, and the harvest could be stored for months on end. These plants have the ability to obtain nitrogen from the atmosphere through the action of special bacteria that live in nodules on their roots. This nitrogen goes into the production of protein for humans when people eat the seeds, and when the plant dies it returns nitrogen to the soil, building up soil fertility. This was an important facet for the nutrient-poor soil in the Mediterranean region.4 There's great variety in the Mediterranean's pulses. Native to the region are the important pulses fava, lentils, and chickpeas, as well as lupine beans, bitter vetch, and field peas. Other pulses were introduced later on, such as the cowpea from East Africa, tepary bean from the Americas, and lima bean from Peru.4

"Historically, people did plant and eat pulses, before developed nations came and told them to grow and eat other things that weren't as well suited for them," says Jenny Chandler, a Bristol, England-based food writer and United Nations Food and Agriculture Organization European Special Ambassador for the International Year of the Pulses. "Pulses have an extraordinary, long storage life; they can last for months dried or canned, and they can be planted again in times of disaster. They have a long root system, can grow in marginal areas, and can be grown as an intercrop with other crops. They're adaptive; they have been grown for hundreds of years, and they have the ability to fix nitrogen in the soil, which means less synthetic fertilizers. They're highly water efficient, requiring less water to grow than wheat, rice, or animal foods, and they contribute to food security."

Applying Lessons From the Mediterranean to Promoting Pulses
There are so many reasons—and ways—to inspire your clients to maximize pulses within a healthful eating pattern. "Incorporating more pulses into your meals is a great way to honor the spirit of the Mediterranean diet, while still allowing ample room for creativity," Toups says. "While 'pulses' aren't yet a household name in the US, Western favorites such as burgers, casseroles, and dips are actually very well suited for this versatile food group."

Pulses can be incorporated in each meal occasion: at breakfast with breakfast bean burritos or English-style baked beans, at snack-time with roasted chickpeas and hummus, for lunch with entrée salads sprinkled with kidney beans or lentil soup, and at dinner with entrées such as chili, bean stews, chickpea curry, and falafels.

Toups also suggests that black beans can add sustenance to veggie burger patties, and hold up beautifully to any number of burger toppings. "Hummus, black bean dips, and fava dips make delicious appetizers or game day bites, especially when paired with whole grain crackers or vegetable crudités. And chili recipes, the pride of many home cooks, are delicious when made with kidney beans or other pulses," Toups adds.

— Sharon Palmer, RDN, is the nutrition editor of Today's Dietitian and author of Plant-Powered for Life and The Plant-Powered Diet. She blogs every day at SharonPalmer.com.

References
1. Ancel Keys. The Seven Countries Study website. http://www.sevencountriesstudy.com/about-the-study/investigators/ancel-keys/. Accessed February 21, 2017.

2. Mediterranean diet. Oldways website. http://www.oldwayspt.org/traditional-diets/mediterranean-diet. Accessed February 21, 2017.

3. 2015–2020 Dietary Guidelines for Americans. Office of Disease Prevention and Health Promotion website. https://health.gov/dietaryguidelines/2015/. Accessed February 15, 2017.

4. Wright CA. The world of legumes. Clifford A. Wright website. http://www.cliffordawright.com/caw/food/entries/display.php/topic_id/6/id/103/. Accessed February 15, 2017.