I LOVE potatoes. Not sweet potatoes, but regular old garden variety white potatoes. What on earth is going on with the spud-related mass hysteria? I’m going to go out on an obvious limb and blame the low-carb diet (see my previous post, and insert an [eye roll]), which is responsible for doing so much harm to public health by pushing excessive quantities of saturated fat-laden meat, cheese and butter, and shunning whole plant foods such as legumes and starchy vegetables.
Potatoes are a natural whole food which have sustained populations for millennia. There’s nothing inherently fattening about potatoes, unless you’re adding fats (oil/butter/cheese/sour cream) to them. There was a paper published in 2011 which found that potatoes were strongly associated with weight gain of around 0.6kg over a four year period (1), which naturally made media headlines all over the world. What they neglected to mention was that the authors of the study lumped french fries and boiled/baked/mashed potatoes all in the same category, which tells us nothing about the effect of potatoes as a whole food on weight gain. French fries have 1137kJ per 100g due to all the added oil, compared with only 250kJ per 100g for boiled potatoes without any added oil.
So, to clarify, I’m talking about potatoes in whole food form, which means baked, boiled or steamed with no added fat. Did you really think I’d write a post about how amazing French fries or potato chips are for you? Sorry, not today.
Anyway, here’s why you should love them too:
They’re not a ‘white carb’
Lumping potatoes in the ‘white carb’ category is completely unjustified. The ‘white’ part refers to any grain or grain product which has had its brown outer bran layer removed in order to make the grain whiter, fluffier and all-round more attractive to consumers who are into that kind of thing (not us, of course).
There’s no question that ‘brown’ or whole grain carbs are much better for us - they’re higher in fibre and contain many more B vitamins and minerals such as iron and zinc than their white counterparts. Flour manufacturers even have to fortify, or put back in, many of the vitamins that they’re removed by stripping the bran layer off.
So, it’s unfair to call potatoes ‘white carbs’ just because they happen to be white in colour. Potatoes are not grains and they don’t have a bran layer to remove, so they’re not white carbs, okay? Glad we got that sorted.
They’re not all high Glycaemic Index (GI)
The GI is a measure of the speed at which a carb-containing food breaks down to sugar, which can be measured by a rise in blood sugar (glucose). Pure glucose is used as the reference food for the GI, and is given a GI value of 100 (which is a high number, as pure glucose ends up in the blood pretty quickly.
Simply saying that 'potatoes are high GI' isn't useful, as the GI varies depending on the type of potato, how you cooked it, and what you're eating it with. If you're eating potatoes with a meal, the other components of the meal (such as protein and fibre) slow down the digestion of the potato which means the GI is less relevant . The GI of potato also ranges from 53 to about 102 depending on the variety and cooking method, but good low-medium GI choices are Carisma potatoes (53, low GI) and Nicola (58, medium GI).
Also - cooking and cooling potatoes and eating them cold (such as in a salad) reduces the GI and also creates resistant starch, which is a type of starch which acts as a prebiotic, feeding the good bacteria in the large bowel.
They’re not actually that high in carbs
You’d eat an apple without being terrified of the carbs, wouldn’t you? So why wouldn’t you eat a potato the same size? This may come as a shock to you, but a medium-sized apple contains around 16g of carb (mostly as sugars), which is almost the same as a medium-sized potato, which contains around 19g of carb (mostly as starch). There’s not much in it, is there? So where did this idea that potatoes are packed with carbs come from?! (cough *low-carb diets* cough).
They’re packed with nutrition
If I told you I’d found a food that was gluten-free, had more potassium than a banana and twice the vitamin C of blueberries, you’d promptly hand over your hard-earned money. Guess what? It’s potatoes.
Potatoes are a surprisingly good source of vitamin C, with 70% of the RDI from just one medium potato, which is much more than apple (and about double that of blueberries), which helps you to absorb the iron they contain.
They’re also a better source of potassium than bananas (645mg vs. 519mg per 150g), and are packed with phenolic antioxidants such as chlorogenic acid and flavonoids such as catechin and anthocyanin (2).
As a general rule of thumb, the more colourful the potato the higher the antioxidant content, so go for the beautiful red and purple varieties for an antioxidant boost.
They’re not all that different to sweet potatoes
I know this is uncool to say, and I don’t care how popular they are, but I still prefer regular old potatoes to sweet potatoes, and am here to tell you they’re not all that different.
Sweet potatoes contain a similar amount of carbohydrate to potatoes (21g vs 19g per 150g, respectively), although the carb is a mix of sugar and starch (which is why they taste sweet), whereas potatoes are all starch.
In terms of the GI, it’s a common misconception that sweet potatoes are all low GI, but they’re actually ranked as medium GI (boiled sweet potato has a GI value of 61).
Where sweet potatoes do stand out, nutritionally, is in their beta-carotene (pro-Vitamin A) content: just one small sweet potato (150g) contains 300% of the RDI, whereas regular potatoes contain negligible amounts. Beta-carotene is known as pro-vitamin A as it converts to vitamin A in the body, and is particularly important if you’re on a plant-based diet, as there are no sources of pre-formed Vitamin A in plant foods. Other great sources of beta carotene are pumpkin and carrots.
So, in summary, potatoes are amazing, and here's how to maximise the health benefits:
- Don't drown potatoes in fats or oils! Serve them baked, boiled or steamed instead
- Choose low GI varieties such as Carisma or Nicola
- Choose brightly-coloured potatoes for the biggest hit of antioxidants. The deep purple potatoes are particularly rich in anthocyanins, the same antioxidant pigment in blueberries
- Eat potatoes cooked and cooled in salads for an easy lunch option, which gives your friendly gut bacteria a boost, due to the resistant starch
1. Mozaffarian D, Hao T, Rimm EB, Willett WC, Hu FB. Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J Med. 2011;364(25):2392–404.
2. Evers D, Deusser H. Nutrition, Well-Being and Health. Chapter 5: Potato Antioxidant Compounds: Impact of Cultivation Methods and Relevance for Diet and Health [Internet]. 2012 [cited 2015 Jan 16]. Available from: http://www.intechopen.com/books/nutrition-well-being-and-health/potato-antioxidant-compounds-impact-of-cultivation-methods-and-relevance-for-diet-and-health