Some of you may be long-time paleo eaters while others may be brand new to this style of eating. Either way, it’s easy to get confused over ‘grey-area’ foods like the white potato.
For years, potatoes have had a reputation for being an empty-calorie, high-glycemic food, leading many people to limit their consumption (or even avoid them entirely). And along with their perceived lack of nutrition, potatoes were originally considered “not Paleo” due to their high starch content and naturally occurring toxins (especially lectins and glycoalkaloids).
Over the past 5-10 years, the spud has slowly rebuilt its reputation as real food and is now widely accepted as a starchy addition by many paleo advocates with a few caveats.
How do white potatoes fit into your Paleo diet?
Looking at the nutritional profile of white potatoes reveal they are far more than simply ‘empty calories’
White Potato Nutrition
Per one large potato (200 grams or so),
- 163 calories
- 4 grams protein (all 9 amino acids although not enough to make potato into a complete protein),
- Up to 5 grams of fibre
- 70% of daily intake of Vitamin C
- 40% DB of potassium
- 30% DV of Vitamin B6
- 12% DV magnesium
- 9% DV iron
- 2% DV calcium.
- 35-40 grams of carbohydrates (depending on the variety).
- 2 grams fat
With a massive amount of vitamin C rivalling red peppers and oranges, plus a fair number of B-vitamins, minerals and fibre, the potato is quite a nutrient dense food. Potatoes are also satiating and comforting, so a little white potato can add a lot of variety and pleasure to your diet.
White Potatoes and The Glycemic Index
The Paleo diet should not be confused with low-carb or keto diet which both restrict carbs significantly. The Paleo is focused on consuming real, nutrient dense foods and avoiding or limiting anti-nutrients as much as possible. When eliminating grains, legumes and processed foods you will naturally eat fewer carbohydrates, but you can still consume carbohydrates by including starchy vegetables and fruits.
Compared to other vegetables, including the sweet potato, white potato is high in carbohydrates. It contains a lot more starch, while sweet potatoes have more sugar and the type of fibre in each is slightly different.
The main concern people have with the carbohydrate content of white potatoes has to do with its glycemic index (GI) which measures how quickly a food converts to glucose and thus raises blood sugar. The glycemic load (GL) looks at how much of that food converts to glucose. The reason it’s important to look at both is that a particular food could have a high GI number but given a common portion size of that food, the actual glycemic load might be more moderate. Foods with GI under 50 are considered healthier because they don’t raise your blood sugar levels as much as the foods with GI over 55, with pure glucose sitting at 100.
For every 150 grams of cooked white potato, the glycemic index can range between 50 to 110 and the glycemic load between 9 and 33.
For example, more floury, starchy potatoes like Russet, have a GI rating of between 85 -111 (when cooked) and a GL of between 17-33. While more waxy potatoes, like New Potatoes have a much lower GI rating (between 55-70) and GL (between 9-15).
(To compare: 150 grams of boiled sweet potatoes have a GI of about 45 and a GL of about 11-13)
Processing methods such as grinding and rolling will raise the GI rating of the food. Generally speaking, the more processed a food is the higher its GI. Furthermore, the longer a food is cooked, the faster its sugars will be digested and absorbed, raising the GI.
Cooling the cooked white potato increases its content of resistant starch (insoluble fibre), and in turn, reduces the glycemic index and glycemic load significantly. An average potato that’s been boiled, then refrigerated and reheated or eaten cold will have a GI of 23-56 and a GL of 8-12 for 150-gram serving
Pairing a food with some fat and acids will also decrease its glycemic index as they slow down the rate at which a food is digested and absorbed.
White Potatoes and Resistant Starch
White potatoes contain a specific type of insoluble fibre which breaks down during digestion to feed the good bacteria in the gut. This is known as resistant starch. It is also present in bananas (especially green ones), and legumes. The amount of resistant starch varies between different types of potatoes and how they are cooked and increases significantly in cooked potatoes that have been cooled.
On average, chilled potatoes (whether originally baked or boiled) contained the most resistant starch (4.3/100g) followed by chilled-and-reheated potatoes (3.5/100g) and potatoes served hot (3.1/100g).
Sweet potatoes are also high in fibre but are significantly less starchy as most of their carbohydrates come from sugars. This results in them containing less resistant starch.
White potatoes and Antinutrients
White potatoes contain some undesirable substances known as antinutrients. Some of these are naturally present compounds such as glycoalkaloids (present in the nightshade family of vegetables), nitrates (present in most plants), and lectins (plant’s defensive compounds). Furthermore, some toxins can be accumulated from the environment or through poor storage and handling.
Glycoalkaloids
The nightshade family includes tomatoes, bell peppers, eggplant, tomatillo and potato as well as coffee. They contain toxic components known as glycoalkaloids. These compounds can be problematic for those with sensitivities or compromised gut health. Consumed in large amounts, these toxins can affect the nervous system, negatively impact gut health and even cause leaky gut. This is why the nightshade foods are avoided on the autoimmune protocol diet.
Glycoalkaloids are mostly saturated in the skin and under the skin and in the eyes of the potatoes or any damaged or green parts. They are also the highest in the sprouts and flowers of the potato plant. Peeling the potato can reduce the number of glycoalkaloids significantly.
Lectins
Lectins are found in most plant foods however, more so in grains and legumes. These compounds are sugar-binding protein molecules that when consumed in large amounts can reduce your body’s ability to absorb nutrients (thus the term antinutrient).
They act as a defence mechanism in plants and travel unchanged through the gut, sticking to cell membranes. They can damage and irritate the gut preventing the body from absorbing nutrients optimally.
Research shows that lectin content can be significantly reduced through cooking, sprouting or fermenting foods. Cooking potatoes can reduce lectins by around 50-60%. Peeling also helps as more lectins are present in the skin of fruit and vegetables.
It is important to note that when cooking potatoes in water or broth, the nutrients and antinutrients both leach into the liquid. Consider boiling your potatoes, discarding the liquid and then adding the pre-cooked potato to a stew or a soup.
Choosing White Potatoes
- Avoid potatoes that are green, have green spots, or are sprouting, blemished, or damaged
- Store them in a cool, dark place. No need for refrigeration, but this will extend their life.
- Peel them before eating if you rely on them as a staple food.
- Buy organic. Potatoes are in the “Dirty Dozen”of foods you should buy organic because they can be heavily sprayed with pesticides. Potatoes have been used in cultivation as a means to pull toxins out of the soil. Pesticide free is necessary as potatoes act as sponges.
- Enjoy your potatoes with a fat, vinegar or vegetables. This reduces its potential glycemic spike.
- Boiling or slow crock pot cooking is the best method of eating potatoes. Cook your potatoes gently but thoroughly.
White Potatoes and Your Paleo Diet
You could choose to safely enjoy white potatoes in small amounts unless you have serious sensitivities to lectins and glycoalkaloids or have leaky gut or an autoimmune condition. If you are diabetic, pre-diabetic or have metabolic syndrome, you may want to avoid potatoes as the carbohydrate content and the glycemic index impact will be significantly more problematic.
You might possibly be able to enjoy a small portion cold (or reheated) cooked potato if you have blood sugar issues as this lower the GL. Remember, the portion size and frequency of eating potatoes matters the most when it comes to both the glycemic load and any possible toxicity.
Try them out for a couple meals a week, and take note of how you feel after consuming them. Potatoes can safely be included as part of your Paleo diet is they align with your health concerns and goals, leave you feeling good and add a little comfort and pleasure to your meals!