Editor’s note: The authors of the journal article are scientific consultants for Ocean Spray Cranberries, Inc. (Lakeville-Middleboro, Massachusetts), which provided unrestricted funding for the study. The sponsor had no input in the study design or interpretation of the results.
Reviewed: Duffey KJ, Sutherland LA. Adult consumers of cranberry juice cocktail have lower C-reactive protein levels compared with nonconsumers. Nutr Res. February 2015;35(2):118-126.
Consumption of sweetened drinks has been shown to correlate with weight gain, obesity, metabolic syndrome, and diabetes. However, unlike other sweetened beverages, fruit juice may provide certain health benefits due to beneficial components such as antioxidants, vitamins, and fiber. Cranberry (Vaccinium macrocarpon, Ericaceae) fruit juice is high in antioxidants, including proanthocyanidins and anthocyanins, which impart a dark red color to the juice. Cranberry juice is tart and naturally low in sugar, so sugar may be added to make the juice more palatable. Sweetened cranberry juice is often designated “cranberry juice cocktail” (CJC). The current observational study examined the association of CJC consumption with anthropometric parameters and concentration of inflammatory biomarkers, insulin, and lipids in the blood.
Data from participants (N = 10,891) aged 19 years or older were taken from the National Health and Nutrition Examination Survey (NHANES) conducted by the US Centers for Disease Control and Prevention between 2005 and 2008. Of these subjects, 557 were excluded because no data were provided on CJC consumption. The study consisted of a physical examination — which included fasting blood collection, anthropometric measurements (height, weight, waist circumference, and body mass index [BMI]), and dietary recall for the previous 24-hour period — and a phone interview 3-10 days later, in which subjects again recalled their diet from the last 24 hours. CJC consumption was calculated as the total consumption for both 24-hour periods.
Researchers collected demographic information and measured blood levels of total cholesterol, high-density lipoprotein (HDL), triglycerides (TG), glucose, insulin, and C-reactive protein (CRP), a marker of systemic inflammation in the body. (High levels of CRP in the blood can indicate an infection or inflammation caused by another source; some research suggests that CRP levels may also provide information about a patient’s risk of cardiovascular disease.1) Low-density lipoprotein (LDL, sometimes referred to as “bad cholesterol”) was calculated by subtracting HDL and TG from the total cholesterol concentration. Data were analyzed with different statistical methods: the Student’s t-test, chi-squared analysis, and linear and Poisson regression.
On average, CJC consumers drank 404 mL of CJC per two-day period, while “nonconsumers” drank 12 mL of the juice during the same period. CJC consumers had significantly higher carbohydrate and polyphenolic intake than nonconsumers (P < 0.05). In addition, CRP concentrations were lower in CJC consumers than nonconsumers (P = 0.015). CJC consumers tended to have smaller waist circumferences as well as lower BMIs and levels of fasting glucose, insulin, total cholesterol, and TG, but the differences were not statistically significant. CJC consumers also were more likely to be of normal weight. The authors suggest that this outcome may be directly related to, but not necessarily caused by, consumption of the sweetened fruit juice; alternatively, the authors propose that CJC consumption simply may be indicative of the juice consumers’ generally healthy diet and lifestyle.
Although this study included a measure of total energy intake, it did not control for the consumption of specific food types, which would have been helpful in identifying confounding factors. Previous studies have found positive relationships between acute cranberry juice consumption and plasma antioxidant levels. This suggests that cranberry juice may lower oxidative stress and inflammation, which would be consistent with the lowered CRP levels found in this study. Yet, other studies have found no relationship between acute cranberry juice consumption and blood antioxidant or CRP levels. This study was limited by its observational nature, which made it difficult to infer a direct relationship between CJC consumption and lowered CRP levels and smaller waist circumferences.
—Cheryl McCutchan, PhD
Reference
- C-reactive protein (CRP). WebMD website. Available at: www.webmd.com/a-to-z-guides/c-reactive-protein-crp. Accessed September 30, 2015.