Sugar and Our Genes: A Sweet Connection
If sugar is always your jam, your DNA may be to blame.
Genetic Variation and Sugar Preferences
An international team of researchers says that a genetic variation in our ability to digest certain sugars may influence how much we like sweet foods — and how much we consume. The scientists are pointing the finger at the sucrase-isomaltase (SI) gene, which plays a key role in breaking down sucrose (also known as table sugar) and maltose (a less sweet compound found in some cereals) into simple sugars for absorption by the small intestine.
Mutations in the GI Gene and Sucrose Consumption
Mutations in the SI gene can make it difficult to digest sucrose and maltose. People with irritable bowel syndrome tend to have more defective SI gene variants than healthy people. About 10% to 15% of American adults suffer from IBS, which is characterized by cramping, bloating, stomach fullness or burning sensations, often accompanied by diarrhea or constipation.
Study Findings
For the new research, the study authors explored the dietary habits of mice that lacked the SI gene. The vermin rapidly reduced their sucrose consumption and preference for it. The researchers then tested their theory on 6,000 people in Greenland and nearly 135,000 UK residents. They found that those in Greenland who couldn’t digest sucrose at all consumed significantly fewer sucrose-rich foods, while the UK residents with a partially functional SI gene preferred sucrose-rich foods less.
Conclusion
The results of this study suggest that genetic variation in our ability to digest dietary sucrose can influence our intake, and preference, for sucrose-rich foods. This research opens up the possibility of targeting SI to selectively reduce sucrose intake at the population level.
Health Risks of Excessive Sugar Consumption
Large amounts of sugar can damage cells, causing chronic inflammation, which can lead to obesity, heart disease, diabetes, liver disease, and cancer. The American Heart Association recommends no more than 9 teaspoons (36 grams or 150 calories) of added sugar per day for men and no more than 6 teaspoons (25 grams or 100 calories) per day for women. A recent poll found that Americans eat and drink an average of 99 grams of sugar a day for a total of 80 pounds a year.
Expert Opinion
“Understanding mechanisms to potentially reduce desire for and intake of sugar is an exciting area of innovation and could have beneficial consequences in the future to reduce the burden of disease,” said Dr. Rifka C. Schulman-Rosenbaum, director of inpatient diabetes at Long Island Jewish Medical Center.
Frequently Asked Questions
Q: How does genetic variation in sugar digestion influence our intake and preference for sweet foods?
A: Genetic variation in the ability to digest sucrose can influence how much we like sweet foods and how much we consume.
Q: What are the health risks of excessive sugar consumption?
A: Large amounts of sugar can damage cells, causing chronic inflammation, which can lead to obesity, heart disease, diabetes, liver disease, and cancer.
Q: How much sugar should we consume daily?
A: The American Heart Association recommends no more than 9 teaspoons (36 grams or 150 calories) of added sugar per day for men and no more than 6 teaspoons (25 grams or 100 calories) per day for women.
