5 reasons why zinc is important as we age

What is zinc?

Zinc is a trace mineral that is used to make stuff like roof cladding and cool, vintage bar tops. They also use it to make coins - it's in the copper-coloured bits in the two-pound coin. It's funny to think that the same metal is a vital nutrient that we need in our bodies, but don't imagine that it is there to give us a shiny surface or to plug any leakage. Likewise, there is no need to go licking money to get some!

Minerals exist in the earth and soil. Zinc enters the food chain through the plants that grow and are eaten by both us and animals. The planet and ourselves working together - who would have thought?!!

Zinc is needed for all sorts of chemical reactions to happen in the body. We need it to make DNA, grow cells, and for a functional immune system. Those are just a few reasons; there are many more

Why do we need zinc as we age?

We don't need that much zinc at all; but the body does not store it, so we need to make sure that we get enough zinc-rich food every day to keep ourselves topped up. In particular, it is essential that we get enough zinc as we get older. There are many reasons for this.

1. Immunity

As we get older, the immune system, like everything else, tends to slow down. They call this immunosenescence: it's a gradual deterioration of immune function. Over our lives, we have built up a memory bank of strategies for fighting illness. This is what is called the 'acquired' immune system. Antibodies are part of this, our little arsenal of ready-to-use weapons. We can use these to fight things like chickenpox or a cold. The acquired immune system should have a record of all infections fought and the weapons used, like our own biological Anarchists' Cookbook or defence manual.

Immunosenescence can be seen as immune system memory loss. The body doesn't remember the bug or how to eliminate it. In the absence of the correct weapon, it can try to strengthen its defences by increasing inflammation. I imagine this as being like fires lit on the castle ramparts to try and frighten the enemy away. This approach doesn't often work very well for castles or for bodies. Inflammation may make complications during illness more prevalent and recovery can take longer.

Zinc is important for both the innate (what you're born with) and acquired immune system. It is needed for many different types of immune cells, to help them develop and function. Zinc deficiency has also been associated with more inflammation during illness¹.

2. Digestion

This is another thing that slows down as we get on in years. Zinc is super important here and has a number of important roles. First of all, we can't make digestive enzymes without zinc.

Everything eaten needs to be processed down to its most basic component for it to be useful. That is why we talk about food as protein, vitamins or minerals: the end result of deconstructing our meals into their component parts. We chew everything to make it smaller; then stomach acid breaks it down even more. Digestive enzymes are the fellas who use chemical means on what mush is left. Consider them our chemical teeth. The proteins, minerals and whatnot can then be absorbed through the intestinal wall and be carried around the body in the bloodstream to supply nourishing goodness. Without zinc, we will not have full access to the nutrients in our food.

On top of this, zinc does another really important job in the gut. Every part of the digestive system is covered in a layer of mucosal goo. We need this to protect all the delicate immune cells that line the intestinal wall - 70% of our immune cells live in the gut and need this protection! The mucosal barrier protects us from our own stomach acid, which is very corrosive. However, zinc deficiency has been shown to weaken this protective barrier, leaving us vulnerable to infection, as many bad bugs and parasites can sneak in with our dinner. Undermining of the mucosal barrier can cause irritation or infection in the gut and result in diarrhoea.

So, zinc protects the gut and the immune cells that hang out there. It helps us digest so that we can benefit from our culinary efforts.

3. Taste and smell

These can dull over time. As if wearing varifocals and having to have the telly blaring wasn't indignity enough. Zinc deficiency is associated with a loss of both taste and smell. Up to 20% of UK adult over 60 have an impaired sense of smell². This can impact both taste and appetite.

The danger is that a lack of enjoyment of food will drive bad eating habits. Sweet or salty flavours may be the only discernible flavours. Strong-tasting processed food may become more appealing but have little nutritional value.

The other thing that can happen is that food becomes a chore. Without taste, the motivation to eat can vanish. Many older people simply stop eating sufficient amounts, and they can get very run down. Both scenarios can result in nutritional deficiencies. Zinc levels can plummet, resulting in even duller taste and smell.

4. Eyesight

We need zinc for our eyes - and there was you, thinking it was all about carrots! Carrot is a good plant-source of vitamin A, which is important for night vision, but what zinc does is it helps that vitamin A get converted into the right form, so that it can do its job. It also does a few other jobs in the retina and in nerve calls. Plus, zinc deficiency is one of the nutritional factors that have been linked to macular degeneration. This is an ageing condition of the eye that can lead to blindness.

5. Fatigue

Zinc levels are important for energy, but in a roundabout way. Zinc loss can impact many functions because it plays so many different roles. We know that it helps us digest our food. Without zinc, we cannot access the energy that we need from the food that we eat.

We also need zinc in order to sleep. Zinc deficiency has been linked to a lack of ability to regulate the sleep pattern. This circadian rhythm of waking and sleeping often changes as a person gets older. They may find themselves waking very early or waking during the night. Lower zinc levels have been found in people who sleep less than five hours a night. It's like the sleep clock has been set to the wrong time. It's believed that correcting zinc levels can help to reset the system³.

My Self-Care Tip: Improve the nutrient value of your food

Valuable nutrients like zinc are really important, especially as we age. In this video, I offer tips on how to maximize the value of the zinc in your diet.

Where can I find more zinc?

It should be easy to get enough zinc in our food. The NHS says men should have 9.5mg a day, and women 7mg a day. We don't need a tremendous amount. It's in many everyday foods like meat, fish, shellfish, wholegrains, seeds and nuts. Vegetables contain zinc in smaller amounts than meat and fish, but it all adds up. Eat as much as you like of spinach, peas, broccoli, sprouts, sweetcorn and asparagus.

• Here are a few examples of meals and snacks that are zinc-rich:
• Cooked chickpeas have over 1.3mg zinc per half a cup. This recipe for homemade houmous is super easy.
• Half a cup of baked beans will give you just over 2.9mg of zinc. Pour them over wholemeal soda toast with some mushrooms and an egg to boost that further.
• Many seeds, but especially pumpkin seeds, are a rich source of zinc at 7.9mg per 100g. These cranberry granola bars are a good snack or breakfast on the run. 
• You may be thinking that this all sounds like too much trouble, can I not just buy a tablet? Yes indeed, if you think that you are showing signs of being deficient or if you tick some of the high-risk factor boxes. A small and steady daily dose (anything from 3mg to 15mg) a day is sensible.

It's worth mentioning that a sudden lack or taste or smell is also associated with COVID-19 infection. Do get this checked out by your GP, especially if you have other symptoms like a cough, fatigue or a temperature.

References:

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2277319/ 
2. https://bit.ly/3cjeB4k 
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5713303/