Dr Catherine Itsiopoulos on the health benefits of legumes, plus a recipe from 'The Mediterranean Diet'

Legumes represent a major protein source in Mediterranean diets, particularly during religious fasting periods where vegan diets are followed.(1) Common legumes in the Mediterranean diet include lentils, cannellini beans, lupins, peas and peanuts. Fassoulada, a traditional Greek tomato based soup with cannellini beans is considered the national dish of Greece.

The “Food Habits in Later Life” (FHILL) study was a prospective cohort study of 785 elderly people from long living populations in Japan, Sweden, Greece and Australia and demonstrated that Australian Greek migrants had a greatest longevity compared with other cohorts and this was attributed to their greater adherence to a traditional Mediterranean diet.(2) When individual components of diet were examined legume consumption was associated with an 8% reduction in mortality for every 20g increase in legume intake. No other individual foods were found to be significant in predicting survival.

Recent reviews shed some light on why people who eat legumes regularly are likely to live longer. A recent systematic review and meta-analysis including 27 prospective cohort studies and randomised clinical trials involving 501,791 participants demonstrated a 14% risk reduction in Ischaemic Heart Disease (IHD) with 4 x 100g serves legumes per week.(3)

In addition, an exhaustive review of pooled/ meta-analyses and systematic reviews examining the association between food groups and diet-related chronic diseases published between 1950 to 2013 showed that plant foods are more effective than animal foods in preventing obesity, type 2 diabetes, cardiovascular disease and cancer.(4) Interestingly, within the plant food groups, grains (including wholegrain cereals, nuts, seeds and legumes) were more protective than fruits and vegetables. Among animal foods higher intakes of dairy was found to be neutral while higher intakes of red/ and processed meats were associated with increased risk. The authors concluded that the findings of this extensive review support the recommendations for a Mediterranean diet, that being to encourage consumption of vegetables, legumes, fruits and nuts, cereal, and fish, and moderate consumption of meat, poultry, and dairy foods.

Observational studies from the USA, Japan and China have previously shown that legume consumption, specifically soy, has been associated with protection from coronary heart disease.(5-7)

The health benefits of legumes are most likely due to the wide range of nutrients and bioactive compounds  found in them. Legumes, are high in protein, fibre, low GI carbohydrate and a rich source of minerals such as iron, zinc, calcium and folate. Legumes are also rich in the isoflavones with potential oestrogen-like and anti-oxidant properties.

Legumes are the richest source of protein amongst the plant foods and combining legumes with grains provides a good complement of proteins as legumes are low in methionine which grains contain.


White Bean Soup (Fassoulada) recipe from The Mediterranean Diet

Serves 6

Ingredients:

·         3 litres water

·         2 ½ cups (500 g) white cannellini beans (dried or canned)

·         2 brown onions, finely chopped

·         2 cloves garlic, finely chopped

·         3-4 stalks celery, thinly sliced

·         2 cups (500 g) pureed tomato

·         ½ cup extra virgin olive oil

·         3 carrots, diced

·         1 tablespoon finely chopped fresh flat-leaf parsley

·         Freshly milled sea salt, to taste

·         Freshly ground black pepper, to taste

·         Chilli flakes, to serve

·         Crusty bread, to serve.

Method:

If using dried beans, place them in a large pot, cover with cold water and ice cubes and leave to soak overnight (or during the day while you are at work). The ice helps soften the beans and prevents skins from separating during boiling, giving a thicker, creamier soup.

Put water in a 5-litre heavy-based stockpot, add beans, onions, garlic, celery, tomato and olive oil and bring to a boil over high heat.

Reduce heat and simmer for 30 minutes

Add carrot and parsley and simmer for another 30 minutes.

Add seasoning and chilli flakes to taste then serve with sliced crusty bread.

Leftover soup can be frozen and easily defrosted in microwave when ready to eat.

About the author

Associate Professor Catherine Itsiopoulos is the founding Head of Dietetics and Human Nutrition at La Trobe University.  Her academic, clinical research, health service management and dietetics career spans 30 years and she is recognised for her expertise in studies using the Mediterranean diet in the treatment of diabetes, heart disease, obesity, and fatty liver. Catherine has published widely in the scientific literature and has recently published her first book titled ‘The Mediterranean Diet’ (Pan MacMillan, 2013), in which she reviews recent evidence on the health benefits of the Mediterranean diet and includes traditional recipes.

References:

1.            Widmer RJ, Flammer AJ, Lerman LO, Lerman A. The Mediterranean diet, its components, and cardiovascular disease. The American journal of medicine. 2015;128(3):229-38.

2.            Darmadi-Blackberry I, Wahlqvist ML, Kouris-Blazos A, Steen B, Lukito W, Horie Y, et al. Legumes: the most important dietary predictor of survival in older people of different ethnicities. Asia Pacific journal of clinical nutrition. 2004;13(2):217-20.

3.            Afshin A, Micha R, Khatibzadeh S, Mozaffarian D. Consumption of nuts and legumes and risk of incident ischemic heart disease, stroke, and diabetes: a systematic review and meta-analysis. The American journal of clinical nutrition. 2014.

4.            Fardet A, Boirie Y. Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews. Nutrition reviews. 2014:n/a-n/a.

5.            Bazzano LA, He J, Ogden LG, Loria C, Vupputuri S, Myers L, et al. Legume consumption and risk of coronary heart disease in US men and women: NHANES I Epidemiologic Follow-up Study. Arch Intern Med. 2001;161(21):2573-8.

6.            Sasazuki S. Case-control study of nonfatal myocardial infarction in relation to selected foods in Japanese men and women. Jpn Circ J. 2001;65(3):200-6.

7.            Zhang X, Shu XO, Gao YT, Yang G, Li Q, Li H, et al. Soy food consumption is associated with lower risk of coronary heart disease in Chinese women. The Journal of nutrition. 2003;133(9):2874-8.

Changing consumer needs and McKenzie’s SuperBlend range

We know that consumers are looking for quick and easy sources of nutritious foods, with foods high in fibre and high in protein being among the top 3 favourite claims consumers look for.* The McKenzie’s SuperBlend products were developed with this in mind.

The McKenzie’s SuperBlend range is making it easier for consumers to include quality carbohydrates, such as whole grains and legumes, into their diets. Available in three different varieties, each variant has been blended specifically to target a nutritional platform - Protein, Fibre and Energy. Ingredients include: lentils, quinoa, pearl barley, freekeh and quick-cook beans.

The other important factor in developing these products was to overcome the barrier and perception of how long it takes to prepare and cook legumes as well as leverage consumer insights that consumers associate legumes with protein and fibre*. . To increase convenience, quick-cook beans are included in the SuperBlend products. This means both the SuperBlend Fibre and SuperBlend Protein can be prepared within 15 minutes.

SuperBlend is great as a tasty and healthy side dish, a boost to a winter soup or a nutritional addition to a salad. A quick snapshot of each of the SuperBlend variants:

McKenzie’s SuperBlend Fibre combines Australian Greenwheat Freekeh, lentils and quick cook beans to provide an excellent source of fibre blend. A serve of this blend will provide an average of 27% of the recommended daily fibre intake.

McKenzie’s SuperBlend Protein combines lentils, quinoa and quick cook beans to provide a good source of protein. A serve of this blend will provide an average of 20% of the recommended daily protein intake.

McKenzie’s SuperBlend Energy combines Pearl and Black Barley. Pearl and Black Barley are known to contain complex carbohydrates which provide a more steady supply of energy.

The SuperBlend range is available from Woolworths (located in the soup aisle).

*Source: Grains & Legumes Nutrition Council. 2014 Australian Grains and Legumes Consumption and Attitudinal Report. Unpublished: 2014.

Watch your weight with legumes (and quality carbs)

With winter approaching it may be tempting to curl up on the couch and give yourself permission to relax your healthy routine. But sadly, evidence shows that weight gained during short periods of over-indulging and reduced exercise like the “winter weight creep” can hang around for months and years to come, making it harder to lose weight and stay trim long term.⁽¹⁾ The evidence continues to support a focus on carbohydrate “quality” rather than “quantity” for a healthy weight, which is why enjoying legumes more often can make big changes to your waistline now and in years to come.   

Shifting the focus to carbohydrate quality

While there is no shortage of fad diets or unsubstantiated advice advocating the restriction of all carbohydrate foods, the scientific evidence consistently shows that the quantity and proportion of carbohydrate in the diet does not predict long-term changes in weight.^{(2, 3)} A key pitfall of such advice is that it does not discriminate between nutrient-rich carbohydrate foods (like legumes, grain foods, starchy vegetables, milk and yoghurt) and nutrient-poor discretionary choices linked with poor health and weight gain (such as sweetened beverages, cakes, biscuits, pasties and confectionary). In addressing the misunderstanding and miscommunication of the relationship between carbohydrates and health, nutrition researchers are increasingly investigating the effect of carbohydrate quality within the diet for reducing risk of weight gain and promoting health over the life span.

To assess carbohydrate quality of an overall diet or specific foods, a number of criteria have been suggested including dietary fibre content, whole grain content, whether the carbohydrate is in a solid or liquid form and the glycemic index (GI).^(4-6) In line with this emerging area of research a recent study, the first study of its kind measured the “carbohydrate quality index” (CQI) (the sum of each of the criteria outlined above up) of young Spanish adults diets and investigated the long-term effect on weight.

In this Mediterranean cohort, a higher CQI was linked with higher intakes of legumes, fruits, vegetables, whole grains, fish and olive oil as well as higher intakes of total carbohydrate, fibre, protein and omega-3 fatty acid. After an average of eight years, the researchers found that people with the highest CQI had the lowest weight gain over time and a 26% lower risk of overweight or obesity, compared to those with the lowest CQI.

This study provides further evidence that making smart carbohydrate food choices (rather than focusing on quantity) is important for promoting a healthy weight, and adds to evidence that higher consumption of legumes is linked with smaller waist circumferences and a lower risk of weight gain.⁽⁷⁾ Considering that legumes tick all the boxes for being good quality carbohydrate foods – being fibre and nutrient rich whole foods which are also mostly low GI – they offer one way for many Australians to improve the overall carbohydrate quality of their diet and reduce weight gain over time.

Weight loss with legumes

As well as reducing risk of weight gain in the long term, choosing legumes and other good quality carbohydrate foods over poor quality carbohydrate foods is an important consideration for people aiming to lose weight. Choosing good quality carbohydrate foods helps people to meet their nutrient needs with less energy intake as well as enhances satiety (fullness after a meal) each of which promote weight loss.

A recent meta-analysis of studies, which provides the highest quality of evidence available, found that legumes had a 31% greater effect on satiety (feeling of fullness after a meal) compared with a control, which was generally white bread.⁽⁸⁾ This finding helps to explain the findings of a previous review of short-term weight loss studies, which found that the inclusion of legumes within an energy restricted diet resulted in significantly greater weight loss compared to energy matched diets without legumes.⁽⁹⁾

Start a healthy habit with legumes

With over two-thirds of Australians currently overweight or obese, and over on- third of Australians daily energy intake coming from energy-dense, nutrient-poor choices, improving the overall quality of carbohydrate food choices should be a high priority for Australians. For many, a simple first step to improve carbohydrate quality and promote a healthy weight is to aim to enjoy legumes at least 2-3 times each week. This healthy habit is easier than you may think. These tips, tricks and meal ideas will assist people to enjoy legumes more often: Legumes – Start a healthy habit and An Everyday Guide to Cooking with Legumes.

References:

1.            Ernersson A, Nystrom F, Lindstrom T. Long-term increase of fat mass after a four week intervention with fast food based hyper-alimentation and limitation of physical activity. Nutrition & metabolism. 2010;7(1):68.

2.            Fogelholm M, Anderssen S, Gunnarsdottir I, Lahti-Koski M. Dietary macronutrients and food consumption as determinants of long-term weight change in adult populations: a systematic literature review. Food & nutrition research. 2012;56.

3.            Naude CE, Schoonees A, Senekal M, Young T, Garner P, Volmink J. Low Carbohydrate versus Isoenergetic Balanced Diets for Reducing Weight and Cardiovascular Risk: A Systematic Review and Meta-Analysis. PloS one. 2014;9(7):e100652.

4.            DiMeglio DP, Mattes RD. Liquid versus solid carbohydrate: effects on food intake and body weight. Int J Obes Relat Metab Disord. 2000;24(6):794-800.

5.            Overby NC, Sonestedt E, Laaksonen DE, Birgisdottir BE. Dietary fiber and the glycemic index: a background paper for the Nordic Nutrition Recommendations 2012. Food & nutrition research. 2013;57.

6.            Shrapnel B, Noakes M. Discriminating between carbohydrate-rich foods: A model based on nutrient density and glycaemic index. Nutrition & Dietetics. 2012;69(2):152-8.

7.            Papanikolaou Y, Fulgoni VL. Bean Consumption Is Associated with Greater Nutrient Intake, Reduced Systolic Blood Pressure, Lower Body Weight, and a Smaller Waist Circumference in Adults: Results from the National Health and Nutrition Examination Survey 1999-2002. Journal of the American College of Nutrition. 2008;27(5):569-76.

8.            Li SS, Kendall CW, de Souza RJ, Jayalath VH, Cozma AI, Ha V, et al. Dietary pulses, satiety and food intake: A systematic review and meta-analysis of acute feeding trials. Obesity. 2014;22(8):1773-80.

9.            McCrory MA, Hamaker BR, Lovejoy JC, Eichelsdoerfer PE. Pulse Consumption, Satiety, and Weight Management. Advances in Nutrition: An International Review Journal. 2010;1(1):17-30.