It probably comes as no surprise that being overweight can hurt emotionally, but did you know it also can be physically painful?
As adipose tissue – what we call fat – expands, it gets infiltrated with immune cells that can increase and worsen inflammation both in that fat tissue and throughout the body. To combat this effect, nutritionists have long recommended healthy foods, such as eating berries and cherries or omega-3 fatty acid-rich fish or fish oil, both of which have been shown to reduce inflammation.
Now, thanks to a $500,000 grant from the National Institute of Food and Agriculture, part of the U.S. Department of Agriculture (USDA), a team of researchers in the Texas Tech University Department of Nutritional Sciences and Obesity Research Cluster is working to determine whether consuming the two together could be even more beneficial, and if so, how.
“The reason for choosing these two dietary compounds is that we and other researchers have shown that, individually, they greatly reduce inflammation and the fat accumulation that accompanies obesity, both in animal and cell culture models,” said principal investigator Naïma Moustaïd-Moussa, founding director of the Obesity Research Cluster, director of the Nutrigenomics, Inflammation and Obesity Research (NIOR) Laboratory and a President’s Excellence in Research Professor in nutritional sciences. “Specifically, we are looking into the effects of fish oil and tart cherries on fat cells and immune cells, which trigger and contribute to inflammation.
“We expect that, at lower doses than when individually consumed, the combination of tart cherries and fish oil will reduce obesity and related inflammation and will improve overall metabolic health in those with obesity.”
Separately, fish oil is well known to reduce triglycerides, even to the extent that it is currently prescribed for people with high triglycerides. Anthocyanins, the beneficial chemicals found in tart cherries, are known for their high antioxidant capacity. Many beneficial effects of tart cherries have been described by others, including reductions in blood pressure, oxidative stress and inflammation, and improvements in memory and protection in exercise-induced muscle damage.
“Based on preliminary data we generated for this project, the individual protective effects of omega-3 fatty acids and tart cherries are amplified when combined, even at lower amounts, than when tested individually,” Moustaïd-Moussa said. “During the performance of this project, we will further dissect the mechanisms by which these food components work to reduce inflammation.”
The bigger picture
For decades, Moustaïd-Moussa’s research has focused on a potential role for fatty tissue in triggering and/or exacerbating obesity and associated co-morbidity. Her research has significantly contributed to scientists’ understanding of the important part adipose tissue plays, impacting not only fat cell expansion but also the whole body’s internal stability.
“As obesity develops, whether it is genetic or high caloric diet-induced obesity, the expanding adipose tissue gets infiltrated with immune cells, which increase and worsen inflammation locally in the fat tissue, but also whole body/systemic inflammation in the blood stream,” Moustaïd-Moussa said. “This occurs because the inflammatory substances that fat tissue secretes, called adipokines or cytokines, interfere with many of the body’s functions. For example, they may impact how well muscle takes up glucose and how well insulin works to help muscle utilize that glucose.
“So, in the presence of high levels of these inflammatory substances coming from the fat, there is whole body, systemic inflammation as these molecules circulate through the blood stream. This causes more glucose to stay in the blood, because it is not taken up by muscle or because insulin is not able to get muscle to utilize it, or insulin is not able to stop the liver from producing and releasing glucose. All of this ultimately leads to more glucose in the bloodstream, hyperglycemia – high blood sugar – and type 2 diabetes.”
During this three-year project, Moustaïd-Moussa and her team will conduct cell studies to test the effects of omega-3 fatty acids and tart cherries individually and in combination on immune cells and fat cells from mice and humans.
“We also will test the effects of these compounds in mice with high-fat-diet-induced obesity to determine whether the combination is beneficial compared to individual dietary supplementation in reducing obesity, the above described inflammation and metabolism,” Moustaïd-Moussa said.
Working with Moustaïd-Moussa are co-investigator Latha Ramalingam, a research assistant professor in the NIOR Laboratory in nutritional sciences; consultant Kate Larson, a USDA Agricultural Research Service scientist and acting research leader at the Grand Forks Human Nutrition Research Center; and John Dawson, an assistant professor in nutritional sciences, who will provide expertise in data analyses. Last year, Jung Han Kim, a professor in the Marshall University Joan C. Edwards School of Medicine, joined the project to provide additional genetic expertise.
Initial funding for this project was provided in part by startup funds from Texas Tech, and internal funds from the Come ‘N’ Go Domestic Research Collaboration Seed Grant Program in the College of Human Sciences helped expand the collaborations with Larson and Kim.
“For the public, it is important to know what food combinations provide added benefits beyond individual ones,” Moustaïd-Moussa said. “More of this type of research is needed to understand the benefits of diversifying your diet and how different components in our diets work together to benefit our health.”