Evidence That Cranberry Juice May Help Fight Heart Disease

EMBARGOED FOR RELEASE: Monday, March 24, 8:00 p.m., Central Time

There's more good news about cranberry juice: Based on human studies, researchers have found that drinking three glasses a day significantly raises levels of "good cholesterol" in the blood and increases plasma antioxidant levels, reducing the risk of heart disease.

Although researchers have long suspected, based on laboratory tests, that the antioxidant-rich juice may help lower risk factors for heart disease, no human studies had established such a link until now. Their findings, the first long-term study of the effect on cranberry juice on cholesterol levels, were described today at the 225th national meeting of the American Chemical Society, the world's largest scientific society.

"This study gives consumers another reason to consider drinking cranberry juice, which has more health benefits than previously believed. People should consider drinking it with their meals, perhaps as an alternative to soda," says Joe Vinson, Ph.D., the study's lead author and a professor of chemistry at the University of Scranton in Scranton, Penn.

Besides heart benefits, previous studies have shown that cranberries can help prevent urinary tract infections and may reduce the risk of gum disease, stomach ulcers and cancer.

In the current study, Vinson measured cholesterol levels in nineteen subjects with high cholesterol after a fasting, baseline blood sampling, followed by monthly samplings. Ten of the subjects were given cranberry juice with artificial sweetener but without high fructose corn syrup, while the other subjects drank cranberry juice with no added sugars. The drinks tested all contained approximately 27 percent pure cranberry juice by volume, like the common supermarket variety.

Each subject was fed one glass (8 ounces) of juice a day for the first month, then two glasses a day for the next month, and three glasses a day during the third month of the study. Subjects were not monitored with respect to exercise, diet and alcohol consumption, the researcher says.

While there were no changes in overall cholesterol levels, good cholesterol (high density lipoprotein, or HDL) appeared to significantly increase by an average of 10 percent after three servings of juice per day. Based on known epidemiological data on heart disease, this increase corresponds to an approximate 40 percent reduction in heart disease risk, says Vinson.

Plasma antioxidant capacity, a measure of the total amount of antioxidants available for the body, was significantly increased -- by as much as 121 percent -- after 2 or 3 servings of juice per day, he says. Like elevated levels of good cholesterol, increased antioxidant levels are also associated with a decreased risk of heart disease.

The mechanism by which cranberry juice changes cholesterol levels has not been clearly established. Vinson suspects that the effect may have to do with the fruit's high levels of polyphenols, a type of potent antioxidant. Previous studies by the researcher have shown that cranberries have among the highest levels of phenols in comparison to 20 of the most commonly consumed fruits.

Eventually, Vinson plans to test the effect of cranberry juice consumption on subjects with normal cholesterol levels. To get the most health benefit from the juice, the researcher recommends drinking a low sugar version that contains an artificial sweetener.

If you don't like cranberry juice, there are other heart-healthy alternatives. A recent study by another researcher showed that drinking three cups of orange juice per day similarly increased levels of good cholesterol. Unlike cranberry juice, however, it did not appear to increase plasma antioxidant capacity, says Vinson.

As both juices are healthy, he suggests that people may want to include both types as part of their daily diet.

Grape juice, another breakfast favorite, increases plasma antioxidant capacity but appears to lower the level of good cholesterol, according to another study by Vinson.

There are many other types of juice whose effect on cholesterol levels is not known, he adds.

But don't forget exercise: Studies have shown that vigorous aerobic exercise has also been linked to increases in good cholesterol, says Vinson.

The current study underscores government health recommendations that people should eat more fruits and vegetables to help maintain a healthy diet and lifestyle.

The Cranberry Institute provided funding for this study.

The poster on this research, AGFD 65, will be presented at 8:00 p.m., Monday, March 24, at the Morial Convention Center, Hall G, during the "Sci-Mix" symposium.

Joe A. Vinson, Ph.D., is a professor of chemistry at the University of Scranton in Scranton, Penn.-- Mark T. Sampson

#13461 Released 03/24/2003

EMBARGOED FOR RELEASE: Monday, March 24, 8:00 p.m., Central TimeAGFD 65 Single-dose and supplementation studies with cranberry juice relevant to its role in heart disease and as an antioxidantJoe A. Vinson, Hassan Al Kharrat, and Najwa Samman, Department of Chemistry, University of Scranton, Scranton, PA 18510,

We have shown that cranberries have more phenol antioxidants (aox) than any of the 20 commonly consumed fruits, whether comparing on a fresh weight basis or by serving size [Vinson, J.A. et al. (2001). J. Agric. Food Chem. 49, 5315-5321]. When comparing phenols in dried fruit, cranberry ranks second behind dates but ahead of raisins, plums, and apricots. Cranberry juice (CJ) is higher in phenol antioxidants than other fruit juices with the exception of grape juice. A previously reported study showed that CJ was an in vivo antioxidant in humans; it significantly increased plasma aox capacity up to 7 hours after a single serving in comparison to a control of the CJ matrix with no CJ concentrate added [Vinson, J. A. (2001) FASEB J. 15, A287]. We performed a long - term study with hypercholesterolemic human subjects, not taking drugs. Nineteen subjects (11 females and 8 males) completed the study that consisted of a fasting baseline sampling and then monthly samplings. Ten of the subjects had CJ with no sugar added and an artificial sweetener. The other subjects consumed regular CJ with sugar. The first month one serving of CJ was consumed, then 2 servings, and finally 3 servings/day. There was no effect of CJ on cholesterol but CJ significantly decreased LDL with 2 servings/day. CJ significantly increased HDL and plasma antioxidant capacity with 2 or 3 servings/day. Triglycerides were elevated at 3 servings/day with the CJ with sugar, but not CJ and artificial sweetener. Thus elevated triglycerides were due to the added sugars in CJ. Two servings/day of CJ significantly improved LDL and HDL, two important parameters that may decrease the risk of heart disease.

EMBARGOED FOR RELEASE: Monday, March 24, 8:00 p.m., Central TimeAGFD 65

Single-dose and supplementation studies with cranberry juice relevant to its role in heart disease and as an antioxidant

*Briefly explain in lay language what you have done, why it is significant and its implications, particularly to the general public.

The public is well aware of the benefits of drinking cranberry juice (CJ) to prevent urinary tract infections. But there has been no long-term study of the effects of drinking CJ. There are two typed of CJ commercially available, one with high fructose corn syrup added and one with artificial sweetener added. We compared the two in a dose-response supplemenation study.

We have shown that cranberries have more phenol antioxidants (aox) than any of the 20 commonly consumed fruits, whether comparing on a fresh weight basis or by serving size [Vinson, J.A. et al. (2001). J. Agric. Food Chem. 49, 5315-5321]. When comparing phenols in dried fruit, cranberry ranks second behind dates but ahead of raisins, plums, figs, and apricots. CJ is higher in phenol antioxidants than other fruit juices with the exception of grape juice. The quality of the aoxs in CJ are not decreased by processing from the original cranberries as measured by an in vitro test which simulated the initial event in atherosclerosis, the oxidation of the lower density lipoproteins, A previously reported study showed that CJ was an in vivo antioxidant in humans; it significantly increased plasma aox capacity up to 7 hours after a single serving in comparison to a control of the CJ matrix with no CJ concentrate added [Vinson, J. A. (2001) FASEB J. 15, A287]. We performed a long - term study with human subjects with high cholesterol who were not taking drugs to lower cholesterol. Nineteen subjects (11 females and 8 males) completed the study that consisted of a fasting baseline sampling and then monthly samplings. Ten of the subjects had CJ with no sugar added and an artificial sweetener. The other subjects consumed regular CJ with sugar. The first month one serving of CJ was consumed, then 2 servings, and finally 3 servings/day. There was no effect of CJ on cholesterol even at the high dose. Triglycerides that were borderline high initially were not changed after 1 serving/day. Two serving of CJ with sugar increased triglycerides but they were still in the borderline range. CJ without sugar did not significantly increase triglycerides at either the 2 or 3-servings/day dose. Thus sugar is responsible for increasing triglycerides, a previously known phenomenon. Initial results indicate that LDL is decreased after 2 and 3 servings/day. HDL also appears to be increased after 2 and 3 servings/day. Fasting plasma aox capacity, which measures the total amount of antioxidants present in plasma, was significantly improved, i.e. increased, at 2 and 3 servings of CJ/day. The subjects were weighed initially and after 3 months of CJ supplementation. Surprisingly the subjects lost an average of 2 pounds that occurred with or without sugar consumption. This beneficial weight loss was almost significant.

The recommendation for a 24 hour prevention of urinary tract infection is 2 servings of CJ/day [JAMA 287:3082-3 (2002)]. Our long-term study shows that this dose of CJ does not detrimentally affect heart disease risk factors, even in subjects with high cholesterol. Initial results indicate that the heart disease risk factors LDL (the "bad cholesterol" and HDL the "good cholesterol") are improved with 2 servings of CJ/day. Two servings of CJ/day significantly increases plasma antioxidant capacity. CJ consumption with sugar does not cause weight gain, rather it produces a small weight loss.

*How new is this work and how does it differ from that of others who may be doing similar research?

This work is brand new.

*Corresponding author's name and business title or position:

Joe A. Vinson, PhD, Professor of Chemistry

*Work department: Department of Chemistry

*Business address including organization: University of ScrantonScranton, PA 18510