Zinc absorption is complex and can be affected by too much folate, cadmium, copper, nickel, magnesium and calcium. It is also affected by how healthy you are or if you have an illness, when not at optimum health zinc tends to travel straight to the liver rather than being absorbed and used by the body.¹

In a wholefoods plant based diet there is also the complication of phytates (phytic acid) in foods. While phytates are an incredible antioxidant known for warding off cancer they also can inhibit the absorption of essential minerals like zinc. Phytates in food bind to minerals in the food and can prevent absorption of those minerals (I will do a whole blog post on phytates as they are fascinating). ²

Phytates are predominantly found in whole grains, legumes and some nuts and seeds. There have been extensive studies on the processing of foods in order to remove the phytates.^{1, 2} What can be done in a household situation is to soak overnight all whole grains, including, wheat, rice, and the pseudo grains millet, buckwheat and quinoa as well as soaking cashews, almonds, brazil nuts, pepitas and sunflower seeds.  Also soaking beans and legumes is important. I just read yesterday in 3 journal articles that soaking beans overnight in water that is heated to 65°C is optimum. Soak the beans or legumes over night and then cook in water that has been heated to 65°C again, discarding the soaking and cooking waters.

In addition fermented foods like miso, tempeh, khoji rice, tamari and soy sauce contain less phytates. Sprouting beans and rice also removes a lot of the phytates.

Even if you follow the soaking and cooking techniques I just mentioned it is also important to possibly increase your daily zinc intake if eating unprocessed grains, legumes and nuts. Phytate content in wholefoods is much greater than in refined grains for example. A study showed that in Sweden where the diet is predominantly refined grains, people were consuming 180mg  phytates per day and those in places like Kenya, Mawai and Mexico where the diet is predominantly whole grains the people were consuming between 1-2 g of phytates. ²

It is safe to say on a whole food plant based diet we would be consuming between 1-2 grams of phytates a day. Both the World Health Organisation (WHO) and European Food Safety Authority (EFSA) decided on an amount of zinc that people on a plant based diet or a diet high in phytates should be consuming daily. The below table shows the zinc amount that the Australian National Reference Values (NRV) suggest as well as the WHO/EFSA recommend. 

I suggest ensuring your zinc intake is based on the WHO/EFSA and you follow the soaking and cooking methods for grains, beans and legumes and nuts mentioned above.

**Note if you have found out you are low in zinc through a blood test then it may be good to take a supplement but be sure to take it at night as it can make you feel nauseous. I also suggest that taking supplements is only a quick fix measure to boost your zinc and not an ongoing thing as it is important to be getting enough zinc through your diet. Supplements have a place but not ongoing as too much zinc can cause problems with cholesterol and have the similar side effects as not enough zinc.

If you would like to see if your present diet is providing you with enough zinc you could book in for a food analysis session. 

Cooking & Nutrition Class