A domestic study found that healthy adults who drank a low-sugar, vegetable-based cold-pressed juice alongside bread had peak post-meal blood sugar levels about 10% lower than those who drank water with the same bread. The findings suggest that pairing a fresh, no-added-sugar vegetable and fruit juice with eggs or nuts could offer a balanced breakfast without significant concern over blood sugar spikes.
According to the Korea Food Communication Forum (KOFRUM) on Monday, a research team led by professor Kwak Jeong-hyeon of the Department of Food and Nutrition and Food Engineering at Inje University analyzed how the composition of cold-pressed juice and its simultaneous consumption with carbohydrate-rich food affected post-meal blood sugar levels in 10 healthy adults.
The researchers gave 10 healthy adults 240 milliliters each of two types of cold-pressed juice made using a low-temperature, slow-extraction method. The celery-cabbage-apple blend was made from 250 grams of celery, 30 grams of cabbage and 30 grams of apple, while the celery-kale-cabbage-lemon blend contained 120 grams of celery, 90 grams of kale, 90 grams of cabbage and 20 grams of lemon. The total sugar content per 100 grams was 2.76 grams for the celery-cabbage-apple juice and 1.77 grams for the more vegetable-heavy celery-kale-cabbage-lemon blend.
After consuming either juice alone, peak blood sugar readings were 102.9 mg/dL for the celery-cabbage-apple juice and 107.5 mg/dL for the celery-kale-cabbage-lemon blend — showing no meaningful difference from fasting blood sugar levels of 95.0 mg/dL and 98.7 mg/dL, respectively. The results confirmed that vegetable-centered cold-pressed juice on its own had little impact on blood sugar levels.
To assess blood sugar response when cold-pressed juice was consumed alongside a carbohydrate food, participants drank the juice with white bread while researchers monitored subsequent glucose changes. When participants ate 100 grams of white bread with either 240 milliliters of the celery-kale-cabbage-lemon juice or 240 milliliters of water as a control, blood sugar at 30 minutes was 149.4 mg/dL and 155.7 mg/dL, respectively — about 4 percent lower in the juice group.
The difference was more pronounced among the five non-obese participants. Their peak blood sugar reached 162.2 mg/dL when they ate white bread with water, but fell to 145.6 mg/dL — about 10 percent lower — when they paired the bread with the vegetable-heavy celery-kale-cabbage-lemon juice.
The research team attributed the effect to the low sugar content and polyphenols in the vegetable-rich juice, which are thought to slow sugar absorption in the body, as well as lemon's ability to inhibit carbohydrate-digesting enzyme activity. Because the study was a small-scale pilot, the team said the findings should be interpreted as preliminary evidence supporting the potential of pairing low-sugar, vegetable-centered juice with carbohydrate foods.
"Multiple studies have reported that adequate consumption of fruits and vegetables — particularly some green leafy vegetables — is associated with a lower risk of type 2 diabetes," said Kwak. "Rather than eating a carbohydrate-heavy breakfast on a busy morning, it may help to develop the habit of pairing a vegetable-rich cold-pressed juice made with ingredients like celery, kale, cabbage and lemon with protein and fat sources such as eggs or nuts for a more balanced meal."
The study — titled "Effects of Cold-Pressed Juice Composition Combined with Carbohydrate Foods on Glycemic Responses in Adults: Pilot Study" — was published in a recent issue of the Journal of the Korean Society of Food Science and Nutrition.
kty@heraldcorp.com
