Nutrition Bytes: July 2022

Consumption of Cranberry Powder Improves Blood Vessel Function in Men

A new study published in Food and Function1 found that daily consumption of cranberry powder improved cardiovascular health, particularly blood vessel function, in men. The researchers took 45 healthy men aged 18 to 45 years and randomly assigned them to consume 9 grams whole cranberry powder (equivalent to approximately 1 cup fresh cranberries) or placebo for one month. Flow-mediated dilation (FMD), which measures how well the blood vessels relax when blood flow increases in an artery, was assessed at the beginning of the study, two hours after first consumption, and one month after the intervention. In contrast to placebo, consuming cranberry significantly increased FMD, or the ability of blood vessels to relax. Improvements in FMD were observed both two hours after and one month following daily cranberry consumption, indicating that consuming cranberries could have immediate and chronic benefits to vascular health. 

Image of cranberriesAlongside enhanced blood vessel function, the researchers also noted significant increases in blood levels of polyphenols following cranberry consumption, which is likely the reason cranberry lead to improvements in cardiovascular health. Polyphenols are health-promoting chemicals naturally produced by plants, and cranberries are a particularly rich source of these compounds. Research shows that polyphenols may support cardiovascular health due to their antioxidant function. They may also increase the bioavailability of nitric oxide (a molecule that helps blood vessels relax) within blood vessels.

Preliminary Research Shows Sulforaphane, a Compound Found in Broccoli, Combats COVID-19

In a recent study published in the Nature journal Communications Biology,2 scientists showed that the plant compound sulforaphane can slow the growth of SARS-CoV-2 and other common cold viruses. Sulforaphane is a phytonutrient found in cruciferous vegetables like broccoli, Brussels sprouts, and kale, and is also sold as a dietary supplement. When the pandemic began, many labs investigating pathogens shifted their focus to SARS-CoV-2 and began investigating compounds that might serve as a potential treatment for this challenging new virus; sulforaphane was one of these compounds.

In the study, scientists exposed cells to sulforaphane for 1-2 hours before infecting the cells with SARS-CoV-2 and a common cold coronavirus. They found that even at low concentrations, sulforaphane reduced the replication by 50 percent of six different strains of SARS-CoV-2, including the delta and omicron variants. The investigators found that sulforaphane reduced replication rates even when the virus was applied to the cells first, showing that sulforaphane has protective effects even with an already established viral infection.

Image Of BroccoliResearchers then conducted studies in a mouse model of SARS-CoV-2 infection by giving mice 30 milligrams of sulforaphane per kilogram of body weight. Pre-treatment with sulforaphane resulted in a significant decrease in the amount of virus in the lungs and upper respiratory tract, as well as a 29 percent decrease in the amount of lung injury compared to infected mice that were not given sulforaphane. Treatment also decreased inflammation in the lungs, protecting the cells from an overexaggerated immune response, the type of immune response that seems to be one of the driving factors that has caused many to die from COVID-19.

Human studies will determine if sulforaphane can help prevent or treat these infections in humans, but in the meantime, we could all benefit from eating more broccoli and leafy greens. Additionally, now is a great time to learn about the many health benefits of sulforaphane in supplement form.


  1. Heiss, C., Istas, G., et al. (2022). Daily consumption of cranberry improves endothelial function in healthy adults: a double blind randomized controlled trial. Food & Function, 13:3812. DOI: 10.1039/d2fo00080f
  2. Alvaro A. Ordonez, C. Korin Bullen, Andres F. Villabona-Rueda, et al. Sulforaphane exhibits antiviral activity against pandemic SARS-CoV-2 and seasonal HCoV-OC43 coronaviruses in vitro and in mice. Communications Biology, 2022; 5 (1) DOI: 10.1038/s42003-022-03189-z