Top 4 Nutrients For Seasonal Allergies
Up to 25% of Canadian adults suffer from seasonal allergies (Wheatley LM, 2015). If you find yourself to be part of this demographic, you are likely to find yourself to be dreading the approaching spring every year, a time that really should be cherished and celebrated. Seasonal allergies, also referred to as hay fever and allergic rhinitis, has only become much more prevalent over the last 3 decades (Quality., 2003) and encompasses an array of symptoms affecting the airways such as sneezing and congestion. These symptoms are a result of an immune-mediated response that releases histamine in the body. There are many known environmental triggers to seasonal allergies, some of the most common being pollens, grasses and weeds. Conventionally, those who suffer from these types of allergies are told to avoid allergens as much as possible as a prevention method. Unfortunately, it is not always possible to avoid allergens that are found in the environment and many find themselves at the mercy of the outdoors or relying on over-the-counter antihistamines as a band-aid solution to the symptoms they experience. However, there are many more natural health strategies that can be leveraged to help reduce the histamine burden in the body. Here are the top 4 nutrients one can consume to help counteract the common symptoms of hay fever. 
1) Omega-3 Essential Fatty Acids (EFAs)
Fish oil is the best source of omega-3 essential fatty acids. Although it can be obtained at a dose of 250mg from fish intake in the diet, often a higher dose through supplementation is required to obtain more therapeutic effects. Supplementation can also help to increase the ratio of omega-3s to omega-6s. Whereas omega-6s are much more prevalent in a Standard American Diet (SAD), and can have a pro-inflammatory effect, it is important to encourage a higher consumption of omega-3s to counteract the omega-6s and favour the anti-inflammatory effects. These anti-inflammatory effects of omega-3 EFAs are largely thought to have a role in helping to reduce the symptoms of seasonal allergies. Some research also suspects that a high intake of eicosapentanoic acid (EPA) in particular, can decrease the risk of hay fever in both men and women, likely through modulation of the immune system (Nagel G, 2003). In another study, research has shown a trend in favour of decreasing the risk of allergic rhinitis in infants whose mothers supplemented with EFAs during pregnancy (Venter C). The role of this nutrient is quite vast and foundational to health.
2) Spirulina
Spirulina, also known as blue-green algae, is often added to green drinks, giving it its distinct color. Spirulina contains a good amount of protein and a high concentration of B vitamins, iron and other minerals. It is thought to have immunomodulating properties acting as a mast cell stabilizer, preventing the release of histamine from these cells. In turn this leads to a significant reduction in many nasal symptoms including nasal discharge, sneezing, congestion, and itching. A study found that consuming 2g of spirulina daily for about 6 months greatly decreased these symptoms in adults compared with placebo (Cingi C, 2008). Please note, that due to the lack of regulatory standards for blue-green algae in the food and supplement industries, it can contain high levels of heavy metals and other toxins (Roy-Lachapelle A, 2017). Be mindful of where you are sourcing this nutrient if you plan to supplement with it. Keep in mind that it is always best practice to consult with your healthcare practitioner before supplementing with any nutraceutical product.
3) Quercetin
Similarly to spirulina, quercetin is a mast cell stabilizer. In addition to inhibiting the release of histamine from these cells, quercetin is also thought to act as an anti-inflammatory by the release of mediators such as leukotrienes and prostaglandins (Otsuka H, 1995). Quercetin also happens to be an important and well-researched bioflavonoid found in many fruits and vegetables, particularly apples, broccoli, onions and berries. It is thought to work even better in synergy with other flavonoids such as green tea and resveratrol. Although the evidence is lacking for the supplementation of quercetin to address seasonal allergies, theoretically, it shows a lot of promise to reduce the well-known symptoms of this condition. There is no harm in increasing the intake of fruits and vegetables, especially those high in quercetin, to leverage its potential benefit.
4) Vitamin C
Vitamin C is an essential vitamin that we must obtain through our diets. It is a powerful antioxidant and is now thought to also have minor antihistamine effects. Although most of the evidence for the benefit of vitamin C for seasonal allergies is still preliminary, some promise has been seen. 
The biggest finding thus far shows that low levels of vitamin C in the blood seems to be associated with higher levels of histamine in the body (Johnston CS, 1996). As we know, histamine circulating in the body is mostly responsible for all of the typical hay fever symptoms from itchy eyes to sneezing, congestion and nasal discharge. As of now, vitamin C supplementation is not recommended for the treatment of seasonal allergies. However, increasing the consumption of vitamin C rich foods such as bell peppers, dark leafy greens, broccoli, berries, and citrus fruits is definitely worth a try.
Conclusion
Although the research on these nutrients for hay fever treatment and prevention is promising, more research is definitely needed. In the meantime, promoting the consumption of these nutrients through healthy foods in the diet may very well yield some benefits even beyond the realm of seasonal allergies.
