Updated: May 30, 2022
According to the Alzheimer's Association, an estimated 6.5 million Americans older than 65 years old are currently living with Alzheimer's Disease. Alzheimer’s disease, the most common type of dementia, is a progressive, neurodegenerative disease that slowly destroys memory and thinking skills, eventually making it difficult to carry out simple tasks. Certain medication has shown promising mild benefits in delaying the progression of the disease, however, more research is showing that what you eat can play a role in preventing and slowing the progression of brain degradation.
ALZHEIMER'S DISEASE PROGRESSION
With Alzheimer’s disease progression, neurons are injured and begin to die; neural networks break down; and the brain begins to shrink. There are two abnormal structures called plaques and tangles that are thought to be linked to these neurological occurrences. Plaques are abnormal clusters of protein that grow between nerve cells and tangles are twisted fragments of protein that grow inside cells. While there are several factors that may contribute to Alzheimer’s disease, let’s take a look at the modifiable dietary risk factors and the protective mechanisms a plant-based diet could have against brain degradation.
FOOD YOUR BRAIN DOES NOT LIKE
You may have heard that a small amount of alcohol can be incorporated as part of a healthy diet. However, recent research is suggesting that too much alcohol can have negative effects on the brain linked to Alzheimer’s disease. The science behind it suggests that alcohol alters gene expression in microglial cells. Microglial cells are the cleansers of the brain and are meant to keep the “bad stuff” from forming, such as plaques and tangles. If you like to enjoy an occasional glass of wine or beer, the amount of alcohol needed to trigger the negative effects seems to exceed the recommendations of one drink per day for women and two drinks per day for men. Consuming no more than one drink a day for women and no more than two drinks a day for men may be okay. However, many neurological experts agree that no alcohol at all is optimal to support brain health.
The composition of fat in the diet has been shown to have a major association to the onset of Alzheimer’s disease. More specifically, a diet higher in saturated fat (mostly found in animal products) and lower in polyunsaturated and monounsaturated fats (found in plant-based foods) can result in high cholesterol. While the mechanisms are unclear, since cholesterol doesn't enter the brain, research shows a link between high cholesterol and the risks of certain types of dementia, like Alzheimer's disease. Ideally, total cholesterol should be less than 200 mg/dL and LDL cholesterol should be less than 100 mg/dL. To learn how to lower cholesterol naturally through plant-based foods visit, Top Ten Plant-Based Foods to Lower Cholesterol.
Saturated fats are found predominantly in animal products such as butter, beef, dairy, chicken, and eggs. In excess amounts, saturated fats have been shown to increase the production of plaques, leading to loss of neurons, compromise of blood flow to important parts of the brain, and an increase in inflammation. The Chicago Health and Aging Project, an ongoing study of dietary risk factors for Alzheimer’s disease, found that intake of saturated fat was associated with doubling the risk of Alzheimer’s disease. Other studies support similar conclusions.
You're probably aware that sugar contributes to inflammation, as well as diseases associated with inflammation, such as obesity, diabetes, and heart disease. These lifestyle diseases are also risk factors for Alzheimer's disease. A recent study, published in the Journal of Prevention of Alzheimer's Disease, looked at whether sugar-sweetened beverage consumption was directly correlated with Alzheimer's disease in 2,664 individuals who were a part of the 20-year Framingham Heart Study. They found that those who consumed one to seven servings of sugar-sweetened beverages per week were 1.91 times more likely to develop Alzheimer’s disease than those who consumed no sugar-sweetened beverages. Also, those who consumed more than seven servings of sugar-sweetened beverages per week were 2.55 times more likely to develop Alzheimer’s disease. Of note, this was an observational study, meaning there was an association and not necessarily a direct cause of Alzheimer's from sugar consumption. While more research is needed, minimizing sugar consumption to support overall health is recommended.
PLANT-BASED FOOD YOUR BRAIN LOVES
Fruits and Vegetables
Just like many lifestyle diseases, the good news is that there are ways we can reduce our risk of Alzheimer’s disease through positive lifestyle actions. Research shows that those who consume higher amounts of plant-based foods, especially fruits and vegetables, have a reduced risk of Alzheimer’s disease. One study that tracked women’s intake of fruits and vegetables for 11 years found that those who ate the greatest amount of green leafy vegetables had a slower decline in brain function compared to those who did not eat as many vegetables.
In contrast to saturated fats, intake of both polyunsaturated and monounsaturated fats have been associated with lower risk of developing Alzheimer’s disease. One study suggested that unsaturated fats found in plant-based foods were strongly protective against Alzheimer’s disease. Polyunsaturated fats include essential fatty acids (omega-3 and omega-6) that are vital for proper brain function. Monounsaturated fats increase the production of acetylcholine in the brain, which is important for learning and memory. Adding nuts and seeds to your diet may help to decrease your risk of Alzheimer's disease. Snack on a handful of almonds, enjoy homemade trail mix, or add nuts and seeds to stir fries and salads. Plus, they add delicious flavor and a fun crunch!
Plant foods rich in monounsaturated fats include:
Plant foods rich in polyunsaturated fats include:
B vitamins, such as folate, vitamin B6 and vitamin B12 are essential for brain function. These vitamins function to metabolize a compound called homocysteine, a risk factor for heart disease. Too much homocysteine in the body is also a risk factor for Alzheimer’s disease. Below is a list of popular B-vitamin foods that can help to keep homocysteine levels in check. Replace beef burgers with bean burgers, add leafy greens to a smoothie, enjoy avocado toast for breakfast, or make a stir fry with brown rice and edamame. When choosing plant-based milk, opt for one that is fortified with vitamin B12.
Plant foods rich in folate include:
Plant foods rich in vitamin B6 include:
Plant foods rich in vitamin B12 include:
fortified plant-based milk
fortified nutrition yeast
fortified plant-based cheese
Flavonoids are phytonutrients, or nutrients specific to only plant-based foods, and are found in berries, apples, onions, and other colorful plant-based foods. According to a study published in the American Journal of Clinical Nutrition, they help protect against Alzheimer’s disease. Researchers looked at flavonoid intake and dementia incidence in 2,801 participants from the Framingham Heart Study Offspring Cohort. Those who had the highest total flavonoid intake from oranges, pears, strawberries, and other plant-based foods were 40 percent less likely to develop dementia when compared to those with the lowest intakes of flavonoids. These plant-based foods also improved cerebrovascular blood flow, which may protect against cognitive decline later in life. The researching attributed the anti-inflammatory effects of the plant-based foods to the reduced risk of cognitive decline.
Plant foods rich in flavonoids include:
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Hi! My name is Lina Abuhamdieh and I am a student at Georgia State University in the Coordinated Program for Dietetics. I have loved every minute of this program, and have especially enjoyed discovering new avenues in which I can work in once I graduate. My hope is to be a private practice dietitian and be able to provide clients with all things nutrition and fitness! I have also found a new passion in writing nutrition blogs, so I hope you enjoy!