Featured article in the Spring 2015 Issue of Nutrition Close-Up; written by Bridget Swinney MS, RDN
Along with eating local and organic, “Eating Clean” is a new trend that is growing in popularity. What exactly is clean eating? Although there are many interpretations, the overriding philosophy is to eat foods as close as possible to their natural state and minimize or avoid processed foods and refined sweeteners.
Though clean eating may be a new buzzword, it’s really nothing new. In fact, the American Institute for Cancer Research (AICR), the Academy of Nutrition and Dietetics, and the Institute of Medicine have all been recommending a diet rich in whole foods for decades. Karen Collins, MS, RDN, FAND, Nutrition Advisor to AICR, says “the concepts of ‘eating clean’ line up with steps to promote long-term overall health and reduce cancer risk as part of an ongoing lifestyle. But it’s important to know that research shows benefit even without changes as dramatic as some advocates of ‘clean eating’ suggest.”
Why eat clean during pregnancy?
A healthy diet before and during pregnancy can not only help a mom have a healthy, uncomplicated pregnancy, it can also positively program her baby’s health for a lifetime. The opposite is also true. Developmental Origins of Health and Disease theory (DOHaD), also known as Barker’s hypothesis, describes how prenatal “insults” such as undernutrition, overnutrition, and stress, could permanently shape or program the body’s structure, function, and metabolism, and lead to obesity and to cardiac, metabolic and psychological disorders in children and adults.
Diet quality plays an important role in pregnancy weight gain and outcomes. An imbalance of nutrients, such as a diet with a high proportion of concentrated sweets and excess saturated fat, or a diet that lacks fruits, vegetables and cereal fiber, has been linked to poor pregnancy outcomes. A high glycemic load in pregnancy has been associated with greater adiposity in offspring in early childhood and markers for metabolic syndrome in early adulthood. Eating more whole instead of processed foods, and limiting sweeteners, as recommended for clean eating, could result in a lower glycemic load and a healthier weight gain during pregnancy. However, if a woman drinks excessive amounts of juice, even organic, or uses a lot of evaporated cane juice or honey, this could have the opposite effect on glycemic load and weight gain.
While some processing increases bioavailability of nutrients like carotenoids and minerals, most forms of processing lead to decreased nutrient content to some extent. A ‘clean eating’ approach during pre-pregnancy and pregnancy potentially increases the antioxidant content of a woman’s diet. Antioxidants are important for fertility and early placental development. Oxidative stress also plays a role in fetal programming for future health and disease.
Some nutrients can protect an infant from negative fetal programming. Choline is one such nutrient, which is found in eggs. Neural tube defects, for example, are much more prevalent in a choline deficient environment.
Choline may also mitigate the negative effects of high cortisol levels caused by prenatal stress or depression. Choline provides methyl groups for cellular methylation reactions. The methylation state of cortisol-regulating genes is particularly sensitive to prenatal and early postnatal exposures. A small study of pregnant women found that women with higher choline intake (903 mg per day vs. 480 mg) were observed to have lower levels of placental cord cortisol and fewer changes in the cortisol-regulating genes. “The study findings raise the exciting possibility that a higher maternal choline intake may counter some of the adverse effects of prenatal stress on behavioral, neuroendocrine, and metabolic development in the offspring,” says Marie Caudill, PhD, an author of the study and a leading choline researcher.
Clean eating is not just about what’s in your food, it’s also about what isn’t. Choosing organic food when possible has been shown to decrease pesticide intake. Picking more whole foods limits food packaging, which can add unwanted chemicals like bisphenol A (BPA). In recent years, it’s been found that all animals, including humans, have a body burden of a variety of endocrine-disrupting chemicals such as BPA, polychlorinated biphenyls (PCBs), and phthalates. In fact, worldwide decreases in fertility have been partly blamed on this persistent burden of chemicals. There is strong but limited evidence that prenatal exposure to some of these chemicals may play a role in breast cancer, preterm birth and prostate cancer, as well as male birth defects. While many fruits and vegetables come in their own “packaging,” eggs are the only food that can be distributed, cooked and eaten out of their own natural, biodegradable package.
Women looking to have the healthiest pregnancy possible should consider clean eating. It’s a trend health professionals can wholeheartedly support, as long as women are counseled that portion size and glycemic load still count.
Bridget Swinney is a registered dietitian nutritionist and author of Eating Expectantly: Practical Advice for Healthy Eating Before, During and After Pregnancy and Baby Bites: Everything You Need to Know about Feeding Infants and Toddlers in One Handy Book. She is a frequent speaker on the topic of how early nutrition affects lifelong health.
- “Clean Eating” can mean many different things but the main philosophy is to eat foods as close as possible to their natural state while avoiding processed foods and refined sweeteners.
- Developmental origins of health and disease theory, or Barker’s hypothesis, suggests that overnutrition, undernutrition, exposure to stress, and environmental chemicals can program a fetus for a variety of physical and psychological disorders in childhood and adulthood.
- Clean eating before and during pregnancy has the potential to improve fertility, prenatal weight gain, and glycemic load; and decrease risk of birth defects.
- Wadhwa PD, Buss Cm Entringer S, et al. Developmental origins of health and disease: a brief history of the approach and current focus on epigenetic mechanisms. Seminars in reproductive medicine. 2009;27(5):358-368
- Junien C, Nathanielsz P. Report on the IASO Stock Conference 2006: early and lifelong environmental epigenomic programming of metabolic syndrome, obesity and type II diabetes. Obes Rev. 2007;8(6):487–502.
- Okubo H, Crozier SR, Harvey NC, et al. Maternal dietary glycemic index and glycemic load in early pregnancy are associated with offspring adiposity in childhood: the Southampton Women’s Survey. Am J Clin Nutr. 2014 Aug;100(2):676-83
- Danielsen I1, Granström C, Haldorsson T, et al. Dietary glycemic index during pregnancy is associated with biomarkers of the metabolic syndrome in offspring at age 20 years. PLoS One.2013 May 31;8(5):e64887.
- Thompson LP, Al-Hasan Y. Impact of Oxidative Stress in Fetal Programming. Journal of Pregnancy. 2012;2012:582748. doi:10.1155/2012/582748.
- Jiang, X., J. Yan, A. A. West, C. A. Perry, O. V. Malysheva, S. Devapatla, E. Pressman, F. Vermeylen, and M. A. Caudill. Maternal choline intake alters the epigenetic state of fetal cortisol-regulating genes in humans. FASEB J.2012;26:3563-3574.
- Shaw GM, et al. Periconceptional dietary intake of choline and betaine and neural tube defects in offspring. Am J Epidemiol. 2004;160:102-9.
- Birhnbaum LS, Director of National Institute of Environmental Health Sciences and National Toxicology Program. DOHaD: Role of environmental chemical exposures. Presentation, October 29, 2014. Boston, MA. Internet: https://www.endocrine.org/~/media/endosociety/Files/Meetings/PPTOX%20IV/53_Birnbaum.pdf. Accessed 2-28-15.