Scientists Just Connected an Underrated Nutrient with Healthier Aging

Reviewed by Dietitian Annie Nguyen, M.A., RD

• A new study suggests that moderate amounts of zinc can help slow down aging.

• Researchers found that adding exercise may enhance the effects of zinc.

• It’s worth noting that too much zinc can increase the speed of aging.

Many of us are continually looking for ways to slow down or reverse aging, and one thing that makes us age more quickly is inflammation. For example, we previously reported on research that suggests that an anti-inflammatory diet may reduce the risk of cognitive impairment—brain aging—by 21%. And another study suggests that eating more antioxidant-rich foods—which are anti-inflammatory—may help you live longer with a higher quality of life.

One of these anti-inflammatory nutrients is zinc, an essential trace mineral that you must get from food or supplements since the body does not make it on its own. While you don’t need a lot of zinc each day, this antioxidant-acting mineral plays an important role in supporting DNA, wound healing and immunity—all things that influence aging.

Scientists have jumped on the anti-aging bandwagon, not just to prevent it, but to measure it. Tools that use algorithms to determine people’s biological age are now available and often used in studies. Biological age is defined as the chronological age-dependent decline of biological functions, characterized by 12 biomarkers that fall under three categories that can be measured with bloodwork.

So, while chronological age is how old you are in years from birth to now, biological age is the speed at which your body is aging. For example, a 48-year-old woman’s biological aging may be keeping pace with her chronological age—or it could be aging more slowly or faster than an average 48-year-old woman.

Researchers from China wanted to know more about the role of zinc in biological aging, plus how exercise might modify zinc’s effect on aging. They recently published their findings in the journal Clinical Nutrition. Let’s break them down.

Related: What Is Zinc & Why Do You Need It? Here’s What Dietitians Say

How Was This Study Conducted?

Data was pulled from the UK Biobank, a long-term study that contains medical and lifestyle information on over 500,000 UK residents. For this current study, researchers drew data on almost 69,000 people who met their criteria, which included having sufficient information on diet, physical activity and biomarkers to calculate biological age.

Participants were divided into two groups: one group without zinc intake and one with it. The group without zinc included over 35,000 people with an average age of 56; 46% were female. The zinc group included over 33,000 people with an average age of 56; about 65% were female.

Zinc intake was calculated based on participants’ food records and responses to questions about supplements. Participants’ zinc intake amounts were compared against the daily recommended intake of 11 mg per day for male participants and at least 8 mg per day for female participants, with neither going over 40 mg per day. Over 40 mg/day is considered zinc overdose for both males and females.

The exercise amount was calculated based on standard questionnaires regarding physical activity and was transposed into metabolic equivalent of task (MET). The World Health Organization (WHO) recommends at least 600 MET per week, which is equivalent to at least 75 minutes of vigorous physical activity per week or 150 minutes of moderate physical activity per week.

Biological aging was calculated using the ENABL Age tool, which, according to these researchers, is the most up-to-date estimation tool for distinguishing healthy aging from unhealthy aging, and for predicting mortality for 5- and 10-year mortality markers.

Confounding factors that affect biological aging and would be adjusted for during statistical analyses included sex, ethnicity group, BMI, family income, sleep disorders, smoking status, alcohol intake and history of cancer diagnosis.

What Did This Study Show?

Overall, this study suggests that participants with delayed biological aging—meaning they’re aging more slowly—tend to have higher levels of daily zinc intake compared to participants with accelerated aging. Specifically, those who got the recommended amount of zinc each day showed an average delay of 0.11 years in biological aging.

However, as with most things, more is not necessarily better, as those with zinc intakes over the recommended limit of 40 mg/day showed an acceleration of almost 7 years in biological aging.

The analysis that included exercise suggests that participants with the recommended dose of zinc intake plus the recommended amount of physical activity had 31% decreased odds of having biological aging acceleration compared to participants with inadequate zinc intake and inadequate physical activity.

Some limitations of this study include the narrow population, since the UK Biobank is mostly made up of white people of European descent. The nature of this observational study cannot conclude causation; in other words, researchers cannot say that zinc causes slower aging, just that it’s associated with it. Also, diet and physical activity information was self-reported, which always leaves room for error and bias.

Related: 7 Medications That Don’t Mix Well With Coffee, According to a Pharmacist

How Does This Relate to Real Life?

According to these researchers, insufficient zinc intake affects approximately 17% of people around the globe, and for this reason, they state that zinc supplements may be useful for some. However, this also comes with caution, as too much zinc speeds up aging—by a lot.

Researchers aren’t exactly sure why zinc seems to slow aging, but they know that zinc influences age-related processes, including DNA synthesis, protein metabolism, cell proliferation (generating new cells) and mitosis (cell replication). Zinc has also been linked with bone health, immunity support, healthy hormones and the prevention of nervous system diseases, like Alzheimer’s. It also acts like an antioxidant, reducing inflammation, researchers add. And less inflammation means slower aging.

If you’re looking to eat your zinc, aim for sources like seafood, meat, poultry, dairy, nuts and seeds. Both our 30-Day High-Protein Meal Plan for Healthy Aging and 30-Day Anti-Inflammatory Meal Plan for Healthy Aging contain plenty of healthy-aging foods, including those high in zinc. If you need more guidance to ensure you’re eating for healthy aging, make an appointment with a registered dietitian to help you design a plan based on your needs, lifestyle and preferences.

This study also included the role of physical activity, noting that when combined with sufficient zinc intake, aging was slowed even further. The study didn’t differentiate between types of exercise—like cardio versus strength training—just that participants were meeting minimal guidelines. If you’re currently not physically active, just start moving more throughout the day and be intentional about it.

For example, do more trips into the house from the car with groceries, or up and down the stairs when putting laundry away. Take frequent breaks throughout the day to stretch, do a set of squats or walk a lap around the house. Over time, gradually increase the amount until you’re more closely meeting the minimum recommendation of 150 minutes of moderate or 75 minutes of vigorous physical activity per week.

Related: I’m a Dietitian & These 6 Small Changes Helped Me Eat More Fiber

The Bottom Line

A new study suggests that adequate zinc intake can slow biological aging, even more so when combined with exercise. But researchers also found that too much zinc was associated with much faster biological aging. Consider assessing which foods you’re currently eating that provide zinc. If you think you’re not getting enough, choose which foods to add. But before supplementing with zinc, meet with your healthcare provider or a registered dietitian to make sure you don’t get more of it than your body needs.

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