Alzheimer’s: Blood oxygen levels could explain why memory loss is an early symptom 阿爾茨海默氏症：血氧水平可以解釋為什麼記憶力減退是早期症狀

Editor’s note

Alzheimer’s disease is found in elderly people only. This means that it is a degenerative disease, which is caused by damage in the brain. The study links low oxygen levels in the hippocampus to risk of Alzheimer’s diseases.

How you can deliver oxygen to the hippocampus? A couple of things to consider: You need good and health blood vessels. Alzheimer’s patients may have had blood vessels to or around the hippocampus damaged. The damage causes other conditions.

Studies have confirmed the correlation between stroke and Alzheimer’s disease. The problem with stroke is that the blood vessels are damaged, either blocked or brittle. So it is likely that Alzheimer’s patients have their blood vessels damaged too. Once damaged, they cannot deliver oxygen and other nutrients to the location and the hippocapmpus is thus at risk of certain pathology.

With healthy blood vessels, you still need to deliver the optimal levels of oxygen. For one thing, you needs to prime the capability of hemoglobins that carry oxygen. Hemoglobins cannot carry that much oxygen when pH is low!

Oxygen is important, so are other nutrients. Antioxidants, tea and even coffee, polyphenols, antioxidant foods like turmeric and garlic, B vitamins, omega 3 fatty acids and essential omega 6 fatty acids can help prevent the degradation of the hippocampus and thus reduce risk of Alzheimer’s disease. Read more here https://www.hindawi.com/journals/bmri/2013/524820/

老年癡呆症僅在老年人中發現。這意味著它是一種退化性疾病，是由大腦損傷引起的。該研究將海馬中的低氧水平與阿爾茨海默氏病的風險聯繫起來。

如何向海馬輸送氧氣？需要考慮的幾件事：您需要良好而健康的血管。阿爾茨海默氏症患者的海馬或周圍的血管可能受損。損壞會導致其他情況。

研究證實中風與阿爾茨海默氏病之間存在相關性。中風的問題是血管受損，阻塞或變脆。因此，阿爾茨海默氏症患者的血管也可能受損。一旦受損，它們便無法將氧氣和其他營養物質輸送到該位置，因此，海豚脂處於某種病理風險中。

對於健康的血管，您仍然需要輸送最佳水平的氧氣。一方面，您需要準備攜帶氧氣的血紅蛋白的功能。當pH值低時，血紅蛋白不能攜帶那麼多的氧氣！

氧氣很重要，其他營養也很重要。抗氧化劑，茶甚至咖啡，多酚，薑黃和大蒜等抗氧化劑食品，B族維生素，ω3脂肪酸和必需的ω6脂肪酸均可幫助防止海馬體退化，從而降低患阿爾茨海默氏病的風險。閱讀更多

Alzheimer’s: Blood oxygen levels could explain why memory loss is an early symptom

News Release 28-May-2021

University of Sussex

Research News

In a world first, scientists from the University of Sussex have recorded blood oxygen levels in the hippocampus and provided experimental proof for why the area, commonly referred to as ‘the brain’s memory centre’, is vulnerable to damage and degeneration, a precursor to Alzheimer’s disease.

To understand why this region is so sensitive, the University of Sussex researchers, headed up by Dr Catherine Hall from the School of Psychology and Sussex Neuroscience, studied brain activity and blood flow in the hippocampus of mice. The researchers then used simulations to predict that the amount of oxygen supplied to hippocampal neurons furthest from blood vessels is only just enough for the cells to keep working normally.

Dr Catherine Hall, Senior Lecturer in Psychology at the University of Sussex says:

“These findings are an important step in the search for preventative measures and treatments for Alzheimer’s, because they suggest that increasing blood flow in the hippocampus might be really effective at preventing damage from happening.

“If it’s right that increasing blood flow in the hippocampus is important in protecting the brain from diseases like Alzheimer’s, then it will throw further weight behind the importance of regular exercise and a low-cholesterol diet to long-term brain health.

“We think that the hippocampus exists at a watershed. It’s just about OK normally, but when anything else happens to decrease brain blood flow, oxygen levels in the hippocampus reduce to levels that stop neurons working. We think that’s probably why Alzheimer’s disease first causes memory problems – because the early decrease in blood flow stops the hippocampus from working properly.

“The same factors that put you at risk of having a heart attack make you more likely to develop dementia. That’s because our brains need enough blood flow to provide energy – in the form of oxygen and glucose – so brain cells can work properly, and because blood flow can clear away waste products such as the beta amyloid proteins that build up in Alzheimer’s disease.

“Now we want to discover whether the lower blood flow and oxygen levels in the hippocampus are what causes beta amyloid to start to build up in Alzheimer’s disease. Understanding what causes early damage will be really important to help us learn how to treat or prevent disease.”

Dr Kira Shaw, a psychology researcher at the University of Sussex who undertook the main experiments, reported:

“We found that blood flow and oxygen levels in the hippocampus were lower than those in the visual cortex. Also, when neurons are active, there is a large increase in blood flow and oxygen levels in the visual cortex. This provides energy to hungry neurons. But in the hippocampus, these responses were much smaller.”

The scientists also found that blood vessels in the hippocampus contained fewer mRNA transcripts (codes for making proteins) for proteins that shape blood vessel dilation. Additionally, the cells that dilate small blood vessels, called pericytes, were a different shape in the hippocampus than in the visual cortex.

Dr Shaw concluded: “We think blood vessels in the hippocampus are less able to dilate than in the visual cortex”.

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The full research paper, ‘Neurovascular coupling and oxygenation are decreased in hippocampus compared to neocortex because of microvascular differences’ is published in Nature Communications. This research was funded by the Medical Research Council, the Academy of Medical Sciences, and the Wellcome Trust.