Beans are a much more commonly used term for a lot of the bean vegetables that we eat. But for some of us Legumes are a new phenomenon and have not been a regular part of our diet. That would be me. In fact I hadn’t heard or maybe hadn’t really acknowledged that they even existed beyond Baked beans until they kept reoccurring (like baked beans) in my study to become a dietitian.

Based on my history or lack of history with legumes, I totally understand the reluctance of many people to include them in a balanced diet. There are a few hurdles to overcome, that’s for sure! Like firstly, what are they? How do I use them in meals? How do I manage the gas? Is there a good reason why I should include them in my diet? And if I should have them, how often is often enough?

I can relate to all these questions. Let’s have a look together at the what, why’s and how’s of this strange grouping of foods.

I guess a logically place to begin is the What.

What are beans versus legumes? And what are legumes versus pulses and is there a difference between them?

It seems that ALL beans are legumes. So if it is a bean it is a legume.

But not all legumes are beans. This just tells you that the legume group is broader than just beans. This was an eye opener for me too! Didinger and Thompson (2021) explain it very well (although it is still hard to get your head around!).

First we have the overarching group of legumes.

Under them there are 2 subgroups –

1) non-oilseed legumes and

2) oilseed legumes.

Under the non-oilseed legumes you get 2 more groups –

1) undried legumes and

2) pulses which are dried non-oilseed legumes.

In the undried legumes you get the sugar snap peas and snow peas, and green beans.

In the dried group you get the chickpeas, lentils, dry peas (split peas), dry beans (Pinto, Kidney, Cannellini beans etc), and cowpeas which include your black eyed peas.

On the oilseed legumes side, it is much simpler. According to Didinger and Thompson (2021) it is just the peanuts and soybeans. With these being higher in fat (thus the name “oilseed”) and lower in fibre than the non-oilseed legumes, which are the opposite – higher in fibre and lower in fat.

I think diagrams are helpful in this situation. Have a look at the diagram I modified slightly from Didinger and Thompson (2021).

Going a bit deeper, legumes are the fruits and seeds of plants that come from the legume family. They are generally plants that have a seed pod like a pea or bean and include peanuts, various forms of beans, lentils, peas, and lupins (lupins are more often used for feeding animals, not humans). They are a huge family of plants with many different edible options available.

Pulses as we saw earlier are also from the legume family and are the dried seeds of the non-oilseed legumes. Harvard University uses the example that a pea pod is a legume while the pea inside the pod is a pulse (“Legumes and Pulses,” 2024). Beans are also known as a type of pulse from the legume family. You would have seen beans like red kidney beans, black beans, cannellini beans etc.

Let’s move on to the “Why” eating them is beneficial. I mean, I survived most of my life without the input of legumes or pulses, why should I start to think about them now?

That was my thinking as well. All I knew was that when I had baked beans, there could be repercussions later.

One of the reasons for the gas production from baked beans and quite a few other legumes is the fibre content, and that is also one of the benefits of having them. More recent research indicates that legumes have a variety of benefits with one of them being beneficial for a healthy gut microbiome. This has onflow effects on our mental health, heart health, metabolism, cholesterol, blood glucose control, cancer risk and possibly a lot more benefits. Dr Tim Crowe (Crowe & Crowe, 2023) also points out that fibre in our diet is a key factor in reducing chronic inflammation in our bodies, which is the silent inflammation that we don’t know we have unless a blood test is done. Chronic inflammation is a key factor in developing many health conditions like heart disease, cancer, and diabetes, but the one I am most interested in for this blog is depression.

Additionally, legumes provide energy in the form of carbohydrates and the B vitamins. They are also high in copper, magnesium, manganese and phosphorous. They don’t have any saturated fat and can help lower high cholesterol. They are low GI with a range of between 10 and 40 with low being less than 55 and medium GI being from 56 to 69, and high is over 70. GI or Glyceamic Index is about how quickly food is absorbed into your blood stream. The slower the better for most people, but especially if you have diabetes, but as a general rule, eating a low GI diet is a great way to manage your weight and appetite. (Polak et al., n.d.).

If you are keen to use pulses or dried beans, you will need to know a bit about food safety. Tinned beans and pulses are pre-prepared for you. They have been soaked and cooked at a high temperature already and are therefore ready and safe to eat. Dried and raw pulses and beans need to be handled a bit more carefully. Some legumes contain a protein known as lectin.

In fact a lot of legumes have this, with some having higher concentrations of it than others. Kidney beans are the standout for high lectin. Eating uncooked or undercooked kidney beans, even if they are sprouted, will give you food poisoning with vomiting and diarrhoea. If you need to know more about this, I have created an infographic to keep handy. You will find it in my resources by following this link. It will give you some tips on how to prepare raw and dried legumes and which ones to handle more carefully.

Speaking of food nutrients, another component of legumes you may have heard about are the galactans. These nutrients have a tendency to cause gas in our gut. Well it turns out that one way to reduce the galactans in legumes is to sprout them. Soaking and cooking also help reduce galactans, but it seems that sprouting has the biggest impact for many legumes (Avezum et al., 2022). So if you want to eat these nutrient powerhouses, and reduce gas production in your gut, sprouting might just be for you. As I mentioned earlier, there are some legumes that are not good to sprout because of the lectin content which does NOT go down enough with sprouting to reduce the chances of food poisoning. Check out my infographic to make sure you don’t sprout the high lectin legumes, but remember that kidney beans are a definite NO to sprouting if you plan to eat them raw. Sure you can sprout and then cook them. It is the cooking process at 100ºC that is the main way to reduce lectins. (Avezum et al., 2022)

Practically speaking, if you don’t normally eat legumes here are my top tips:

1. First tip is to start slow. Don’t have a huge serve of legumes if you are not used to eating them. Gradually increase the quantity over a few weeks until your gut starts to get used to them. You will find that gas production will decrease with exposure.
2. If you are not having any regularly at the moment, start with one serve a week. When you feel as though you are getting more used to them, you can increase the regularity to 2 serves a week and so on.
3. Remember they can be added to meat dishes. You don’t need to only eat them with vegetarian meals. If you can include them from 3 to 4 times a week, you are doing really well. Of course, if you follow a vegan diet, you will need to have legumes (or nuts, seeds or tofu), 2 – 3 times a day to get your nutritional needs for protein, zinc and iron.
4. If you feel a bit nervous about the gas production, start with small amounts of tofu, canned black beans, kidney beans, cannellini beans or lentils. As your body gets used to these in small amounts, gradually increase the quantity. Try about ¼ cup for starters until you can tolerate around 1 cup per meal.
5. If you are using tinned legumes, rinse them well to reduce the lectin and galactans in the water.
6. Lentils are the quickest to prepare from dry if you don’t want to use tinned. Dry legumes keep for a long time. You can also cook extra when you are cooking them and freeze any leftovers to be used when needed.

I am on this journey too and will be sharing some of the recipes I have been trying, but here are a few general ideas with some links to some interesting recipes I may or may not try! Just click on an image below to go to the recipe.

REFERENCES:

Legumes and pulses. (2024, May 9). Retrieved from https://nutritionsource.hsph.harvard.edu/legumes-pulses/

Crowe, T., & Crowe, T. (2023, September 3). Inflammation: the good, the bad and the ugly – Thinking Nutrition. Retrieved from https://www.thinkingnutrition.com.au/inflammation/

Polak, R., Phillips, E. M., & Campbell, A. (2015). Legumes: Health Benefits and Culinary Approaches to Increase Intake. Clinical diabetes : a publication of the American Diabetes Association, 33(4), 198–205. https://doi.org/10.2337/diaclin.33.4.198

Didinger C, Thompson HJ. Defining Nutritional and Functional Niches of Legumes: A Call for Clarity to Distinguish a Future Role for Pulses in the Dietary Guidelines for Americans. Nutrients. 2021; 13(4):1100. https://doi.org/10.3390/nu13041100

Avezum, L., Rondet, E., Mestres, C., Achir, N., Madode, Y., Gibert, O., … Rajjou, L. (2022). Improving the nutritional quality of pulses via germination. Food Reviews International, 39(9), 6011–6044. https://doi.org/10.1080/87559129.2022.2063329

Grains & Legumes Nutrition Council. (2022, August 30). Types of Legumes – Grains & Legumes Nutrition Council. Grains & Legumes Nutrition Council. https://www.glnc.org.au/resource/types-of-legumes/