Fructose puts you at risk of wide range of diseases

Washington D.C.: Just when you thought fruit sugar is a healthier way to sweeten things, a team of researchers found that fructose actually wreaks havoc on your health.

The UCLA scientists found that fructose may damage genes in the brain, playing a role in changes in the brain linked to diseases ranging from diabetes to cardiovascular disease and from Alzheimer's disease to attention deficit hyperactivity disorder.

However, the researchers discovered good news as well: An omega-3 fatty acid known as docosahexaenoic acid, or DHA, seems to reverse the harmful changes produced by fructose.

Senior author Xia Yang said that DHA changes not just one or two genes; it seems to push the entire gene pattern back to normal, which is remarkable. "And we can see why it has such a powerful effect."

DHA occurs naturally in the membranes of our brain cells, but not in a large enough quantity to help fight diseases. "The brain and the body are deficient in the machinery to make DHA; it has to come through our diet," said co-senior author Fernando Gomez-Pinilla.

DHA strengthens synapses in the brain and enhances learning and memory. It is abundant in wild salmon (but not in farmed salmon) and, to a lesser extent, in other fish and fish oil, as well as walnuts, flaxseed, and fruits and vegetables, said Gomez-Pinilla, who also is a member of UCLA's Brain Injury Research Center.

Of the 900 genes they identified, the researchers found that two in particular, called Bgn and Fmod, appear to be among the first genes in the brain that are affected by fructose. Once those genes are altered, they can set off a cascade effect that eventually alters hundreds of others, Yang said.

That could mean that Bgn and Fmod would be potential targets for new drugs to treat diseases that are caused by altered genes in the brain, she added.

The research also uncovered new details about the mechanism fructose uses to disrupt genes. The scientists found that fructose removes or adds a biochemical group to cytosine, one of the four nucleotides that make up DNA. This type of modification plays a critical role in turning genes "on" or "off." The research is published online in journal EBioMedicine.