Age Matters Clinic


Toronto Geriatric Assessment and Memory Clinic

The Truth about Alzheimer's & Seafood Mercury

Alzheimer's disease is a progressive, permanent physical brain disorder that gradually leads to memory loss, thinking skills and general dysfunction. Usually, the symptoms are more visible when the brain is damaged by diseases and in people at mid-60s. As at now, about 520,000 in the United Kingdom suffers from the menace with the United States estimated to have about 5 million people living with the condition.

Despite the numerous studies aimed at establishing specific causes of the threat, Scientists are yet to attribute the disease to a particular cause. However, the early onset is often associated with genetic mutation while the late-onset arises from an intricate series of brain alterations over several years.

With the disease being the most common form of dementia, it ranks sixth in the leading fatal disease in the United States. The most recent study indicated that the disease could rank third behind heart disorder and cancer as the leading causes of deaths among the elderly. As the time goes, Alzheimer's disease gradually causes brain destruction causing more symptoms that may become severe.

Once infected, the proteins accumulate in the brain inhibiting nerves' connections, eventual destruction of the nerve cells and damage to the brain tissue. The patients lack essential chemicals in the brains that help in transmitting neural messages in the brain. Based on medical experts' research, it takes more than ten years for the cognitive and mental effects appear. Before then, the victims look healthy despite the noxious alterations occurring in their brain.

The seafood mercury and Alzheimer's disease

While there is ample evidence that a diet containing seafood lowers the risk of Alzheimer's disease, several concerns exist on the effects of mercury contained in seafood on the victims. Mercury is a toxic component that affects the neural system and is commonly found in aquatic animals. Seafood remains the primary source of mercury exposure to human beings.

A recent study showed that people who consume seafood on a weekly basis accumulated higher levels of mercury in the brain than those that didn't at all. However, those with hereditary risk factors-ApoE4 manifested lower levels of harmful proteins when they consumed more fish. About 30% of the general populations are estimated to have one copy of the risk factor-ApoE4 that raises the risk of the diseases compared to the rest. In the same study, 22.7% of the older population were identified to have a copy of the hereditary risk factor.

According to Morris, those without the genetic variant are likely to benefit from seafood as opposed to those that lacks the modification. The research does not recommend anyone to depend on seafood to prevent from Alzheimer's. While the findings gave a reassurance that seafood leads to accumulation of mercury in the brain, it's failed to link the amount of mercury to a higher risk of contracting the disease.

A separate research conducted among the older people in Chicago Area surveyed a subset of about 286 participants that died between 2004 and 2013. The brain autopsies confirmed more mercury in those that had reportedly eaten seafood than their counterparts. Although the heavy metals are associated with neurocognitive development, the benefits of consuming seafood among the older people outweigh the risks.