Lisa Nainggolan | Disclosures
SAN FRANCISCO — Improving the quality of food consumed was associated with a significant 10% reduction in risk for type 2 diabetes among healthy adults, while a worsening diet had the opposite effect, boosting the chance of developing diabetes by about 20%, new observational research shows.
“Improving diet quality could be helpful in diabetes prevention — changing your diet matters,” lead author Sylvia H Ley, PhD, of the department of nutrition at the Harvard School of Public Health, Boston, Massachusetts, told a press conference here at the American Diabetes Association (ADA) 2014 Scientific Sessions.
Dr. Ley presented her findings during an oral session today, and while she acknowledged the outcomes were perhaps not rocket science, she ventured: “Healthy eating is still somewhat abstract, and people have difficulty understanding what better-quality eating means. Whole grains, fruits and vegetables, and nuts and seeds are all healthful, and these were not huge changes [to make].”
Moderator of the press briefing, diabetes educator Melinda Maryniuk, RD, from the Joslin Diabetes Center, Boston, Massachusetts, said: “This is known, but isn’t it great to have more science to prove what we know makes sense?
“An improved quality of diet really does matter, [as does] getting that message — what we mean by quality nutrition — out to people.”
Dr. Ley said they also found that diet was associated with diabetes “independent of weight loss and increased physical activity,” indicating that “improving diet quality alone has significant benefits.”
Ms. Maryniuk added to Medscape Medical News: “It’s exciting that we don’t have to put as much focus on weight loss, which can feel so frustrating to patients because so often it’s not successful. Whereas making small changes and improving the quality — whether it’s whole grains or more fruit and vegetables, or less saturated fat — really can make a significant difference in reducing the risk for getting type 2 diabetes.”
For Better, for Worse: Both Changes Have an Impact
Dr. Ley explained that while randomized controlled trials have shown that lifestyle changes can prevent or delay type 2 diabetes in individuals at high risk, it has not been clear that improving diet quality would be associated with a reduced risk for diabetes among healthy adults.
So she and her colleagues looked at those who changed the quality of the food they ate, for better or worse, during a 4-year period and examined the impact of these changes on subsequent 4-year type 2 diabetes risk among 3 observational cohorts of men and women: the Nurses’ Health Study (NHS) I (1986–2010), NHS II (1991–2011), and the Health Professionals Follow-up Study (1986–2010).
The Alternative Health Eating Index 2010 score was used to assess diet quality and comprised 11 variables, Dr. Ley explained, including consumption of red meat; nuts; sugar-sweetened beverages; vegetables; fruits; polyunsaturated fats; trans fats; omega-3 fats (fish); alcohol; whole grains; and sodium.
They documented just over 9000 incident cases of type 2 diabetes during almost 2,500,000 person-year follow-up.
A greater than 10% decrease in diet quality score over 4 years was associated with an almost 20% higher subsequent diabetes risk (pooled hazard ratio [HR], 1.18 with multiple adjustment).
Conversely, an improvement of 10% in dietary score was associated with a lower risk for type 2 diabetes (pooled HR, 0.91).
“So the message is, there is impact on both ends,” Dr. Ley observed.
And Where You Start Doesn’t Matter
She and her colleagues also looked at starting points and whether being on a poor-, medium-, or high-quality diet to begin with had a bearing on the results.
“We learned that at all these different starting points, people who improved their intake had an improvement in their diabetes incidence. This shows that regardless of where you start, improving your diet quality is helpful to diabetes prevention,” she observed.
And, she noted, most people were eating a very poor-quality diet to begin with; “this is what people were doing naturally.”
Dr. Ley and Ms. Maryniuk have reported no relevant financial relationships.
American Diabetes Association 2014 Scientific Sessions; June 14, 2014. Abstract 74-OR
