Not all sugar is the same, at least in the way that it affects the body. The type of sugar that is consumed can influence the risk of health problems, according to a study by researchers in Spain and California.

Using rat models, the researchers found that the risk of health problems varied with the type of sugar that was eaten. One group of animals consumed glucose, the sugar formed in the body after carbohydrates get broken down. Another group of animals was given fructose, the naturally occurring sugar found in fruit and fruit juice. Both groups of animals got the sugar in addition to their regular food. The animals were fed the sugar diets for eight weeks, the equivalent of a human consuming significant amounts of sugar for six years.

Both of the sugar-fed groups of animals took in more calories than the control group, with the glucose-fed rats consuming the most calories overall. Still, the animals that ate fructose  — the fruit-based sugar — were the only ones to gain weight, researchers said.

The findings, published in the American Journal of Physiology, showed the fructose-eating animals had more indicators of liver damage and vascular disease. Those included elevated levels of fat in the blood, decreased fat-burning in the liver and constriction of the body’s main artery.

Ultimately, they found that eating fructose had a greater effect on metabolic and circulatory dysfunction than eating glucose among the laboratory animals.

For humans, the American Heart Association recommends no more than nine teaspoons of added sugar a day for men and six for women. That’s in addition to sugars that occur naturally in foods. The moral is, limit sugar intake of all kinds for better health.