A new study has shown that aging mice lose the ability to absorb and utilize zinc. For a long time, that has been suspected in humans as well. Dr. Walter Pierpaoli, who is responsible for introducing the world to melatonin, believes that the failure of zinc nutrition is responsible for much of the frailty and decrepitude of old age. And, he is very interested in preventing it. He discovered that melatonin tends to reverse the effect. Yes, melatonin enhances your body's ability to absorb and utilize zinc. And that is why he puts a little zinc in his melatonin supplement- so that it will be there at the same time as the melatonin, so that it can work on it.
Zinc absorption is a dicey situation even in the young. Are you aware that the essentiality of zinc in human nutrition wasn't discovered until the 1960s? And I'll tell you how it was discovered. It involved some growth-retarded boys in Iran. It was found that their diet was heavily weighted in unleavened bread made of wheat- which was high in phytic acid. Phytic acid, which is a form of phosphorus, binds minerals, rendering them unabsorbable, including zinc. Raising bread with yeast breaks down some of the phytic acid- so it is less of a problem. Even though I do not avoid wheat completely, I'm willing to admit that it's a food we should go light on, and some people shouldn't eat it at all.
But, phytic acid occurs in much more than wheat. It occurs in virtually all grains, nuts, and legumes, and also vegetables to some extent. Phytic acid is so widespread in plant foods, that's why they call it phytic acid, which means plant acid.
But, there is also oxalic acid which is also widely distributed in plants, including, fruits, vegetables, sesame seeds- even coffee beans. Oxalic acid combines with minerals forming insoluble oxalates which cannot be absorbed. The spinach family vegetables, including chard and beets, are high I oxalic acid, but there is some in just about every fruit and vegetable.
Because of these digestive antagonists, we only absorb a small portion of the zinc we consume. The recommended daily quota is 12 mg, but that is based on the idea that we will absorb just 20% of it. So, that means that only 2.4 mgs of zinc actually gets through. But, there may be times and conditions in which even less than that gets absorbed.
I should also mention that the fiber in plant foods- wonderful as it is- can also interfere with zinc absorption.
So, getting some supplemental zinc each day isn't a bad idea no matter who you are. But, if you are older, then it is especially important. Zinc is one of the top reasons why taking a good multi is a good idea.
By the way, an excellent source of zinc are pecans. They really are loaded, and pecan growers in Texas have to use a foliar spray of zinc or else the nuts won't fill out properly. I have a pecan tree at my health retreat that is not starting its 3rd year, and I give it foliar zinc as well. And, pecans are relatively low in phytic acid and oxalic acid, compared to other nuts. And what a tasty way to get your zinc.
So, the fact is that zinc is one of the weakest links in the modern diet, and the damage it is doing is probably incalculable. Making sure you are supplied with optimal zinc is one of the best things you can do for your health.