Healthful Diet Staves Off Hypertension in Women with a History of Gestational Diabetes
With commentary by lead study author Cuilin Zhang, M.D., Ph.D., senior investigator at the National Institute of Child Health and Human Development in Rockville, Maryland.
Women who have had pregnancy-related diabetes may be able to reduce their future risk of hypertension by maintaining a healthful diet, new research shows.1
“Our findings send out a hopeful message to women with gestational diabetes,” said the study’s lead author, Cuilin Zhang, M.D., Ph.D., senior investigator at the National Institute of Child Health and Human Development in Rockville, Maryland. “Although they are at high risk, adopting a healthful diet and lifestyle may lower their future risk of hypertension.”
The Connection Between Healthy Eating and Lower Blood Pressure
The prevalence of gestational diabetes (GDM) may be as high as 9.2% in the U.S., according to the Centers for Disease Control and Prevention, and is said to be on the rise. The condition is a known risk factor for hypertension later in life, and also increases a woman’s odds of developing type 2 diabetes and cardiovascular disease. 2,3
But the new research found that adopting a healthful eating plan can offset the increased risk of hypertension, which has been shown to exceed 25% in this population. The investigation--which looked at 3,818 women in the Nurses’ Health Study II with a history of GDM—found that those who maintained a high-quality diet were up to 35% less likely to have developed hypertension at a 17-year follow-up than those with less healthful eating patterns.
The study focused on three types of diets: the alternative Healthy Eating Index, the alternative Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH), which have several things in common: high consumption of vegetables, fruit, fish, nuts, legumes and whole grains and low consumption of red meat, salt, sweets, sugar-sweetened beverages and processed meat.
The researchers undertook the recent investigation after an earlier study they carried out found that women who followed the same three diets prior to their pregnancies had a significantly reduced risk of GDM—up to as much as 46%. And that study came after previous research found an association between the three diets and a reduced risk of type 2 diabetes.4
Weight Gain and Diet Both Factors
While the latest study of women with a history of GDM found that less weight gain contributed to some of the reduced hypertension risk seen in those who maintained healthful eating patterns, the study found that a healthy diet—regardless of weight gain or loss—still offered significant protection against high blood pressure.
“This study emphasizes the lasting benefit of a heart-healthy dietary pattern on the risk of hypertension in women with a history of gestational diabetes, whether or not there are changes in body weight,” said Robert Eckel, M.D., professor of medicine at the University of Colorado Anschutz Medical Campus and past president of the American Heart Association, adding that the recent findings corroborate the lifestyle guidelines to reduce cardiovascular risk issued in 2013 by the American Heart Association and the American College of Cardiology, which call for a dietary pattern similar to those in the new study: high consumption of vegetables, fruits and whole grains; focusing on fish, legumes and poultry as protein sources; and limiting sugar-sweetened beverages and red meats.5
About 70 million adults in the U.S. currently have hypertension—that’s almost 30% of the adult population, while an additional nearly 1 in 3 has prehypertension, blood pressure numbers that are higher than normal but not yet in the high blood pressure range. Hypertension is a major risk factor for some of the leading causes of death in the U.S: heart attack and stroke as well as kidney disease.6
While the alternative Healthy Eating Index, DASH and Mediterranean diets have been associated with healthy blood pressure in the general population, the new research is the first to document the benefits of these diets in women who face a high risk of hypertension due to a history of gestational diabetes, the study authors wrote.1
Dr. Zhang further emphasized the need for women who have had GDM to follow a healthful eating pattern after the condition has clinically passed. “While the majority of these women’s glucose levels will return to normal after delivery, our study should serve as an early warning signal,” she said, adding that physicians and other healthcare providers should encourage these mothers to pursue healthful practices after delivery.
The alternative Healthy Eating Index emphasizes nuts, legumes, whole grains, fish, polyunsaturated fatty acids (PUFAs) and limited amounts of sugar-sweetened beverages. DASH, originally developed to reduce blood pressure, calls for low consumption of sodium, animal protein and sweets; moderate consumption of low-fat dairy products; and high consumption of fruits, vegetables, legumes and nuts. The alternative Mediterranean diet emphasizes large amounts of vegetables, fruits, fish, whole grains and olive oil; moderate amounts of dairy products and alcohol; and small quantities of meat and meat products.1