Q. Is it a good idea to soak raw nuts before eating them?
A. Jennifer Mayer, a dietetic intern at Tufts' Frances Stern Nutrition Center, answers: "Raw nuts contain a compound called phytic acid. Phytic acid binds to minerals such as iron, calcium, zinc and magnesium in the digestive tract, making them poorly absorbed as a result. Soaking raw nuts for at least 20 minutes can neutralize the acid to make these minerals more readily available."
But studies of this issue have focused on populations that have marginal nutrient intakes and high intakes of the nuts - not typical of most in the US. Nuts aren't a major source of these minerals, anyway (less than 10% of the DV in raw almonds except for magnesium at 15%), so this is a minor worry. Mayer adds, "Moreover, phytic acid isn't completely bad news - it also acts as an antioxidant. So, if you have a handful of raw nuts once in a while it’s okay to eat them without soaking first."