Eating with loved ones may ease blood sugar spikes

photo: collected

After a meal of white bread, blood sugar climbs and the body works to bring it back down. That job is usually treated as something each body handles on its own. Yet in new experiments, healthy adults who ate the same bread with a romantic partner nearby had smaller spikes that settled faster than when they ate alone.

So the people at the table may shape what a meal does to the body, along with the food on the plate. The researchers call the idea Social Physiology. They saw a similar pattern when adults were cold or given mild shocks, and in babies whose mothers stayed with them.

The work was led by Monia Masalha and Shir Atzil at the Hebrew University of Jerusalem, with Shai Fuchs of the pediatric endocrine and diabetes unit at Sheba Medical Center. All the adults were young, healthy, and free of diabetes, reports Earth.com.

Atzil, who studies bonding in the university’s Department of Psychology, picked the closest pairs on purpose.

“For this first proof of concept, we deliberately went to the closest bonds we could test, romantic partners in adults and mothers in infants, because if Social Physiology exists, these are the relationships where we expected to see it most clearly,” she said.

For the blood sugar test, the team recruited 108 adults from 54 couples who had been together for at least nine months. Each person ate about 3.6 ounces (102 grams) of white bread, a standard test meal that delivers about 1.8 ounces (50 grams) of carbohydrate.

Each person ate the same meal twice that day. Once they ate alone, and once with their partner in the room. The order was random, and the two sessions were at least four hours apart.

The room looked more like a living room than a lab, with a sofa, a carpet, and natural light. Partners could talk or touch if they wanted. A finger prick checked blood sugar before the meal and six more times over the next two hours.

To compare the two meals, the team added up how far each person’s blood sugar rose above a normal fasting level and how long it stayed there. With a partner present, that total was about 15% smaller.

Blood sugar started out about the same in both sessions. After the bread, it ran lower in the partner session at each check from 45 minutes to two hours.

The researchers also compared people using only their first session. There, people who ate with a partner had a total about 24% smaller than people who ate alone. That comparison rules out any lingering effects from the first meal.

Meal timing and a short walk after eating are already known to change what blood sugar does after a meal.

“Blood sugar regulation is not just about what we eat, but who we eat with,” Atzil said.

The team checked whether a partner simply made people calmer. Sensors on the skin tracked sweat-gland activity, a standard sign of stress, for the full two hours.

Those readings didn’t differ between the two sessions, and they weren’t linked to how high blood sugar went. Blood sugar levels remained lower with a partner present even after the team accounted for stress.

Touch didn’t explain it either. Couples who touched more during the meal didn’t have lower blood sugar, and the partner effect remained after touch was taken into account.

In a second experiment, 116 adults stepped into a room chilled to 54°F (12°C) for five minutes, then warmed up at 77°F (25°C). Their skin temperature dropped less and recovered faster with a partner there.

In a third, 115 adults got two mild electric shocks on the forearm. People tested with a partner showed a smaller stress response than those tested alone, but the effect was less clear when researchers compared each person’s two sessions.

An earlier pilot tested 56 babies, 2.5 to 13 months old, who heard a brief loud sound. Their stress response was smaller with their mother in the room.

Asked by Earth.com what surprised her most in the results, Atzil pointed to how general the effect was. “We saw the same principle across very different systems, glucose, temperature, and stress, which are usually studied separately,” she said.

She was also struck by “the enormous individual differences: some people benefited a lot from social proximity, while others did not.” Some participants did worse with their partner present.

Why does closeness benefit the body?

Earlier work has linked loneliness to type 2 diabetes and heart trouble, and to fewer healthy years. Those payoffs take years to appear, though, which leaves a puzzle about why people seek each other out day to day.

“Long-term benefits cannot motivate every hug, meal, or moment together,” Atzil said in her Earth.com interview.

Her proposed answer is a reward in the moment. “Close partners can make regulation easier for the body, creating a metabolic gain in the moment,” she added. “That gain may feel like comfort, and reward us for staying close.”

Source:Earth.com