Does Low Iron Make You Crave Smells? The Link Between Anemia and Desiderosmia

An excessive desire to smell certain non-food items, a condition known as desiderosmia, has been linked to iron deficiency anemia. This unusual symptom often goes unreported due to embarrassment but can be an important clinical clue for healthcare providers.

Quick Summary

Low iron can cause smell cravings, a condition called desiderosmia, which is linked to iron deficiency anemia and resolves with iron treatment. This differs from pica, the craving to consume non-food items.

Key Points

• Desiderosmia is real: Low iron can cause a condition called desiderosmia, which is an excessive craving to smell non-food items like cleaning products or exhaust fumes.

• Not the same as pica: Desiderosmia is distinct from pica (craving to eat non-food items), although both are associated with iron deficiency.

• Cravings resolve with treatment: In documented cases, olfactory cravings have been shown to disappear after iron deficiency is corrected with supplementation.

• Iron's role in the brain: The connection is likely neurological, involving iron's role as a cofactor for enzymes in neurotransmitter synthesis, particularly dopamine.

• Consult a doctor: If you experience unusual smell cravings, it's a valuable clinical symptom that warrants investigation by a healthcare professional.

• Treatment is effective: Treatment for the underlying iron deficiency, whether oral or intravenous, is typically effective in resolving desiderosmia.

• Consider other symptoms: Pay attention to other signs of iron deficiency, such as fatigue, pale skin, and restless legs, which may occur alongside smell cravings.

Understanding the Connection: Anemia and Olfactory Cravings

Yes, low iron, especially in cases of iron deficiency anemia (IDA), can indeed cause you to crave smells. This phenomenon is clinically known as desiderosmia, defined as an excessive desire to smell specific odors without any urge to consume them. Researchers have documented cases of patients, including pregnant women, who developed intense olfactory cravings for substances like cleaning products, gasoline, or earthy smells. In these instances, the cravings significantly decreased or resolved entirely after iron deficiency was corrected through supplementation, highlighting a clear connection. The link is thought to be tied to iron's crucial role in brain function and neurotransmitter synthesis.

The Neurobiological Mechanisms at Play

While the exact physiological mechanism is not yet fully understood, several hypotheses point to iron's involvement in neural pathways related to both mood and sensation. Iron is a cofactor for enzymes involved in the synthesis of key neurotransmitters like dopamine and serotonin. Dopaminergic pathways are particularly associated with reward and compulsive behaviors, suggesting that low iron might alter these circuits, leading to unusual cravings. Studies have also shown that iron deficiency can impact olfactory perception directly, possibly by affecting the function of the olfactory system or its connection to other brain regions. This sensory disturbance could then manifest as an intensified or distorted sense of smell that creates a craving for specific odors.

Desiderosmia vs. Pica

It is important to differentiate between desiderosmia and pica, another condition linked to iron deficiency. While both are considered atypical cravings, their manifestations differ significantly.

Feature	Desiderosmia	Pica
Symptom	Compulsive desire to smell a non-food substance.	Compulsive desire to eat a non-food substance.
Observed in	Adults and pregnant women with iron deficiency anemia.	All ages, but often linked to pregnant women, children, and those with certain psychiatric conditions.
Common Cravings	Pungent odors like cleaning products, gasoline, or rubber.	Ice (pagophagia), dirt or clay (geophagia), starch, or paper.
Health Risk	Risks associated with inhaling toxic fumes, but not ingestion.	Potential for gastrointestinal blockage, infection, and poisoning.
Cause	Primarily associated with iron deficiency anemia.	Often linked to iron deficiency, but can also be caused by zinc deficiency, stress, or mental health issues.
Resolution	Cravings resolve with iron supplementation.	Typically resolves with correction of nutritional deficiency.

Why is Iron Important for Brain and Olfactory Function?

Iron is essential for numerous cellular processes, and the brain requires a significant amount of it to function optimally. Iron's role goes beyond just hemoglobin production, extending to the synthesis of myelin (nerve insulation), neurotransmitter production, and energy metabolism. When iron levels are insufficient, these processes can be disrupted. For the olfactory system, this can lead to impaired odor perception or altered signals that result in intense, specific cravings for certain smells. A study using rats demonstrated that iron deficiency alters olfactory behavior, with iron-deficient rats exhibiting a significantly longer duration of sniffing than a control group. This provides further evidence that low iron status can directly influence the sense of smell and related behaviors.

Additional Contributing Factors

While iron deficiency is a key contributor, other factors may also play a role in developing desiderosmia or unusual smell cravings. These can include:

• Hormonal Changes: Fluctuating hormones during pregnancy can alter the sense of smell and are frequently associated with both pica and desiderosmia.
• Psychological Factors: Anxiety, depression, and other mental health conditions can sometimes cause sensory distortions, including phantom smells, even without iron deficiency.
• Cultural Practices: In some cultures, certain forms of pica, such as geophagia, are common, which may be linked to a preference for earthy odors.

Diagnosis and Management

If you experience unusual smell cravings, it is crucial to consult a healthcare professional to rule out iron deficiency or other underlying medical conditions. A doctor will typically perform a physical examination and order blood tests to check your iron and ferritin levels. If iron deficiency is confirmed, the primary treatment involves iron supplementation. This can be done through oral iron therapy, which is often sufficient, or intravenous (IV) iron in more severe cases. Successful iron repletion has been shown to resolve desiderosmia in most documented cases. A healthcare provider will monitor your iron levels and other symptoms to ensure the deficiency is fully corrected.

The Role of Awareness and Diet

Raising awareness about unusual symptoms like desiderosmia is essential for early diagnosis and treatment. Many individuals are hesitant to disclose these cravings due to feelings of embarrassment, but a simple conversation with a doctor can uncover an easily treatable underlying cause like iron deficiency. Alongside supplementation, addressing the underlying cause of iron deficiency is vital. For some, this may mean dietary changes, focusing on iron-rich foods such as lean red meat, poultry, beans, and leafy greens. In cases of malabsorption (due to conditions like Celiac disease or gastric bypass surgery), addressing the primary issue is also necessary to correct iron levels. By acknowledging these unconventional symptoms, healthcare providers can offer better, more holistic patient care.

Conclusion

While a craving for smells may seem bizarre, it is a clinically documented symptom known as desiderosmia, and there is a direct and treatable link to low iron levels. The connection is thought to stem from iron's critical role in maintaining normal brain and olfactory function. Addressing the underlying iron deficiency through proper diagnosis and treatment is the key to resolving this unusual symptom. Open communication with a healthcare provider is the first and most important step toward finding relief.

Comparison of Iron Deficiency Effects on Sensation

Sensory Alteration	Common Manifestation	Link to Iron Deficiency	Resolution with Treatment
Desiderosmia (Smell Cravings)	Craving scents of cleaning products, gasoline, or earth.	Affects neuronal enzymes crucial for olfactory processing.	Resolves with iron supplementation.
Pica (Eating Non-Food Items)	Craving ice, dirt, clay, or starch.	Linked to altered neurotransmitter function and nutrient-seeking behavior.	Resolves with iron replacement.
Restless Legs Syndrome (RLS)	Irresistible urge to move the legs, often at night.	Associated with changes in dopaminergic pathways due to low brain iron.	Symptoms improve with iron therapy.

Symptoms of Iron Deficiency

Besides unusual cravings, here is a list of other common symptoms of iron deficiency:

• Extreme fatigue
• Weakness
• Pale skin
• Chest pain, fast heartbeat, or shortness of breath
• Headaches and dizziness
• Cold hands and feet
• Inflammation or soreness of the tongue
• Brittle nails (koilonychia)
• Unusual cravings for non-food items (pica)
• Poor appetite, especially in children

If you experience any of these symptoms, especially in conjunction with unusual smell cravings, it is highly recommended to seek medical advice for a proper diagnosis. A doctor can help determine if iron deficiency is the root cause and prescribe the correct course of treatment.

Frequently Asked Questions

What is desiderosmia?

Desiderosmia is a medical term for the excessive and compulsive desire to smell certain odors without the urge to consume them, a symptom that has been directly linked to iron deficiency anemia.

What kind of smells do people with low iron crave?

People with low iron who experience desiderosmia may crave pungent or unusual smells, such as gasoline, menthol, rubber, earthy smells (geosminophilia), or specific cleaning products.

How does iron deficiency cause smell cravings?

Iron is crucial for neurotransmitter synthesis in the brain, especially dopamine, which influences compulsive behaviors. When iron is low, these brain pathways may be disrupted, leading to an abnormal desire for certain sensory inputs like smell.

Are smell cravings the same as pica?

No, desiderosmia (smell cravings) is different from pica (eating non-food items), although both can be symptoms of iron deficiency. Desiderosmia involves only smelling or inhaling, not consuming, the desired substance.

Can iron supplements stop the smell cravings?

Yes, in many documented cases, supplementing iron has been shown to be an effective treatment for desiderosmia. The olfactory cravings typically diminish and resolve as iron levels return to normal.

Who is most at risk for desiderosmia due to low iron?

Pregnant women and individuals with iron deficiency anemia are particularly susceptible. Women are more likely to experience desiderosmia due to iron deficiency, possibly due to hormonal changes and higher iron needs.

When should I see a doctor about smell cravings?

You should see a doctor if you experience persistent or unusual smell cravings, especially if they are accompanied by other symptoms of iron deficiency like fatigue, weakness, or pale skin. A healthcare provider can properly diagnose the cause and recommend treatment.