Heavy Metal Toxicity Symptoms: Could Heavy Metals Be Affecting Your Health?
When I was five years old, I was exposed to lead, and nobody knew it. My parents were renovating our family home themselves to save money. Every weekend I followed my dad around, "helping" him strip old paint from windows and door frames with a heat gun. Years later, I discovered those layers of old paint contained lead.
At the time, no one connected the dots on how my personality changed after this exposure, no matter how many doctors my parents took me to, looking for answers. Looking back now as a functional nutrition practitioner, I can connect the dots for my own health history. My story isn't unusual, many of my clients have also been in the same position.
What are heavy metals, and should we be worried?
Heavy metals are naturally occurring elements found in the earth. Some, like iron and zinc, are essential for good health in small amounts. Others, including lead, mercury, arsenic and cadmium, serve no beneficial role in the body and can become harmful when we're exposed to them in excessive amounts over time.
When most people hear the words heavy metal exposure, they picture an industrial accident, a contaminated factory site or someone working in a hazardous occupation. While these situations certainly exist, they're not what I most commonly see in clinic with clients. Instead, I'm interested in the small, everyday exposures that quietly add up over a lifetime.
Unlike an acute poisoning event, which causes obvious symptoms and requires urgent medical attention, most of us are exposed to tiny amounts of heavy metals through multiple sources over many years. On their own, these exposures may seem insignificant. Together, they contribute to what's known as your body's "body burden" the cumulative load of environmental toxins your body has been exposed to over time.
The important thing isn't to become fearful of every possible source. It's to understand where exposure comes from so you can make informed decisions about reducing it where practical.
Everyday sources you may not have considered
Many of the most common sources of heavy metal exposure are found in places we rarely think to question.
Older homes
If your home was built before the 1980s in New Zealand or before 1997 in Australia, there's a chance lead-based paint was used during construction. In New Zealand, lead-based paint was commonly used in homes until around 1980. White lead was banned from domestic use in 1965, but yellow, orange and red lead pigments continued to be used into the late 1970s. In Australia, lead wasn't fully removed from domestic paint until 1997.
For families renovating older homes, sanding, scraping or using heat guns on old paint can release fine lead dust into the air. Young children are particularly vulnerable because their developing brains absorb lead more readily than adults.
Soil
Since 2021, scientists from the University of Auckland's Soilsafe Aotearoa programme have tested more than 6,200 backyard soil samples from over 1,300 New Zealand homes for lead and other metals through a free public testing programme. The programme exists because soil contamination is common enough to warrant widespread community testing.
Elevated arsenic levels have also been identified across parts of Northland, Coromandel, South Auckland, Waikato, Hawke's Bay, Nelson, Marlborough and north-western Otago, largely due to the historic use of lead arsenate pesticides in orchards and market gardens.
Heavy metals aren't just outside they're inside our homes too
Our modern lifestyles have introduced new opportunities for exposure that previous generations never considered. Depending on the product and how it's manufactured, heavy metals may be found in cosmetics, hair dyes and personal care products. Older aluminium cookware, damaged non-stick pans, some ceramics, ageing kettles and coffee machines may also contribute small amounts over time. For many adults, mercury amalgam fillings remain another historical source of exposure.
None of these examples mean you should throw everything away or panic. Instead, they highlight a principle I often share with clients: the goal isn't zero exposure, it's understanding where your exposure comes from and reducing the load where it makes sense for you and your family.
Everyday foods that can contribute to your exposure
Food is one of the many ways we're exposed to small amounts of heavy metals in everyday life.
Rice
Rice naturally absorbs arsenic from soil and water more readily than most other grains. A 2025 US report tested 145 rice products and detected arsenic in every sample. Around one in four exceeded the US FDA's limit for infant rice cereal. Brown rice grown in the south-eastern United States generally contained the highest levels, while California-grown white rice, Thai jasmine rice and Indian basmati tended to test lower.
Chocolate
Dark chocolate is rich in antioxidants, but cacao plants can also absorb cadmium and lead from the soil in which they're grown. This doesn't mean giving up chocolate (yes, really!). Instead, look for companies that routinely test their products for heavy metals Seleno Health and SG Cacao both publicly share testing information for their cacao products.
Fish and seafood
Larger predatory fish such as swordfish and some varieties of tuna accumulate more mercury over their lifetime. Canned tuna is a very common daily occurrence of heavy metals in a lot of people's diets. Choosing a wider variety of seafood and including smaller fish can help reduce exposure while still gaining the nutritional benefits.
Protein powders
Independent testing in 2025 found many plant-based protein powders contained measurable amounts of heavy metals, highlighting the importance of choosing brands that undertake third-party testing.
Tea, herbs, spices and salt
Plants naturally absorb minerals from the soil they grow in, including heavy metals when present. Choosing reputable brands that test their products can help minimise unnecessary exposure.
Could heavy metals be affecting your health?
One of the challenges with heavy metals is that there isn't a single symptom that points directly to them. As a functional nutrition practitioner, I'm always looking for patterns rather than isolated symptoms. If someone has ongoing health concerns that haven't responded to the usual approaches, it's worth asking whether their environment, nutrition and long-term exposures could be contributing to their overall body burden.
Some of the patterns I commonly investigate include:
Persistent fatigue despite getting enough sleep
Brain fog or difficulty concentrating
Forgetfulness or feeling mentally "slower" than usual
Frequent headaches
Mood changes, including increased irritability or emotional reactivity
Thyroid concerns that haven't improved as expected
Digestive symptoms that don't respond to dietary changes
Fertility challenges
Difficulty losing weight despite eating well and exercising regularly
None of these symptoms confirm heavy metal toxicity on their own, and they can occur for many different reasons. However, when several of these patterns occur together particularly alongside known environmental exposures they may warrant further investigation as part of a broader health assessment.
As I often tell my clients: don't guess, test.
The hidden impact of long-term exposure
Research suggests that even relatively low levels of long-term exposure may have important health implications. A large 2018 systematic review published in The BMJ, involving more than 350,000 participants across 37 studies, found that chronic exposure to arsenic, lead and cadmium was associated with an increased risk of cardiovascular disease and cardiovascular mortality.
While this doesn't prove that heavy metals directly cause heart disease, it highlights why reducing unnecessary exposure is an important public health goal. It's another reminder that we shouldn't think about heavy metals only in the context of acute poisoning. Sometimes it's the slow, cumulative exposures over many years that deserve our attention.
Why blood tests don't always tell the whole story
One of the most common comments I hear is:
"My doctor tested me and said everything was normal."
Blood tests are extremely valuable, but it's important to understand what they're measuring. For many heavy metals, blood reflects recent or ongoing exposure rather than the body's longer-term storage. Once metals such as lead enter the bloodstream, the body works quickly to remove them from circulation. Some are excreted, while others can be stored in tissues such as bone and organs, where they may remain for years.
Lead, for example, has a relatively short half-life in blood around a month but can remain stored in bone for decades. During times of increased bone turnover, such as pregnancy, breastfeeding or menopause, some of that stored lead can be released back into the bloodstream.
That's why a normal blood test doesn't always tell the whole story. One of my favourite ways to explain it is this:
Blood tells you what's passing through your body. Your hair tells you what your body has been carrying.
Hair Tissue Mineral Analysis (HTMA) isn't used to diagnose heavy metal poisoning, and it's not a replacement for medical testing when acute exposure is suspected. However, many functional practitioners, inlcuding myself use it as part of a broader assessment to explore longer-term mineral patterns and potential environmental exposures.
As hair grows, minerals and some metals are incorporated into the hair shaft, providing a record of exposure over several months rather than a single moment in time. While HTMA has limitations and should always be interpreted alongside a person's health history, symptoms and other investigations, it can offer another piece of the puzzle when trying to understand someone's overall health picture.
So what can you actually do?
After reading this, it's easy to feel like heavy metals are everywhere. But that doesn't mean you need to throw out everything in your kitchen, laundry and make-up bag, stop eating chocolate and give up your daily cup of tea. When I work with clients, I encourage them to think about heavy metals in two simple stages: reduce what you can, and support what your body already does naturally.
Start by reducing the load where it's easy
You don't have to change everything overnight. Small, practical changes made consistently can make a meaningful difference over time.
If you're renovating an older home, take precautions around lead-based paint.
If your local water supply is known to contain contaminants, consider using an appropriate water filter.
Choose brands that are transparent about testing their products.
If you find yourself eating the same foods every day, particularly rice or larger predatory fish — try introducing more variety into your weekly meals.
Then support your body's natural detoxification systems
One of the biggest misconceptions I see is that we need to "detox" our bodies. The reality is your body is already doing that every single day. Your liver, kidneys, digestive system and skin work around the clock to process and eliminate waste products, including environmental toxins.
Our bodies are incredibly well equipped to process and eliminate waste. The challenge is that many of us are now exposed to a far greater number of environmental chemicals than previous generations. Supporting these natural detoxification pathways through good nutrition and lifestyle habits has never been more important. Rather than looking for a quick fix, I encourage people to focus on supporting these remarkable systems with simple daily habits.
6 daily habits to support your body eliminating heavy metals
Eat as many colourful veggies as possible each day. Focus on dark leafy greens for your liver health, and wash your fruit and vegetables to remove heavy metals from the leaves and skin.
Eat as much coriander (cilantro) and parsley as possible daily. These are two herbs I encourage clients to include regularly. Laboratory and animal studies have explored coriander's potential role in binding certain metals, although human research is still emerging. Regardless, both herbs are rich in antioxidants and phytonutrients, making them an excellent addition to a whole-food diet.
Stay hydrated and filter your water.
Sweat daily, in a sauna, through exercise, red light therapy or anything else that makes you sweat.
Epsom salt baths and foot soaks.
AMD Ion foot detoxes a gentle way to help eliminate heavy metals for all ages.
Here are two recipes I regularly make at home and share with clients as an easy way to incorporate more herbs and greens into everyday life.
Green Herb Shot
A refreshing way to boost your intake of leafy greens and fresh herbs.
Ingredients:
Juice of 2 lemons
1 cucumber, peeled
1 bunch of spinach
1 bag of rocket (arugula)
1 bunch fresh coriander (cilantro)
1 bunch fresh parsley
Filtered water to blend
Blend until smooth and enjoy fresh.
Daily Herbal Tea
This herbal tea has become part of my own daily routine.
Ingredients:
1 bunch fresh coriander
1 bunch fresh parsley
6 tablespoons dried dandelion leaf
1 cm piece of fresh ginger, roughly chopped
5 tablespoons dried lemon balm (or green tea bags if preferred)
Filtered water
Bring the water to a gentle simmer, add the herbs and ginger, then steep for around 15 minutes before straining. I often make a large batch to enjoy throughout the day.
Please note: no tea or green shot can "detox" heavy metals on their own they are supportive choices as part of a broader daily protocol.
For some people, further investigation may also be appropriate. If you have ongoing symptoms, multiple known environmental exposures, or simply want to better understand your mineral status, Hair Tissue Mineral Analysis may be one tool worth discussing with me. Like any test, it shouldn't be interpreted in isolation, but alongside your symptoms, health history and other investigations.
Final thoughts
One of the biggest misconceptions about heavy metals is that exposure only happens after a major event. In reality, it's often the opposite it's the tiny, everyday exposures we don't think to question.
The body gives clues before it gives disease, and heavy metal exposure is no different. You don't need to be fearful, and you don't need to overhaul your entire life overnight. What you need is knowledge enough to understand where exposure comes from, notice the patterns your body may be showing you, and make informed decisions for you and your family.
Stop guessing, start testing.
If you'd like support connecting the dots on your own health picture, including whether Hair Tissue Mineral Analysis or my Heavy Metal Program could be a useful next step for you, I'd love to help email the office@shelleygawith.com or https://shelley-gawith.mykajabi.com/10-day-heavy-metals
This article is general education and not a substitute for individual medical advice. If you have concerns about acute heavy metal exposure, please see your doctor.
References
Chowdhury R, Ramond A, O'Keeffe LM, et al. Environmental toxic metal contaminants and risk of cardiovascular disease: systematic review and meta-analysis. The BMJ. 2018;362:k3310. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6113772/
Soilsafe Aotearoa, University of Auckland — free residential soil testing programme. https://soilsafe.auckland.ac.nz/
