Legumes: a food exalted and condemned at alternate stages, why?

There was a time when many experts did nothing but recommend the use of legumes until, the trend was reversed and, as a result of numerous criticism more or less reliable, and legumes have become foods not recommended to avoid... What is the truth? There are positive aspects and others that are less positive but, as always, the important thing is to know the reasons of both sides.

Let’s see together the real benefits and possible problems arising from the consumption of legumes.

What are the legumes?

The term legumes refer to the family of legumes that identify the plants producing a pod with seeds inside.

We have, as examples, lentils, peas, chickpeas, beans, soya and peanuts (yes, even peanuts are legumes although, nutritionally, are common to dried fruit).

Nutritional values

Legumes have an excellent nutritional profile because they are rich in protein, averagely rich in carbohydrates, and variable fat content.

For example, 1 cup (198 grams) of cooked lentils provides [1]:

  • Calories: 230
  • Protein: 18 grams
  • Fibre: 16 grams
  • Carbohydrates: 40 grams
  • Iron: 37% of recommended daily value or Daily Value (DV)
  • Folate: 90% of DV
  • Magnesium: 17% of DV
  • Potassium: 16% of DV

In addition, the same amount offers more than 10% of the DV for vitamins B1, B3, B5 and B6, in addition to phosphorus, zinc, copper and manganese.

As is well known, legumes are among the best sources of vegetable protein. Their amino acid pool is not complete but is balanced by proteins derived from cereals (for this reason it is always recommended to combine a cereal in meals without sources of noble protein such as an animal).

Anti-nutrient

One of the reasons why they are put in the spotlight is their content of anti-nutrients, that is, elements that reduce the assimilation of food (macro and microelements). Let’s see the main.

Phytic acid

Phytic acid, or phytate, is an antioxidant found in all edible plant seeds, including legumes.

The main problem with this element is that it reduces the absorption of iron, zinc and calcium thus leading to an increased risk of mineral deficiencies in people who abound in the consumption of legumes. However, it must be said that this is only relevant when the intake of meat is low and foods rich in phytate regularly constitute a large part of the meals. In other words, we only have to worry about that when we bring in very little iron, zinc, calcium and minerals and we have a disproportionate diet for the consumption of legumes.

In addition, many methods of preparing legumes already reduce their phytic acid content (soaking, germination and fermentation).

[2] [3] [4] [5]

Lectine

Lectins are a family of proteins that can make up up up to 10% of the total protein content of legumes. They resist digestion and can affect the cells that line the intestinal tract. They have a toxic effect on the organism but it must be said that the amount of lectin in legumes is really reduced and, to cause serious problems, one should consume an unused amount of the same.

[6] [7]

In addition to these elements we have others such as saponins but, again, as long as we follow a proper preparation process and do not abound in the consumption of the same, we have nothing to worry about.

Fibre content

Legumes are particularly rich in healthy fibres, such as resistant starch and soluble fibres. Both types pass undigested through the stomach and small intestine until they reach the colon, where they feed the friendly intestinal bacteria. We will thus have an improvement in our intestinal microflora that will affect many aspects of our health! The unpleasant side effects of these fibres include intestinal gas and swelling, however, they also help to form short-chain fatty acids (SCFA), such as butyrate, which can improve colon health and reduce the risk of colon cancer.

The fibres also help to reduce the glycemic impact of the meal with a consequent improvement in the sense of satiety and insulin sensitivity.

Conclusions

Legumes are therefore an excellent food that should not be missing from our table. As usual, the keyword is always moderation and knowledge of what are the foods we take in our food plan. The recipe for well-being is always to follow a healthy, varied and balanced diet.

References

 [1] https://fdc.nal.usda.gov/fdc-app.html#/food-details/172421/nutrients

[2] https://pubmed.ncbi.nlm.nih.gov/17693180/

[3] https://ifst.onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2621.2002.00618.x

[4] https://pubmed.ncbi.nlm.nih.gov/24871479/

[5] https://pubmed.ncbi.nlm.nih.gov/12936958/

[6] https://pubmed.ncbi.nlm.nih.gov/2227211/

[7] https://pu