2-year study reveals that carotid artery atherosclerosis reduction is due to weight loss-induced decline in blood pressure from either low-carbohydrate, low-fat or Mediterranean diets
A two-year study led by researchers at Ben-Gurion University of the Negev (BGU) found that healthy, long-term weight loss diets can significantly reverse carotid (main brain artery) atherosclerosis, a direct risk factor for strokes and heart attacks. The study is one of the first to prove the potential of moderate weight loss as a strategy to reverse atherosclerosis (hardening of the arteries) in overweight and mildly obese people.
According to the just published study in Circulation, the leading journal of the American Heart Association, the researchers used novel technique imaging of three-dimensional ultrasound at the beginning and after two years, measuring changes in carotid artery vessel thickening of plaque to determine whether diet can reverse atherosclerosis, a process that naturally increases with age.
The research team compared three diets among moderately overweight, mostly male, participants. The findings, using ultrasound, showed that after two years, there was a five percent decrease in average carotid vessel-wall volume and a one percent decrease in carotid artery thickness.
Compared to participants who experienced an increased carotid wall volume, those with decreases showed significantly greater weight loss (11.7 pounds vs. 7 pounds); decreased systolic blood pressure (6.8 mmHg vs. 1.1 mmHg) and an increase in apolipoprotein A1 (Apo A1), a marker of "good cholesterol" ( HDL). These participants also had reduced homocysteine levels, an amino acid in the blood that is related to higher risk of stroke or heart attack.
This study was conducted in Israel by researchers led by Dr. Iris Shai, Ben-Gurion University of the Negev, with the Nuclear Research Center in Dimona and Soroka University Medical Center in Beer-Sheva.
According to Dr. Shai, "Even if we experience some partial weight re-gain over time, long-term adherence to weight loss diets are effective for reversing carotid atherosclerosis as long as we stick to one of the current options of healthy diet strategy. This effect is more pronounced among mildly obese persons who lose more than 5.5 kgs. [12.1 lbs.] of body weight and whose systolic blood pressure decreases by more than 7 mmHg." Dr. Iris Shai is a researcher at the S. Daniel Abraham International Center for Health and Nutrition in the Department of Epidemiology at Ben-Gurion University of the Negev.
Dr. Yaakov Henkin, a cardiologist at Soroka University Medical Center, who led the carotid measurements, explains that "the importance of these results is in the understanding that over two years, changes in carotid atherosclerosis are more strongly predicted by diet-induced changes in blood pressure than by changes in lipoprotein levels, which are commonly believed more important for the coronary arteries."
Researchers studied 140 people (88 percent men, average age 51, Body Mass Index 30.4) who were randomly assigned to a low-carbohydrate, low fat or Mediterranean diet as part of the Dietary Intervention Randomized Controlled Trial-carotid (DIRECT) study.