Field Notes

Chicken Protein May Be More Bioavailable Than Protein From Plant-Based Meat

Plant-based meat alternatives are highly popular, with novel varieties emerging constantly. Plants high in protein, such as soybeans, are common ingredients, but it’s been unclear how much of that protein human cells can absorb.

In the American Chemical Society’s Journal of Agricultural and Food Chemistry, researchers report that proteins in a model plant-based substitute weren’t as accessible to cells as those from meat. The team says this knowledge eventually could be used to develop more healthful plant-based products.

Plant-based meat alternatives often are thought of as more healthful than animal meats because the plants used to make them are high in protein and low in undesirable fats. However, lab tests have shown that proteins in substitutes don’t break down into peptides as well as those from meats. Study authors wanted to go a step further and see whether human cells can absorb similar amounts of peptides from a model meat alternative as they can from a piece of chicken.

The researchers created a model meat alternative made of soy and wheat gluten with the extrusion process. When cut open, the material had long, fibrous pieces inside, just as chicken does. Cooked pieces of the substitute and chicken meat were then ground up and broken down with an enzyme that humans use to digest food.

In vitro tests showed that meat substitute peptides were less water-soluble than those from chicken, and they also weren’t absorbed as well by human cells. With this new understanding, the researchers say the next step is to identify other ingredients that could help boost the peptide uptake of plant-based meat substitutes.

— Source: American Chemical Society

 

Daily Avocado Consumption Linked to Improved Diet Quality, Lower Cholesterol

Eating one avocado a day for six months was found to have no effect on belly fat, liver fat, or waist circumference in people with overweight or obesity, according to a new study. However, it did lead to a slight decrease in LDL cholesterol levels.

In the randomized trial, the team—including Penn State researchers—also found that participants who ate avocados had higher-quality diets during the study period.

While prior, smaller studies have found a link between eating avocados and lower body weight, BMI, and waist circumference, this was the largest, most extensive study to date on the possible health effects of avocados, including the large number of participants and length of the study period.

“While the avocados did not affect belly fat or weight gain, the study still provides evidence that avocados can be a beneficial addition to a well-balanced diet,” says Penny Kris-Etherton, PhD, Evan Pugh University Professor of Nutritional Sciences at Penn State. “Incorporating an avocado per day in this study did not cause weight gain and also caused a slight decrease in LDL cholesterol, which are all important findings for better health.”

Kristina Petersen, PhD, APD, FAHA, an assistant professor of nutritional sciences at Texas Tech University, says the study also found that eating avocados daily improved the overall quality of the participants’ diets by eight points on a 100-point scale.

“Adherence to the Dietary Guidelines for Americans is generally poor in the United States, and our findings suggest that eating an avocado per day can substantially increase overall diet quality,” Petersen says. “This is important because we know a higher diet quality is associated with lower risk of several diseases including heart disease, type 2 diabetes, and some cancers.”

The research—recently published in the Journal of the American Heart Association—was conducted in conjunction with Loma Linda University, Tufts University, and UCLA, with coordinating support from Wake Forest University.

For the study, the researchers conducted a six-month experiment involving more than 1,000 participants experiencing overweight or obesity, one-half of whom were instructed to eat an avocado every day while the other half continued their usual diet and told to limit their avocado consumption to less than two a month. Fat in the abdomen and around other organs was measured precisely using MRI before and at the end of the study.

“While one avocado a day did not lead to clinically significant improvements in abdominal fat and other cardiometabolic risk factors, consuming one avocado a day did not result in body weight gain,” says Joan Sabaté, MD, DrPH, a professor of nutrition and epidemiology at Loma Linda University School of Public Health. “This is positive because eating extra calories from avocados doesn’t impact body weight or abdominal fat, and it slightly decreases total and LDL cholesterol.”

They also found that daily avocados were associated with total cholesterol decreasing 2.9 mg/dL and LDL cholesterol decreasing 2.5 mg/dL.

The researchers say that in the future, they will continue to analyze data from the study. For example, participants weren’t instructed on how to eat their avocados each day, and future research could investigate how participants incorporated the avocados into their diet and whether any differences in the results may be attributed to how participants ate the avocado.

— Source: Penn State University