The Science behind Zestt Wellness

Zestt Breathe+

Immunity and Lung Health

Good lung health allows us to breathe freely, perform optimally and recover quickly should we become ill.  The most important function of our lungs is to take oxygen from the environment and transfer it to the bloodstream.  

What Happens If Our Lungs Are Damaged?

If our lungs are suffering from damage, inflammation or infection, our lung tissue may be stiff and scarred, and airways filled with mucus. This makes it difficult for the lungs to expand and contract, meaning breathing is harder and the oxygen we take in can be less.

Fortunately, our lungs are the first out of any of our body’s organs to receive the benefits of consumed and absorbed bioactives (after our liver). This means that consumption of powerful bioactives will result in benefits to the lungs early.

A lozenge formulation featuring anthocyanins, quercetin, zinc and BlisK12 may improve lung health by reducing oxidative stress and helping us defend against pathogen invasion, or infection, resolve inflammation, reduce blood pressure and aid the post inflammatory healing processes.

Bioactives from Boysenberries

Boysenberries contains a unique combination of bioactives which support stressed lungs.  Boysenberry ingestion targets innate proinflammatory pathways to mitigate inflammation and supports fibrolytic macrophages which repair lung inflammatory damage (Shaw et al., 2016Shaw et al., 2021).  

What boysenberry extract does is summarised below:

  • Boysenberry consumption significantly reduces airway inflammation through decreased cell infiltration and mucus production;
  • Boysenberry consumption reduces collagen deposition from chronic inflammation and assists in the repair of damaged tissue by supporting fibrolytic M2 macrophages
  • Boysenberry consumption prophylactically prevents airway inflammation.

Potential modes of action by boysenberry bioactive molecules are summarised below:

  • Reduce immune cell infiltration and mucus over secretion via anthocyanin cyanidin-3-Oglucoside modulating the IL-4Rα-STAT6 signaling pathway (Ma et al., 2019);
  • Cyanidin acts as an agonist (activator) for peroxisome proliferator-activator receptor (PPAR)-γ (Jia et al., 2013); this may increase numbers and activity of M2 fibrolytic macrophages, thereby helping with removal of inappropriately deposited collagen;
  • Anthocyanins also inhibit CCL11 and CCL26 eosinophil recruitment, presumably through inhibition of the STAT6 pathway (Sawyer et al., 2017);
  • The procyanidins epicatechin (EC) and epigallocatechin (EGC) inhibit TNF-α NFκB signaling to reduce CCL11 eosinophil recruitment (Sawyer et al., 2017Coleman et al., 2016);
  • Procyanidins also potentially inhibit IL-4/IL-13 signaling through receptor internalisation, membrane polarisation and/or affecting the redox potential of the cell which decreases inflammatory signaling pathways.

Bioactives from Blackcurrants

Blackcurrants contain bioactives which support healthy lungs and vascular system, as well as being cardioprotective.  Blackcurrants have also been shown to increase VO2 max and sport performance in elite athletes.

Blackcurrants have been shown to reduce inflammation in asthmatics.  Blackcurrant anthocyanins attenuated OVA-induced airway inflammation, eosinophilia, and CCL11 production in a murine asthma model.  Similarly, higher levels of IL-17 in asthmatic patients have been shown to stimulate neutrophil-mobilizing cytokines such as IL-6 and -18 through MAPK and NF- k B pathways (Shaw, et al., 2017Kim et al,. 2011). 

Blackcurrants support a healthy vascular system in older adults.  Carotid-femoral pulse-wave velocity, an index of central arterial stiffness, and central blood pressure were measured at baseline and again at the end of the 7-day study period.  Carotid-femoral pulse-wave velocity and central blood pressure decreased significantly after the 7-day study period with blackcurrant intake. In addition, carotid-femoral pulse-wave velocity and central blood pressure in the blackcurrant intake trial decreased significantly more than in the placebo intake trial (Okamoto et al., 2020).

The anthocyanins found in blackcurrants, according to in vitro and in vivo experiments with animals, as well as several epidemiological or clinical studies in humans, have been demonstrated to be effective in protection of the heart against ischemia/reperfusion-induced injury and in reduction of mortality related to cardiovascular diseases (Zern, et al., 2005Cassidy, et al., 2015Cassidy, et al., 2013Mink et al., 2007Scarabelli et al., 2009Toufektsian, et al., 2008Wang, et al., 2014).

New Zealand Blackcurrants were shown to increase VO2 max, and the total running distance of elite athletes by 10.6%.  Also, as greater distances were covered with repeated sprints, there was 15% higher lactate at exhaustion, and larger changes in lactate during early recovery after repeated sprints to exhaustion when blackcurrant was consumed (Perkins, I. C. et al., 2015).


Quercetin (2-(3,4-Dihydroxyphenyl)-3,5,7-Trihydroxy-4-Chromen-4-One)) is a yellow coloured flavonol, which is poorly soluble in hot water, insoluble in cold water, but soluble in fats and alcohols.  It is well tolerated during human clinical dosage studies, and dosages over 1,000mg per day for several months have shown no side effects (Azuma et al., 2010Han et al., 2020).

Quercetin is widely known in the scientific literature for its anti-inflammatory, antihypertensive, antihypercholesterolemic and antiatherosclerotic and vasodilatory properties, as reviewed by David et al., (2016). It has been used in the treatment of cardiovascular diseases and allergic, metabolic and inflammatory disorders (Batiha et al., 2020).  Quercetin is found in many plants, including nuts, citrus, grapes, berries, cruciferous vegetables and onions. 

Quercetin is believed to be able to inhibit coronavirus MERS-CoV, SARS-CoV and SARS-CoV-2 by inhibiting viral protease activity of the main protease 6LU7 (3CLpro) (Jo et al., 2019Khaerunnisa et al., 2020), as well as being a potential pandemic mitigation agent through downregulation of putative coronavirus infection-promoting disease conditions.  

In a recent pilot study, quercetin supplementation statistically improved all the clinical outcomes considered (need and length of hospitalisation, need of non-invasive oxygen therapy, progression to intensive care units and death) in Covid-19 infections (Di Pierro et al., 2021).  The results were in line with systematic reviews and meta-analyses of preclinical studies (Glinsky 2020., Brito, et al., 2021). 

Quercetin is a potent anti-inflammatory compound (Li et al., 2016Bureau et al., 2008Garcia-Mediavilla et al., 2007Ginawala et al., 2019):

  • Reducing cytokines TNF, IL-8, IL-1 and IL-4;
  • Inhibiting proinflammatory enzymes COX-2, MAPK, NFkB, AP-1, NOS and CRP;   Inhibiting VCAM-1 and ICAM-1 and E-selectin expression; and
  • Inhibiting histamine release.

Quercetin is a potent antioxidant and has shown protective effects against:

  • Reactive oxygen and peroxide species;
  • The oxidative stresses arising from cancers;
  • Excessive androgens;
  • Cardiac dysfunction, trauma and calcium overload, acrylamide, radiation, and neurodegenerative diseases.

(Boots et al., 2008Stefek et al., 2011Moretti et al., 2012Maciel et al 2013Coballase-Urrutia et al., 2013Tátraaljai, et al., 2014Ravichandranet et al., 2014Sharmila et al., 2014aSharmila et al., 2014bLi, et al., 2016Yarahmadi et al., 2017Kalantari et al., 2018Xu, et al., 2019)

Quercetin also exhibits antiviral properties, this has been shown against a variety of viruses, including:

  • Japanese encephalitis virus;
  • Human T-lymphotropic virus 1;
  • Dengue virus type 2;
  • Hepatitis C virus.

Quercetin acts by inhibiting viral NS3 protease activity and inhibits influenza virus invading cells by binding to the hemagglutination protein HA (Ramadan et al., 2009Fan et al., 2011CoelhoDos-Reis et al., 2011Zandi et al., 2011Song et al., 2011Johari et al., 2012Bachmetov et al., 2012Wu et al., 2016). 

A multi-drug approach has been proposed combining quercetin and vitamin C (ascorbic acid), which may disrupt virus entry, replication, enzyme activity and assembly, and concurrently fortify the immune response promoting early IFNs production, modulating interleukins, promoting T-cell maturation, and phagocytic activity (Colunga et al., 2020)

Quercetin and ascorbic acid co-administration represents an experimental strategy for prophylaxis and treatment of several respiratory viruses, such as SARS-CoV-2. The blockage of virus entry represents a key strategy and quercetin impedes viral membrane fusion for both influenza and SARS-CoV in vitro (Yi et al. ,2004). 

Quercetin was safely tolerated by chronic obstructive pulmonary disease (COPD) patients, in doses up to 2,000 mg/day as assessed by lung function; FEV1/FVC, blood profile and COPD assessment test questionnaire (Han et al., 2020). Quercetin use at 1,000 mg daily, for 12 weeks, demonstrated a reduction in upper respiratory tract infection, total sick days and in severity, for both middle aged and older subjects (Heinz et al., 2010).

Quercetin has shown antimicrobial properties, including against airway-relevant bacteria such as Pseudomonas aeruginosa, P. fluorescens, Aeromonas hydrophila, Staphylococcus aureus, S. epidermidis and the fungi Aspergillus niger (Wang et al., 2018, Abd-Allah et al., 2015).


Zinc is a potent antiviral compound and a key mineral for maintaining a healthy immune system.  Zinc is critical for maintaining membrane barrier structure and function. Its deficiency causes damage to epidermal cells and to the linings of the gastrointestinal and pulmonary tracts, which may facilitate the entrance of pathogens and noxious agents into the body (Shankar, et al., 1998).  Zinc deficiency is prevalent throughout many parts of society and leads to suppressed immunity and poor healing (Sandstead, 1991).  

Zinc is involved in the regulation of the innate and adaptive immune responses.  Zinc is also involved in the modulation of the proinflammatory response by targeting NFkB, a transcription factor that is the master regulator of proinflammatory responses. It is involved in controlling oxidative stress and regulating inflammatory cytokines.  In terms of adaptive immunity, zinc deficiency is responsible for thymic atrophy and subsequent T-cell lymphopenia as well as reduction of B cells, affecting antibody production (Wessels et al., 2017, Gammoh et al., 2017, Jarosz et al., 2017).  

Insufficient zinc levels in cells can lead to excessive inflammatory response, producing excess cytokines and chemokines such as TNF-α, IL-6, IL-8 and IL-10 (Mayer et al., 2014). 

Covid-19 patients with poor outcomes have shown significantly lower zinc levels in comparison to healthy controls (Jothimani et al., 2020).



Zestt Oral+

Periodontal Oral Health

Periodontal (gum) disease is an infection of the gum, bone and surrounding structures of the teeth caused by the bacteria found in plaque. It is the leading cause of tooth loss in adults and can cause halitosis (bad breath), bleeding gums and moving teeth.

Plaque is a sticky film of bacteria that constantly forms on the teeth. In periodontal disease, plaque develops under the gums on tooth roots and breaks down the bones that support teeth.

Our oral cavities have their own microbiota which act as our first line of defence against invaders and bacteria which cause tooth decay and gum disease.

There are many environmental influences which can affect the health of our oral microbiota, reducing the number of "good bacteria."

In Zestt Oral+ Periodontal Oral Health lozenges, we combine scientifically proven probiotics, produced in New Zealand and prebiotics from New Zealand gold kiwifruit for oral health. 

Natural bioactives used in Zestt Oral+


Blis K12® and BlisM18® Streptococcus salivarius, are colonising, immune-enhancing probiotics that have been shown in multiple clinical studies to prophylactically inhibit invaders in the oral, throat, and nasal cavities.

These probiotics have also been shown to induce an anti-inflammatory response and decrease pro-inflammatory cytokines.

The probiotics in EXhale® colonise the oral cavity and crowd out bad bacteria. This process is known as bacterial interference and leads to fewer respiratory tract infections.

Link to some scientific papers herehere and here.

GOLD KIWIFRUIT is a good source of calcium, a dental super mineral, which help neutralise damaging acids and bolster enamel defence.  Gold kiwifruit is also great sources of vitamin C, folate and dietary fibre.  

Peer reviewed clinical research has shown good bacteria in the mouth are bolstered by the presence of kiwifruit in oral lozenges.

Link to some scientific papers here and here.



Zestt Cardio+

Heart Restoration and Health

The heart and lungs work together to provide our body with oxygen rich blood.  There are two loops which describe how blood and oxygen move around our body:

  1. The Pulmonary Loop.

The right side of the heart picks up the oxygen-poor blood from the body and moves it to the lungs for cleaning and re-oxygenating.

  1. The Systemic Loop.

Once the blood is re-oxygenated, the left side of the heart moves the blood throughout the body, so that every part of the body receives oxygen.

We recommend watching this video from the Mayo Clinic for a great explanation of how our circulatory system functions link here.

Like your lungs, your heart is a muscle and needs exercising to maintain optimum strength.  Health professionals advise us to exercise enough to raise our heart beat 3-5 times a week.  As we improve aerobic fitness, our bodies can move more oxygen and blood into our muscles more efficiently.  Over time, this means we can move with less effort.

Natural bioactives used in Zestt Cardio+


Peer reviewed scientific research shows that New Zealand grown blackcurrants and boysenberries keep our hearts healthy and maintain optimal blood flow and oxygenation.  This is due to the high levels of anthocyanins which have anti-oxidant properties and help clean up damaging free radicals.  Anthocyanins also enhance oxygen transport within the circulatory system.

Read more herehere and reviewed here.


Also known as ubiquinone, Coenzyme Q10 is a naturally occurring and powerful antioxidant. Coenzyme Q10 is in every cell in our bodies, predominantly occurring within the mitochondria (which are organelles which generate ATP - energy).  The heart has more mitochondria than any other organ in the human body, except for the liver.  

As we age, our levels of Coenzyme Q10 decline, so supplementing with the enzyme supports healthy organ and cellular function.  

The co-enzyme Q10 in Zestt Cardio+ lozenges is attached to an amino acid to enhance absorption and maximise cardiovascular health.

Read more herehere and here.

QUERCETIN is a naturally derived flavonoid, extracted from Japonica sophora flower buds.  Quercetin is a zinc ionophore and supports zinc to cross cell membranes.  It is also a powerful antioxidant, acting as a cardio-protectant for heart health.

Read more herehere and here.

BLIS M18 PROBIOTICS represent a new generation of advanced oral probiotics which work by crowding out the bad bacteria - and colonising the mouth with good, healthy bacteria. 

Heart health and oral health are directly correlated.  Gum disease is associated with an increased risk of developing heart disease.  Poor dental health increases the risk of a bacterial infection in the bloodstream, which can affect the heart valves.  Oral health may be particularly important if you have artificial heart valves.  

Read more here and here.

The Science of Lung Health

Free Downloadable Booklet on The Science of Lung Health and what you can do it Improve your Lung Health