The Week in Review: The science of nutrition

Cruciferous Vegetables and Cancer Prevention: The mechanism. Previously published work has demonstrated that compounds present in cruciferous vegetables, such as broccoli, can help to prevent cancer. A new study now begins to elucidate the mechanism. Cruciferous vegetables contain a compound called sulforaphane. Recently, researchers have discovered that this compound actually affects the expression of portions of our RNA called long non-coding RNAs (IncRNAs). This portion of genome in the past was thought to be without significant function. However, as with almost everything in the human body, there is a function to be found. lncRNAs have increasingly been found to participate in the development of numerous types of cancer including prostate, breast, stomach, and lung cancers.

lncRNAs have been thought to perhaps be able to regulate gene expression. This could open a whole new study of nutritional strategies related to cancer prevention or therapeutic control of cancer once it has developed, and prevention of cancer recurrence. This study was recently published in my new favorite journal, Nutritional Biochemistry, by Laura Beaver and her colleagues from Oregon State University. These investigators found that sulforaphane mediated alterations in lncRNA which correlated with genes that regulate cell cycle, signal transduction, and metabolism. These are all important players in the role of cancer development.

Nutrition and Stress Management in Women New research investigating the links between nutrition and psychogenic stress, has demonstrated that by eating nutritious fruits and vegetables of up to seven servings per day can lower the risk of psychogenic stress for middle-aged women. This stress includes irritability, anger, nervousness, anxiety, and depression. These investigators found that women who ate five to seven servings of fruits and vegetables each day had a 23% lower risk of stress compared with women who consumed no servings of fruits and vegetables each day. This study was published by Binh Nguyen and colleagues from New South Wales in Australia in the British Medical Journal recently. While it might not be easy in our modern-day society to actually escape stress, we can learn how to manage it not only through mindfulness, finding joy in life, but also through a healthy diet of seven servings of fruits and vegetables each day.

Probiotics; More is not always better. There is emerging data that indicates that gut bacteria can impact brain function. Animals who are on gut disrupting antibiotics that change the gut microbiome have impaired memory and anxiety-like behaviors. Probiotics may not always be needed and indeed may be harmful when not used appropriately. Recent laboratory studies have demonstrated that in rats with grosslydysregulated gut health due to poor diet “junk food diet”, that probiotics would positively change the bacterial makeup in their digestive track and benefited brain function. However, in rats that are fed excellent diets, brain function may actually be impaired by probiotic supplementation. It was also interesting to note that the “junk food diet” actually not only altered the gut microbiome, but also affected the expression of genes in the brains that are involved in neuroplasticity, which are most likely involved in memory impairment

Based on this laboratory data, it may be that probiotics are great when you have a poor diet but not so great when you're nutrition is already good. We definitely need more information on how to appropriately incorporate probiotics in out health lifesyle.This study was published in the Journal of Molecular Psychiatry by JE Beilharz and colleagues.

Vitamin C: Effects on cancer stem cells. A recent study from the Journal Oncotarget was published that demonstrated that cancer stem cells are more susceptible to vitamin C , when compared toother medications or natural substances. The stem cells are the renewing cells in a tumor that may lead to treatment failures.  Vitamin C was demonstrated to inhibit glycolysis, the process by which glucose is broken down within the cells' mitochondria and turned into energy for the cells' division and proliferation. Vitamin C may be then studied to be used in addition to more conventional therapies to prevent tumor recurrence, progression and metastasis. This is the first study that has demonstrated that vitamin C or ascorbic acid can specifically target cancer stem cells.

Gluten Free: Diabetes risk may be altered. Gluten free diets may increase the risk of type 2 diabetes. More and people are going gluten free today, however it might not be so good for some people. In a recent analysis of three long term studies: the Nurses Health Study 1 and 2, and the Health Professionals Follow-Up Study, it was found that individuals who consumed gluten had a 13% less likelihood of having diabetes. Those that had the highest gluten intake, up to 12 grams per day, had a lower risk of developing type 2 diabetes over the 30 year period which was studied; compared to those who consumed below four grams per day. This study was presented at the American Heart Association's Epidemiology Prevention and Lifestyle 2017 scientific session, and was presented by Geng Zong; from the Department of Nutrition at Harvard University. Again, we need more information on the topic.