Impairs Blood Flow To The Brain, Which Allows Toxins To Accumulate
By Dr. Mercola
Alzheimer’s disease, a severe form of dementia, affects an estimated 5.2 million Americans, according to 2013 statistics. Approximately 7.7 million new cases of dementia are identified every year—which amounts to one new case every four seconds. One in nine seniors over the age of 65 has Alzheimer’s, and the disease is now thought to be the third leading cause of death in the US, right behind heart disease and cancer.
While you cannot change your age and family history, there are modifiable lifestyle factors you can act upon to effectively reduce your risk for developing this tragic disease. These modifiable risk factors include things like diet, physical activity, obesity,cognitive activity, and tobacco use. Recent research indicates that tobacco use may play a significant role in Alzheimer’s disease.
In 2014, the World Health Organization (WHO) published a report entitled “Tobacco Use & Dementia,” based on a comprehensive scientific review of tobacco use, exposure to secondhand smoke, and incidence rates for all types of dementia, including Alzheimer’s.
The report found that smokers have a 45 percent higher risk of developing dementia than non-smokers, and concluded that 14 percent of all Alzheimer’s cases worldwide may potentially be attributed to smoking.
These risks hold true across nearly every income level and geographic boundary—including US, China, India, and Latin America. Smokers with dementia also die earlier than non-smokers with dementia.
Smoking is thought to cause dementia by the same biological mechanisms as its contribution to coronary artery disease, cerebrovascular disease, and stroke, namely by promoting the following three pathological processes:
- Increasing total plasma homocysteine, which is a known risk factor for stroke, cognitive impairment, Alzheimer’s, and other dementias;
- Accelerating atherosclerosis in your heart and brain, which deprives your brain cells of oxygen and important nutrients. Arterial stiffness is associated with the buildup of beta-amyloid plaque in your brain, which is a hallmark of Alzheimer’s disease; and
- Oxidative stress, excitotoxicity, neural death, and inflammation that may directly or indirectly be related to brain changes seen in people with Alzheimer’s
For those who have a past history of smoking but do not currently smoke, the risk is less predictable, which suggests that smoking cessation later in life is beneficial and may reduce your dementia risk, as well as lowering your overall mortality.
This conclusion matches the findings of prior studies, which point to the benefits of smoking cessation regardless of your age. One study showed that women who quit smoking before age 40 avoid more than 90 percent of the overall increased mortality caused by continued smoking, and those who quit by age 30 avoid 97 percent of the increased mortality.
Another study found smokers over age 65 who quit smoking might reduce their risk of dying from heart-related problems to that of a non-smoker within just eight years.
A link between secondhand smoke and dementia is very likely, although studies are limited. According to the WHO:
“The pathophysiological link between secondhand smoke exposure and dementia is not well understood. At this time, an indirect causal pathway is biologically plausible because of recognized associations between secondhand smoke exposure, increased risk of cardiovascular conditions and stroke.
The cardiovascular effects of secondhand smoke are nearly as great as for smoking, and operate through essentially the same biological mechanisms…”
The report cites six studies that all suggest exposure to secondhand smoke increases your risk for Alzheimer’s disease and other types of dementia. The risk appears to be “dose-dependent”—related to the frequency and duration of exposure. Even less is known about smokeless tobacco use and dementia risk. The WHO scientists state:
“Smokeless tobacco contains over 2000 chemical compounds, including nicotine. It is biologically plausible that the use of smokeless tobacco could increase the risk of dementia through cardiovascular disease-related mechanisms, as use of snus [a type of Swedish smokeless tobacco sold in loose form or in paper sachets that users stuff under their upper lip] has an increased risk of death from cardiovascular disease.”
It should also be noted that secondhand smoke is dangerous to the health of your pets. Animals can develop lung damage and certain kinds of cancers from exposure to smoke, residual chemicals left behind by cigarettes, and from toxins that cling to a smoker’s hands and clothing. Studies show that secondhand smoke may double your cat’s risk for lymphoma.
A growing body of research suggests there’s a major connection between your diet and your risk of developing Alzheimer’s disease, via similar pathways that cause type 2 diabetes, as explained by Dr. Perlmutter in the interview above. If you are diabetic, your risk of Alzheimer’s is TWICE that of someone with optimal metabolic function.
Even if you are perfectly healthy, excess sugar and other carbohydrates can disrupt your brain function. Over the long term, sugar can contribute to the shrinking of your hippocampus, which is a hallmark symptom of Alzheimer’s disease.
This connection between diet and brain function is so profound that Alzheimer’s disease was tentatively dubbed “type 3 diabetes” in early 2005, when researchers discovered that in addition to your pancreas, your brain alsoproduces insulin, and this brain insulin is necessary for the survival of your brain cells.
Contrary to popular belief, your brain does not require glucose and actually functions better burning alternative fuels, especially ketones, which your body produces in response to digesting healthy fats. According to some experts, such as Dr. Ron Rosedale, Alzheimer’s and other brain disorders may in large part be caused by the constant burning of glucose for fuel by your brain.
There is strong evidence that overconsumption of carbohydrates and underconsumption of healthy fats are central to the Alzheimer’s epidemic. It is conceivable that lowering glucose levels in older people may have a positive influence on cognition, even if they’re within the “normal” range.