Can a Low-Fat Diet Reverse Neuropathic Pain?

By Pat Anson, PNN Editor

Low fat diets are often recommended for people suffering from obesity and cardiovascular disease, but changes in eating habits are rarely recommended for people who live with chronic pain.

That could be changing thanks to a new study by researchers at the University of Texas Health Science Center, who found that diets high in omega-6 fats are strongly associated with inflammation and neuropathic pain. Omega-6 fats are widely found in typical Western diets of fast food, processed snacks, cakes, and fatty or cured meats.

Conversely, researchers say foods containing healthy omega-3 fatty acids – such as fish, flaxseed and walnuts – could reduce or even reverse neuropathic pain associated with diabetes. Their findings were recently published in the journal Nature Metabolism.

Diabetic neuropathy is a progressive and painful disease that causes burning or stinging sensations in the hands and feet. Many drugs used to treat neuropathic pain, such as gabapentin and pregabalin, often don’t work or have unpleasant side effects.

“This paper is a high-profile contribution for a huge unmet translational need as there are no treatments altering the nature of this neurological disease,” said José Cavazos, MD, director of the South Texas Medical Scientist Training Program at UT Health San Antonio.

In experiments on humans and laboratory animals, UT researchers found that mice fed a diet high in omega-6 polyunsaturated fats became hypersensitive to pain, cold and heat stimulation – signs of peripheral nerve damage. Lowering the amount of omega-6 fats and increasing omega-3 fatty acids reduced pain sensitivity in the mice.

The researchers also found that high levels of omega-6 lipids in the skin of patients with Type 2 diabetes were strongly associated with neuropathic pain and the need for analgesic drugs.

“We believe that these data warrant continued investigation of peripheral fatty acid and metabolite levels as potential pain biomarkers. Such biomarkers could provide clinicians with reliable objective endpoints to guide diagnoses as well as decision making on treatment regimens, including therapeutic diets,” wrote lead author Jacob Boyd, MD, UT Health San Antonio.

About 34 million people in the U.S. have diabetes and about half have some form of neuropathy, according to the American Diabetes Association.

A 2015 study found that a vegetarian diet coupled with vitamin B12 supplements significantly reduced pain and improved the quality of life of people with diabetic neuropathy. Participants also had lower blood pressure and cholesterol levels, and lost an average of 14 pounds.

Can Fish Oil Supplements Help Prevent Lupus?

By Pat Anson, Editor

Taking fish oil supplements could help prevent lupus and other autoimmune diseases, according to animal studies at Michigan State University.

Researchers gave female mice genetically disposed to lupus an omega-3 fatty acid called DHA, or docosahexaenoic acid, which is found in fatty, cold-water fish. The findings, published in PLOS ONE, were “overwhelmingly positive,” according to researchers.

“What we discovered was when lupus was triggered by crystalline silica, a toxic mineral also known as quartz that’s linked to human autoimmunity, DHA blocked the activation of the disease,” said Melissa Bates, one of the study’s lead authors and a doctoral student in MSU’s Department of Food Science and Human Nutrition and the Institute of Integrative Toxicology.

Lupus is a genetic disease that can be triggered by inhaling crystalline silica and by other environmental factors such as sun exposure. Quartz is the most common, and most dangerous form of crystalline silica, and is often found in the agriculture, construction and mining industries, where workers can breathe in the mineral dust.

“Lupus is the body’s immune system attacking itself and it can damage any part of the body including skin, joints and organs,” said James Pestka, an MSU professor of food science and human nutrition.

The study looked at the effect of DHA on lupus lesions in the lungs and kidneys of laboratory mice.  

“Ninety-six percent of the lung lesions were stopped with DHA after being triggered by the silica,” said Jack Harkema, a pulmonary pathologist. “I’ve never seen such a dramatic protective response in the lung before.”

Harkema says the DHA could be changing the way lung cells, also known as macrophages, react to the silica and somehow alter the immune system’s response.

“Cells in the lung can gobble up the silica, but it’s so toxic, it kills these cells,” Harkema said. “When they die, signals are sent out to the immune system that something is wrong. The body then produces such a strong response that it also starts to target healthy cells.

“Our next step is to figure out exactly what’s happening,” he said.

One theory is the DHA helps cells send an anti-inflammatory signal to the body so it doesn’t overcompensate and trigger an autoimmune response. Another is that DHA allows the cells to swallow up and remove the toxic silica from the lung without dying, preventing any inflammatory signals from being sent.

“What we do know is this study is a clear indication that eating DHA can prevent this one type of environmental triggering of lupus,” Pestka said. “It can suppress many of the disease’s signaling pathways, which current drugs on the market now try to target and treat.”

The National Institute for Environmental Health Sciences and the Lupus Foundation of America funded the MSU research.

DHA is produced by the algae that cold water fish eat and store in their bodies. It can also be found in fish oil supplements, which are used by more than 30 million Americans.

Previous studies have found that fish oil lowers an inflammatory response associated with autoimmune diseases. Fish oil may also help prevent cardiovascular disease and hypertension, although consuming large amounts of it may increase the risk of internal bleeding or stroke.