Writing in the International Journal of Molecular Sciences, researchers showed that, like human beings, bottlenose dolphins can experience amyloid-ꞵ plaques and neuroinflammation in the hippocampus, the part of the brain associated with memory. According to the research, C15:0 has two dose-dependent activities shown in animal models to decrease amyloid-ꞵ plaques, neuroinflammation and improve cognitive health.
Specifically, C15:0 inhibited fatty acid amide hydrolase (FAAH) and inhibited monoamine oxidase B (MAO-B), which may contribute to cognitive decline.
“While C15:0 is known to be a pleiotropic nutrient with multiple beneficial mechanisms of action, we were surprised to find two entirely new C15:0 activities specifically relevant to brain health,” Stephanie Venn-Watson, an author on the paper, told NutraIngredients. “By inhibiting MAO-B and FAAH, C15:0 supports healthy dopamine and endocannabinoid levels, both of which protect our long-term cognitive health.”
The research was funded by the U.S. Office of Naval Research.
US Navy marine research
Aging-related cognitive health conditions, such as Alzheimer’s disease (AD), are expected to rise as people age. By 2030, 78 million people may experience AD, a disease that can increase when risk factors such as chronic co-morbidities of aging (chronic inflammation, metabolic syndrome, iron overload, oxidative stress, type 2 diabetes, cardiovascular disease and hearing loss) are also considered.
For over 60 years, the U.S. Navy Marine Mammal Program (MMP) has cared for a population of bottlenose dolphins living in the open ocean and, consequently, the lifespan of these dolphins is greater than 30 years old, more than 10 years longer than wild dolphins.
Dolphins are also susceptible to age-related health changes, but fatty acid and broader metabolomic studies have “revealed that bottlenose dolphins with higher circulating concentrations of odd-chain saturated fatty acids (OCFAs C15:0 and C17:0) have a lower risk of having metabolic syndrome and related conditions; further, increasing dolphins’ dietary OCFAs results in improved cardiometabolic, iron and red blood cell indices,” the researchers wrote.
They noted that C15:0 has emerged as an essential fatty acid needed by animals to support both early development and long-term health, especially related to metabolic, heart, liver and red blood cell health.
Most studies have linked C15:0 as an essential nutrient to protect metabolic, heart and liver health, but few studies connect the fatty acid to mental and cognitive health.
“Interestingly, the core histologic changes of AD in humans, including amyloid-β plaques, hyperphosphorylated tau proteins and neurofibrillary tangles, have been well documented in the brains of numerous wild cetacean species, including bottlenose dolphins,” the researchers noted.
“Among all animals, only primates and cetaceans naturally develop histologic changes that include amyloid-β plaques, hyperphosphorylated tau proteins, and neurofibrillary tangles, and as such, it is hypothesized that these changes are a result of longevity and post-reproductive lifespan, not just aging…Additional studies, including clinical trials, are needed to determine whether C15:0 plays a direct role in preventing or slowing the onset and progression of AD.”
Study details
The researchers studied the brains of 19 deceased dolphins previously cared for by the U.S. Navy Marine Mammal Program. By studying hundreds to thousands of small molecules, metabolomics provided the scientists with an approach to finding molecules, including C15:0, that have meaningful, healthy aging benefits, Venn-Watson said.
They utilized panels that screen these ‘promising’ molecules for dose-response activities that can address specific conditions, including Alzheimer’s disease. These panels efficiently identify beneficial activities of a given molecule based on specific doses and to gold-standard positive controls.
“These technologies have been game-changers, not only for pharmaceutical drug development but for finding nutrients that naturally and tangibly protect our long-term health, including our cognitive health,” said Venn-Watson.
These newly discovered activities of C15:0 are consistent with a prior human study which showed that among people with type 2 diabetes, those with higher C15:0 had better overall cognitive performance scores, including better memory. Several large studies have also shown that people with higher C15:0 levels have a lower risk of having or developing type 2 diabetes, heart disease and fatty liver disease, risk factors that may contribute to cognitive decline.
“Understanding that type 2 diabetes, fatty liver disease and heart disease are closely linked to cognitive decline and Alzheimer’s disease [demonstrates] there is an urgent need to further understand how C15:0, as an essential nutrient, can support not only our long-term metabolic, liver and heart health, but our brain health, too,” Venn-Watson said.
Source: International Journal of Molecular Sciences, doi: 10.3390/ijms26083746. “Aging-Associated Amyloid-β Plaques and Neuroinflammation in Bottlenose Dolphins (Tursiops truncatus) and Novel Cognitive Health-Supporting Roles of Pentadecanoic Acid (C15:0)“. Authors: S. Venn-Watson and E.D. Jensen
