Sinusitis

Synopsis:
Background
Causes & Risk Factors
Nutritional Interventions
Suggested Supplementation
References

Sinusitis is inflammation of the sinuses, which are small air-filled cavities within the bones of the face surrounding the nose. Sinusitis symptoms include congestion, mucus discharge, and facial pain. The condition affects an estimated 16% of the United States adult population (Leung 2008; Smith 2012).

Sinusitis should not be confused with rhinitis, which is characterized by inflammation associated with the mucosal surface of the nasal cavity (Hytonen 2012). However, since most cases of sinusitis also include symptoms of rhinitis, the term rhinosinusitis is often used (Fokkens 2005; NIH 2012).

Sinusitis can be acute, subacute, chronic, or recurrent acute; categorization is dependent upon duration and frequency of symptoms (Leung 2008; Radojicic 2010). Acute sinusitis typically causes mild symptoms that resolve on their own, but very rarely may progress into severe or even life-threatening complications, such as a brain abscess (Onisor-Gligor 2012; Boto 2011; Suhaili 2010; Ferri 2012). Chronic sinusitis causes persistent symptoms and is often difficult to treat (Leung 2008).

Throbbing facial pain or pressure is a prominent feature in many cases of sinusitis. This symptom typically originates in the same location as the affected sinus (e.g., in the forehead, cheeks, nose, or between the eyes). The pain associated with sinusitis is a result of increased pressure caused by trapped air and mucus, which pushes on the sinus mucous membrane and bony wall behind it.

Sinusitis is also often marked by a change in the characteristics of nasal secretions, which progress from clear and watery to thick and opaque (e.g., white, yellowish, greenish, or blood-tinged) (DeMuri 2009; NIAID 2012). The mucus becomes thick because it loses its water content while trapped in the sinus cavity. 

Conventional pharmaceutical options to reduce inflammation in the sinuses and nasal passages include corticosteroids and decongestants, though some people receive limited, or minimal, symptom relief (Rossberg 2005). Moreover, antibiotics are often needlessly overprescribed since most cases of acute sinusitis are caused by viruses, which do not respond to antibiotics, and chronic sinusitis can be caused by chronic inflammation or anatomic irregularities (Leung 2008; Mayo Clinic 2012c; PubMed Health 2012). The inappropriate use of antibiotics can lead to antibiotic-resistant organisms and an unnecessary increase in antibiotic-related adverse events such as diarrhea (Smith 2012; Guarch Ibanez 2011).

Anatomy of Sinuses

The sinuses circulate air and are lined with specialized cells that produce mucus and cells that possess tiny hairs called cilia (DeMuri 2009). The sinuses contain a thin layer of watery mucus that traps and filters out pathogens and other harmful particles from inhaled air, while the cilia rhythmically pulsate or “beat”, sweeping the stagnant mucus out of the sinuses and into the nasal cavity (AAFP 2008; NIAID 2012). In addition to catching unwanted material before it reaches the lungs, mucus and cilia also work together to warm and humidify the sinuses and nasal cavities so they remain moist and do not dry out during breathing (NIAID 2012; Jurkiewicz 2011). The sinuses also generate high concentrations of nitric oxide, a free radical and immune-mediator, which may serve to maintain sterility, strengthen immune defense against viruses and bacteria, and enhance the efficiency of cilia in clearing excess mucus (DeMuri 2009; Keir 2009).

 

The drainage openings (ostia) that allow the sinuses to empty into the nasal cavity are relatively small, and are thus vulnerable to becoming blocked easily (Merck 2006; Osguthorpe 2001). When this drainage system is blocked, the stagnant mucus begins to accumulate, allowing bacteria and other pathogens to colonize in the sinus cavity, resulting in inflammation and infection (i.e., sinusitis) (NIH 2012A; Merck 2006).

The potential causes of ostia blockage are:

Swelling Factors

• Viral upper respiratory tract infection (i.e., common cold)
• Allergies (e.g., hay fever)
• Cystic fibrosis
• Chemical inhalation (e.g., tobacco smoke)
• Immune disorders
• Facial injury
• Changes in atmospheric pressure (e.g., flying, scuba diving)
• Over-using nasal decongestant sprays

 Mechanical & Anatomical Obstructions

• Deviated septum
• Nasal polyps
• Foreign body
• Congenital deformity
• Tumor
• Nasal bone spur

Although there are multiple risk factors that can contribute to ostia obstruction, allergic inflammation and viral upper respiratory infections (URIs) are the most significant (DeMuri 2009). Infection with a common cold virus is the most frequent cause of viral sinusitis (Mayo Clinic 2012b; Balkissoon 2010). 

 

Lactoferrin

Lactoferrin and its active metabolite, lactoferricin, are multifunctional proteins known to possess antibacterial, antifungal, and antiviral activities, as well as immune regulatory and anti-inflammatory actions (Psaltis 2008). Lactoferrin is a component of whey protein that can also be found in high concentrations within mucosal secretions, such as airway mucus, tears, and breast milk (Roxas 2007; Acioglu 2012). Lactoferrin is produced and stored within the cells of the nasal mucosa and is presumed important as a first line of defense against invading pathogens (Acioglu 2012).

Research suggests that lactoferrin may be beneficial for alleviating the symptoms and complications of the common cold for at least 2 reasons. First, it can kill bacteria through the binding of iron molecules that would otherwise be needed for essential bacterial functions (Acioglu 2012; Roxas 2007). Second, lactoferrin exerts an antioxidant effect by preventing the formation of free radicals, thus decreasing nasal tissue oxidative damage (Acioglu 2012).

Studies suggest that decreased levels of lactoferrin may play a role in the development of chronic sinusitis, especially when nasal polyps, asthma, and/or allergies are involved (Zielinska-Blizniewska 2012; Psaltis 2008). Lactoferrin production is reduced in people with sinus conditions compared to healthy subjects. Moreover, lactoferrin levels are particularly low in sinusitis patients with nasal polyps. The low levels of lactoferrin associated with sinusitis are due to both its decreased expression/down-regulation as well as its increased utilization to fight infection (Acioglu 2012).

 

Vitamin C

Research shows a sufficient daily intake of ascorbic acid is required for the immune system to defend the body against infections (especially viral infections) (Ely 2007).

Evidence suggests that supplementation with 1000 mg daily of vitamin C can decrease the risk of catching a cold (Holt 2010). When given in doses greater than 200 mg daily, vitamin C has been shown to reduce the duration of cold symptoms by 1-4 days (Khalid 2011). Vitamin C markedly improves immune function by enhancing natural killer cell activity, interferons (signaling proteins that boost immune response), macrophages, T-lymphocyte production, cell movement (i.e., chemotaxis), and cell-mediated immunity (Heimer 2009; Khalid 2011).

Individuals with sinusitis typically exhibit decreased serum levels of vitamin C (Cho 2009; Unal 2004). Topical vitamin C may be associated with enhanced mucociliary clearance of the paranasal sinuses, through the loosening of thick mucus secretions, and an increase in ciliary beat frequency (Cho 2009; Zhang 2012). Oral vitamin C supplementation also reliably decreases plasma levels of histamine, a known contributor to inflammation and nasal congestion, especially among people with allergy-induced sinusitis (Helms 2006; Naclerio 2010).

 

Zinc 

Zinc is an essential trace element required for a variety of metabolic processes (Classen 2011), including the maintenance of a healthy immune function (Roxas 2007). Unfortunately, zinc deficiency is prevalent throughout developed Western countries (Maggini 2012). Zinc deficiency, which is common among the elderly and the young, is linked to the impairment of many components of the immune response, including T- and B-lymphocyte function, natural killer cell activity, macrophage phagocytosis, and antibody formation (Maggini 2012; Pae 2012; Nriagu 2007). As a result, zinc deficiency is associated with an increased risk of infection (Maggini 2012; Pae 2012). In one study, children with chronic rhinosinusitis exhibited lower levels of antioxidants, including zinc, than healthy control subjects (Unal 2004). Correcting zinc deficiency through supplementation is efficacious for a variety of viral infections (Pae 2012; Nriagu 2007). This may be partly attributable to zinc’s positive effect on the expression of interleukin-2 and interferon-γ, as well as on natural killer and cytotoxic T cells, which help the immune system kill viruses (Sandstead 2010).

Zinc supplementation has long been considered an effective therapy for reducing the duration of the common cold (Roxas 2007; Nriagu 2007). A 2011 study concluded that zinc supplementation significantly reduced both duration and severity of the common cold when administered within 24 hours of the onset of symptoms. This study also revealed that zinc supplementation over 5 months was helpful for preventing infection by common cold viruses (Singh 2011). Likewise, a clinical study involving zinc nasal gel (given within 1-2 days of illness onset) found that zinc was able to reduce the severity and duration of common cold symptoms among healthy adults (Mossad 2003). In a 2012 study, researchers found that the combination of zinc plus vitamin C was more efficacious than placebo at reducing runny nose, and it also appeared to accelerate recovery in common cold patients (Maggini 2012).

 

Vitamin E

Numerous studies have demonstrated that vitamin E may have a positive effect on the human immune system. For instance, elderly patients who took 200 IU of vitamin E daily for 1 year were 20% less likely to catch a cold (Burton 2004). In one study, children with chronic rhinosinusitis were found to have lower serum levels of several antioxidants, including vitamin E, than healthy children (Unal 2004). A 2011 study found that topical vitamin E (in combination with other antioxidant oils) was able to persistently reverse oxidative stress and nasal inflammation, similar to that by viral infections, chronic sinusitis, and allergic disease (Gao 2011). Furthermore, animal studies show that vitamin E may affect the risk and severity of viral respiratory infections (Hemila 2006).

 

Bromelain

Bromelain, which is a proteolytic enzyme complex found in pineapple, is frequently used to treat sinusitis because it reduces inflammation and loosens mucus. Specifically, bromelain may inhibit pro-inflammatory prostaglandin biosynthesis and prostaglandin E1 accumulation. This in turn inhibits the release of leukocyte enzymes. Among sinusitis patients, bromelain has been shown to hasten symptom recovery and resolve inflammation better than standard treatment or placebo. Typical oral doses of bromelain are between 500-2000 mg daily (Helms 2006).

 

Black cumin seed oil

Nigella sativa, also known as black cumin, is a flowering plant that grows in Eastern Europe, the Middle East, and Western Asia. The small black seeds of nigella sativa have a rich history of medical use in the Middle East and Asian countries. Modern scientific inquiry has examined the potential benefit of black cumin seeds and the oil derived from them in a variety of contexts ranging from cardiovascular disease to cancer (Shabana 2012; Randhawa 2011; Woo 2012; Butt 2010). Several lines of evidence suggest that black cumin seed oil and some of its active constituents are powerful anti-inflammatory agents and also combat oxidative stress (Inci 2012; Umar 2012; Ammar el 2011). In an animal model of rhinosinusitis, an active constituent derived from black cumin seed was found to be as effective as antibiotic therapy in reducing manifestations of sinusitis such as vascular congestion, inflammation, and epithelial injury in sinus tissue (Cingi 2011).

 

Xylitol nasal irrigation

Xylitol is a sugar alcohol that appears to enhance the body’s natural defense against bacterial pathogens. An animal model showed that administering xylitol solution simultaneously with a bacterial pathogen reduced the amount of bacteria detectable upon a later examination of the sinuses (Brown 2004). In one trial, 20 subjects with chronic rhinosinusitis were randomized and instructed to rinse their sinuses daily with either a xylitol or saline solution. Fifteen subjects completed the study. Nasal irrigation with the xylitol solution was associated with a significant improvement on a standardized assessment of sinusitis symptoms (Weissman 2011). 

 

• Lactoferrin (providing 95% of apolactoferrin [285 mg]): 300 mg daily
• Vitamin C: 1000 – 5000 mg or more daily
• Zinc: 30 mg daily
• Vitamin E: 400 IU daily with at least 200 mg gamma tocopherol
• Bromelain: 500 – 2000 mg daily
• Black cumin seed oil: 1000 mg daily
• Nasal wash containing xylitol: Per label instructions

 

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