A new study published in the The Journal of Nutrition found that substituting two tablespoons of pure maple syrup for refined sugars reduced several cardiometabolic risk factors in humans. It was the first placebo-controlled clinical trial exploring potential health benefits of maple syrup in humans. 

“We know from decades of research that maple syrup is more than just sugar. It contains over 100 natural compounds, including polyphenols, that are known to prevent disease in part through their anti-inflammatory effects,” says Dr. André Marette, lead scientist on the study.

“Because the fundamental chemistry of maple syrup is unique, I wondered if ingesting maple syrup instead of an equivalent amount of refined sugar would differently impact the cardiometabolic health and the intestinal microbiota in humans,” he continues.

“The results were extremely encouraging. I did not expect to see so many improvements of risk factors within a relatively short treatment period.”

The study was jointly funded by Canada’s Québec Maple Syrup Producers and the Québec Department of Agriculture, Fisheries and Food through its healthy food production initiative, the Programme Alimentation santé.

Québec Maple Syrup Producers represents over 13,500 maple producers and 8,400 maple enterprises. Québec produces 72% of the world’s maple syrup and exports it to over 70 countries.

Study protocol

The study was conducted by a Laval University team led by Marette at the Quebec Heart and Lung Institute and Dr. Marie-Claude Vohl, at the Institute of Nutrition and Functional Foods.

Forty-two volunteers from the greater Québec city area, between the ages of 18–75 in good health, and with a BMI of 23–40, participated in the study. Participants substituted 5% of their daily caloric intake (corresponding to two tablespoons) from refined sugars with either Canadian maple syrup or an artificially flavored sucrose syrup. 

Each phase lasted eight weeks with participants switching between maple syrup and sucrose syrup groups after a four-week washout period. The cross-over design ensured that the same test subject was his or her own control, consuming both placebo and maple syrup.

Primary outcomes focused on the oral glucose tolerance test (OGTT). Secondary outcomes included changes in blood lipid profile, blood pressure, body fat composition (measured by a DEXA scan) and changes in gut microbiota composition.

Blood sugar and pressure lowered

Study participants who consumed pure maple syrup had an improved response to the OGTT than those who received a flavored syrup of refined sugar. Their bodies managed blood sugar levels better after eating (-50.59 versus +29.93).

Blood pressure was also lowered in the subjects who consumed maple syrup during the trial. Systolic blood pressure decreased significantly in the maple syrup group (-2.72 mm Hg) while it increased slightly in the sucrose group (+0.87 mm Hg).

“Lowering blood pressure continues to be an important factor in lessening the risk of cardiovascular disease,” says Dr. Marette. “Natural sweeteners, such as pure maple syrup, when substituted for refined sugars, can be part of an overall solution in helping to prevent metabolic diseases.”

Healthier and trimmed gut

The maple syrup trial showed that android fat mass, the fat in the abdominal region, significantly decreased in the maple syrup group, while it increased in the group consuming the sucrose solution (-7.83 g vs. + 67.61 g).

An unexpected discovery was the improved levels of potentially beneficial gut bacteria and a decrease in levels of potentially harmful gut bacteria in the maple syrup participants.

The study showed a reduction in Klebsiella species and Bacteroides pectinophilus, which are linked to inflammation and metabolic disorders, and the increased growth of beneficial bacteria like Lactocaseibacillus casei and Clostridium beijerinckii.

“Both individually and collectively, the study findings are quite significant,” Dr. Marette notes. “The combined decrease of such key risk factors may help to reduce the risk of diabetes and cardiovascular disease. Making a commitment to lifestyle changes and small adjustments to our everyday diets is important and can be a powerful tool in preventing future diseases.”

First human trial builds on animal studies

Dr. Marette’s clinical study builds upon his own work in animal models of diabetes and previous work on maple syrup and its bioactives by US scientist Navindra Seeram, PhD, of the University of Rhode Island, College of Pharmacy. Dr. Seeram’s extensive foundational work with maple syrup set the stage for this first human clinical trial. 

“With each new study, we learn more benefits that natural products from medicinal plants and functional foods, like maple syrup, provide,” says Dr. Seeram. “The significant promising results of this first human trial provide more reasons for us to educate consumers about maple syrup’s many health benefits. It is truly a ‘smarter sweetener’ and a healthier alternative to refined sugar.”

Dr. Marette comments: “While this study was limited to a relatively small sample size (42 men and women) and took place during a relatively short duration of time, the results are still significant.” 

“We now have human evidence to support replacing refined sugars with maple syrup, a natural sweetener, for preventing metabolic diseases. Our next goal is to conduct larger studies with other populations to explore how replacing refined sugars with maple syrup might impact their unique health conditions.”

General nutrition claims for two tablespoons of maple syrup indicate that it is an excellent source of manganese (35%), a good source of riboflavin (15%), a source of calcium (2%), thiamin (2%), potassium (2%) and copper (8%). It contains 12% fewer calories than light corn syrup.

By comparison, refined sugar requires a large amount of processing and lacks any real nutritional value.

Maple has made its way to health product offerings, with UK-based natural sports nutrition company Protein Rebel launching Maple Ignite, a sports energy gel made from maple syrup harvested from Canadian maple trees.