Science

Researchers discover how fructose enhances fat absorption in the gut

Researchers discover how fruct...
Excessive fructose consumption, particularly in the form of high fructose corn syrup, may increase the ability of intestinal cells to absorb dietary fats
Excessive fructose consumption, particularly in the form of high fructose corn syrup, may increase the ability of intestinal cells to absorb dietary fats
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Excessive fructose consumption, particularly in the form of high fructose corn syrup, may increase the ability of intestinal cells to absorb dietary fats
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Excessive fructose consumption, particularly in the form of high fructose corn syrup, may increase the ability of intestinal cells to absorb dietary fats

A new preclinical study published in the journal Nature is demonstrating how fructose can alter cells in the small intestine, subsequently enhancing nutrient absorption and promoting weight gain. The research indicates excessive fructose consumption, such as drinks sweetened with high-fructose corn syrup (HFCS), increases the body’s ability to absorb dietary fats.

The new research stemmed from a 2019 study investigating the effect of HFCS on colorectal cancer. That study discovered a molecular mechanism by which fructose directly enhances tumor cell growth. So the next logical study target was the effect fructose had on non-cancerous intestinal cells.

Lining our small intestine are millions of tiny, hairlike protrusions known as villi, which serve a number of functions, including absorbing nutrients from food.

The first finding in the new research was that mice fed high-fructose diets were found to have villi up to 40 percent longer than animals not fed fructose. Subsequent investigation revealed mice with these longer villi gained more weight on a high-fat diet than mice fed a high-fat diet without added fructose.

Drilling down into the molecular mechanism at work, the researchers detected high levels of fructose-1-phosphate accumulating in cells. Fructose-1-phosphate is a metabolite of fructose and it can boost the survival of villus cells. It is this mechanism, the researchers suggest, that is responsible for fructose promoting villi length, leading to increased fat absorption and weight gain.

Samuel Taylor, first author on the new study, hypothesizes an evolutionary reason for animals developing this unusual mechanism, saying it makes sense for mammals to maximize fat absorption from fructose in overripe fruit.

“In mammals, especially hibernating mammals in temperate climates, you have fructose being very available in the fall months when the fruit is ripe,” says Taylor. “Eating a lot of fructose may help these animals to absorb and convert more nutrients to fat, which they need to get through the winter.”

But the problem that arises in modern times is one of overconsumption of fructose in forms of sweeteners such as high-fructose corn syrup. As senior author Marcus DeSilva Goncalves explains, the issue is simple, we now eat too much fructose.

“Fructose itself is not harmful,” notes Goncalves. “It's a problem of overconsumption. Our bodies were not designed to eat as much of it as we do.”

This is not the first study to shine a light on the potential damage caused by excessive fructose consumption. An influential 2019 study looked at the influence of fructose on the liver and found it exerted novel metabolic effects on the organ, resulting in greater accumulations of fat. This effect was not seen with glucose.

More work needs to be done to confirm the findings of this new study in humans, but Goncalves says if these findings are validated in humans they could potentially lead to new methods for treating colorectal cancers and obesity.

“There are already drugs in clinical trials for other purposes that target the enzyme responsible for producing fructose-1-phosphate,” says Goncalves. "We're hoping to find a way to repurpose them to shrink the villi, reduce fat absorption, and possibly slow tumor growth.”

The new research was published in the journal Nature.

Source: Weill Cornell Medicine

4 comments
4 comments
Aross
Once again an article about a study that concludes that a drug is needed to stop the problem. To me a recommendation to avoid high fructose containing foods would be helpful here. I don't understand the need for every study in to dietary problems to conclude that drugs are the answer.
Karmudjun
Once again an article that points out how dysfunctional our industrialized food supply has become. HFCS makes everything taste "better" and the foods 'fortified' with this additive are abundant and cheap.

GIVEN - that our food industry isn't taking the initiative in reducing HFCS levels in order to protect their market share;
GIVEN - that our population follows the not-so-subliminal drive to eat sweeter tasting foods;
GIVEN - that our health conscious population prefers a pill to the hard work of thinking about everything that they wish to digest - and the subsequent effects suffered;
Researchers SUGGEST utilization of already developed drugs as a crutch to circumvent both "Givens" 1 & 2, and meeting "GIVEN" 3 for those who don't understand.

For those who do understand? Read, digest, refrain from HFCS. I don't understand why that isn't obvious - we have known HFCS induces a life-shortening trajectory. That is why we physicians caution high intake of High Fructose Corn Syrup.
jerryd
Since I eat a lot of fruit, how does that effect me? Does it in fiber help?
Dirk Scott
The over provision of fructose to modern humans is not down to fructose syrup alone. Wild, uncultivated fruits are small and not very sweet (think crab apples). Wild fruit is also typically only available for a short period each year. Even without fructose syrup a diet containing fat, sweet fruit shipped in 12 months of the year, plus made into juice or smoothies is already heavily over supplied with fructose.