Ultraprocessed foods may increase risk for glaucoma

Key takeaways:

• In subgroup analyses, the association between glaucoma and UPFs was significant in men and older adults.
• High blood glucose levels from UPF consumption may explain the findings, researchers said.

Higher consumption of ultraprocessed foods, particularly sweets, was associated with an increased risk for glaucoma, a study published in Nutrients showed.

Ultraprocessed foods, or UPFs, have previously been linked to several negative health outcomes, like higher risks for CVD, all-cause and cancer mortality as well as depression.

Meanwhile, “there is growing recognition of the impact that modifiable environmental factors, such as nutrition, exercise, and lifestyle can have on the development of glaucoma,” José Francisco López-Gil, PhD, a senior researcher at Universidad de Las Américas in Mexico, and colleagues wrote. “Due to the limited strength of evidence linking diet to glaucoma, further research is necessary to make these findings applicable to clinical practice.”

The researchers examined a sample of 19,225 participants (mean age, 38 years; 60.1% women) who were enrolled in a large prospective cohort study known as the Seguimiento Universidad de Navarra, or SUN, Project. They analyzed the participants’ dietary intakes with a 136-item food-frequency questionnaire over a mean follow-up period of 12.9 years.

Overall, the researchers found that those who had higher UPF consumption were typically younger and had higher caffeine and energy intake. In addition, they identified 230 new glaucoma cases during the follow-up period.
López-Gil and colleagues reported that participants who consumed more than four UPF servings per day were at higher risk for glaucoma compared with participants who consumed up to one UPF serving per day (HR = 1.84; 95% CI, 1.06-3.21).

However, in subgroup analyses, the association was found in only:

• adults aged 55 years and older;
• men;
• those in the most physically active group;
• former or nonsmokers;
• those with a low energy intake; and
• those with a low omega-6/omega-3 ratio.

When analyzing UPF subgroups — like fried foods, fast foods or dairy products —individually, only sweets showed a significant risk effect (HR = 1.52; 95% CI, 1.08-2.14).

A potential reason behind the findings “could lie in the increase in blood glucose levels caused by higher UPF consumption,” López-Gil and colleagues explained.

“High blood sugar levels, along with oxidative stress and limited cell division in many eye tissues, can lead to the formation and accumulation of advanced glycation end products, which can cause damage to eye tissues,” they wrote. “UPF consumption is also a major source and contributor of dietary advanced-glycation end products. As a result, eye tissues become susceptible to damage caused by glycation.”

There were a couple study limitations, according to the researchers. For example, because of the study’s observational design, “it is not possible to disregard the possibility of residual confounding, as there may be unmeasured confounders,” they wrote.

López-Gil and colleagues concluded that the findings underline the importance of monitoring and limiting UPF consumption, “especially those rich in sugar,” for preventing glaucoma.

“Given the increasing trends of UPF consumption in our society, promoting adherence to an unprocessed or minimally processed food pattern should be encouraged,” they wrote. “We consider that UPFs can be easily identified, so the advice of limiting their intake for promoting glaucoma health in the clinical consultation can be straightforward.”