Nuts and seeds are rich in a variety of nutrients and a popular dish on the Paleo plate. However, some nuts can be significantly higher in carbohydrates than others, which can be important for those of us who follow a low-carb diet to know.
Additionally, some nuts and seeds are much higher in PUFAs than others and most of that consists of omega-6. Although omega-6 plays a critical role in our health, when eaten in excess, it can lead to an imbalance in omega-3 and omega-6, contributing to inflammation and the many associated disorders like heart disease, Alzheimer’s, insulin resistance, type 2 diabetes, cancer, autoimmune disorders, and more.
Furthermore, the body prefers saturated and monounsaturated fat when eating low-carb. Therefore, eating those that are richer in monounsaturated fat more often will be preferred.
Here is a list of the carbohydrate, PUFA, and MUFA content of the most commonly eaten nuts and seeds to guide your choices.
1 oz Almonds = Total Carbs 6 grams – MUFA 9 grams – PUFA 3.4 grams
1 oz Brazil nuts = Carbs 3.5 – MUFA 7 – PUFA 6
1 oz Cashews = Total Carbs 9 grams – MUFA 7 – PUFA 2
1 oz Chestnut (roasted) = Carbs 15 MUFA 0.2 – PUFA 0.2
1 oz Hazelnuts = Carbs 4.7 – MUFA 13 – PUFA 2.2
1 oz Macadamia nuts = Carbs 3.9 – MUFA 17 – PUFA 0.4
1 oz Pecans = Carbs 3.9 – MUFA 12 – PUFA 6
1 oz Pine nuts = Carbs 3.7 – MUFA 5 – PUFA 10
1 oz Pistachios = Carbs 8 – MUFA 7 – PUFA 3.9
1 oz Walnuts = Carbs 3.9 – MUFA 2.5 – PUFA 13
1 oz Chia seeds = Carbs 12 – MUFA 0.7 – PUFA 7
1 oz Pumpkin seeds = Carbs 3 – MUFA 4.6 – PUFA 6
1 oz Sunflower seeds = Carbs 6 – MUFA 5.2 – PUFA 6.5
1 oz Sesame seeds = Carbs 7 – MUFA 5.3 – PUFA 6.1
1 oz Hemp seed = Carbs 2 – MUFA 0 – PUFA 0
1 oz Flax seed = Carbs 8 – MUFA 2.1 – PUFA 8.00
As you can see, cashews, chestnuts, pistachios, and chia seeds are on the high end as far as carbs go and pecans, walnuts, macadamia, sesame, pumpkin, sunflower, and pine are on the low end. Macadamias are a rich source of MUFAs, and pecans and hazelnuts aren’t too far behind. Sunflower seeds, walnuts and chia seeds are significantly higher in PUFAs. The healthiest nut all around is the macadamia.
All numbers provided above are in raw form, except for the Chestnuts. Nuts and seeds are best consumed in their raw state, because cooking a nut or seed oxidizes their PUFAS (polyunsaturated fats) and makes them rancid. Oxidized and rancid oils in the nut break down into a variety of toxins that increase free radicals, which can contribute to a wide variety of degenerative health conditions. However, dry roasting results in less oxidation than oil roasting. Additionally, all carb numbers provided above are total carbohydrates, not net carbs.
Nuts that are high in PUFAs (polyunsaturated fats) are more vulnerable to oxidation than nuts that are higher in MUFAs (monounsaturated fats). Therefore walnuts, chia seeds and sunflower seeds would be more vulnerable to oxidation than the macadamia. Additionally, the temperature at which the nut is heated, how long it is exposed to the heat, and the presence of antioxidants like vitamin E, and flavonoids can affect the degree of oxidation as well, so they should be roasted lightly when roasted. This is also true of all oils extracted from a nut or seed – overheating will result in oxidation as well.
However, since nuts and seeds are also a good source of protein and fat and rich in a variety of minerals and antioxidants like vitamin E, it is not the same as consuming other substances high in omega-6 like corn oil, soybean oil, or even the oil of these nuts and seeds themselves. These nutrients provide some degree of protection from oxidation and minimize the impact of the high PUFA content, so don’t be too concerned about their omega-6 PUFA content as long as you are eating them sensibly. It is refining and isolating the oil from the nut and excess consumption that are most problematic.
Keep in mind that nuts and seeds should compliment the meal, not serve as the main course of the meal, and should be eaten in moderation. If you have Candida, SIBO, leaky gut, irritable bowel, an autoimmune disorder, and/or are trying to lose weight, the nuts and seeds may need to be restricted more or possibly eliminated at least for a period of time, due to their calorie, carbohydrate, fiber and mold content, and anti-nutrients that can feed Candida or bacteria, degrade the integrity of the gut, prompt an immune response and contribute to weight gain. If you are in fairly good health, nuts and seeds can typically be enjoyed and beneficial to health as long as they are not overcooked or eaten too excessively. Nuts and seeds are most healthful when they are soaked, as this helps reduce anti-nutrients. Simply cover them with water for eight to ten hours, then drain, pat completely dry and store in fridge if eating soon or the freezer for longer keeping.
USDA Food Database via Google Search
Dr. Volek and Phinney, The Art and Science of Low Carbohydrate Living.