Low-fat diet linked to improved metabolic health
MedWire News: A low-fat diet may reduce risk for the metabolic syndrome among postmenopausal women, report researchers.
Decreased fat intake may also reduce such women's need to use antihypertensive and cholesterol-lowering medications.
"Data from NHANES (National Health and Nutrition Examination Survey) suggest that 34% of all US adults meet the criteria for metabolic syndrome and the prevalence is six times greater in women over the age of 60 compared with younger women," note Marian Neuhouser (Fred Hutchinson Cancer Research Center, Seattle, USA) and colleagues.
The team examined whether the low-fat diet used in the Women's Health Initiative Dietary Modification (WHI-DM) trial influenced the risk for the metabolic syndrome among a subsample of 2816 postmenopausal women who were assessed for five individual components of the metabolic syndrome at baseline and during follow up.
The participants, who originally derived at least 32% of their total energy intake from fat, were randomly assigned to follow either a low-fat diet (intervention diet), which was designed to reduce energy intake from fat to 20% or less, or their usual diet (control diet).
The women in the intervention group received intensive nutritional and behavioral modification therapy during 18 group sessions held throughout the first year of the trial, followed by quarterly refresher sessions thereafter. Participants self-monitored their food intake throughout the intervention, which lasted for a mean of 8.1 years.
The women on the usual diet were sent the Dietary Guidelines for Americans, but had no contact with the nutrition interventionists and were not asked to self-monitor or make specific dietary changes.
Blood pressure, waist circumference, fasting blood glucose, high-density lipoprotein cholesterol, and triglycerides were assessed at baseline and at 1, 3, and 6 years after randomization.
As reported in Metabolism, linear regression analysis that simultaneously modeled the five risk components showed that following the intervention diet was significantly associated with a reduced risk for the metabolic syndrome at 1 year, but not at 3 and 6 years.
When analyses were restricted to only women who adhered to the intervention (attended ≥9 sessions in year 1 and ≥2 in subsequent years), the overall intervention effect remained highly statistically significant at 1 year and was of borderline significance at 3 and 6 years.
Furthermore, the researchers found that at year 1, women on the intervention versus usual diet were a significant 19% less likely to use cholesterol-lowering or antihypertensive medications.
"If confirmed using long-term data then the findings… will have important and relevant translational potential," conclude the researchers.
By Sally Robertson