Food for thought: nutrition that boosts brain power

As pets live longer, cognitive decline is becoming an increasingly important concern for owners and veterinarians alike. New scientific evidence highlights how targeted nutrition, including the use of medium-chain triglycerides and mushroom-derived compounds, can help maintain mental sharpness and improve wellbeing in aging pets.

Cognitive dysfunction in pets

An estimated 28% of dogs are affected by cognitive dysfunction syndrome (CDS) by the age of 11 years, with over 66% affected by 15 years. CDS has been likened to Alzheimer’s disease in humans, with affected dogs commonly showing similar symptoms of disturbed sleep cycles and social interactions, disorientation and a reduction in learned behaviors.

Cognitive decline also affects cats, who show signs of confusion, disrupted sleep patterns, reduced social interaction and vocalization. These behaviors in elderly cats have been connected to tau protein accumulation, suggesting that cats are also affected by Alzheimer’s disease type conditions.

Nutrition for brain health

Many nutrients are essential for brain health, focus and cognition. Amino acids, fatty acids (including omega-3s), vitamins, minerals and antioxidants all play key roles in the maintenance of the brain’s everyday health.

Deficiencies in, and imbalances of, nutrients can affect mood, behavior and cognitive health. The importance of feeding a complete and balanced diet to ensure that no deficiency or oversupply of nutrients is present cannot be overstated.

Functional ingredients can additionally support cognitive health and focus.

Role of medium-chain triglycerides

Dietary medium-chain triglycerides (MCT) act in the brain on two levels. Firstly, sufficient dietary MCT increases fatty acid oxidation, raising the quantities of omega-3 polyunsaturated fatty acids (PUFAs) within the brain. Omega-3 PUFAs have a structural role within neuronal membranes, as well as being involved in neurogenesis and cell signalling.

Concentrations of PUFAs within the brain reduce with age and are lower still in those affected by Alzheimer’s. In rodent studies, impaired learning and memory is seen where omega-3 PUFA concentrations are reduced, and in affected humans, impaired cognitive performance is observed.

Secondly, MCT act within the brain as an energy source. Brain glucose metabolism has been shown to be significantly reduced in dogs at six years old compared to those aged one year. This age-related decline is consistent with that seen in humans, monkeys and rats. Elderly human patients with Alzheimer’s are reported to have significantly lower cerebral glucose metabolism than healthy older people.

MCTs as supplements

Glucose is utilized inefficiently as the brain ages – although this is not specific to Alzheimer’s disease or CDS. Dietary MCT is a therefore a potential tool to support the continued provision of energy for the brain and polyunsaturated fatty acid concentrations. As the pet population ages, MCT supplementation could support cognitive health and wellbeing.

A study from researchers at the University of Toronto, published in Neurochemical Research in 2009, found that dietary enrichment with MCT raised omega-3 PUFA levels in the brains of older dogs, suggesting that dietary MCT could work as a potential strategy for the restoration of structural and functional aspects of age-related decline.

The effect of dietary MCT in dogs was investigated in a study published in Frontiers in Nutrition in 2018, by researchers at Nestle Purina Research in the US and CanCog Technologies, Canada. The study found that 6.5% MCT in the diet of dogs gave significant improvement in cognitive dysfunction symptoms by day 90, when compared with the control. Improvements seen included reduced disorientation, altered social interaction and reduced loss of house training, with most benefits seen by day 30.

Hepatic oxidation of MCT oils produces ketone bodies. Ketone bodies are an alternative source of energy for the brain, usually utilized under starvation conditions. In supplementation conditions, these ketone levels are lower than that induced during chronic starvation (0.5 mmol/l), and no adverse health effects in dogs have been recorded. In the 2018 study, no toxic effects were seen at any dose, up to 15% MCT inclusion, over 90 days.

Mushroom varieties such as reishi, lion’s mane and cordyceps have been traditionally used within alternative and Chinese medicine for a wide variety of reported health benefits, including antidepressive and neuroprotective qualities.

In observational studies, higher mushroom consumption is connected to better cognitive performance and reduced likelihood of the development of mild cognitive impairment.

Clinical double-blind studies of medicinal mushroom varieties have been carried out in humans, across age ranges from students to the elderly. Reported results include increased sense of wellbeing, improvements to cognitive impairment, alleviation of anxiety and depression, and improvements to sleep quality and stress levels.

Range of reported benefits

Mushrooms contain bioactive compounds, on which their functional benefits are based. For instance, ergothioneine, a sulfur-containing amino acid, has been studied to understand its potential applications in neurodegeneration. Preliminary trials in adults showing mild cognitive impairment resulted in markers of neuronal damage stabilizing, and modest improvements seen.

Similarly, lion’s mane mushroom contains erinacines and hericenones, which easily pass through the blood brain barrier. These compounds stimulate synthesis of nerve growth factors and have shown benefits for neurodegeneration and cognitive maintenance.

Erinacin A has a protective effect against Parkinson’s disease in a mouse model, while Erinacin C shows neuroprotective properties and supports reduced inflammation of neurons. Turkey tail mushroom contains a polysaccharide peptide which shows anti- aging properties, promoting memory and learning.

Reishi’s action is different again, although similarly many active compounds are present, with a study showing the inhibition of oxidative stress-induced aging and the neutralization of oxidation damage.

Furthermore, mushrooms are rich in polysaccharides, such as B-glucans, which are responsible for immunomodulatory benefits, but also terpenes and proteins, reportedly providing anti- inflammatory, antioxidant and anti-tumor properties.

Although more studies are required to understand more about how different mushroom varieties affect health and wellbeing, it seems clear that they have great potential to benefit mental and cognitive health.

Next-generation nutraceuticals

Mushroom varieties have been present on the register of animal feed materials for some time, however studies to substantiate their use within functional nutrition, particularly in pets, has been lacking.

A study that is currently in the preprint stage, from researchers at the Veterinary Health Research Centers, utilized mushroom pet supplement manufacturer MycoDog’s Clarity product to support claims that mushroom-derived nutraceuticals may stabilize or improve cognitive decline in aging dogs. Trial data of 30 dogs showed 59% improvement and 23% stabilization of cognitive decline.

Smart collar data confirms that supplementation resulted in improved sleep with fewer interruptions. Behaviors such as disorientation and interactions showed a greater improvement with supplementation, than did behaviors such as anxiety and the regression of house training.

This study suggests that mushroom supplementation is most effective for early CDS, showing less effect as the condition advances.

Mushroom supplementation in the canine diet was found to be safe, palatable and well tolerated – important considerations for pet owner compliance when feeding functional ingredients, to encourage long-term inclusion in the pet diet.

Growing area of interest

Medium-chain triglycerides and mushrooms are just two methods which may benefit cognitive and mental health through functional nutrition. More research into their efficacy and safety is needed, and studies to support other similar ingredients and nutrients are set to be welcomed.