by David Accomazzo
A recent study from the Mexican National Institute of Public Health found that fish oil was more than twice as effective as soy oil in reducing the damaging effects of air pollution.
Air pollution damages the human body when particles smaller than 2.5 micrometers inhibit protective antioxidant enzymes in the human body. Research indicates that supplementing the diet with omega-3 fatty acids might help prevent the damage air pollution causes. The results appear to be dosage dependent. Study participants received two grams of either soy or fish oil each day, but the fish oil capsules contained five times the amount of omega-3 fatty acids than the soy oil capsules contained. Scientists noted this difference in the study.
"The fact that fish oil appears to be more effective against oxidative stress related to PM2.5 exposure... than soy oil suggests the small amount of [omega-3 fatty acids]... in soy oil might be insufficient to protect against the adverse effects of PM2.5 exposure," the researchers wrote.
But the study's methodology might be problematic, said Anthony Almada, president and chief executive officer of GENr8 Inc., who called the study's statistical analysis "funky." "They did not provide data showing the change from before [the subjects] started taking supplements to after they started taking supplements," Almada said.
Also missing from the study is the chemical composition of the capsules themselves, which are often fortified with Vitamin E that might affect the study results, Almada said. "The way the capsules are manufactured leaves a number of questions unstudied," he said. "You don't know whether the capsules are stable; it's a very myopic and very novice treatment of the actual capsule."
The study subjects lived in smoggy Mexico City with the same PM2.5 levels indoors as in the outdoor environment. Researchers recruited 52 nursing home patients with an average age of 76.5 to participate in the study, which had no placebo group. The subjects acted as their own controls.
The activity for one enzyme, copper/zinc superoxide dismutase, increased 49 percent for those taking fish oil and 23 percent for those taking soy oil. Another enzyme, glutathione, increased 62 percent in the fish oil group and 55 percent in the soy oil group, according to the study.
For one particular air-pollution damage marker, the soy oil group reported no change while the fish oil group saw a 72.5 percent decrease.
"We based our results on a limited sample size but suggest that essential fatty acids might play an important role in modulating the impact of PM on health, which warrants further investigation in larger populations," the researchers wrote.