Alzheimer's disease: omega-3s stimulate elimination of harmful molecules from the brain

Alzheimer's disease: omega-3s help eliminate harmful molecules from the brain

Fish oil omega-3s may improve the function of the glymphatic system, a structure similar to the lymphatic system that drains waste away from the brain, promoting the elimination of certain molecules involved in the onset of Alzheimer's disease, including β-amyloid protein. This finding adds to the many studies that have demonstrated the role of omega-3s in counteracting the disease and maintaining brain health through various molecular mechanisms.

The new research, published in The FASEB Journal, was conducted by researchers at the University of Macau, China.

Alzheimer's disease. Alzheimer's disease: the leading cause of dementia in the West

Alzheimer's is a degenerative brain disease with a chronic, slow and progressive course characterized by widespread atrophy of nerve tissue, causing decline in all intellectual functions. It represents the most common cause of dementia in the elderly population in Western countries. 

There are an estimated 36 million sufferers worldwide, including 6 million in Europe and 1 in Italy. Neuropathologically, the brains of patients with Alzheimer's disease are characterized by plaques formed by the accumulation of a protein, Beta-amyloid, and the formation of tangles of another protein, called Tau. 

The presence of Tau and Beta-amyloid structures is believed to be responsible for the degenerative process. These protein substances accumulate due to defective metabolic processes in the brain, where they are deposited causing nerve cell death. Beta-amyloid protein is positioned between nerve cells where it forms plaques, and also on vascular walls worsening their permeability. This results in disturbances in oxygen and nutrient transport to the brain. 

Instead, Tau protein is deposited inside nerve cells, forming filaments called neurofibrillary tangles. These phenomena cause an active inflammatory response and extensive neuronal damage, resulting in reduced brain volume, as well as impaired neurotransmitter activity. 

Alzheimer's disease is characterized by neuronal death associated with increasing memory impairment and other disorders such as difficulty in performing daily activities, speech disorders, spatial and temporal disorientation, and personality changes. Although the disease is not curable, a proper lifestyle and healthy diet can prevent it or slow its progression. 

According to several studies, a diet rich in omega-3 fatty acids, found in fish and some oil seeds, as well as fruits and vegetables, helps prevent mild cognitive impairment, which often anticipates Alzheimer's.

According to new study, omega-3 stimulates removal of Beta-amyloid from the brain

In the recent Chinese study, scientists investigated the role of omega-3s on the function of the glymphatic system, a system that drains waste from the brain and acts similarly to the lymphatic system, but is regulated by brain glia cells. In fact, to eliminate waste from cellular metabolism, the brain cannot use the lymphatic system like the rest of the body because it is isolated by the blood-brain barrier, the structure interposed between blood and nerve tissue. 

The study conducted in laboratory mice showed that supplementation with omega-3-rich fish oil can improve the function of the glymphatic system, thus facilitating the removal of Beta-amyloid protein from the intercellular space from the brain and limiting the injury that plaques cause. As Thoru Pederson, editor-in-chief of The FASEB Journal, explained, this study highlights a different capability of omega-3 fatty acids: in addition to its role in maintaining vascular health, omega-3 fatty acids can have a direct impact on neurons and other brain cells.

The details of the study

To reach the discovery, scientists studied transgenic laboratory mice that expressed high amounts of omega-3 in the brain, and that showed improved glymphatic function and increased elimination of Beta-amyloid protein from brain tissue, compared with normal mice. 

When they were given omega-3 supplements orally, the researchers found that even in normal mice the ability to eliminate harmful molecules via the glymphatic system increased, and that this responded to omega-3 by stimulating the removal of extracellular Beta-amyloid protein.

The action of omega-3s in combating Alzheimer's is based on many mechanisms

The results of this study demonstrated a new mechanism by which omega-3s exert protective roles against the disease. The other strategies by which omega-3s counteract the onset or progression of Alzheimer's are diverse and confirmed by numerous studies, conducted in recent years. 

Some important discoveries were made by researchers at karolinska Institutet (Sweden) who showed that omega-3s can cross the blood-brain barrier and change the fatty acid composition of neurons. In addition, according to the same study, EPA- and DHA-based supplements are able to influence the amount of harmful substances in the brains of Alzheimer's disease patients, acting positively on neurodegenerative processes. 

This research was followed by more complex research that showed how a beverage formulated with high doses of DHA and EPA and other neuroprotective nutrients, such as B vitamins, administered to Alzheimer's patients was associated with an improvement in the subjects' ability to perform daily activities and better spatial orientation. 

Most of the mechanisms by which omega-3s may act on the symptoms of Alzheimer's disease have yet to be investigated, but they are certainly also related to their antioxidant and anti-inflammatory properties. In particular, DHA, the omega-3 most commonly found in the membranes of neurons, may counteract the oxidative damage that appears in the early stages of the disease and leads to neuronal loss, while some molecules originated from omega-3s could prevent and reverse the progression of Alzheimer's disease by stimulating healing from inflammation and reabsorption of the beta-amyloid protein. 

In addition to those on DHA, other clinical studies have shown that EPA plays a role in brain physiology by leading to increased cerebral blood flow, with effects on cognitive ability and behavior. Several strands of research therefore have sprung up to investigate new strategies that can improve brain function and delay or prevent the onset of Alzheimer's disease by exploiting the properties of omega-3s to protect brain function and structure.

Increasing DHA consumption with Omegor supplements

Consuming DHA is therefore critical for brain health. In this regard, Omegor supplements can help achieve the right amounts and protect brain health and beyond. 

Omegor Vita DHA 1000is a dietary supplement that has a high DHA content, in fact, one capsule contains as much as 470 mg of DHA and 100 mg of EPA, and contributes to the maintenance of normal brain and visual function.

Source: Huixia Ren, Chuanming Luo, Yanqing Feng, Xiaoli Yao, Zhe Shi, Fengyin Liang, Jing X. Kang, Jian-Bo Wan, Zhong Pei and Huanxing Su. (2016). "Omega-3 polyunsaturated fatty acids promote amyloid-β clearance from the brain through mediating the function of the glymphatic system."