Welcome to our nutrition and food questions page. You are encouraged to ask a question and/or read the Q & A. Responses are provided by Cooperative Extension Specialists Dr. Cassandra Nguyen and Dr. Jennifer Smilowitz from the Department of Nutrition at the University of California Davis, in collaboration with the Nexus Center.
Cassandra J. Nguyen, Ph.D.
Assistant Professor of Cooperative Extension
University of California Davis
Jennifer T. Smilowitz, Ph,D.
Assistant Professor of Cooperative Extension
University of California Davis
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Responses from our collaborators, Drs. Nguyen and Smilowitz
Jump to topic: Monk fruit | Types of salt | Plastic cutting boards |
Is Monk fruit a better alternative sweetener?
By Dr. Jennifer Smilowitz, Cooperative Extension Specialist
4/14/2025
Monk fruit (also known as luo han guo) is a popular non-nutritive sweetener (NNS), meaning it provides little to no calories. It's made from the extract of the monk fruit and contains compounds called mogrosides, which are responsible for its sweetness—about 100 to 250 times sweeter than sugar. Mogrosides have antioxidant properties and do not spike glucose or insulin levels. Thus, monk fruit has been promoted as a natural sweetener for people who would like to manage blood sugar or avoid using artificial sweeteners.
While it is generally recognized as safe (GRAS) by the FDA, there are potential drawbacks to using it.
- First, commercially sold monk fruit products are often blended with other sweeteners such as erythritol, dextrose, or allulose to reduce intensity and to bulk them up. These other sweeteners may have undesirable effects such as digestive intolerance (bloat, gas, diarrhea) or other health effects. For example, erythritol consumption was recently reported across different study designs to increase cardiometabolic risk.
- Second, while consumption of NNS has been shown to reduce body weight in the short-term in certain subgroups of the population, a systematic review and meta-analysis suggests that use of NSS does not confer any long-term benefit in reducing body fat in adults and children. Results suggest there may be detrimental effects such as increased risk of type 2 diabetes, cardiovascular diseases, and mortality in adults, but these data are inconclusive.
- Finally, there is only a paucity of research on the long-term health effects of monk fruit sweetener consumption in humans.
Taken together, like all sweeteners, NNS should be used in moderation.
What is the difference between Celtic salt, Himalayan salt, and table salt? Is one better than the other?
By Dr. Jennifer Smilowitz, Cooperative Extension Specialist
9/4/2024
The difference between all three is based on how they are processed, where they are harvested and their mineral composition.
- Table salt is mined from salt deposits in the earth, which were often formed by ancient bodies of water;
- Celtic salt is sea salt harvested from saltwater lakes or the sea through evaporation; and
- Himalayan salt is harvested from the Himalayas in South Asia.
The latter two are less processed than the former and may have slightly more minerals and are moister than table salt but table salt is fortified with iodine while the other two are not. They usually are larger in size than table salt and have a distinctive taste due to the different mineral content. They are also more expensive than table salt. There is no data on any health outcomes related to using the different salt types but I will caution that if people use the Celtic and Himalayan salts, they should know the lack of iodine fortification would require them to take this essential nutrient as a supplement.
How safe is it to use plastic cutting boards, thinking about microplastics?
By Dr. Jennifer Smilowitz, Cooperative Extension Specialist
The World Health Organization has identified Micro- and nanoplastics are environmental contaminants of potential public health concern. These particles range from about the size of a grain of sand down to pieces much smaller than the width of a human hair.
Micro- and nanoplastics include intentionally manufactured small particles (e.g., in some personal care products) or after breakdown of larger plastics, such as food packaging or through use of plastic cutting boards. For example, a large systematic study found that normal use of plastic food containers can release micro- and nanoplastics into food [1].
What is the relationship between using plastic cutting boards and human health?
Recent experimental studies show that plastic cutting boards can release microplastics during normal food preparation [2]. A published review has revealed the detection of microplastics in human tissues, including blood and organs [3]. However, there is no direct evidence demonstrating that exposure from cutting boards or dietary microplastics causes specific health outcomes in humans.
National recommendations do not currently suggest avoiding plastic cutting boards. The U.S. Department of Agriculture (USDA) recommends using cutting boards that are easy to clean, including plastic, wood, glass, marble, or pyroceramic surfaces, to reduce foodborne illness risk.
It may take many years before research clearly determines whether microplastics exposure from food preparation tools affects human health.
For individuals who are concerned and want to reduce exposure:
- Consider using glass, wooden, or other non-porous cutting boards that are easy to clean to reduce foodborne illness risk.
- Replace cutting boards (plastic or wood) when they become deeply scratched or worn.
- Avoid placing very hot foods on plastic boards, which may increase material breakdown.
References
- Zimmermann, L., et al., Food contact articles as source of micro- and nanoplastics: a systematic evidence map. npj Science of Food, 2025. 9(1): p. 111.
- Yadav, H., et al., Cutting Boards: An Overlooked Source of Microplastics in Human Food? Environmental Science & Technology, 2023. 57(22): p. 8225-8235.
- Li, Y., et al., Microplastics in the human body: A comprehensive review of exposure, distribution, migration mechanisms, and toxicity. Sci Total Environ, 2024. 946: p. 174215.