How Diet Impacts Alzheimer's Disease
Alzheimer’s disease is the most common form of dementia and in the UK alone it is estimated that 520,000 people suffer with it. Sadly this number is only set to rise. Most people are familiar with the common symptoms associated with this disease, which include memory loss and the significant loss of thinking and behavioural skills, which over time results in the person being unable to function independently. Alzheimer’s is classed as a progressive disease meaning that symptoms get worse over time and with the type of debilitating symptoms it inflicts, it is no wonder that this disease is often described as a very cruel one, especially in the latter stages of the disease when recognition of once familiar things, such as loved ones, is lost altogether.
Currently there is frustratingly no cure for Alzheimer’s disease, despite it affecting one in five people over the age of 80. We can only hope that science soon rectifies this and can provide a solution to this growing problem that affects so many, but until it does we can only do what we can to help prevent and manage the disease and its symptoms. So how does this relate to diet and nutrition you may ask. Well what science has told us is that there are potentially certain foods and eating behaviours that have been shown to have a positive impact on brain health and that can potentially offer a protective effect against dementia such as Alzheimer’s disease. The trick here is to ensure we implement these dietary changes early enough in our lives for them to actually offer a positive effect and also keep our brain healthy for as long as possible.
To understand better how diet and nutrition can potentially help Alzheimer’s disease, it’s important to understand a bit about the disease and what causes it. Alzheimer’s disease is actually caused by a build-up of ‘plaque’ (called beta-amyloid plaque) in the nerve cells in the brain. This plaque build-up eventually causes the nerve cells to die, which then causes the brain to reduce in size. One of the first parts of the brain often affected by early Alzheimer’s disease is a part called the Hippocampus, which is the part of the brain associated with recent & new memory and learning. This explains why the early symptoms and indications of Alzheimer’s disease are often associated with recent memory loss and often this can be very simple memory loss such as not remembering what they have just eaten or how to work something that is used regularly.
So now we understand the disease a bit more, what should we be eating to give ourselves the best chance of protection against Alzheimer’s disease and improve brain health?
Of all the diets in the world, it is the Mediterranean diet which time and time again has shown to be the healthiest in the world providing many proven health benefits. Despite its name, the Mediterranean diet is not a diet at all, more just a specific way of eating, and science has shown if you eat like they do in the Mediterranean then your health will greatly benefit and that includes brain health. The general descrip-tion of the Mediterranean diet is that it incorporates an abundance of plant based foods, has a high olive oil and olive consumption and limited intake of red meat, promoting fish and white meat consumption instead. Red wine, in moderation, is also a usual component of this diet too.
Research has shown that the Mediterranean diet can offer a protective benefit for Alzheimer’s disease; in fact some evidence has shown that eating a Mediterranean diet can help delay the onset of Alzheimer’s disease by about 3.5 years compared to those people who follow Western style diets. In other words a diet that is rich in fruit, vegetables, grains, olive oil and low in red meat and sugar can help reduce de-mentia and Alzheimer’s risk.
One ingredient that is a big component of the Mediterranean diet is found in almost every kitchen and that’s olive oil. Some research has shown that consumption of extra virgin olive oil can maybe help re-move plaques associated with Alzheimer’s disease, although more research is needed on this before a proper conclusion can be made here, but it looks promising. Olive oil has also shown to have a potential protective effect on learning and memory too. These positive brain benefits of olive oil are thought to be attributed to a specific polyphenol it contains called oleuropein Aglycone (OleA), so make sure you are drizzling on salads, adding to bread/toast instead of butter, or just have a spoonful a day.
Now one thing that isn’t eaten enough of in this country is oily fish, which is packed full of Omega 3 fatty acids. Although we often mention Omega 3 fatty acids, many people are still not getting enough of it in their diet (guidelines propose we should be consuming two portions a week) and when it comes to protec-tion against Alzheimer’s disease, consuming enough Omega 3 fatty acids is important. Science has shown that those people who consume low levels of omega 3 fatty acids are at an increased risk of developing age related cognitive decline, including Alzheimer’s disease. Herring, mackerel and salmon are the highest sources of Omega 3, or if you can’t bring yourself to eat fish, invest in a good quality Omega 3 supple-ment.
The brain of a person with Alzheimer’s disease has lower levels of a chemical called Acetylcholine, which is basically a chemical messenger (a neurotransmitter) that helps send messages between nerve cells. This reduced amount of Acetylcholine in people with Alzheimer’s means that nerve cells cannot communicate as effectively with one another and messages between nerve cells can become less efficient and cause further problems with memory and thinking. Food can play a helpful part here, because foods high in the essential nutrient Choline, which is found in whole eggs, fish, whole grains and soybeans, have been shown to potentially increase levels of acetylcholine in the brain so can be very helpful to add to the regular diet of those suffering with Alzheimer’s disease. In fact many of the drugs prescribed to manage Alzheimer’s disease focus on trying to increase the levels of this neurotransmitter Acetylcholine.
Although you may not have heard of it, there is one specific polyphenol found in many foods that is really proving to be a fantastic phytonutrient (a natural chemical found in plants) by offering a multitude of health benefits, including protective benefits for the brain. Its name is Resveratrol and the research is showing it plays an important role in both protecting against the onset of Alzheimer’s disease as well as slowing down the effect of the disease. Resveratrol has been shown to have multiple brain protective ac-tions and is both a powerful antioxidant and an anti-inflammatory agent, both of which are important in protecting brain health, so if it’s not already in your diet it really should be. Foods high in Resveratrol in-clude grapes, red grape juice, red wine (yes this gives you another justification for that second glass and the highest source of resveratrol is found in Malbec and Pinot Noir), blueberries, peanuts and pistachios. To a smaller extent it is also found in dark chocolate and cocoa too.
Zinc has been found in many studies to be critical for brain power, enhanced memory and thinking skills, so it’s clear to see why this little mineral is key when it comes to brain health and age related cognitive decline. Zinc deficiency is actually linked to memory loss in people with Alzheimer’s so it’s important to ensure good zinc intake through diet by consuming foods such as shrimps, dark chocolate, pumpkin seeds, almonds, leafy greens such as spinach, kidney beans and if you are feeling adventurous oysters, which are packed with zinc.
So although there is a lot more research to be done on how nutrition and diet effects the prevention, on-set and severity of Alzheimer’s disease, the studies done so far clearly show there is an association be-tween diet and Alzheimer’s disease and this is one risk factor we can all do our best to modify. Remem-ber it’s not all bad though as red wine and dark chocolate are both allowed.
REFERENCES:
• Mediterranean diet and risk for Alzheimer's disease, 2006. Annals of Neurology
• MIND diet associated with reduced incidence of Alzheimer's disease, 2015. Alzheimer's & Dementia
• Diet, cognition, and Alzheimer’s disease: food for thought, 2013. European Journal of Nutrition
• Alzheimer's disease and diet: a systematic review, 2017. International Journal of Neuroscience
• Role of antioxidants and a nutrient rich diet in Alzheimer's disease, 2020. Open Biology
• Olive Oil Phenols as Promising Multi-targeting Agents Against Alzheimer’s Disease, 2015. Natural Compounds as Therapeutic Agents for Amyloidogenic Diseases. Advances in Experimental Medicine and Biology,
• Natural Compound from Olive Oil Inhibits S100A9 Amyloid Formation and Cytotoxicity: Implications for Preventing Alzheimer’s Disease, 2021. ACS Chemical Neuroscienc
• Resveratrol and Neuroprotection: Impact and Its Therapeutic Potential in Alzheimer's Disease, 2020. Frontiers in Pharmacology