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.