What secrets does hair hold? It can reveal your diet, income and health, study says
Every meal you eat is recorded in each strand of hair on your head, revealing to researchers what health risks you might face based on diet alone.
And if that’s not wild enough, hair can also reveal how much money you make, according to a new study conducted by University of Utah researchers.
Experts found that hair can draw potential connections among diet, socioeconomic status and health while exposing how mass animal-feeding operations in the U.S. contribute to high obesity rates in the country.
Their conclusions were reached after plucking hair out of barbershop and salon trash cans; the method even helped the team accurately guess how much people spent on their haircut, according to the study published Monday in the journal Proceedings of the National Academy of Sciences.
“They would let us go to the trash bin and pull out a handful or two of hair, which we then sort into identifiable clusters representing individuals,” study author Jim Ehleringer, a distinguished professor at the University of Utah’s School of Biological Sciences, said in a news release. “As an integrated, long-term measure of an individual’s diet, the measurement can be used to understand dietary choices among different age groups and different socioeconomic groups.”
How did they do it?
Isotopes are variants of a particular chemical, and different foods have different ratios of them. As food breaks down in your stomach, the isotopes make their way into many parts of the body — including hair — in the form of amino acids, the researchers said.
Hair strands are built from these amino acids, so they can preserve chemical traces such as proteins from your meals. “It’s a strong enough record to show whether you prefer veggie burgers or double bacon cheeseburgers,” the team wrote in the release.
The researchers collected samples from hair salon trash bins in 65 cities across the U.S., giving them a sample size of nearly 700 people, according to the release.
They also grabbed pieces of hair from 29 ZIP codes in Salt Lake Valley, Utah to study trends in a single urban area. Minus the isotope record, people’s age, gender, income and health status remained a mystery.
After analyzing the isotopes in the hair samples, the researchers found that “corn-fed, animal derived proteins” were more common in areas associated with lower socioeconomic status.
This is because animals that provide beef, poultry, pork, eggs and milk — foods that make up the majority of Americans’ diets — are fed corn in concentrated animal-feeding operations, the team said. This corn is then incorporated into the animals’ tissues, which then show up in people’s hair after eating them.
Breaking down diets
Foods from corn-fed animals are cheaper to buy in the U.S. than plant-based ones, the researchers noted, which is why diets made up of these animal proteins correlated with the cost of living in the ZIP codes where hair samples were collected.
What’s more, the team used driver’s license data to identify trends in body mass index in particular ZIP codes and found that the isotope ratios also matched obesity rates in those areas.
Similarly, that’s how the researchers accurately guessed the average price of a haircut at each sampling location.
Diets rich in animal proteins have been linked to the rapid rise in obesity, diabetes, kidney disease and other diet-related diseases in the U.S., according to the study; nearly 40% of American adults are obese today.
Because these diets are more common in low-income communities, these populations are “at a potentially greater risk for increased health problems.”
Given the unbiased nature of hair samples over self-reported surveys, the researchers said this method of data collection can help inform public health initiatives in communities most affected by dietary disease.
This story was originally published August 4, 2020 at 6:21 PM.
