By Stephanie Stahl

PHILADELPHIA (CBS) — There’s more evidence that eating a lot of processed food increases the risk for memory loss and Alzheimer’s disease. The FDA has banned trans fat, but it’s still in all kinds of products.

Scientists say trans fat, found mainly in processed food, impacts blood flow and can reduce serotonin production, leading to depression and memory loss.

Even though it’s being fazed out, trans fat is still in coffee creamer, popcorn and all kinds of snacks and frozen foods.

Hydrogenated oil used to increase shelf life has been linked to heart disease, and now there’s more evidence that trans fat increases the risk for Alzheimer’s disease.

The new study covered 1,600 people over the age of 60, who had normal brain function.

Researchers measured the levels of trans fats in their blood, as well as their overall health and diet, and followed up after 10 years.

“What they see is that having higher levels of trans fat in the blood increases your risk of onset of dementia – whether it’s from Alzheimer’s disease as a cause of dementia, or other kinds of dementia,” Dr. Jagan Pillai said.

After adjusting for other dementia risk factors — such as high blood pressure, diabetes and smoking — the researchers found the dementia risk was 52% more likely among those with the highest levels of trans fat.

The best way to avoid trans fat is to eliminate or reduce eating processed food.

A healthy diet of whole grains, produce and healthy fat can have a protective effect on the risk of developing dementia.

“This research clearly demonstrates that your diet and what you’re putting in your body has an impact on the onset of dementia later on in life,” Pillai said.

Even though it’s technically banned, experts say foods with less than a half-gram of trans fats can be labeled as containing zero.

So if you eat a lot of processed food, that trans fat accumulates and can cause dementia and other problems.

Stephanie Stahl