Air pollution is harmful to health, with bad effects on the lungs, heart and cardiovascular system. New research suggests that the nervous system, particularly the brain, is also subject to damage from the fine particles in polluted air.
Wildfire Smoke Increases the Risk for Dementia:
Evidence is growing that exposure to smog or smoke may damage the brain as well as other organ systems. The most recent study, published in JAMA Neurology, followed more than one million seniors (JAMA Neurology, Nov. 25, 2024). These people were enrolled with Kaiser Permanente Southern California from January 2006 to December 2019. Those who lived where wildfire smoke was a problem during that time were at higher risk for developing dementia. Of course, air pollution attributed to other sources also increased the risk for cognitive difficulties, though not by as much.
Air scientists measure pollution in terms of tiny particles called PM2.5. Taking a deep breath when these are in the air pulls them deep into the lungs. Over three years, an increase of 1 microgram/cubic meter of PM2.5 particulate matter from wildfires increased the odds of a dementia diagnosis by 18%. People who belong to racial minorities and those living in high-poverty census tracts appeared most affected by wildfire-derived air pollution.
Lowering the Impact of Air Pollution with Diet:
Even if you can’t completely avoid air pollution, you might be able to soften its impact. Data from the National Institutes of Health (NIH)-American Association of Retired Persons (AARP) Diet and Health Study suggests that people who follow a Mediterranean-style eating pattern with lots of vegetables, fruits and whole grains are less vulnerable to the toll of air pollution. The study included nearly 550,000 individuals with an average age of 62 at the outset (Circulation, April 9, 2019).
It tracked their health for 17 years, during which time more than 126,000 of them died. The participants reported on their dietary habits and residences. The researchers used that data to calculate dietary antioxidants and exposure to particulates, nitrous oxide and ozone. The risk of cardiovascular disease rose 13% with each 10 microgram/cubic meter increase in PM2.5.
How Much Did Diet Help Against Air Pollution?
As exposure to particulates and nitrous oxide increased, so did deaths from cardiovascular disease. But those whose diets resembled the Mediterranean pattern most had only a 2 percent increase, compared to 10 percent for those eating a standard American diet. People who ate more like Americans rather than Mediterraneans were 12 percent more likely to die of heart attacks with each part-per-billion increase in nitrous oxide. Those who followed the Mediterranean model saw only a 4 percent increase in heart attack deaths as nitrous oxide levels rose 1 ppb.
On the other hand, the scientists found no correlation between diet and the effects of ozone. Antioxidants may not help reduce that form of air pollution.
What About Other Benefits of a Mediterranean Diet?
An analysis of 56 studies of the Mediterranean diet found that people following this eating pattern have a lower likelihood of developing diabetes, heart attacks, strokes and breast cancer (Annals of Internal Medicine, Oct. 4, 2016). To be included in the research, a study had to have at least 100 participants. Each study lasted at least a year. Volunteers needed to adhere to at least two of the following seven components:
- more monounsaturated fat (usually from olive oil or nuts, with little if any animal fat like butter);
- lots of vegetables and fruits;
- plenty of legumes such as peas, beans and lentils;
- mostly whole grains;
- moderate amounts of red wine;
- limited dairy products;
- and reduced consumption of meat, with fish as a substitute.
Importantly, the diets were not restricted in fat. Many physicians and nutrition experts have thought that avoiding red meat and dairy products would be beneficial primarily because people eat less fat. That was not necessarily true for these study diets.
The Envelope:
The research doesn’t demonstrate cause and effect. But by now the consensus is that even a high-fat Mediterranean diet is good for the heart, the brain and various other organs. People following a Mediterranean pattern lowered their chance of a heart attack or stroke by 29 percent. They were 57 percent less likely to be diagnosed with breast cancer. The risk of diabetes was 30 percent lower.
Do Try This at Home:
The study authors suggest trying to eat this way at home by using olive oil rather than other fats and focusing on plant foods, especially vegetables, beans and seeds. Mediterranean-style menus from Italy, Spain, France, Turkey and Israel are delicious, so adopting such a plan shouldn’t mean sacrificing flavor. If you would like guidance on following a Mediterranean diet, you will find it in our book, The People’s Pharmacy Quick & Handy Home Remedies.
Needless to say, the greatest effect would be to avoid exposure to smog, wildfire smoke or other sources of air pollution. Wood smoke, even that from logs in the fireplace, contains polycyclic aromatic hydrocarbons. These can trigger inflammation and may be carcinogenic. Unfortunately, the air we breathe is far harder to control than the food we eat.
