Nutrition and Alzheimer's Disease - What's the Link?
It's Alzheimer's awareness month so let's dive into some nutrition-related information about the prevention of Alzheimer's. We'll discuss some background information about this condition, as well as up-to-date nutrition research regarding this population.
What is Alzheimer's Disease?
Alzheimer's disease (AD) is the most common form of dementia. It is a brain disorder where cognitive function and memory slowly deteriorate due to microscopic changes in the brain, including deposits of amyloid plaques, tau proteins and neurofibrillary tangles. There are 4 stages of AD, which can be summarized here.
What's important to note is that each person experiences AD differently, so focus should be placed on any symptoms being experienced rather than the stage they may present with. AD usually presents in one's mid-60s; however, early-onset Alzheimer's can present between a person's 30s and early 60s.
Nutrition Evidence for Preventing Alzheimer's Disease
Can Alzheimer's Disease Be Prevented?
There is a wide range of risk factors that can lead to the development of AD. Some are unavoidable, such as age, having a family history of AD, or having a diagnosis of Down Syndrome; whereas others can be altered, such as having high blood pressure, high cholesterol or poorly controlled type 2 diabetes, excessive alcohol consumption, and smoking.
The cause of AD is still unknown, so there is no way to prevent it with certainty. However, reducing the risk of developing the condition can be done by maintaining healthy practices.
With this, of course, nutrition can be instrumental - working with patients to control their blood pressure, cholesterol, blood sugars, and alcohol consumption (among others) can be ways to reduce the risk of developing AD with nutrition.
Dietary Changes for Alzheimer Prevention
Research has shown that a few diets have properties that benefit the brain. For one (and most popularly), there's the Mediterranean diet, rich in unsaturated fats (especially omega-3s), vitamins, minerals, anti-inflammatory agents, etc, that have been shown to benefit brain health.
Similar to the Mediterranean diet, the DASH diet includes foods that benefit the brain, alongside the heart (which may reduce risk factors associated with AD).
Furthermore, a hybrid of these two diets has been developed by Martha Clare Morris, a nutritional epidemiologist, and colleagues at the Rush University Medical Center.
This diet, called the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet, is based on research of positive and negative effects of studied foods on brain health. To summarize, the MIND diet does not have any set guidelines; rather, it suggests incorporating 10 foods more often in the diet, and limiting 5 other foods.
The 10 foods to encourage more often include:
Nuts: 5+ servings per week
Olive oil: using olive oil as a main cooking oil
Legumes and pulses: 4+ servings per week
Fish: 1+ serving each week (especially fatty fish for omega-3s)
Poultry: 2+ times per week
Berries: 2+ times per week (for antioxidant benefits, especially related to anthocyanidins)
Green, leafy vegetables: 6+ servings per week
All other vegetables: 1+ serving per day
Whole grains: 3+ servings per day
Red Wine: 1 serving per day at most (related to its resveratrol content)
The 5 foods to limit include:
Fried food: less than once per week
Butter and margarine: less than 1 tablespoon per day
Red meat: less than 3 servings per week
Cheese: less than once per week
Pastries and sweets: less than 4 times per week
In this 2015 article in the Journal of the Alzheimer's Association (Alzheimer's & Dementia), it was found that strictly following the Mediterranean, DASH or MIND diet may reduce the risk of developing AD.
What was notable about this study was that even moderately following the MIND diet may decrease the risk of AD development. A quick search on PubMed will show more evidence supporting the MIND diet for reducing the risk of cognitive decline.
The bottom line
Alzheimer's disease can have a significant impact on individuals' lives and those of their loved ones, especially in its later stages. Although aging does bring typical levels of cognitive decline, developing AD or other forms of dementia can become quite impactful; individuals can forget to eat, lose abilities to cook for themselves, have difficulty using utensils, and much more.
Although there is no set way to prevent Alzheimer's and some risk factors are unavoidable, there is some research demonstrating ways to reduce risk factors associated with one's lifestyle.
Following a healthy lifestyle by eating nutritious foods and meeting physical activity guidelines can make a big change in the course of one's life. Encouraging patients to follow a Mediterranean, or MIND-like diet, may be helpful in reducing the risk of developing AD.
With more research surfacing about nutrition and brain function, there is much to learn about their relationship. For now, I hope this article provides a good base for going forward with patients who may be at risk for Alzheimer's Disease.
If you have any questions, feel free to comment below!
-Justine Chriqui, MScA Human Nutrition