Zinc is Vital for Immune Response, Cellular Signalling, and Vision
Zinc deficiency is dangerous.
That danger increases as we age.
Zinc is essential to immune health, reducing inflammation and boosting brain health. It is one of many elements that cause significant problems when you are deficient in them. The risks of supressed immune response, lower vaccine responses and chronic low-level inflammation are higher in in older people. This population is at-risk of zinc deficiency.
You get zinc through food, especially meats, shellfish, and dairy. Supplements are popular, though unless you have a low level of zinc, the benefits are limited.
After doing this deep dive into the clinical work on zinc supplements, I changed my routine. This page is a high-level overview, covering the risks, benefits and best ways to make sure you have enough Zn for healthy cellular signalling.
Zinc and Healthy Aging: Overview of Zn
Zinc is a trace element that is vital to cellular signalling.
Without it, hundreds of health-critical processes break down. Intracellular signalling is important for immune function. Without 300+ enzymes that we use to maintain the delicate balance between biological systems, risk of neurodegenerative diseases, chronic inflammation (one of the Hallmarks of Ageing) and macular degeneration increase.
We don’t create our own zinc, so it must come from food.
It is used up slowly, though foods high in phenols (simple carbs like bread) will cause binding – reducing usable zinc faster.
Elderly people frequently show zinc deficiency, though younger people can also be unknowingly deficient.
Unhealthy Ageing: The List of Conditions Clinically Linked to Low Zinc
With 1000’s of clinical papers covering zinc and Longevity, it comes as no surprise to see this element linked to multiple nasty conditions.
Impaired immune function is the biggest worry. Zinc deficiency is linked to reduced memory T-cell function and lowered ability of new immune to detect and respond to new viruses.
Chronic inflammation contributes to rapid aging. This boosted by low zinc levels, via inhibition of a protein called A-20, which stops a cascade of reactions which leads to cytokine storms and low-level inflammation. Find out more in this paper.
Brain diseases are linked to chronic zinc deficiency by neurogenesis. Studies link dementia, Alzheimer’s disease, and memory loss with low levels of this vital element.
Macular degeneration – a leading cause of blindness in later life – is also linked to low zinc levels. Studies show that boosting levels reduces, and even reverses the degradation of vision.
In younger people, zinc deficiency causes growth retardation.
Adding Zinc: What are the Benefits?
Low zinc is terrible for longevity and healthy ageing, but what about high zinc levels?
If you have a cold, then added zinc will reduce the duration and severity of the symptoms. Lozenges containing zinc are safe for short periods – even if your blood levels are normal. Note that this effect is not universally accepted.
Other than that, all the science points to a big downside of not having enough zinc, though no significant benefits for having extra zinc.
Recommended Daily Allowances Vary Significantly
RDA for zinc changes as you cross international borders.
The differences are big. In the UK, 9.5mg / day (for men) and 8mg / day (women) is recommended by the NHS. Head to Spain and you get a 15mg / day score. The lowest recommendation is 8mg / day – which is close to half of the amount for Spain.
Zinc levels build over time. It builds up over time. 45mg / day over 2 months or more can cause toxicity, the effects are nausea, stomach cramps and vomiting. Keep up the high dose and immune function is impaired. Excessive Zn will eventually interfere with biological processes that involve copper – leading to further health complications.
That said, multiple clinical trials show positive effects used 45mg / day+ for months.
You’ll get most of your zinc from food. This means that supplementing the full RDA and eating red meat and eggs could tip you into excessive quantities.
What Foods are Naturally High in Zinc?
As we don’t store or produce zinc from any other minerals, a constant intake is needed to replenish what we use.
A heathy balanced diet will provide all the zinc you need.
Here is a list of zinc-heavy food:
- Meat: Red meat is high in zinc – though it is also present in poultry.
- Legumes and Seeds: Lentils and pumpkin seeds are non-meat sources
- Shellfish: A dozen oysters or some delicious muscles.
- Dairy: Both milk and cheese are sources of zinc.
- Eggs: A superfood that provides zinc.
Whole grains do contain some zinc. The phenols binding properties reduce the useable quantities. White bread, pasta and added sugar are negatives (to zinc levels, and especially to your chances of healthy ageing).
Without meat and fish, you’ll need make sure you are choosing zinc-heavy alternatives.
Zinc Supplements: Are They Needed?
You can only get an accurate indicator of your zinc levels through blood tests.
Normal levels vary by age and sex.
Unless you are at the lower range of normal or below (or have a cold!), then supplements are not needed. If you have a healthy diet including the foods listed above, there is no reason that supplements are needed.
Zinc and Longevity
Deficiency in zinc is clinically linked to processes which age you faster.
That said, having excess zinc does not convey any additional benefits.
Immune health is the biggest win. This goes beyond fighting off viruses (and clearing them faster). The immune system clears senescent cells, a major factor in healthy ageing.
Zinc has powerful antioxidant qualities. It maintains intracellular hormesis (communication) as a critical component of hundreds of enzymes and proteins. This role can’t be understated in terms of overall health span effects.
Add to that recorded benefits for sight though reducing macular degeneration, and protection against neurodegenerative disorders – and I rate zinc as critical for longevity.
Wrapping Up: Zinc is a Vital Element for Longevity and Healthy Aging – Though You Almost Certainly Have Enough
I’ll end with an admission.
Until I completed this deep dive into the clinical papers on zinc, I diligently took 10mgs daily.
I’m not in the at-risk group for a deficiency, and my last blood tests put me squarely in the normal range. Add to that my healthy diet that includes meat, shellfish, leafy greens, and eggs.
My supplements were unnecessary. And I’m happy that the science to change my mind was freely available.
To determine whether zinc supplements are right for you, a blood test is ideal. Low zinc levels are dangerous, and you may be at risk if you:
- Are over 65 (biologically, if not chronologically!)
- Your diet is low in meat, dairy, shellfish, and eggs
- Your diet is high in white bread, pasta and other foods which promote phenols.
One final take-away that I’m not looking forward to trying out. Next time I get a cold, I’ll boost the zinc levels significantly. Clinical data shows that it works, and it is hard to overdose on zinc for very short periods.
More Popular Pages:
- Four Types of Death (real, physical, emotional and cognitive)
- Detailed Review of David Sinclair’s book Lifespan
- Deep Dive into Metformin and Longevity