People with a parent or sibling diagnosed with glaucoma should consider restricting caffeine into the amount in two cups of java per day, says Louis Pasquale, MD, an ophthalmology professor at Mount Sinai Health System in New York City.
“It’s a suggestion,” he states. “It’s not something set in stone, but if you’re interested in reducing your risk of the disease, it’s something I would definitely entertain.”
Pascale and his colleagues reported their findings Ophthalmology.
Glaucoma causes damage to the optic nerve, often from increased pressure from a buildup of fluid inside the eye. It can result in blindness.
The disorder is more common in people with close family members who have it. And scientists have identified variations in multiple genes which are more prevalent in people with glaucoma.
In prior studies, people who take large doses of caffeine have experienced temporary increases in eye strain. So researchers have wondered whether getting caffeine during a lengthy time period could pose a risk.
To help answer that question, Pasquale and his colleagues looked at the records of more than 100,000 people. The documents came in the UK Biobank, a large survey conducted in the United Kingdom. The documents included information on individuals’ genes, how much tea or coffee they drank, their eye pressure, and whether they had glaucoma.
Looking at each of the participants together, the investigators didn’t find any increased risk of glaucoma from caffeine. In fact, they found that people who got the most caffeine really had marginally lower eye pressure.
But when they looked only at people whose genes were associated with glaucoma, they found that caffeine was connected to higher average eye pressure and to a higher risk of glaucoma.
That has been particularly true when they looked at the 25percent of individuals who obtained more than 321 milligrams of caffeine — the equivalent of three cups of coffee — daily. When these individuals were in the very best 25% of hereditary risk for increased eye pressure, they had a higher risk of glaucoma. They were almost four times more likely to have the disease than people who did not eat caffeine and were in the lowest 25% genetic risk.
The researchers found that the mix of genes and caffeine increased the danger of glaucoma more than the genes alone.
The researchers could not find a statistical connection to higher eye pressure or glaucoma to get java, just for tea. But That’s probably Due to a statistical problem, says study co-author Anthony Khawaja,