Alzheimer’s disease was first described in 1906. It was little known at the time and did not even enter medical textbooks until decades later. So, how come this disease is at epidemic proportions and now a leading cause of death in the UK?
We know that certain genes can predispose some people to have an increased risk of developing the disease. Specifically the ApoE4 genotype is known to increase the risk. But our genes do not determine our destiny. After all not everyone with this genotype develops Alzheimer’s disease, and it is not necessary to have the ApoE4 genotype to develop Alzheimer’s. Indeed genetics alone can not explain such a rapid increase in the incidence of Alzheimer’s disease.
We also know that our it is diet, lifestyle and other environmental factors, the so called epigenetics, and their influence on our genes that matters. So, might poor diet and lifestyle choices influence the risk of developing Alzheimer’s in a similar way to their influence on the risk of type 2 diabetes, obesity and high blood pressure?
It seems at least possible, so the connection between food and risk of Alzheimer’s disease is an area of intense research at the moment. One aspect is the potential role of meat and animal products in the diet. Most modern day diets include a much greater amount of meat and meat products than were eaten a hundred years ago. Scientists believe that there may indeed be a link between Alzheimers disease and iron intake.
Meat is generally a rich source of iron, and while iron is crucial for normal brain function, excess iron increases free radical damage, a potential contributor to Alzheimer’s disease progression. In fact, both too little and too much iron in the brain can cause problems.
In the body, iron is generally stored as the protein ferritin. This protein is found mainly inside cells, but a small amount circulates freely in the blood and is used as a measure for body iron stores.
In this study researchers measured ferritin levels in the cerebrospinal fluid as a measure of iron in the brain. They then compared the ferritin levels of study participants with their cognitive performance. People with normal cognition, mild cognitive impairment and people with Alzheimer’s disease took part, and participants were followed for 7 years. At the end of the study the researchers found that higher iron levels in the brain were associated with increased Alzheimer’s disease progression.
What’s more the researchers in this study suggested that people with the ApoE4 genotype may have an increased susceptibility to Alzheimer’s disease because this genotype increases ferritin levels in the brain. So, the ApoE4 genotype might not be a cause of Alzheimer’s disease, but instead it could act as an accelerator for the disease in people with unhealthy diets and/or lifestyles.
However, it is not all doom and gloom for those with ApoE4. Scientists found that people with the ApoE4 genotype that adhered to a healthy Mediterranean diet had a greater benefit for brain health from this healthy eating pattern than those with other genotypes.
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