Research: low GI does not benefit heart health, diabetes
18 Dec 2014New research suggests that heart-healthy eaters – those following a diet rich in fruits, vegetables and whole grains, and low in sweets – don’t need to worry about choosing low glycaemic index foods to lower the risk of diabetes and heart disease. Though the study was not designed to test the effects of low glycaemic […]

New research suggests that heart-healthy eaters – those following a diet rich in fruits, vegetables and whole grains, and low in sweets – don’t need to worry about choosing low glycaemic index foods to lower the risk of diabetes and heart disease. Though the study was not designed to test the effects of low glycaemic index foods on weight control, its lead researchers looked at studies that did focus on weight and found no clear proof of a benefit.
The glycaemic index is a measure of how quickly foods containing carbohydrates, such as fruits, cereals and baked goods, raise glucose levels in the bloodstream. Conventional wisdom says that high glycaemic index foods like bananas and pasta are “bad” for heart health and may increase diabetes risk. But in a clinical trial reported in the Journal of the American Medical Association, researchers at the Johns Hopkins University School of Medicine and Harvard Medical School found little evidence to support these claims.
Study volunteers followed carefully planned diets high or low in carbohydrates and with high or low glycaemic index scores. Tests tracked the volunteers’ blood pressure, cholesterol levels and sensitivity to insulin at the beginning and end of each diet. The results showed little difference between high and low glycaemic index foods, said study co-director Lawrence J. Appel, a professor of medicine and director of the Welch Center for Prevention, Epidemiology and Clinical Research at Johns Hopkins Medicine.
“We were really surprised,” Appel said. “We did not detect any clear benefit of the low glycaemic index diets on the major risk factors for heart disease, and we found no evidence of benefit for diabetes prevention.”
The authors looked closely at other studies focusing on the use of low glycaemic index foods in weight control. “The evidence has been inconsistent that low glycaemic foods help people lose more weight or keep it off,” Appel said. “In looking at the causes of obesity and ways to combat it, a narrow focus on the glycaemic index seems to be unwarranted.”
Several popular diets recommend choosing carbohydrates that score low on the glycaemic index, but that’s not always easy, the researchers note. Only laboratory tests can determine a food’s glycaemic index, and the results can be unexpected: apples score low, but cantaloupe scores high.
Appel and study co-director Frank M. Sacks, a professor of medicine at Harvard Medical School, wanted to find out whether foods’ glycaemic index matters to heart health and diabetes prevention. They recruited 163 volunteers from Baltimore and Boston — all of whom were overweight and had above normal blood pressure — and randomly assigned them to follow one of four diets. Each diet contained the same number of calories, but those calories came from foods that were either high or low in carbohydrates, and also either high or low on the glycaemic index. The volunteers ate the day’s main meal at a research centre and took home their next two meals.
After five weeks on their assigned diets, the volunteers switched to a different one. Researchers tested the volunteers’ blood pressure; sensitivity to insulin; and levels of “good” high-density lipoprotein (HDL) cholesterol, “bad” low-density lipoprotein (LDL) cholesterol and triglycerides — fat molecules, or lipids, that play a role in heart health. The low glycaemic index diets did not lower blood pressure or LDL cholesterol, and they did not improve insulin resistance.
Women made up 51% of the study’s volunteers, and African-Americans made up 52%, so the results have broad relevance, said Appel, who offers simple advice for anyone overwhelmed by conflicting messages about diet and health.
“Get back to the basics that most people already know,” he said. “Don’t drink sugar-sweetened drinks. Try to eat fruits, vegetables and whole grains. Try to avoid sweets, salt, and foods high in saturated and trans fats. People who follow these principles will reap the benefits.”
Appel and Sacks led three earlier clinical trials that tested ways to reduce the risk of cardiovascular disease and diabetes, providing volunteers with carefully designed diets and measuring the effects on key health indicators. Their work established the health benefits of the DASH (Dietary Approaches to Stop Hypertension) and OmniHeart Mediterranean-style diets.
Related news

Scouting out the latest health trends and innovations at Vitafoods Europe
20 May 2022
From mood, cognition, and gut health to the importance of selling experiences rather than products, the Healthy Marketing Team (HMT) rounds up the biggest trends it spotted at Vitafoods Europe last week.
Read more
Top trends to watch at Expo West
18 Feb 2022
From the foodification of supplements to mission-driven commerce, trendspotters at Natural Products Expo West have identified the top 10 trends shaping the US healthy food industry.
Read more
New Product Zone showcased the most innovative products at Fi Europe
15 Dec 2021
Attendees of Fi Europe 2021 were able to discover an extensive selection of the most innovative products, showcased alongside insightful information at the New Product Zone.
Read more
Startup Innovation Challenge 2021: Recognising disruptive ideas in F&B innovation
6 Dec 2021
The Fi Global Startup Innovation Challenge aims to support innovative projects within the F&B industry by offering startups the opportunity to showcase their innovations and meet the industry's foremost ingredients professionals.
Read more
Fi Europe Innovation Awards: Recognising innovative ingredient solutions at Fi Europe 2021
6 Dec 2021
The Fi Europe Innovation Awards recognise ground-breaking work in food and beverage ingredients at the annual Fi Europe, co-located with Hi Europe, event. This year has featured some outstanding ingredients and concepts in the fields of health, sustain...
Read more
Fi Europe opens its doors to in-person attendees today!
30 Nov 2021
After a week-long online program Fi Europe opens for in-person attendees under 2G measures in Frankfurt today – if you’re not able to attend in-person, you can follow the program from the show floor live on the online platform.
Read more
Obama celebrated 60 with top vegan brands
9 Aug 2021
Plant-based foods have become so widely accepted that former President Barack Obama’s 60th birthday celebration featured a vegan, plant-based menu, according to a menu leaked by Bloomberg.
Read more
Plant-based nugget prices cheaper than real chicken
3 Aug 2021
Chickenflation is a real thing, and plant-based protein maker Alpha Foods is taking advantage of skyrocketing chicken prices to grab the attention of non-meat eaters and meat eaters alike.
Read more
Future of Nutrition Award debuts at the Fi Europe Innovation Awards
16 Jul 2021
The Fi Europe Innovation Awards, held at Fi Europe 2021 co-located with Hi Europe, celebrate people, companies and organisations breaking new ground in the Food & Beverage industry.
Read more
Flavor company Givaudan crowdsources flavors with its Aroma Kiosk
12 Apr 2021
Swiss flavor giant Givaudan has rolled out its Aroma Kiosk, a digital sensory tool that crowdsources flavor preferences. These kiosks are located globally in grocery and retail stores as well as universities where shoppers can interact with the technol...
Read moreAre you a supplier?
Here's what we can do for you
- Generate quality leads for your business
- Stay visible for 365 days of the year
- Receive product inquiries and respond to meeting requests directly
- Improve company online presence through Search Engine Optimisation