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Ruth MacDonald

Professor and Chair, Food Science and Human Nutrition, Assistant Dean of Graduate Programs, College of Agriculture and Life Sciences, Iowa State University

Expert Bio

Ruth MacDonald is currently the Chair and Professor of the Department of Food Science and Human Nutrition at Iowa State University since 2004. She received her Ph.D. in Nutrition and Food Science from University of Minnesota, and since then, she has written multiple publications about the relationship between soy components and botanicals and breast, prostate, and colon cancer progression.

For the 17 years before her position at Iowa State, she served on the faculty at University of Missouri in the Departments of Food Science and Nutritional Sciences. She was a member of the Food for the 21st Century Nutrition Cluster, and she serves on the editorial board of the Journal of Nutrition, The Korean Journal of Nutrition, been on grant review panels for the US Army Breast Cancer Program, US Department of Agriculture, National Institutes of Health and other funding groups. Additionally, she is a member of the American Association for Nutritional Sciences, American Association for Cancer Research, Sigma Xi, and the Institute for Food Technologists.

Studies, Articles and Answers

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Showing 10 out of 12 results

Question

Q: Hasn’t the rise in obesity been linked directly to when GMOs were introduced into our diet?

Answered By Ruth MacDonald - Jul 30, 2013

A: First, let’s start with the definition of obesity. “Obesity occurs when, over time, the body takes in more calories than it burns,” according to the Endocrine Society.  When a person’s body mass index (BMI) is over 30, that person is considered obese.  Because obesity is related to the number of calories a person consumes, a GM crop would have to contain considerably more calories than non-GM varieties of that crop to be linked to obesity. But the fact is that GM crops are carefully reviewed to make sure they are substantially equivalent to non-GM crops in their composition and [...]

GMO Basics Health & Safety

Question

Q: How come food items that contain GMOs are unlabeled in America?

Answered By Ruth MacDonald - Sep 05, 2013

A: The U.S. Food and Drug Administration, which regulates food labels, has determined that the process of using biotechnology to produce foods does not need to be identified on a food label unless the process has modified the food or ingredient in a manner that changes how it is used in the food, its nutritional composition or whether it includes a potential allergen. Based on scientific evidence, the FDA scientists have concluded that the GM foods and food ingredients being used in the United States today are no different from their non-GM counterparts in any way that would requi [...]

GMOs in Groceries Health & Safety Labeling

Question

Q: How can you say that there are very few products in our grocery stores that have GMO's, when every packaged food is filled with them. My estimate is 75% and I read labels all of the time and I know what foods have genetically modified corn, soy, etc. Just

Answered By Ruth MacDonald - Aug 27, 2013

A: There is a great deal of confusion about what foods are GMOs in the grocery store. Many people believe that the produce aisle is full of GM foods, which is not accurate. Nothing in the produce aisle in the United States is GM―with the exception of papayas from Hawaii and some squash and sweet corn. The majority of corn and soybeans grown in the United States are GM. These commodities are processed to generate food ingredients that enter the food supply. From corn we obtain corn oil and corn starch. The starch can be converted into corn syrup, and sweeteners as well. From soybeans we obtain soy [...]

GMO Basics How GMOs Are Made

Question

Q: Does Xanthin gum come from a genetically modified source

Answered By Ruth MacDonald - Oct 02, 2014

A: Xanthan gum is made by allowing a very specific bacteria (Xanthomonas campestris) to grow in a liquid solution that contains carbohydrates and other nutrients. While growing, the bacteria uses the carbohydrate to produce the xanthan gum which is released into the liquid. The xanthan gum is then separated completely from the bacteria and the liquid and dried into a powder. Xanthan gum has a chemical structure that is in the same family as carbohydrates but has unique properties for adding texture and volume to foods. Depending on what company is making the xanthan gum, the source of carbohydra [...]

Answered By Ruth MacDonald - Oct 02, 2014

A: Xanthan gum is made by allowing a very specific bacteria (Xanthomonas campestris) to grow in a liquid solution that contains carbohydrates and other nutrients. While growing, the bacteria uses the carbohydrate to produce the xanthan gum which is released into the liquid. The xanthan gum is then separated completely from the bacteria and the liquid and dried into a powder. Xanthan gum has a chemical structure that is in the same family as carbohydrates but has unique properties for adding texture and volume to foods. Depending on what company is making the xanthan gum, the source of carbohydra [...]

GMO Basics Health & Safety

Question

Q: Does Xanthin gum come from a genetically modified source

Answered By Ruth MacDonald - Oct 02, 2014

A: Xanthan gum is made by allowing a very specific bacteria (Xanthomonas campestris) to grow in a liquid solution that contains carbohydrates and other nutrients. While growing, the bacteria uses the carbohydrate to produce the xanthan gum which is released into the liquid. The xanthan gum is then separated completely from the bacteria and the liquid and dried into a powder. Xanthan gum has a chemical structure that is in the same family as carbohydrates but has unique properties for adding texture and volume to foods. Depending on what company is making the xanthan gum, the source of carbohydra [...]

Answered By Ruth MacDonald - Oct 02, 2014

A: Xanthan gum is made by allowing a very specific bacteria (Xanthomonas campestris) to grow in a liquid solution that contains carbohydrates and other nutrients. While growing, the bacteria uses the carbohydrate to produce the xanthan gum which is released into the liquid. The xanthan gum is then separated completely from the bacteria and the liquid and dried into a powder. Xanthan gum has a chemical structure that is in the same family as carbohydrates but has unique properties for adding texture and volume to foods. Depending on what company is making the xanthan gum, the source of carbohydra [...]

GMO Basics Health & Safety

Question

Q: Can the body tell the difference between gmo and non gmo foods?

Answered By Ruth MacDonald - Jun 05, 2015

A: The way the body digests and utilizes food is the same regardless of how the food was originally produced. GMO technology allows for the insertion of a specific gene (a small piece of DNA) into a plant seed, which then becomes part of the entire pool of DNA in that plant. The inserted gene looks the same as the rest of the DNA, and when we eat the plant, our body breaks down all of the DNA in the same way. The products produced by the DNA are proteins (DNA is a code that tells the plant how to link amino acids together to generate proteins), which are also digested by the enzymes present in o [...]

Health & Safety

Question

Q: what are some chemical reactions of gmo chemicals and the body?

Answered By Ruth MacDonald - Mar 13, 2015

A: The primary type of ‘reaction’ that would occur in response to a chemical consumed in food would be an allergic reaction. There has never been any documented allergic reaction associated with the consumption of a GMO-derived food that is currently available in the US food system. The FDA requires that any new GMO product be tested to ensure there are no potential negative effects due to the proteins expressed by the inserted DNA. Humans and animals have been consuming GMO derived foods for several decades, and there is no evidence that any negative reactions have occurred from the [...]

GMO Basics Health & Safety

Question

Q: do normal i mean natural foods dna enter into my blood stream through ingestion????

Answered By Ruth MacDonald - Jul 10, 2015

A: The answer to this question is, “no.” DNA is present in all fruits and vegetables, meat, milk and eggs. The molecular structure of DNA is actually pretty simple; it is made up of nucleic acids linked with bonds to create the double helix we are so familiar with seeing. When in that structure DNA is able to transfer information about how to build proteins, DNA is transcribed by RNA and then RNA translates the code to put amino acids together to form proteins.   When DNA is consumed in foods, it enters the small intestine and is digested by enzymes that come from the pancreas [...]

Answered By Ruth MacDonald - Jul 10, 2015

A: The answer to this question is, “no.” DNA is present in all fruits and vegetables, meat, milk and eggs. The molecular structure of DNA is actually pretty simple; it is made up of nucleic acids linked with bonds to create the double helix we are so familiar with seeing. When in that structure DNA is able to transfer information about how to build proteins, DNA is transcribed by RNA and then RNA translates the code to put amino acids together to form proteins.   When DNA is consumed in foods, it enters the small intestine and is digested by enzymes that come from the pancreas [...]

Other

Question

Q: do normal i mean natural foods dna enter into my blood stream through ingestion????

Answered By Ruth MacDonald - Jul 10, 2015

A: The answer to this question is, “no.” DNA is present in all fruits and vegetables, meat, milk and eggs. The molecular structure of DNA is actually pretty simple; it is made up of nucleic acids linked with bonds to create the double helix we are so familiar with seeing. When in that structure DNA is able to transfer information about how to build proteins, DNA is transcribed by RNA and then RNA translates the code to put amino acids together to form proteins.   When DNA is consumed in foods, it enters the small intestine and is digested by enzymes that come from the pancreas [...]

Answered By Ruth MacDonald - Jul 10, 2015

A: The answer to this question is, “no.” DNA is present in all fruits and vegetables, meat, milk and eggs. The molecular structure of DNA is actually pretty simple; it is made up of nucleic acids linked with bonds to create the double helix we are so familiar with seeing. When in that structure DNA is able to transfer information about how to build proteins, DNA is transcribed by RNA and then RNA translates the code to put amino acids together to form proteins.   When DNA is consumed in foods, it enters the small intestine and is digested by enzymes that come from the pancreas [...]

Other

Question

Q: Hello, Im doing a school project about GMOS and if they are causing obesity in the world. It would be great if I could have some information about the subject.

Answered By Ruth MacDonald - Oct 02, 2015

A: Obesity is a major health concern for the U.S. but also in many countries around the world. There are many factors that may have influenced the rapid rise in obesity observed over the past 50 years. Among these are more sedentary and stressful lifestyles, larger portion sizes and more access to fast food. Also, higher consumption of sweetened beverages, especially by children and young adults, has been reported. All of these factors create an imbalance of energy leading to more calories consumed than expended which leads to gain in body fat. Other ideas about the causes of obesity have been p [...]

Environment Health & Safety