New research indicates that resistant starch may positively affect metabolism.
According to a study published today in the journal Cell Metabolism, this type of starch could also help reduce liver injury and inflammation, lowering the risk of developing non-alcoholic fatty liver disease (NAFLD).
In their study, researchers recruited 200 people with NAFLD. They provided the participants with a balanced diet designed by a nutritionist.
Half of the participants received a resistant starch powder derived from maize. The other half received a calorie-matched, non-resistant corn starch.
The scientists instructed both groups to drink 40 grams of the starch mixed with 300 milliliters (1 ¼ cups) of water before meals twice a day for four months.
What the study on starch and liver disease revealed
After four months, researchers reported that the group that received the resistant starch treatment had almost a 40% lower liver triglyceride level compared to people in the control group.
They also had reduced liver enzymes and inflammatory factors associated with NAFLD.
The improvements remained when the scientists statistically adjusted for weight loss.
In the second stage of this study, the researchers analyzed fecal samples from the participants. They found the resistant starch group had a different microbiota composition. The treatment group had a lower level of Bacteroides stercoris, a type of bacteria that can affect fat metabolism in the liver.
The researchers transplanted fecal microbiota from the resistant starch treatment participants to mice with a high fat, high cholesterol diet. The researchers reported that there was a significant reduction in liver weight and triglyceride levels and improved liver tissue grading in the mice compared to those that received microbiota from the control group.
“This study provides a very interesting mechanism on the potential role of the gut microbiome and fatty liver disease,” Dr. Hardeep Singh, a gastroenterologist with Providence St. Joseph Hospital in Orange in California who was not involved in the study, told Medical News Today.
“It does provide some promising results. However, the data is very preliminary and, at this point, not something I would recommend to patients as a treatment option for fatty liver disease. Further study is required,” he added.
A buildup of fat in the liver can cause NAFLD. This can lead to severe liver disease and contribute to other medical conditions, such as type 2 diabetes and cardiovascular disease.
These conditions also make you more likely to develop NAFLD.
“Treatment options for fatty liver disease are limited at this time,” Singh said. “Unfortunately, currently, there are no medications that have been proven to be effective for this condition. Weight loss via diet and lifestyle modification is the mainstay of therapy.”
“A study showed that weight loss for morbidly obese patients via bariatric surgery can reduce fatty liver disease and scarring in the liver,” Singh added. “Multiple studies, such as this one and this one, have confirmed that 2 to 3 cups of coffee per day is effective at reducing fat and scarring in the liver in patients with fatty liver disease. We do advocate for coffee intake in patients who can tolerate 2 to 3 cups of coffee per day. The coffee has to be regular black coffee and not decaf. A few studies have documented improvement in fatty liver disease using vitamin E 800 units per day. This can be considered in select patients.”
Ways to help prevent NAFLD
NAFLD is an accumulation of fats in the liver. Sometimes, these cause injury, inflammation, or fibrosis.
These effects can sometimes be avoided by maintaining a healthy lifestyle, according to the Ohio State University, Wexner Medical Center. Following the Mediterranean diet could help, as well as monitoring your intake of simple sugars.
“In some specific situations, fatty liver disease may be prevented,” Singh said. “What I mean by this is if you are obese or overweight, that will lead to insulin resistance and eventual metabolic syndrome. That is a precursor to fatty liver disease. In some patients, this can be modified and altered with lifestyle modification. Therefore, if those patients become more active and lose weight, their insulin resistance can be reduced, and they may not develop fatty liver disease.”
“However, in another subset of patients with more aggressive genetics, I don’t believe fatty liver disease can be prevented,” he added. “For example, just as we have skinny patients who develop diabetes, there are a subset of patients with fatty liver disease who have a normal body mass index and no risk factors for metabolic syndrome. In those patients, the condition cannot be prevented as it appears they have a genetic predisposition.”
“Resistant starch is a type of carbohydrate that acts more as a fiber than a starch,” according to Caroline Thomason, RD, CDCES, a dietitian based in Washington, D.C., who was not involved in the study. “It is digested slowly and has positive health applications for diabetes, heart disease, and digestive health.”
“Anywhere between 20 grams to 50 grams of resistant starch has been studied in the research with the few side effects,” Thomason told Medical News Today. “Too much resistant starch may cause some gas and bloating in sensitive folks.”
“Foods with resistant starch are often cooked – then – cooled carbohydrates,” she added. “This means if you cook white rice, let it cool in the fridge, and reheat it later as part of a meal, you will benefit from resistant starch. You may find that your blood sugar doesn’t rise quickly, and you feel fall longer, in addition to any other potential health benefits of resistant starch.”
There isn’t a recommended daily allowance for resistant starches. Experts note that it is healthy to get fiber from a wide range of sources so that you have soluble, insoluble, and resistant starches every day.
According to Anne Danahy, MS, RDN, a Scottsdale, Arizona-based registered dietitian and integrative nutritionist, good sources of resistant starch include:
- legumes (especially lentils)
- cooked and cooled potatoes and rice (I love potato or rice salads for a good source)
- overnight oats
- green bananas
- whole grains
– Medical News Today
Written by: Eileen Bailey
Fact checked by: Jill Seladi-Schulman
How resistant starch may help people with non-alcoholic fatty liver disease