While walnuts, almonds, and pecans have already been found to reduce the risk of cardiovascular disease, Penn State researchers are currently working on showing that pistachios are heart healthy, too. xxlPistachios are also a source of plant sterols, which help to lower cholesterol, and antioxidants, which help to reduce oxidation and inflammation.
High cholesterol and high oxidation and inflammation in the body increase the risk of cardiovascular disease. Pistachios are also low in saturated fat and high in unsaturated fat.
Through a study being conducted by nutrition professor Penny Kris-Etherton, it is believed that pistachios' specific antioxidant content and fatty acid profile will be found to help reduce the risk of cardiovascular disease.
"There have been similar studies with almonds and walnuts that have found beneficial cholesterol lowering effects, so our study is trying to see if adding pistachios to the diet can have beneficial effects on cardiovascular disease risk factors," said Sarah Gebauer (graduate-molecular medicine).
"There are antioxidants in pistachios, so we're trying to see if incorporating pistachios in the diet can reduce oxidation," Gebauer said.
Researchers are confident that pistachios are heart healthy. They think the more pistachios a person eats, within reason, the lower that person's risk of cardiovascular disease.
Colin Kay, postdoctoral fellow, said the general public believes nuts are high in fat and unhealthy. To prove the positives of pistachios, the researchers are conducting their study with controlled feeding trials.
"Studies of this nature are very time consuming and very expensive to run, and this is where we give the subjects 100 percent of what they eat every day for the duration of the trial," Kay said.
The benefits of pistachios can be had either by eating the nuts alone or by incorporating them into other foods, said Dee Bagshaw, clinical coordinator. Pistachios can be detrimental to someone who eats too many of them or is allergic to them, Bagshaw said.
"They contain lots of good kinds of fat, but you do have to pay attention to how many calories you're eating," Bagshaw said.
The study is being conducted with 28 men and women with moderately high cholesterol. The nutrition department and the General Clinical Research Center are housing the study, Bagshaw said. The study has been running for about nine months and will end in March.
"To our knowledge, there hasn't been a controlled feeding study with pistachios looking at cholesterol levels and other cardiovascular disease factors that we're looking at in this study," Gebauer said.
Additionally, new research on the relationship between cardiovascular disease and inflammation is prompting the researchers to pay special attention to pistachios' specific antioxidant content, whereas the studies on walnuts, almonds, and pecans may not have taken antioxidant content into consideration, Kay said.
Currently, pistachios are not available in residential dining facilities, and the outcome of the study will not determine if they are made available in the future.
"Menu items are added to our program if the demand is there by the customer," said Lisa Wandel, associate director of food services.
Wandel expressed concern over the cleanliness of a dining facility offering pistachios. She said that food services is hesitant to offer shelled nuts because the shells tend to end up on the floor and buying pistachios without shells would be costly, she said.
However, this fall food services began stocking its salad bars daily with nuts that were only offered sometimes in the past, said Lori Nicolini, staff assistant, food services. Sliced almonds, walnut pieces, cashew pieces and roasted soy nuts are offered, as well as two trail mixes that contain nuts.
