Scientists talked about the possible effect of feijoa on blood pressure
Whole feijoa fruit powder can help lower upper blood pressure in people participating in a weight loss program. Preliminary data on this was obtained by researchers at the University of Auckland in New Zealand. However, they did not confirm the additional effect of the product on weight loss or blood sugar levels. How the test took place and why its results cannot yet be considered proof of the therapeutic effect of feijoa — in the material of Izvestia.
What the scientists wanted to test
The study was devoted to the possible prevention of type 2 diabetes. The researchers tested whether daily intake of feijoa powder would help improve the results of a weight loss program, including reducing blood glucose levels. The trial included 97 overweight or obese adults who were identified as having prediabetes.
Prediabetes is a condition in which the blood sugar level is already higher than normal, but has not yet reached the values that make it possible to diagnose diabetes. It is associated with an increased risk of developing the disease.
The researchers assumed that the substances in feijoa could complement the effect of dietary changes. However, the most noticeable result was related to another indicator — blood pressure.
Why was feijoa specifically investigated?
Scientists' interest in feijoa is related to the biologically active substances it contains, including polyphenols. This is a large group of plant compounds whose effect on metabolism and vascular health is being studied by researchers.
The presence of such substances in fruits does not in itself mean that the product is capable of treating the disease. To test the possible effect, human trials are needed — this is exactly the task that the authors of the study solved.
How did the test go?
The participants were randomly divided into two groups. In the first, 48 people received 1.15 g of whole feijoa fruit powder daily, in the second, 49 people took a placebo, a comparison product that did not contain the studied component.
The trial lasted six months. For the first two months, the participants lost weight using a low-calorie program that included replacing regular meals with special products. The next four months were devoted to maintaining the achieved result.
What has changed among the participants
In both groups, weight decreased in the first two months. Later, some of the lost weight gradually returned. The researchers did not find an additional advantage of feijoa powder over placebo in this indicator. No additional effect on fasting blood sugar levels has been confirmed.
However, in the main analysis, systolic blood pressure decreased more in feijoa users than in the comparison group. Differences between the groups were observed at the fourth and sixth months.
Systolic pressure is the upper number in the blood pressure monitor readings. For example, with a result of 120/80, it is 120 mmHg. This indicator reflects the pressure of blood on the walls of the arteries at the time of heart contraction. The lower number, or diastolic pressure, characterizes the pressure between contractions when the heart relaxes. For lower blood pressure, there was no additional improvement in its dynamics over six months compared with placebo.
Why the conclusions remain preliminary
The effect on pressure was not the same for different methods of analysis. When the scientists separately examined the participants who initially did not have high blood pressure, the additional decrease on the background of feijoa was not confirmed.
"This is not what we were going to find, but the result is interesting and definitely deserves further study," said Ibrahim Mohamed, a researcher at the Department of Human Nutrition at the University of Auckland.
This may mean that the overall outcome was primarily related to participants with hypertension. However, the authors admit another explanation: there were too few people in a particular subgroup to reliably identify the differences. Larger trials are needed for the final conclusion.
The data obtained also cannot be automatically transferred to the consumption of fresh feijoa. In the test, a certain powder was tested in a prescribed amount and simultaneously with a weight loss program. Therefore, the study still provides grounds to continue studying the product, but does not allow us to recommend fruits or supplements as a treatment for high blood pressure.
Переведено сервисом «Яндекс Переводчик»
