In a recent study published in the journal BMJ Open Diabetes Research & Care, researchers extolled the virtues of a regular meal rich in walnuts. Does it make sense for us all to consume more Waldorf salad?
For a long time, walnuts were thought to provide a wide range of health advantages; however, substantial research on the majority of these claims has yet to be published.
A recent trial, on the other hand, sought to investigate the effects of a walnut-rich diet on a variety of health parameters, including cholesterol levels, total weight, and the nutritional content of the diet.
According to the findings of the study, eating walnuts on a regular basis leads to an improvement in blood vessel wall (epithelial) function as well as a reduction in cholesterol levels.
In addition, the trials revealed that walnuts had little or no influence on a variety of other measures, including blood pressure.
Many dietitians consider the walnut to be a nutritious meal, despite the fact that it is not technically a nut in the traditional sense. Walnuts are a dense and fatty food that contains approximately 15% protein and a whopping 65% fat by weight, making them a high-protein and high-fat food.
Previous research has suggested that walnuts may have the ability to delay prostate cancer growth, lower cholesterol levels, improve insulin sensitivity, and lower levels of IGF-1 (implicated in prostate and breast cancer). Others have asserted that walnuts lower blood pressure, reduce oxidative stress, and lower inflammatory indicators in the body.
Despite the fact that some of the health claims are more believable than others, the present study – conducted by Dr. David Katz at Yale University Prevention Research Center, Griffin Hospital in Connecticut – sought to look into some of the claims in further depth.
The experiment included 112 participants, 31 men and 81 women, ranging in age from 25 to 75, all of whom had a high risk of acquiring diabetes. The participants were divided into two groups for the purpose of this activity. The difference between the two groups was that one received therapy to help them lose weight and the other did not.
Individuals were randomly divided into two subgroups within each of the groups, and this was repeated within each group. In the first grouping, participants ingested 56 g of walnuts each day, while in the second, they abstained from walnut consumption for six months. After a three-month pause, the intervention arms were switched back to their original positions.
In the beginning of the experiment, as well as after three, six, twelve, and fifteen months, the participants were evaluated for a wide range of markers.
Dietary intake, weight, height, body mass index (BMI), waist circumference, blood pressure, fasting blood glucose (glucose measured after 8 hours of fasting), cholesterol, and HbA1c (glycated haemoglobin – this marker provides an indication of average glucose levels over prolonged periods) were the markers used.
Does walnuts really work?
After taking into account variables such as age, the amount of regular activity performed, and the number of calories and fat consumed, the researchers came to the conclusion that walnuts were related with a higher overall quality of diet.
Importantly, the participants in the study who took the walnuts appeared to have better epithelial function, according to the findings. In addition, the researchers discovered a decrease in LDL (bad) cholesterol.
It was discovered that these beneficial benefits were independent of whether or not calorie intake was restricted or not.
In contrast, and perhaps unsurprisingly given their calorie intake, those on uncontrolled diets who consumed walnuts on a daily basis experienced a rise in total body fat. While on a calorically limited diet, however, their waist circumference shrank by an impressive amount.
Adding walnuts to the participants’ diets had no significant influence on blood pressure, blood glucose, or HDL (good) cholesterol levels; nevertheless, HbA1c levels increased in both types of diet, independent of whether or not the participants were receiving nutritional counselling.
The researchers come at the following conclusion:
“Our data suggest that inclusion of walnuts in the diet, with or without dietary counseling to adjust caloric intake, improved diet quality and may also improve [endothelial function], and reduce total and LDL cholesterol in this sample of adults at risk for diabetes.”
Keep in mind that the California Walnut Commission funded this research, and the researchers believe that additional research will need to be undertaken before any firm conclusions can be drawn. It will be important to do additional research with a broader range of persons in order to present a complete picture.