Heavy metal cadmium may be linked to memory problems for some

The heavy metal cadmium, found in air, water, food and soil, is known to cause health problems. A new study published in the September 4, 2024 online issue Neurology investigated whether thinking and memory skills were related to cadmium exposure.

The researchers found no connection when they looked at the group as a whole. However, when they looked at black and white people separately, they found that cadmium may be linked to problems with thinking and memory in white people. The study found no such association in black people. The study does not prove that cadmium causes memory problems in white people; it only shows a connection.

Cadmium is a highly toxic heavy metal that enters the body mainly through cigarette smoking, inhaling polluted air and food. It enters the environment through industrial and agricultural activities.

“With the high incidence and cost of dementia to families and society, it is important to identify risk factors for early cognitive problems that may be influenced by changes in people’s behavior or in society,” said study author Liping Lu, M.D., Ph. D., from Columbia University in New York City.

The study involved 2,172 people with an average age of 64 and no problems with thinking or memory. Black people made up 39% of participants and white people 61%. At the beginning of the study, cadmium levels in the urine were tested. Participants took annual tests on thinking and memory skills and were followed for an average of ten years.

During that time, 195 people developed cognitive impairment. When researchers looked at the overall group, they found no link between cadmium levels and cognitive impairment. However, when they looked at black and white participants separately, they found that white people with high cadmium levels were more likely to develop cognitive impairment. They found no association in black people.

Because participants were divided into two groups based on cadmium levels, white people with high cadmium levels were twice as likely to develop cognitive impairment as those with low cadmium levels, even after adjusting for other factors that might contribute to cognitive impairment. can influence, such as physical activity, alcohol consumption and alcohol consumption. education. Overall, 9.2% of those with high levels developed thinking and memory problems, compared to 6.7% of those with low levels.

Lu said one explanation for the difference between white and black people could be cigarette smoking. After dividing participants into three groups based on cadmium levels, researchers found that white people at the highest level smoked an average of 23 pack-years, compared to nine pack-years for black people at the highest level. Pack-years are a way to measure smoking over time. It is determined by multiplying the number of packs smoked per day by the number of years smoked. So 23 pack years is equal to, for example, one pack per day for 23 years, or two packs per day for 11.5 years.

“These results need to be confirmed with studies that measure cadmium levels over time, include more people and follow people over longer periods of time, but there are many reasons to reduce cadmium exposure, whether that is by implementing of policies and regulations for air pollution and binge drinking, water or people changing their behavior by quitting smoking or being around cigarette smoke,” Lu said.

A limitation of the study was that urine cadmium levels were only tested at the beginning of the study and exposure may have changed over time.