For years, we’ve understood that having high blood levels of HDL (high density lipoprotein) cholesterol, also known as “good” cholesterol(1), lowers a person’s risk of heart disease. According to a 2010 study, it now appears that high HDL levels (at least 56 milliliters) are also associated with a reduced risk of Alzheimer’s disease.
Alzheimer’s disease is the most common form of dementia, and causes enough loss of memory and other cognitive abilities to compromise daily life. It is characterized by lack of synaptic communication between damaged brain cells, especially in areas of the brain in which new memories are formed, due to build-up of amyloid plaques and tangled neuron fibers. Although Alzheimer’s is considered an aging-related disease, it is not a natural cause of aging; rather genetic predisposition and environmental factors play into its development. Early onset Alzheimer’s also can afflict younger people. Five million people currently live with Alzheimer’s, a number which is expected to rise to sixteen billion by 2050.
(1) Please note: characterizing HDL and LDL cholesterol as “good” and “bad” cholesterol, respectively, is an outdated practice. Over the past few years years, cardiologists have realized that LDL cholesterol is not “bad,” per se, and that the body needs sufficient amounts of it for normal hormonal and cell membrane function. Our brains require cholesterol for neuron function. Small, dense LDL particles are harmful in that they are more prone to oxidation, which can eventually lead to blood clots that cause heart attacks and strokes. HDL cholesterol is still considered “good” when higher in ratio to LDL cholesterol, though.
Inflammation and Alzheimer’s Disease
Researchers have long recognized that brain inflammation plays a role in Alzheimer’s, and many believe that inflammation is the cause, rather than the result of, the onset of Alzheimer’s. Free radicals, which cause oxidative stress, and inflammatory cytokines, which cause cyto-toxicity, are markers of brain inflammation. Excess free radical and immune system activity can lead to chronic inflammation in the body. With age, free radical activity in the body generally increases, due to longer-term exposure to nutritional deficiencies, exposure to environmental toxins, and emotional stress. At the risk of oversimplifying a complex disease like Alzheimer’s, reducing free radical and other inflammatory activity, as much as possible, is a no-brainer for healthy brain aging, and overall body health.
Inflammation is a systemic beast, which may explain why reducing cardiovascular inflammation also helps to preserve brain health. Adopting anti-inflammatory lifestyle practices is one way to reduce risk of developing both cardiovascular and Alzheimer’s diseases. For example, regular, moderate exercise, which is a cardiovascular mainstay, increases blood flow to the brain and stimulates formation of substances needed to produce nerve cells. It is also a means of reducing risk of obesity, cancer and type 2 diabetes. Remember, though, that high intensity, strenuous exercise can createexcess free radical activity in the body. What’s important is to elevate your heart rate for 20 to 30 minutes a day through moderate movement, such as brisk walking, dancing, swimming, or biking.
A Link between Diabetes and Alzheimer’s?
Diabetics were once thought to be at greater risk of developing Alzheimer’s because they tend to be overweight and have high blood pressure. However, the insulin resistance which characterizes type 2 diabetes may be the most significant factor for increased Alzheimer’s risk. While the exact link between insulin dysfunction and Alzheimer’s is not yet known, researchers believe that impaired glucose metabolism causes cell death; as glucose is the brain’s primary energy source, inability to take it in may cause brain cells to starve. Additionally, too much insulin and blood sugar circulating in the bloodstream causes arterial inflammation and free radical damage.
Now Back to HDL Cholesterol
Not only does moderate aerobic exercise help reduce inflammation in the body, it also helps increase blood levels of HDL cholesterol. Researchers believe that higher HDL levels may protect against Alzheimer’s because they reduces a person’s risk of stroke, and may also help prevent amyloid proteins from accumulating in the brain.
Other ways to increase HDL levels include quitting smoking, losing excess weight (obesity is associated with reduced HDL levels), avoiding trans-fats (which increase LDL, and reduce HDL, blood cholesterol levels), consuming more soluble fiber, monounsaturated and omega-3 fats, and even having a glass of wine each day.
Prevention via Lifestyle is Best Defense
Unfortunately, the medical world has not yet found a cure for Alzheimer’s. In addition to engaging in moderate, regular exercise, preventative lifestyle measures include:
- Eating a Mediterranean-type diet full of fresh fruits and vegetables, fish (omega-3s), legumes, and olive oil. Not only good for the heart, this anti-inflammatory diet is associated with a reduced risk of cognitive decline as well as slower decline in those already diagnosed with mild impairment;
- Substituting coconut oil, a saturated fat, for all polyunsaturated oils (omega-6 fats) when possible. As a medium chain triglyceride, coconut oil is converted by the liver to ketones, which are an alternative source of fuel for the brain.
- Supplementing with antioxidants and high quality fish oil (full of anti-inflammatory omega-3s);
- Earthing. By making direct skin contact with the earth (or using an Earthing device) we connect to the earth’s natural electro-magnetic energy and absorb negative free electrons which neutralize free radical activity and soothe the nervous system.
- Stress management through mind-body practices;
- Getting enough sleep;
- Sunning – at least 15 minutes a day – which will help your body make Vitamin D.
These techniques help keep the immune system from getting overly burdened, and help protect the aging brain, as well as the cardiovascular system.
Lastly, avoid exposure to aluminum, which is the most abundant neurotoxic metal on earth. Aluminum may be one of the greatest aggravating factors related to Alzheimer’s disease.
- Switch to aluminum-free deodorant;
- Never cook with aluminum pans or pans with Teflon surfaces that have been scratched or chipped;
- Avoid consuming or using products that have been stored in aluminum containers.
References and Resources:
- Rabin, Roni Caryn. “’Good’ Cholesterol may Lower Alzheimer’s Risk.” NYTimes.com, Dec. 16, 2010.
- Reitz C, Tang M, et al. Association of Higher Levels of High Density Lipoprotein Cholesterol in Elderly Individuals and Lower Risk of Late Onset Alzheimer’s Disease. Arch Neurol. 2010;67(12):1491-1497.
- Alzheimer’s Association
- Alzheimer’s Association. 2010 Alzheimer’s Disease Facts and Figures
- Baker LD, Cross DJ, et al. Insulin Resistance and Alzheimer’s-like Reductions in Regional Cerebral Glucose Metabolism for Cognitively Normal Adults with Pre-Diabetes or Early Type 2 Diabetes. Arch Neurol. 2010 Sept. 13. [Abstract.]
- R?nnemaa E, Zethelius B, et al. Impaired Insulin Secretion Increases Risk of Alzheimer’s Disease. Neurology, 2008 Sep 30; 71(14):1065-71 [Abstract.]
- Ansari MA, Scheff SW. Oxidative stress in the progression of Alzheimer’s disease in the frontal cortex. J Neuropathol Exp Neurol. 2010 Feb;69(2):155-67. [Abstract.]
- Deng Y, Li B, et al. Dysregulation of Insulin Signaling, Glucose Transporters, O-GlcNAcylation, and Phosphorylation of Tau and Neurofilaments in the Brain – Implication for Alzheimer’s Disease. Am J Pathol.2009 November; 175(5): 2089–2098.
- Parker-Pope, Tara. “Mediterranean Diet May Prevent Mental Decline.” NYTimes.com, Feb. 10, 2009.
- Newport M. “What if there was a Cure for Alzheimer’s Disease and No One Knew?” July 22, 2008.
- Krauss D, M?ller N. Neruoinflammation, Microglia and Implications for Anti-Inflammatory Treatment in Alzheimer’s Disease. Int J Alzheimer Dis.June 2010; 2010.
- Galasko D, Montine TJ.Biomarkers of oxidative damage and inflammation in Alzheimer’s disease. Biomark Med.2010 February; 4(1): 27–36.
- Tomljenovic L. Aluminum and Alzheimer’s Disease: After a Century of Controversy, is there a Plausible Link?J Alzheimers Dis.2010 Dec 14. [Abstract.]
- Belluck, Pamela. “With Alzheimer’s Patients Growing in Number, Congress Endorses a National Plan.” NYTimes.com, Dec. 15, 2010.
- Alzheimer’s Association. Press Release: “Congress Passes Historic Legislation That Provides Framework for National Alzheimer’s Strategy.” Alz.org, Dec. 15, 2010.
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