In the news: Vitamin C Helps Protect Against Pollution; Magnesium Important for Diabetics

Air Pollution Contributes to Chronic Diseases

Exposure to air pollution generated by traffic, wildfires, industrial processes, dust, tobacco smoke and other sources is becoming more common. According to key findings of the American Lung Associations’s State of the Air Report, 131.2 million people in the US lived in areas with unhealthy air pollution in 2024 – 11.7 million more than the previous year.

Exposure to these pollutants, especially fine particulate matter (PM), can make existing diseases worse and increase the risk of developing new ones such as respiratory problems.

Fine PM can irritate and constrict the airways, causing inflammation and worsening asthma and COPD symptoms. Long-term, fine PM, especially PM2.5, can damage the alveoli and lead to lung disease.

Pollution also impacts cardiovascular disease (CVD). Exposure has been linked to heart attacks, strokes and other cardiovascular diseases. It can lead to inflammation and damage to blood vessels and the heart.

A newly published study(1) reports that exposure to air pollutants can also raise the risk of common eye diseases. Nearly 115,000 participants in the UK biobank who did not have preexisting common eye diseases were followed for about 12 years.

Higher levels of air pollutant exposure raised the risk of diabetic retinopathy, glaucoma, retinal detachment and macular degeneration, For some of these eye conditions, air pollution had stronger effects in those with myopia (near sightedness).

Vitamin C May Help Stave off Vessel Damage

Some of the damage to blood vessels from fine PM pollution is thought to come from inflammation and oxidative stress.

Vitamin C is an antioxidant that can support healthy blood pressure and the function of the inner lining of blood vessels, the endothelium. To determine whether vitamin C might have vascular benefits under conditions of pollution, researchers conducted a double-blind, cross-over trial(2) .

Fifty-eight healthy young adults were randomly assigned to receive vitamin C supplements (2,000 mg) daily or placebo for a week. Then, after a 2-week break, the groups crossed over to the other intervention. Average exposure to fine PM (PM 2.5, PM 10) was uniform for all participants.

The researchers found that vitamin C had favorable effects by modestly lowering systolic blood pressure and pulse pressure and causing sizable decreases in inflammatory markers (IL-6, CRP & TNF-alpha).

These results provide preliminary but promising evidence that vitamin C may help stave off vessel damage from air pollution.

Magnesium Shortfall & Diabetic Nerve Pain

Several studies have shown conflicting results regarding the link between magnesium and diabetic neuropathy (nerve damage), a major complication of diabetes and the most common cause of nerve pain.

A new comprehensive review(3) of evidence from preclinical to clinical studies on the link between the mineral and diabetic neuropathy (DR) found that: 1.    Magnesium depletion (low total body levels) is common and linked to DR in both type 1 and type 2 diabetics. 2.    Low concentration of blood magnesium is associated with impaired nerve function and neuropathic symptoms. 3.    Magnesium supplemention has nerve-protective effects and helps restore magnesium levels.

References

1. Wang Z, et al. Associations between ambient air pollution and five common vision-threatening ocular dseases in middle-aged and older adults: A large prospective cohort study. Am J Ophthalmol. Published online March 6, 2025.
2. Ren J, et al. Vascular benefits of vitamin C supplement-ation against fine particulate air pollution in healthy adults: A double-blind randomized crossover trial. Ecotoxicol Environ Safety. 241:113735, 2022.
3. Smithiseth K, et al. Unraveling the link between magnesium and diabetic neuropathy: Evidence from in vitro to clinical studies. Nutr Res. 135:13-31, 2025.