Researchers have recently linked air pollution, long recognized as a cause of respiratory and car-diovascular disease, with harm to the brain, as well.
An extensive review published January 2014 in the journal Biomedical Research International examined research conducted over the last 10 years into the effects of pollution on the brain. After looking at in vitro laboratory studies, as well as animal and human research, the study authors concluded that air pollution is a major cause of neurotoxicity, negatively affecting the brain in a variety of ways and contributing to the development of central nervous system diseases. Their review suggests that age is the most relevant factor in susceptibility to harmful outcomes, with the young and the elderly bearing most of the health burden.
“Young children, with their fast-developing brains, are highly vulnerable to pollution, as are older adults who have been exposed to pollution for many years,” explains Jack Rogers, PhD, Program Director of the Laboratory for Neurochemistry at MGH and an expert in the neurological effects of heavy metal contamination. “In older people, the damage occurs over time, and eventually sets off a deleterious cascade within the brain that can lead to neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s disease (AD), along with other con-sequences.”
WHAT YOU CAN DO
Dr. Rogers suggests restricting your exposure to airborne toxins as much as possible by using strat-egies such as the following:
- Do not smoke, and try to avoid tobacco smoke, if possible.
- Track levels of particulate matter in your area and restrict physical activities or stay indoors during days when air pollution levels are high.
- Close windows and use air conditioners or house filters to keep indoor air clean when pollution levels are high. Limit indoor pollution from fireplaces, dusting and vacuuming, or using chemical cleaners.
- When travelling in traffic, use the air recirculation setting in your vehicle.
- If possible, wear respiratory masks when exposed to activities that generate airborne particles. Wear long sleeves and gloves to protect your skin from toxins.
- Choose organic fruits and vegetables to help reduce pesticide residues in your food. Eat a diet high in antioxidants and increase your intake of natural chelators (substances that bind the toxins so they can be eliminated by the body), such as green tea and turmeric.
- Ask your doctor about taking melatonin supplements, which may help neutralize the toxic effects of metals.
- See your medical care provider about any persistent neurological symptoms.
“Air pollution tends to be especially detrimental for the brain because pollutants are inhaled through our nasal passages, move through the blood-brain barrier, and pass directly into the brain,” says Dr. Rogers. “Once in contact with brain tissue, these substances increase inflammation, oxidative stress, and the destruction of support cells called glial cells in the brain’s white matter. Research has linked the inhalation of air pollution with the generation of toxic beta-amyloid and tau proteins, both hallmarks of AD, and with impairment of the transmission of messages among brain cells. Air pollu-tion is also linked with damage to the brain’s vascular system, leading to hemorrhages and other effects associated with vascular dementia.”
Research has associated the effects of air pollution on the brain with symptoms such as cognitive impairment; memory loss; premature brain aging; greater risk for depression; and, in children, developmental problems such as autism and hyperactivity.
The review’s authors defined air pollution as a mixture com-posed of several components, including ambient particulate matter (PM), gases, organic compounds, and metals. Lead and mercury, smoke, fumes from solvents and diesel fuel, and chemicals associated with pesticides and industrial processes all can be inhaled and travel to the brain. Of these, the researchers suggest that particulate matter is the most heavily involved in disease, especially ultrafine particulate matter (UFPM), which is small enough to enter cells and trigger toxic effects. UFPM easily circulates to bodily organs including the brain, and is able to enter the brain directly via the nasal passages. The researchers point out that dysfunction of the olfactory bulb (the brain structure that receives and processes information about odors) is an important early symptom of neurodegenerative diseases. They found that oxidative stress and neuroinflammation was the hallmark of the adverse effects of air pollution.
“Inflammation and oxidative stress are associated with a buildup of reactive oxygen species, a byproduct of metabolic processes that, when produced in large quantities as a re-sponse to stress, can kill nerve cells,” says Dr. Rogers. “However, there are strategies people can use to protect their brains.”
See What You Can Do for possible ways to prevent, reduce, or reverse neurotoxicity.
Powered by WPeMatico