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Examining the Influence of Iron on Exceptional Longevity with Functional Medicine in Toronto: Part I


Human nutrition is a vast topic – however, clinical nutrition and functional medicine from Toronto can help you decipher and address aging effects with a tailored approach to health.

“Exceptional longevity” refers to living beyond the standard life expectancy, which is considered age 85 and up. By bringing awareness to various blood biomarkers and their link to healthy aging, a longevity-focused diet may be considered for optimal health. 

This article from the Toronto Functional Medicine Centre is Part I in a series on exceptional longevity. We explain how iron levels can contribute to elongating your lifespan, and how our clinic services work. 

Understanding iron and ferritin 

Several scientific studies have attempted to understand the factors behind exceptional longevity, especially the impact of nutrient levels. For example, in a study published in Geroscience, blood biomarkers of centenarians were measured. Exceptional longevity was associated with prominent normal iron levels (within range); in total, 1,224 participants (84.6% females) of the original 44,636 participants lived to be 100 years old. Though the study used blood iron levels to monitor iron status, this article will focus on ferritin. Ferritin is the blood protein that contains iron, and it’s measured to assess iron levels in the human body. 

Ferritin plays a crucial role in iron storage and iron metabolism. It indicates if your stores are low and whether or not you’re deficient. Think of it as a bank savings account, but instead of money, you have iron levels. 

When you have inflammation or infections, ferritin could become elevated, which has been noticed in many acute and chronic disease conditions (autoimmune disorders, acute infections). With inflammation in particular, the body gathers available iron and stores it in ferritin to reduce the availability of iron in the bloodstream. This is a protective response that limits the amount of iron accessible to invading microorganisms, which require iron for their growth and replication.  

In the Gutenberg Health Study from the University Medical Center Mainz, one of the definitions of functional iron deficiency (which is more prevalent in younger or menopausal women) was ferritin levels below 100ng/mL and iron deficiency was defined as <30ng/mL (these numbers have been converted into Canadian values). The study investigated multifactorial influences that may be involved in developing metabolic diseases, immune function-related conditions and the psyche etc. With that said, the study concludes that iron deficiency is individually related to medium-long term all-cause mortality.

The consequences of low iron levels

Low iron levels can have negative impacts on the body’s transport and utilization of oxygen.  If we don’t have enough iron, we cannot make enough hemoglobin; also, we cannot get ample oxygen to our organs, including the lungs, heart, brain and muscles. This is how vital maintaining optimum levels are as we age! Iron is also involved in neurogenesis, DNA and RNA production, energy metabolism, collagen synthesis and plays a role in vitamin D metabolism.  

Symptoms of iron deficiency may include: 

    • Cognitive and behavioural changes; symptoms of depression, anxiety, psychotic disorders; reduced production of the neurotransmitters serotonin, epinephrine and norepinephrine;
    • Decreased lung function, laboured breathing, chest pain, shortness of breath;
    • Left ventricular dysfunction, heart failure, heart palpitations;
    • Compromised gut lining (the cells lining the intestinal wall require iron for normal function and repair);
    • Decreased immunity;
    • Bone loss, osteopenia, osteoporosis;
    • Reduced thyroid function; 
    • Cold hands and feet; 
    • Slow wound healing;
    • Iron deficiency anemia: pale skin, fatigue;
    • Hair loss;
    • Muscle weakness/pain, joint pain;
    • Weight gain,
    • Headaches, dizziness, light-headedness, increased risk of fainting;
    • Restless leg syndrome;
    • Inflamed tongue, cracks at the corners of the mouth;
    • Unusual cravings (eg. ice, dirt, paper);
    • Poor appetite, especially in children;
    • Brittle nails.
Quick Fact
Athletes may experience significant iron losses and may have an increased risk of developing iron deficiency.

Nutritional sources of iron 

Bioavailable sources of iron are animal based (heme iron) and include organ meats, beef, lamb, chicken, turkey (dark meat contains more), salmon, sardines, clams, oysters, mussels, shrimp and scallops. 

Plant based iron (non-heme) sources of iron may not be readily absorbed by the body, which is why you’d need to eat about double the amount to get the recommended daily value. Non-heme sources of iron include tofu, lentils, blackstrap molasses, teff, buckwheat, oatmeal, cooked spinach, kidney beans, chickpeas, lima beans, sesame seeds, tempeh, quinoa, baked beans and barley.

It should be noted that the rate of absorption (the amount of iron that is actually absorbed) differs for each type of iron source; for example, organ meats 25-30%, beef 20%, green leafy vegetables about 7-9%, etc. Nutrition labels do not show bioavailability. In reality, you absorb a significantly low amount of iron in comparison to what the nutrition label states. Below, we highlight a table of how iron absorption may be increased or decreased in the body. 

Factors that may increase iron absorption 

Factors that may decrease iron absorption 

  • Vitamin C with meals;
  • Lacto-fermented foods;
  • Soaking, sprouting and fermenting grains, nuts, legumes and seeds to reduce phytates;
  • Cast iron cookware increases absorption;
  • Cooking (i.e. cooked spinach contains a high amount of iron compared to raw);
  • Meat/organ meat increases the absorption of non-heme iron within the same meal;
  • A healthy gut microbiome;
  • Alcohol consumption;
  • Genetic polymorphisms, leading to excess iron absorption (a condition called hemochromatosis).
  • Phytates, oxalates and polyphenols in non-heme iron foods;
  • Tannins (i.e. tea, coffee, chocolate, nuts);
  • Dysbiosis in the gut, h.pylori infection;
  • Reduced gastric acid secretion;
  • Use of proton pump inhibitors, H2-blockers, cholestyramine;
  • Celiac disease, inflammatory bowel disease, chronic gastritis;
  • Bariatric surgery,
  • Chronic renal failure;
  • Calcium/dairy foods (decreases both heme and non-heme absorption);
  • Vitamin A deficiency;
  • Various supplements: curcumin, berberine, quercetin, inositol hexaphosphate (IP6), EGCG;
  • Infrared sauna use. 

Why consider the functional medicine approach for iron levels

Iron is essential, yet excessive amounts could also potentially cause harm. An iron overload or elevated ferritin levels can cause detriment in these ways: organ damage (liver, heart, pancreas,) increased risk of developing diabetes, joint pain, hormonal imbalances, skin discoloration (bronze/grey), neurodegenerative issues, an increased risk of infections (high iron levels can promote the growth of certain pathogenic bacteria) and increased risk of cancer and tumour growth. Oregon Health and Science University defines possible hemochromatosis as >200 ng/mL if transferrin saturation (TSAT) is greater than 45%.

Finding your optimal ferritin level as you age is an individual matter – this is why it’s imperative to consult with a holistic nutritionist and/or functional medicine practitioner, as these health providers can analyze your health status to address your iron health concerns. For example, if you have some of the above-mentioned deficiency symptoms, eating additional iron-rich foods may be advised. You may also be taught that keeping an eye on your ferritin level – and understanding why it’s high or low and how to make necessary adjustments – is a way to increase your chances for exceptional longevity. 

Genetic variations can also affect the regulation of iron homeostasis; if you cannot achieve proper ferritin levels, your health care provider may recommend genetic testing. At a minimum, by testing ferritin levels yearly and confirming lab results will help direct you in choosing the nutrient-dense foods specific to your needs. 

Suggested Reading: Pay Attention to Low T: Our Functional Medicine Toronto Clinic Explains Why

Contact the TFMC Today

Let’s help you work towards optimal functioning with functional medicine therapies! 

A tailored comprehensive treatment plan from the TFMC could offer improvements to your biology. Next to helping you unravel iron issues and other nutritional deficiencies, we can adapt treatment plans for several health conditions, especially those linked to cellular health, sexual health, autoimmune disease, acid reflux, irregular periods, digestive issues, inflammatory conditions, cognitive decline, and more. 

We adhere to the integrative functional medicine model, which is how we modify therapies for each individual patient. Integrative medicine practices that are available at the TFMC include functional lab tests, Western medicine, naturopathic medicine, holistic nutrition, herbal medicine, Chinese medicine, hormone optimization programs, among others. 

The TFMC is also home to the IV Lounge, which is where adjunctive intravenous therapy drips are provided. Their dosages are uniquely customized according to the principles of functional medicine; when they’re administered with regular oral supplementation, a healthy lifestyle and other treatment modalities, they can support overall wellness. 

Are you curious about your iron levels or longevity? Our functional medicine Toronto clinic is available for consultations. A personalized approach to wellness could improve hormone imbalances, nutritional deficiencies, and long-term health – request a session with us by clicking here

Disclaimer: The information in this article is designed for educational purposes only and is not intended to be a substitute for informed medical advice or care. This information should not be used to diagnose or treat any health problems or illnesses without consulting a doctor. You should always consult with a health care practitioner before relying on any information in this article or on this website. Never delay or disregard seeking professional medical advice from your doctor or other qualified healthcare provider because of information you have read from the Toronto Functional Medicine Centre website or other affiliate media. 



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