Scientists find new tool to measure sugar consumption
June 17, 2013
907-474-7412
6/18/13
Scientists at 性欲社 have identified a new tool that can dramatically improve the notoriously inaccurate surveys of what and how much an individual eats and drinks. Their research is published in the June 2013 issue of the Journal of Nutrition.
Conventional wisdom says that consumption of sugar-sweetened beverages such as soda and fruit juice is a significant contributor to obesity and chronic disease risk, but the science surrounding this issue is inconclusive. Part of the problem is that in a typical diet survey few people accurately and consistently recall what they consumed. The problem becomes exaggerated when people underreport foods they know are less healthy for them, like sugars.
鈥淲e were looking for an objective biomarker that could accurately measure long-term sugar intake from a single blood or hair sample,鈥 said Diane O鈥橞rien, project leader and biologist with the Center for Alaska Native Health research at the 性欲社 Institute of Arctic Biology.
The biomarker O鈥橞rien and her CANHR research group pilot-tested was the ratio of two different carbon atoms鈥攈eavy carbon 13 and light carbon 12鈥攚hich are incorporated into plants during photosynthesis. The ratio, called an isotopic signature, is distinct in corn and sugar cane, which are the sources of nearly all of the sugars found in sugar-sweetened beverages.
鈥淲e used the isotopic signature of alanine, an amino acid and building block of protein that essentially traps the carbon from dietary sugar so that it can be measured in the protein component of hair or blood,鈥 O鈥橞rien said.
Even after foods and beverages are consumed, metabolized, transported in blood and stored in body tissues, these isotopic signatures remain largely intact. The more sugar-sweetened beverages an individual consumes, the greater alanine鈥檚 carbon isotope ratio will be. Importantly, O鈥橞rien鈥檚 group found that alanine was uncorrelated with other foods that can contribute to elevated carbon ratios.
Although the use of isotope signatures to study food webs and diet is not new, previous efforts to accurately measure sweetener intake have not been particularly successful. The use of alanine and the technique employed by O鈥橞rien鈥檚 group makes their findings particularly exciting.
鈥淓ven for validated and well-accepted biomarkers of diet, associations with self-reported intake are generally very weak. Our biomarker was able to explain almost half of the variation in self-reported sugar-sweetened beverage intake, which in this field is a very high level of explanatory power,鈥 said O鈥橞rien.
The scientists鈥 findings are also being used in other health and diet-related research.
鈥淒iane鈥檚 research program has provided CANHR with incredibly valuable objectively measured biomarkers of food intake,鈥 said CANHR director Bert Boyer. 鈥淭hese biomarkers are currently being used to help us understand the role polyunsaturated fatty acids play in disease prevention, including the modification of genetic risk.鈥
The tool is not without its drawbacks, caution the authors.
鈥淭he gas chromatography-combustion-isotope ratio mass spectrometry process we used isn鈥檛 inexpensive and or widely available,鈥 O鈥橞rien said. 鈥淲e expect that our findings will be most useful as a calibration tool, either for self-reported dietary data or more high-throughput biomarkers of sweetener intake.鈥
About CANHR
The Center for Alaska Native Health Research was established through a five-year grant awarded by the National Institutes of Health, National Center for Research Resources to 性欲社. The purpose of CANHR is to investigate weight, nutrition and health in Alaska Natives. CANHR approaches this thematic focus from a genetic, dietary and cultural-behavioral perspective. The funding comes through a program for Centers of biomedical Research Excellence. This project is a partnership with the Yukon-Kuskokwim Health Corporation.
The participants and data in this project are from the CANHR Neqem Nallunailkutaa (The Foods鈥 Market) study conducted in 2008-2009 in two coastal Yup鈥檌k communities in Southwest Alaska.
ADDITIONAL CONTACTS: Diane O鈥橞rien, associate professor of biology, dmobrien@alaska.edu, 907-474-5762. Bert Boyer, professor of molecular biology, bboyer@alaska.edu, 907-474-7733.
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