Air pollutants: omega-3 and vitamin E together reduce damage in mice

The combination of omega-3 and Vitamin E supplements could protect against cardiovascular damage caused by certain airborne pollutants. In fact, a study in laboratory mice showed that the two nutrients can reduce inflammation and oxidative stress caused by breathing in certain particulate pollutants, called PM2_.5. The effects of simultaneous administration of Vitamin E and omega-3 supplements turns out to be more effective than that of the single molecules, showing an additive beneficial effect against pollutant injury.

These are the most significant findings of a study conducted by researchers at the Jiao Tong School of Medicine in Shanghai, China, and published in the journal Chemosphere.

The effects of air pollution can also be fought with nutrients

Numerous studies have shown how air pollution can damage both the respiratory and cardiovascular systems; in particular, scientific work has confirmed the association between fine particulate matter PM2_.5 and an increased risk of cardiovascular morbidity and mortality. Fine (or fine) particulates are small pollutant particles, of different nature and origin, in the air. 

Among them, PM2_.5,so called because they possess a diameter of less than 2.5 microns, can be breathed in and push into the deepest part of the respiratory system until they reach the bronchi and probably the blood vessels. These particles are considered the most harmful pollutant in the air; a recent study reported that environmental exposure to PM2_.5 can independently induce acute systemic inflammatory responses. Although the mechanism linking particulate matter and cardiopulmonary disease is unclear, some studies have shown that inflammatory response and oxidative stress may be responsible for the damage caused. 

Oxidative stress is caused by both the production of reactive oxygen molecules and the decrease in those with antioxidant activity, resulting in damage to cellular components, such as DNA and proteins. The association between PM2_.5 and lung disease, cerebrovascular disease, diabetes, and heart disease, including ischemia and myocardial infarction, has been the subject of extensive epidemiological and experimental studies, and has prompted governments and researchers in recent years to investigate effective measures to protect the health of citizens.

Can the correct intake of antioxidants limit the damage of pollution?

Previous studies have found that vitamin E consumed with food can improve antioxidant metabolism and reduce lipid oxidation typical of oxidative stress, revealing the key role of proper nutrition in helping to protect individuals from external pathogens. 

In this regard, antioxidants and anti-inflammatories are the likely strategies to block the harmful effects induced by exposure to air pollution. Vitamin E and omega-3 fatty acids are among the healthiest antioxidant and anti-inflammatory molecules for humans. In fact, omega-3 fatty acids are known for their ability to reduce inflammatory reactions by modifying membrane lipid content, while vitamin E has been found to be effective in decreasing signal molecules of oxidative damage, as well as improving antioxidant defenses.

The combined action of omega-3 and vitamin E against oxidative stress and inflammation

Although several human intervention studies have indicated that omega-3 and antioxidants can reduce the damage caused by air pollution, their protective function has not yet been clarified. Therefore, the Chinese study investigated the effect of combined treatment of vitamin E and omega-3 on cardiovascular damage caused by particulate matter, and at the same time, the right combination of the two molecules was studied. The research was conducted on laboratory mice exposed to PM2_.5,which were given different doses of vitamin E and omega-3, both individually and simultaneously. 

After the treatments, analyses on the animals' cells showed that the combination of the omega-3 and vitamin E supplements had increased the activities of antioxidant enzymes and reduced ROS, the molecules responsible for oxidative damage and inflammatory molecules. Finally, cell membranes were less damaged in mice that had consumed both nutrients under investigation, showing less injury to the endothelium, the tissue that lines the inside of blood vessels. In addition, the action of omega-3 and vitamin E had been shown to be more effective than that exerted by the molecules administered individually.

Some details of the study

During the research, lab rats were divided into four groups; one that had received supplements with different doses of vitamin E, another treated with different doses of omega-3; a third group that had received the combination of vitamin E and omega-3 in various dosages (low, medium and high), and finally a control group that had not consumed any supplements. All animals had followed the treatment for 14 days before being exposed to pollutant particles. The results of the analysis showed that, compared with the severe lesions found in rats in the group exposed only to PM2_.5 without any supplementation, rats in the pretreated groups had developed less damage in heart tissue. Notably, treatment with vitamin E alone or omega-3 alone had induced a significant reduction in inflammatory molecules and an increase in antioxidant activity. These effects were greater in animals that had received the combination of the two nutrients. In addition, the protective effects of vitamin E and omega-3 had demonstrated a dose-dependent response.

Further studies will need to confirm the effects in humans

Supplementation with vitamin E and omega-3 proved to be a potent combination against air pollution-induced cardiovascular injury in rats, suggesting that vitamin E and omega-3 are adept at limiting the oxidative stress and inflammatory response caused by PM2_.5, producing more effective effects than that of the separate nutrient. According to the researchers who conducted the study, the results suggest the protective effect from injury by environmental pollutants through proper dietary intake of nutrients. 

These observations will have to be further investigated as the study authors themselves admit that although the nutrient dosage was calculated strictly based on food intake and absorption rates in humans, the nutrient delivery patterns were not fully representative of human food consumption. 

Source: Xihao Du, Shuo Jiang et al. "Combined effects of vitamin E and omega-3 fatty acids on protecting amb ient PM2.5-induced cardiovascular injury in rats." Chemosphere.