Six surprising facts about potatoes

Everybody knows potatoes and their qualities. But in reality, it looks a bit differetly. Against common convictions, potatoes are not only a “concentrated source of carbohydrates with high glycemic index”, but a highly nutritious product with many interesting qualities. You think you know everything about potatoes? This article may surprise you.

Potato is a “light” product

Although it is commonly thought that potatoes are rich in calories, it has to be underlined that comparing to other starch products they are some kind of “light” food. To make the differences clear, I will present rough calorific content of the most popular complex carbohydrate sources from food (on 100 edible pieces of raw product basis):

  • oat flakes: 365 kcal (70 g of carbs),

  • semolina noodles: 365 kcal (76 g of carbs),

  • white rice: 350 kcal (78 g of carbs),

  • brown rice: 320 kcal (76 g of carbs),

  • buckwheat: 335 kcal (70 g of carbs),

  • late potatoes: 85 kcal (20 g of carbs),

  • young potatoes: 70 kcal (16 g of carbs).

As you can see, comparing to other carbohydrate products, potatoes are not only “light” but almost “low carb”...

Potatoes are nothing but “empty calories”

It is quite a common conviction that potatoes supply “empty calories”. In other words, it is thought that potatoes' only value is the calorific one. Of course, it's a misunderstanding. Potatoes, apart from the carbohydrate dose, supply many other nutrients such as vitamins and minerals to our bodies. Half a kilo of potatoes covers about:

  • 40% of vitamin C demand,

  • 25% of folic acid demand,

  • 20% of vitamin B1 demand,

  • 15% of vitamin B2 demand,

  • 70% of vitamin B6 demand,

  • 25% of niacin demand,

  • 50% of potassium demand,

  • 30% of magnesium demand,

  • 14 / 25% of iron demand (for women/men),

  • 50% of copper demand,

  • 15% od zinc demand.

The doses mentioned above include the loss of nutrients caused by the thermal treatment (boiling). As a reminder – 500g of potatoes supplies the same amount of energy as 100g of rice. Comparing rice (brown, which is more valuable) to potatoes, it can be noticed how much poorer it is, because with 100g of rice we cover only:

  • 0% of vitamin C demand,

  • 15% of folic acid demand,

  • 20% of vitamin B1 demand,

  • 3% of vitamin B2 demand,

  • 25% of vitamin B6 demand,

  • 15% of niacin demand,

  • 5% of potassium demand,

  • 25% of magnesium demand,

  • 7 / 13% of iron demand (for women/men),

  • 15% of copper demand,

  • 20% od zinc demand.

The only thing that brown rice beats potatoes with is the dose of vitamin E, which is several times higher. It can be easily noticed that potatoes are highly valuable food products.

Potatoes deacidificate the body

Vast majority of starch products is highly acidic. It concerns almost all the products of cereal origin (except for the millet which is neutral). For a change, potatoes have base-forming qualities, what can be checked by the balance of miliequivalents or the PRAL method (potential renal acid load). It is connected with a high content of potassium and the presence of magnesium.

Potatoes supply great amount of proteins

Although the amount of proteins in potatoes is quite low (about 2g per 100g), it is worth to know that it is very nutritious and it is not much worse than the animal produce! It is very important information for all the vegans and people on a mixed diet, who do not count vegetable proteins in their diets. Eating 500g of potatoes is a supply of 10g of highly valuable proteins containing the set of all exogenous amino acids.

Potatoes fill very well

Although it may seem strange, the fact is that potatoes belong to a group of very solid products (as for their calorific content). It can be checked in reality by trying to supply 150 – 200g of carbs from noodles and potatoes in comparison. It will be much easier to eat noodles for most of the people. The filling qualities of potatoes are mostly connected with their quite low energy density, as for a starch product. It may be also caused by the presence of a hormone called cholecystokinin (the efficiency of this substance in blocking hunger has been assessed positively in research).

Enough is enough

Potatoes have many advantages, but they also have some disadvantages. They are, most of all, a natural source of glycoalkaloids, which are toxic. A proper thermal treatment may lower the amount of these substances in potatoes, but will never remove them completely. Their starting level depends on many factors and, therefore, it is hard to estimate their amount. That is why it is not advised to eat potatoes as the only source of carbs in diet (unless the total number of saccharides is low).

Summary

As it can be noticed, potatoes have many interesting qualities which cause that these vegetables are a very precious ingredient of diet – including that directed at body fat reduction. As for a starch product they don't have many calories or carbs (comparing to other food products of cereal origin), additionally, they have alkalising properties and are highly nutritious and filling. Their only disadvantage is the presence of compounds such as solanine, which may be potentially dangerous with high intake of potatoes. Although, only people who eat extremely large amount of this products should be really worried about it.

Sources: Crit Rev Food Sci Nutr 2009 Nov; 49 (10): 823-40. . J Am Coll Nutr. 2014; 33 (5): 375-84. Int J Obes (Lond). 2011 Feb; 35 (2): 236-243. Rev Med Liege 2003 Jan; 58 (1): 25-32.