Smoking And Smoke Exposure
6.1.1. In vitro and animal studies
In vitro studies by Giunta and colleagues168 showed that cigarette smoke condensate increased A140 and A142 levels in a concentration-dependent manner in cells transfected with human APP . In addition to elevated markers of OxS in cigarette smoke exposed rats, Ho et al.,175 reported these rats concurrently demonstrated significantly increased -sAPP, but not -sAPP, levels in homogenized hippocampal tissue and markedly increased A accumulation in the CA3 and dentate subfields of the hippocampus. The smoke exposed rats also showed significantly increased hippocampal hyperphosphorylated tau, but not total tau levels. Moreno-Gonzalez and colleagues208 exposed 3-month-old APP/presenilin1 transgenic mice to high or low dosage cigarette smoke 5 days/week for 4 months. The high-dosage group showed levels of cotinine, the primary metabolite of nicotine, that were physiologically consistent with human smokers. Both high-and-low-dosage groups begin to develop neuritic plaques at 56 months of age. The high-dosage group demonstrated a significantly greater number of A deposits and fibrillar neuritic plaques, increased density of activated microglia and reactive astrocytes, and positive hyperphosphorylated tau staining in the majority of the cerebral cortex and hippocampus relative the low-dosage group and controls.
6.1.2. Post-mortem human studies
6.1.3. Synopsis
Aluminum In The Environment
Aluminum has a non-metallic form that makes up eight per cent of the earth’s surface. In small amounts, aluminum is referred to as “trace elements”, and occur naturally in the foods we eat, in our drinking water and are even added to the water treatment process in some municipalities.
Trace elements of aluminum may also be found in:
- Many processed foods
- Cosmetics and personal hygiene products, such as deodorants and nasal sprays
- Some drugs in order to make them more effective or less irritating
- The air we breathe from dry soil, cigarette smoke, pesticide sprays and aluminum-based paint.
Smoking Linked To Alzheimer’s And Dementia
Study Shows Heavy Smoking Between Ages 50 and 60 May Raise Risk of Alzheimerâs Disease
Oct. 25, 2010 — People who are heavy smokers in their midlife years are more than doubling their risk of developing Alzheimerâs disease or other forms of dementia two decades later, a new study shows.
While smoking has long been known to increase the risk of dying from cancer and heart disease, researchers in Finland say theyâve found strong reason to believe that smoking more than two packs of cigarettes daily from age 50 to 60 increases risk of dementia later in life.
Scientists at the University of Eastern Finland and at Kuopio University Hospital, Finland, analyzed data from 21,123 members of a health care system who took part in a survey between 1978 and 1985, when they were between ages 50 and 60.
Diagnoses of dementia, Alzheimerâs disease, and vascular dementia were tracked from Jan. 1, 1994, when participants were 71.6 years old, on average, through July 31, 2008.
Among the key findings:
- 25.4% of the participants, or 5,367 people, were diagnosed with dementia an average of 23 years later.
- Of patients with dementia, 1,136 were diagnosed with Alzheimerâs disease and 416 with vascular dementia.
Researchers say that people who smoked more than two packs of cigarettes a day in middle age had an elevated risk of dementia overall and also of each subtype, Alzheimerâs and vascular dementia, compared with nonsmokers.
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Smoking Doubles The Risk Of Alzheimers
Sure, when you quit smoking you save money on mints, gum, and Febreze. Those are nice, but heres a HUGE reason to stop! Smoking DOUBLES the risk of Alzheimers! Also, your loved ones will love you for it. They love you long time, and you can loveem backeven longer!
The World Health Organization estimates that 14% of dementia cases worldwide could be caused by smoking.
Nicotine Nicotinic Acetylcholine Receptor Agonists And Antagonists And Ad Pathophysiology
6.2.1. In vitro and animal studies
6.2.2. Post-mortem human study
In a human autopsy study, the effect of several nAChRs agonists and antagonists on 11C-Pitsburgh compound B binding were evaluated in frontal lobe homogenates of elder controls and AD. The smoking status of AD and control cases was not provided. The 7 nAChR agonists varenicline and JN403, but not the 42 nAChR agonist cytisine, increased PiB binding in both AD and controls. This effect was abolished by the 7 nAChR antagonists -bungarotoxin, mecamylamine, and methyllycaconitine, but not by the 42 antagonist dihydro–erythroidine. Increased PIB binding promoted by varenicline and JN403 was significantly inhibited by pre-incubation with the amyloid ligand, BF-227. The acetylcholinesterase inhibitor and allosteric nAChR modulator galantamine, and the N-methyl-D-aspartate receptor blocker memantine did not significantly influence PiB binding levels in AD cases.227
6.2.3. Synopsis
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What Should I Take Away From This Research
Smoking is the main cause of avoidable death, through heart disease, stroke, and lung cancer. It is a risk factor for lung disease, diabetes, rheumatoid arthritis, and poor immune function, and also adversely affects fertility and maternal health. There are therefore many general health reasons for not smoking.
Some of the known effects of smoking are known causes of the diseases that cause dementia, and there is evidence that a current smoker is more likely to develop dementia. Some researchers estimate that 14% of dementia cases worldwide may be attributable to smoking.
However, on a positive note, stopping smoking reduces this risk, so it is never too late to adopt healthier lifestyle choices. It is also likely to help if second-hand smoke is avoided where possible.
Drinking Smoking Up Early Alzheimer’s
Study Shows Cigarettes and Alcohol Lead to Earlier Development of Alzheimer’s Disease
In what is being lauded as a significant finding, research presented at the American Academy of Neurology’s 60th Anniversary Annual Meeting this week in Chicago shows that smoking and drinking are among the most important preventable risk factors for Alzheimer’s disease.
Researcher Ranjan Duara, MD, of the Wien Center for Alzheimer’s Disease at Mount Sinai Medical Center in Miami Beach, Fla., found that a combination of heavy drinking and heavy smoking leads to an earlier onset of Alzheimer’s disease.
“It has been projected that a delay in the onset of the disease by 5 years would lead to a nearly 50% reduction in the total number of Alzheimer’s cases,” Duara says in a news release. “If we can reduce or eliminate heavy smoking and drinking, we could substantially delay the onset of Alzheimer’s disease for people and reduce the number of people who have Alzheimer’s at any point in time.”
Duara’s study involved 938 people aged 60 and older with possible or probable Alzheimer’s. Family members provided information regarding the patients’ alcohol consumption and cigarette usage.
Heavy smoking was defined as one or more packs of cigarettes a day heavy drinking was defined as more than two drinks per day. The researchers also grouped participants according to whether they carried the apolipoprotein E-4 gene variant, which increases risk for Alzheimer’s disease.
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Does The Amount You Smoke Affect The Risk Of Dementia
There were only four studies in the World Alzheimer’s Report that looked at the number of cigarettes smoked and dementia risk. Two showed a relationship between higher tobacco consumption and a higher risk of dementia, but currently, there is not enough evidence to know for sure whether this is the case.
Can Nicotine Reduce Dementia Risk
There is some evidence that exposure to nicotine, which is one of the components of cigarette smoke, can actually reduce the risk of dementia. Such reports may be useful in indicating possible research directions for drug design.
However, nicotine intake through smoking would not be beneficial as any positive effects would be outweighed by the significant harm caused by the many other toxic components in cigarette smoke.
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Cigarette Smoke/combustion Products And Oxs
Cigarette smoke is a complex admixture of approximately 5000 combustion products , which contains a high number of cytotoxic and carcinogenic compounds.164 The gas and particulate phases of cigarette smoke have extremely high concentrations of short-and-long-lived ROS, RNS, and other oxidizing agents.92, 133 In addition to increased free radical concentrations, smoking is associated with markedly elevated carboxyhemoglobin levels,165 altered mitochondrial respiratory chain function,166 and induction of proinflammatory cytokine release by peripheral and CNS glial cells,167 which collectively promote significant cerebral OxS.
5.2.1. In vitro and animal studies
5.2.2. Human studies
Sonnen et al.,177 conducted post-mortem comparisons of human smokers and never-smokers without significant AD or microvascular pathology. Active-smokers showed significantly higher cortical F4-neuroprostanes, a measure of neuronal free radical-mediated lipid peroxidation, but groups were not different on measures of cerebellar lipid peroxidation. Additionally, numerous human studies have shown elevated markers of OxS in the serum or plasma of smokers.132, 178184
Smoking May Not Be Related To Dementia Risk After All
There is no doubt that smoking damages health and increases the risk of many diseases and premature death. However, a study that followed hundreds of older adults for more than 10 years found no link between tobacco smoking and raised dementia risk.
Dementia is the general name for conditions that diminish the capacity to think, remember, reason, and interact with others. These symptoms can progress to the point that people are no longer able to carry out their daily activities and take care of themselves.
The recent finding contradicts many earlier studies that have tied smoking to higher risk of dementia. This could be because, for the new investigation, researchers from the University of Kentucky in Lexington analyzed the data in a different way.
They used a statistical method called competing risk analysis to allow for the strong effect that smoking has on risk of death.
In a paper that now features in the Journal of Alzheimers Disease, first study author Erin L. Abner Ph.D., an associate professor in the universitys Sanders-Brown Center on Aging, and her colleagues describe their approach and findings.
Dr. Abner explains that while previous dementia studies had used solid data, they had not taken into account the idea of competing risk of mortality.
50 million people were living with dementia worldwide in 2015. The WHO expect this number to triple to 152 million by 2050.
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Why Does Smoking Increase Alzheimers Risk
The dangerous brain consequences of smoking are probably linked with smokings effects on the brains blood vessels. Smoking increases circulating levels of a blood chemical called homocysteine, which is toxic to the arteries. Increased homocysteine levels have been linked with increased risk for stroke and dementia. Smokers arteries are damaged by atherosclerosis at an earlier age, and this is very dangerous to the brain, which relies upon blood flow for nutrients and oxygen.
Smoking, furthermore, is associated with increased oxidative stress, a damaging effect that results in increased inflammation and the death of brain cells. Smoking is considered an additive risk factor, contributing additional risk to that resulting from other health features. Individuals already at increased risk for dementia as a result of having the e4 version of the APOE gene face even greater risk if they are current smokers.3
Researchers warn of an additional concern, the danger of exposure to second-hand smoke. Although not so damaging as direct exposure, one study evaluating the effect of second-hand smoke found that dementia risk was increased by more than 25 percent and that longer duration and greater frequency of exposure carried increased risk.3
What Is Good For The Heart Is Good For The Head
We cant change our age or our genes, and there is currently no way we can completely prevent dementia. However, there are some simple steps we can all take to help lower our risk.
Risk factors for cardiovascular disease, like high blood pressure, are also risk factors for dementia, so what is good for your heart is good for your brain.
Looking after your health by stopping smoking will help lower your risk of cardiovascular disease and dementia. Other behaviours associated with good heart and brain health include being physically active, eating a healthy balanced diet, maintaining a healthy weight and, if you drink alcohol, drinking within NHS lower-risk guidelines.
While its never too late to make positive changes, keeping your heart healthy in your forties and fifties seems to be particularly important for helping to reduce your risk of dementia.
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Smoking And Nicotine: Relationships To Ad Pathophysiology
As previously summarized in section 5, cerebral OxS has been implicated in the initiation of AD neuropathology, rather than strictly developing as a physiological consequence of existing and/or progressing amyloid-or-tau-based pathophysiology.42, 131, 202, 203 Smoking is strongly associated with cerebral OxS , and OxS promotes increased-secretase cleavage of APP and abnormal tau phosphorylation. Thus, smoking-related OxS may directly facilitate the amyloidogenic pathway involved in A oligomers production and extracellular fibrillar A aggregation,168 as well as abnormal tau phosphorylation, which is the basis of neurofibrillary tangle pathology.
Smoking Does Not Protect The Brain Against Dementia Or Alzheimer’s Disease
For more about the effects of smoking on health, please visit our Forum on Smoking. And for further information about dementia andAlzheimer’s disease, please see our Forums onDementia and Alzheimer’s Disease.
— Editor, MedicineNet.com
Smoking does not protect against dementia or Alzheimer’s disease, according to a study in the British Medical Journal , contradicting the implications of some earlier research.
Sir Richard Doll and colleagues from the Clinical Trial Service Unit and Epidemiological Studies Unit, Radcliffe Infirmary at Oxford reported on observations of over 34,000 male British doctors whose smoking habits have been reviewed every six to 12 years since 1951 to determine the impact on their health. The research team also reviewed the published data on the associations between smoking andAlzheimer’s disease.
Over 24,000 of the doctors had died by the end of 1998.Dementia was mentioned on the death certificates of 483.Among 473 whose smoking habits were recorded at least 10years before their death, when they would not have beeninfluenced by the start of the disease, the prevalence of both Alzheimer’s disease and of other types of dementia was similar in both smokers and non-smokers.
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What Can Make Quitting Easier
Quitting smoking can be tough, but its possible. That said, there are steps you can take to help stay nicotine-free for life.
- Talk to your doctor. Russell-Chapin says the first step is to consult with a healthcare provider, as quitting smoking often produces a variety of withdrawal symptoms. Your doctor can work with you to create a solid plan that includes ways to deal with cravings and symptoms.
- Nicotine replacement therapies. There are a variety of medications and nicotine replacement therapies that can assist with quitting. Some over-the-counter products include nicotine gum, patches, and lozenges. If you need more support, your doctor may recommend a prescription for a nicotine inhaler, nicotine nasal spray, or medication that helps block the effects of nicotine in the brain.
- Counseling support. Individual or group counseling can help you get support for dealing with cravings and withdrawal symptoms. It can also help when you know other people are dealing with the same challenges as you.
- Learn relaxation techniques. Being able to relax and deal with stress may help you get through the challenges of quitting. Some helpful techniques include diaphragmatic breathing, meditation, and progressive muscle relaxation.
- Lifestyle modifications. Regular exercise, quality sleep, time with friends and family, and engaging in hobbies can help keep you on track with your quit goals.
Can Passive Exposure To Tobacco Smoke Cause Dementia
Second-hand smoke has been shown to increase the risk of cancer, cardiovascular disease, and other diseases. Studies have shown that it may also increase a persons risk of developing dementia later in life. Research suggests that the more exposure to second-hand smoke a person has, the higher the dementia risk.
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How Smoking Affects Atherosclerosis Risk
Smoking is considered one of the biggest risk factors for atherosclerosis. Cigarette smoke increases the risk of atherosclerosis in the following ways:
- Cholesterol: The toxins in tobacco smoke lower your HDL levels while raising levels of LDL .
- Nicotine and carbon monoxide: The nicotine and carbon monoxide in cigarette smoke damage your endothelium, setting the stage for the build-up of plaque.
- High blood pressure:While cigarette smoking won’t cause high blood pressure, if you smoke and you also have hypertension, smoking can increase the risk of malignant hypertension, a dangerous form of high blood pressure.
Smoking In Mild Traumatic Brain Injury
In those with a mild traumatic brain injury , we observed that active-smokers demonstrated significantly poorer recovery than never-smokers over 6 months post injury on measures of processing speed, visuospatial learning and memory, visuospatial skills and global neurocognition. Similar to AUD cohorts, greater smoking exposure was robustly related to less improvement on measures of visuospatial learning, visuospatial memory, working memory, visuospatial skills, and global cognition.128
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Elevated Cholesterol And Triglyceride Levels
Elevated levels of cholesterol and triglycerides in your blood cause damage to your endothelium. The body needs cholesterol , but too much comes with health risks. Your body usually produces most of the cholesterol it needs in your liver. The rest comes from animal fat in your diet.
While our bodies also need some low-density lipoprotein cholesterol, too much can raise your cholesterol levels dangerously and put you at risk for atherosclerosis and heart attack. Foods that come from animals, such as chicken, eggs, dairy products, beef, and pork, contain cholesterol. Foods from plants do not contain cholesterol.