In my understanding, the true superfoods are those that contain one or more micronutrients (vitamins and minerals are examples of micronutrients) in quantities that make a significant difference to your diet. And that means that they would come close to 100 % of the recommended daily allowance (RDA). Thus, these superfoods, even if consumed sparingly, could deliver true health benefits.
In the first part of this article, I provided you with a list of foods that are the greatest sources of all the vitamins that we need on a daily basis. Today we will look at the foods that are the best providers of the eight major minerals that we need.
I’ve spent a lot of time searching and documenting the amounts of minerals in foods. For reference, my major data source is Food Data Central of the US Department of Agriculture.
Adult persons need to consume 3.500 mg (3.5 g) potassium per day. Potassium is found in pretty much all foods, therefore a crucial deficiency is rare under normal circumstances. However, you can easily become depleted of potassium if you are dehydrated, for instance, because of vomiting or diarrhea, intense physical activities or simply hot weather.
No foods provide 100% of the RDA of Potassium per portion. Therefore, it is necessary to eat a variety of foods that are good sources of this mineral.
Beans are truly a great source of Potassium. Per 100 g beans provide on average 1250 – 1750 mg potassium, over one third of the RDA.
Furthermore, when you think Potassium, think green:
- 100 g raw spinach provide 650 mg potassium.
- 100 g kohlrabi provide 500 mg potassium.
- 100 g kale provide 500 mg potassium.
- 100 g broccoli provide 465 mg potassium.
- One banana provides approximately 400 mg potassium.
Exotic fruit, such as papaya, guava, mango, kiwi and stone fruit such as peaches and apricots, contain significant amounts of potassium. Guava is probably the champion of all fruits in terms of potassium content. It provides 415 mg per 100 g. But hey, try to find guava in the Netherlands (where I live).
One portion (200 ml) tomato juice provides 475 mg potassium. That could explain why people like to drink tomato juice while travelling by air (which is a dehydrating process for your body).
The RDA of mineral calcium for the adult population is, on average, 1000 mg (= 1g) per day.
The following foods are great sources of calcium (the amount of calcium is provided per 100 g of food):
- Parmesan: 950 mg calcium;
- Cheddar: 707 mg calcium;
- Mozzarella: 693 mg calcium;
- Chia seeds : 630 mg calcium;
- Tahini: 425 mg calcium;
- Feta cheese: 371 mg calcium;
- Tofu: 300 mg calcium;
- Almonds: 273 mg calcium;
- Beans: 200-235 mg calcium;
- Kale: 250 mg calcium.
The RDA for magnesium is 300 (women) – 350 (men) mg per day. Contrary to what many people think, a deficiency in magnesium is not common as it is found in a great variety of foods. For instance:
- 100 g hulled hemp seeds provide 700 mg magnesium.
- 100 g pumpkin seeds provide 550 mg magnesium.
- 100 g sesame seeds provide 345 mg magnesium.
- 100 chia seeds provide 335 mg magnesium.
- 100 g cashew nuts provide 300 mg magnesium.
Iron deficiency is the most common deficiency in the world. Women of reproductive age are especially prone to iron deficiency due to the repeated blood loss during menstruation. The recommended dietary allowance of iron varies per gender and age. Children need 8 mg iron per day, men of all ages and women > 50 years old need 9 mg iron per day, and women of reproductive age need 16 mg of this mineral. The following plant-based foods are the iron champions (the amount of iron is given per 100 g of food):
- Dark chocolate (70-85% cacao solids): 12 mg iron;
- Tahini: 9 mg iron;
- Pumpkin seeds: 8.8 mg iron;
- Hemp seeds: 8 mg iron;
- Chia seeds: 7.7 mg iron;
- Beans provide 5 mg (adzuki beans) – 7 mg (Lima beans) iron per 100 g.
- Lentils provide 5-6.5 mg iron per 100 g.
The RDA for zinc is 7 (adult women) – 9 (adult men) mg per day. The following plant-based foods are superior sources of zinc (the amount of zinc is given per 100 g of food):
- Hemp seeds: 10 mg zinc per 100 g;
- Pumpkin seeds: 7.8 mg zinc per 100 g;
- Sesame seeds or pure tahini: 6-7 mg zinc per 100 g;
- Cashew nuts: 5.8 mg zinc per 100 g;
- Sunflower seeds: 5.3 mg zinc per 100 g.
Please have a look at the longer list of zinc-rich foods and read about health benefits of zinc in this article.
The RDA for copper in the Netherlands is 0.9 mg/day for the adult population. The following foods are the greatest natural sources of copper (the amount of copper is provided per 100 g):
- Cashew nuts: 2.2 mg Copper;
- Sunflower seeds: 1.9 mg Copper;
- Dark chocolate (70-85% cacao solids): 1.8 mg Copper;
- Hemp seeds: 1.6 mg Copper;
- Walnuts: 1.6 mg Copper;
- Pumpkin seeds: 1.4 mg Copper;
- Sesame seeds: 1.4 mg Copper;
- Pine nuts: 1.3 mg Copper;
- Pecan nuts: 1.2 mg Copper;
- Buckwheat: 1 mg Copper;
- Chia seeds: 1 mg Copper;
- Almond butter: 1 mg Copper.
If you are interested in how Copper influences our health, please read this article.
The recommended daily allowance of iodine depends on age and physiological state and varies from 90 to 250 micrograms.
Edible seaweed has an extremely large amount of iodine, varying from 1.600 to 8.000 micrograms per 100 grams of dried weight.
The content of iodine in sea-fish and shellfish is 100-500 mcg per 100 g. Other, non-marine, foods contain non-essential amounts of Iodine.
The recommended daily intake of selenium for adult persons is 60-70 microgram (mcg).
Brazil nuts are the richest dietary source of selenium on Earth. A single Brazil nut (3 g) contains about 50-70 mcg of selenium! Another good source of Selenium is flaxseed. It provides 135 mcg of this mineral per 100 g. But obviously, nobody can eat that much flaxseed in one go. Other plant foods do not contain significant amount of Selenium.