How does Alzheimer’s Disease Develop?
Although the etiology of Alzheimer’s disease still holds many mysteries, researchers have succeeded in identifying certain risk factors and conditions that contribute to the development of the disease.
A brain afflicted by Alzheimer’s disease is a brain plagued with widespread inflammation, containing fewer and less efficient cells than a healthy brain.
Current research is focused on detrimental clumps of protein called Beta-Amyloid Plaques, and their ability to erode communication between cells.
When Beta-Amyloid Plaques develop, they affect synaptic activity: Synapses are contact points between nerve cells where information is relayed between the cells.
If synaptic activity is disrupted or eliminated, brain function deteriorates.
Although Beta-Amyloid Plaques are often considered the hallmark of Alzheimer’s Disease, Neurofibrillary Tangles are the second.
Neurofibrillary Tangles are often referred to simply as “tangles”; they are twisted, misfolded proteins that further inhibit cellular communication.
Healthy nerve cells contain structures called microtubules that transport nutrients and relay neurotransmitters (chemical messengers between neurons).
Tangles cause the microtubule system to collapse, disintegrating the chemical transport system: messages can no longer be relayed between cells.
Who is at an Increased Risk for Alzheimer’s disease and dementia?
Individuals who are overweight or obese, have a metabolic condition, or a condition that taxes the heart and circulatory system (high blood pressure, high cholesterol, etc) are at an increased risk for dementia and Alzheimer’s disease.
How can I prevent these conditions?
Researchers are currently focused on methods to prevent inflammation, beta-amyloid plaques, and tangles from occurring, all of which seem to significantly curtail the development of dementia and Alzheimer’s Disease.
A large body of research has supported the importance of the prevention and treatment of heart conditions and obesity-related concerns, both of which drastically increase cellular inflammation and degeneration that court neurodegenerative conditions.
The Heart-Head Connection: What starts in the heart ends in the brain
We often take for granted the immense power of a single heartbeat.
With each contraction, the heart delivers oxygen and nutrients to every cell and organ in the body, via the circulatory system.
The brain, rich in blood vessels, depends on the heart to deliver the necessary components for its function and integrity.
When the heart is taxed, failing to deliver sufficient oxygen and nutrients to the brain, brain health begins to deteriorate, setting the stage for a loss of neural function and disease.
Conditions that damage or stress the heart and negatively impact brain health include diabetes, high blood pressure, hypertension, atherosclerosis, high cholesterol, obesity, stroke, and heart disease.
Luckily, these conditions are all highly treatable through a combination of diet, exercise, and- if necessary- medication.
While heart-related illnesses have always been a vital health concern, the implications of what scientists have dubbed the “heart-head connection” makes the treatment and optimally- the reversal- of these conditions an even more poignant undertaking for many patients.
Weight: A Matter of Caloric Balance
Although much progress has been made in educating the public on weight related concerns, many people continue to focus on the cosmetic issues of weight rather than the serious health concerns of elevated body weight.
Furthermore, many overweight individuals have a false sense of security regarding their condition: they compare their weight to larger individuals, believing that their weight isn’t as great of a concern.
However, this isn’t the case: elevated levels of body fat secrete inflammatory compounds that initiate disease processes, including cardiovascular disease.
In a study published in the 2011 journal Neurology (The official journal of the American Academy of Neurology), researchers found that overweight individuals were 71% more likely to develop dementia than those in a healthy BMI range; obese individuals were 288% more likely to be afflicted.
Obesity is defined as a body mass index (BMI) greater than 30, while overweight is defined as a BMI between 25 and 29.9
BMI is calculated by dividing weight in kilograms by height in meters squared.
The average American man, for example (5’10) would be considered overweight at 180 lbs, obese at 209 lbs.
The average American woman (5’4) would be considered overweight at 146 lbs, obese at 175 lbs.
While muscle mass is a factor in the validity of BMI, only a dietician or physician can accurately assess body fat levels to determine whether your lean tissue is great enough to validate a higher BMI.
Body fat assessments provided via scale, consumer device, or gym are widely inaccurate and may provide a false sense of security, preventing necessary actions to mediate what could be a real issue.
Weight gain and obesity develop when there is an imbalance between Caloric Consumption and Caloric Output.
In other words, more Calories are being consumed (through diet) than are being expended (through bodily processes, exercise, and daily activities).
Despite the fact that Caloric balance is the single most important factor in weight maintenance, a culture of fad dieting has perpetuated the myth that trendy diets, cleanses, or supplements are the ticket to “fast-acting” weight loss.
While certain dietary habits do promote healthier outcomes and macronutrient (protein, carbohydrate, fat) balances than others, Caloric balance is the foremost factor in weight loss and maintenance: if too many Calories are consumed- even through healthy foods- the Caloric excess will be stored as fat.
As such, it is imperative to know how many Calories your body requires to maintain or, if necessary, lose weight.
To assess your Caloric needs, consult a dietitian or use a predictive equation, such as the Miflin-St Jeor equation, which takes into account your age, sex, height, weight, activity level, and weight goals.
In a massive review of journal studies, researchers concluded that high cholesterol levels are significantly associated with an increased risk of Dementia and Alzheimer’s Disease.
The review, published in the American Journal of Geriatric Psychiatry, found that, across a board of 8 longitudinal studies with follow-ups ranging from 3 to 29 years- and with a massive pool of over 14,300 participants- a participant with a high cholesterol level in midlife was much more likely to develop Dementia later on than a participant with a healthy cholesterol reading.
Although researchers have long recognized the correlation between high cholesterol and dementia, there has been some debate as to how cholesterol affects the development of the disease.
In a 2013 study published in the American Medical Association’s Journal, JAMA Neurology, researchers at UC Davis found that having high levels of HDL cholesterol (also known as “good” cholesterol) and low levels of LDL (“bad” cholesterol), were associated with lower levels of the beta-amyloid plaques that are a hallmark of Alzheimer’s disease.
Researchers found that participants with low HDL and high LDL, on the other hand, were significantly more likely to have increased deposits of beta-amyloid plaque.
Cholesterol is measured in milligrams of cholesterol (mg) per deciliter of blood (dL).
A healthy Total Cholesterol reading is less than 200 mg/dLl.
To calculate Total Cholesterol, you must know your blood levels of HDL, LDL, and Triglyceride.
Total Cholesterol= HDL+LDL+ 20% of Triglyceride.
A healthy HDL level is 60 mg/dL and higher, while a healthy LDL reading is 100 mg/dL and lower.
Healthy Triglyceride levels are less than 100 mg/dL.
Always speak with a doctor regarding your Cholesterol results and any specific recommendations to assess your risk or manage your condition.
Dietary Concerns and Preventative Methodologies
- Replacing “bad fats” with “good fats”
The types of fat we consume include polyunsaturated fat, monounsaturated fat, saturated fats, and trans fats. Fats can be roughly categorized as “good” or “bad” relative to their effect on total health.
Polyunsaturated and monounsaturated fats are considered to be good fats, while saturated and trans fats are bad fats.
While many people still believe the old myth that dietary cholesterol (the cholesterol found in food) negatively impacts blood cholesterol, saturated and trans fats are much more detrimental to blood cholesterol levels than the cholesterol consumed in food.
However, if you have diabetes or another condition, your doctor may also recommend that you reduce your intake of dietary cholesterol.
Saturated and trans fats are found in fatty cuts of meat (red meat, sausage, bacon, etc), butter, and full-fat dairy products, coconut oil and palm oil, shortening, deep-fried foods, baked goods, and packaged goods (cookies, crackers, chips).
Polyunsaturated and monounsaturated fats (including Omega-6 and Omega-3 fatty acids) are both essential to our diets: however, most Americans over consume Omega-6 and underconsume Omega-3, an imbalance that can be detrimental.
High Omega-6 consumption and low Omega-3 consumption is largely thanks to a reliance on packaged and prepared foods, many of which are prepared with corn, soybean, and vegetable oils: all are rich in Omega-6. Grain and flour based desserts, pizza and pasta dishes, bread, and salad dressings are among the most common sources of Omega-6 in the American Diet.
On the other hand, Omega-3 food sources are fairly absent in the typical Western Diet: cold water fish such as salmon, sardines, and trout, as well as walnuts, flaxseed, and canola oil all provide healthy sources of Omega-3.
It should be noted that fat is the most Calorie-dense nutrient we consume.
Fats contain 9 Calories per gram, more than twice as much as that of Carbohydrate or Protein (both 4 Calories per gram).
As such, a little fat carries a hefty Caloric price tag: even “good” fats can be over-consumed, leading to weight gain and adverse health conditions.
Fat consumption should be capped at 20-35% of Caloric intake (50-70 g on a 2000 Calorie diet), with saturated fat comprising less than 10% of that total. Trans fat consumption should always be kept as low as possible.
- Increasing Vegetable Consumption
High intake of dietary fiber is consistently associated with lower levels of LDL cholesterol, as well as a lower risk of heart disease, diabetes, and obesity.
Fiber helps to lower cholesterol by reducing the amount of cholesterol that is absorbed into the bloodstream.
Furthermore, fiber aids satiety- aka, your feeling of fullness- which can help thwart unnecessary snacking and excess food intake.
While many people choose to focus on whole grains as a means of increasing fiber intake, it is essential that much of your fiber come from vegetables and fruit.
Although whole grains, such as oatmeal, whole wheat bread, and brown rice, do offer significant amounts of fiber, the large majority of people already consume enough grain in their diet that adding additional grain for the sake of fiber would be superfluous.
On the other hand, a mere 26% of Americans consume enough vegetables and fruit on a daily basis to support nutritional status and positive health outcomes.
Furthermore, vegetables and fruits contain high concentrations of vitamins and minerals that are essential to brain function and total health, boasting anti-inflammatory properties that prevent disease and quell existing inflammation.
In particular, cruciferous vegetables have been shown to have superior anti-inflammatory effects.
Cruciferous vegetables include broccoli, cabbage, brussel sprouts, kale, and bok choy.
However, any vegetable added to the diet has the capacity to promote wellness and prevent disease, especially if vegetable consumption replaces less healthy options.
An English Health Survey spanning 8 years and encompassing a pool of 65,000 participants found that eating 7 servings of vegetables each day was associated with a 42% lower risk of death from all causes, as well as a 31% reduction in heart disease and stroke, and 25% lower risk of cancer.
Researchers, whose findings were published in the Journal of Epidemiology and Community Health, also found that high vegetable consumption seemed to be significantly more protective against these diseases than fruit consumption.