Giving seniors purple grape juice
The study included 21 people, age 68 and older, diagnosed with mild age-related memory decline and not meeting the criteria for dementia. They were randomly assigned to receive either 100% Concord grape juice or a placebo drink every day for 16 weeks. The total amount of juice consumed per day (444 to 621 ml, or 14 to 21 ounces) was determined by each person's body weight.
Concord grapes are deep blue to purple due to their high content of pigments known as polyphenols. Polyphenols are anti-inflammatory and antioxidant, which may account for some of their previously demonstrated health benefits.
The participants underwent memory and mood testing at the beginning and end of the trial. In addition, brain imaging was performed during testing to see if there were differences in activation levels of regions of the brain thought to be involved in memory.
Fewer errors in juice drinkers
The two groups performed similarly on memory tests at both ends of the study; however, there were two important differences between the groups:
The grape juice drinkers made fewer intrusion errors on memory tests at the end of the trial. Intrusion errors occur when information that is related to the theme of a memory, but is not actually part of the event being remembered, become associated with the memory. For example, during memory tests, subjects may be given lists of words and told to remember just one list; when asked to recall that list, remembering a word from a different list would be an intrusion error. A high number of intrusion errors on a memory test would indicate that a person has difficulty distinguishing actual memories from irrelevant thoughts. This is a common characteristic of the early stages of memory loss.
Drinking grape juice was associated with a higher degree of activation in parts of the right brain hemisphere where researchers believe memory retrieval occurs.
"On balance, the findings provide further indications that polyphenol-rich Concord grape juice supplementation has benefit for neurocognitive function in older adults with mild memory decline," the study authors said.
Grapes are great food
Preventing memory loss might be one of a number of good reasons to eat Concord grapes and enjoy grape products like juice and wine. Here are some others:
- Better blood sugar control. Polyphenols from grapes have beneficial effects on metabolism and might improve blood sugar control.
- Lower blood pressure. Some researchers have found that drinking Concord grape juice can reduce blood pressure in people with hypertension.
- Nerve cell protection. The antioxidant effects of grape polyphenols have been found to protect nerve cells from damage.
- Higher immunity. Drinking Concord grape juice was found to increase immune cell activity in healthy people.
(J Agric Food Chem 2012;dx.doi.org/10.1021/jf300277g)