A new trial found differences in blood sugar stability and metabolites, potentially explaining lower diabetes rates among dairy consumers.
As plant-based diets continue to grow in popularity, new research suggests that vegans may miss out on a notable blood sugar benefit linked to dairy products.
Key Differences in Blood Chemistry
The two-week clinical trial, recently published in Clinical Nutrition, involved 30 healthy adults who were assigned to follow either a vegetarian diet that included dairy or a strictly vegan diet consisting of only plant foods.
Those who ate a vegetarian diet had reduced body fat, while those on a strictly vegan diet lost more weight.
Blood tests revealed notable differences between the two groups. Participants eating dairy showed higher levels of acetyl-L-carnitine, a compound that helps cells use fat for energy and reduces cellular damage caused by elevated blood sugar.
Researchers said that this might explain why participants’ blood sugar stayed lower and more stable.
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He said that people who included dairy in their diet had beneficial compounds in their blood, which may explain why their blood sugar levels stayed more stable throughout the day.
All participants wore continuous glucose monitors for 14 days to track glucose concentrations. This provided detailed data on how glucose levels fluctuated throughout the day under both dietary patterns.
In a subgroup of 13 participants, researchers collected fasting and post-meal blood samples on days 1 and 15 to analyze metabolite levels—small molecules produced during metabolism that can offer insights into how the body processes nutrients.
The trial carefully controlled variables by ensuring both diets contained the same number of calories, protein, and carbohydrates. The dairy group had about 558 grams of dairy products daily, primarily milk with some yogurt and cheese, while the vegan group used plant-based alternatives like soy milk and tofu.
Measured Effect on Blood Sugar
After accounting for factors like age, sex, body weight, and baseline blood sugar levels, researchers found that participants on the lacto-vegetarian diet maintained lower average blood glucose levels compared to those following the vegan diet.
Both groups had increased blood glucose levels when beginning their diet, though this increase started to decrease in the lacto-vegetarian group by day seven, while blood sugar levels continued to increase in the vegan group. With the exception of day 12, the vegan group had more periods of high blood sugar on all other days.
Researchers noted that these findings may help explain previous epidemiological research showing lower rates of Type 2 diabetes among people who regularly use dairy products.
The findings suggest that dairy supports glycemic control, possibly through bioactive compounds like acetyl-L-carnitine, said Desiree Kretchmar, a registered dietitian nutritionist at Eternal Glow Nutrition and Pilates, who was not involved in the study.
Options for Nondairy Consumers
Kretchmar said people who don’t include dairy in their diet—like vegans or those who are lactose intolerant—can instead focus on fortified plant-based milks, like pea, soy, or fava bean, that offer similar protein profiles to reap comparable benefits.
Emily Feivor, a registered dietitian at Northwell Health in New York who was also not involved in the study, emphasized quality choices regardless of preference.
“It’s preferable to choose an option that is low in saturated fat and sodium, high in vitamin D, contains no added sugars, and has live and active cultures, like yogurt or kefir,” she told The Epoch Times. “When looking at plant-based, same rules apply,” she added, noting that soy-based options are preferable.
The study highlighted the importance of these findings for India, which has the second-largest number of people with diabetes in the world.
Balancing a Healthy Diet for Blood Sugar Control
Experts emphasize that both vegan and vegetarian diets can support good health when properly planned, but certain approaches may better support blood sugar stability.
If you’re vegan or vegetarian, it’s a good idea to stay away from refined or processed foods, which can easily raise blood sugar and cause inflammation in the body, said Stephanie Schiff, a registered dietitian nutritionist at Huntington Hospital in New York, who was not involved in the study. “They won’t do your health any good.”
A balanced diet that helps maintain healthy blood sugar levels, Kretchmar noted, should focus on protein-rich, minimally processed options, whether they’re plant- or dairy-based.
She recommends choosing unsweetened yogurts, soy milk, cottage cheese or tofu, lentils, and tempeh as plant-based options for people who don’t eat dairy.
“Pairing protein with high-fiber carbs, like beans or oats, helps flatten glucose curves,” she said. “Avoid skipping meals, and build meals around consistent timing, fiber, and protein. This matters more than whether the protein comes from cow’s milk or soy.”
Kretchmar emphasized that both vegan and vegetarian diets can support health when thoughtfully planned. However, she added that this study shows that removing all animal products may not always be better.
“A vegetarian diet that includes modest amounts of dairy, especially fermented or cultured forms, might offer unique metabolic advantages,” Kretchmar said. Still, she noted that every body is different. “It’s not about ideology; it’s about what supports stability, energy, and long-term adherence.”
