Go to Health: News about Walnuts & Cranberries

Walnuts – Breast and Prostate Cancer:
Dr Elaine Hardman, at Marshall University School of Medicine in West Virginia, has been investigating diet and cancer for years. She noted that walnuts contain multiple ingredients that slow cancer growth, including omega-3 fatty acids, antioxidants, and phytosterols (healthy compounds in plants that are similar to cholesterol, and reduce cholesterol in humans). Hardman worked with mice that are genetically likely to develop breast cancer at high rates. She studied mice given walnuts during pregnancy through weaning, and then the pups were fed a walnut supplemented diet. These mice developed breast cancer at less than half the rate of a group on a typical lab-mouse diet. Additionally, the number of tumors and their sizes were smaller. Gene analysis showed that those on the walnut diet had different expression of genes associated with the breast cancers in mice and humans. The amount of walnuts fed to the rats would correspond to about 2 oz. daily in humans. One cup of walnut halves is about 3 1/2 ounces. Hardman also found that increases in omega-3 fatty acids did not fully account for the anti-cancer effect, and that tumor growth decreased when dietary vitamin E increased. Dietary vitamin E is found in nuts, sunflower seeds, spinach and other leafy vegetables, and many natural foods.

Dr. Paul Davis at UC Davis has studied the benefits of walnuts in mice genetically programmed to develop prostate cancer. When he compared 8 week pups given added walnuts to control pups given added soy oil, those in the walnut group had cancers 30-40% smaller. They also had reductions in several proteins that may increase cancer growth, including insulinlike growth factor-1. Davis said the amount of walnuts humans should eat to correspond to the mouse diet was about 2.4 ounces daily.

Walnuts also contribute to heart health, by decreasing LDL cholesterol, lowering the risk of clotting, and decreasing inflammation. Numerous studies have shown that they do not cause weight gain, but rather make people less hungry for other high-fat, sugary foods.

Cranberries- Blood vessel flexibility and infection prevention:
Researchers at Boston and Tufts Universities recently reported that people with heart disease (coronary artery disease) showed a decrease in the stiffness of the aorta after drinking double-strength cranberry juice. Blood vessel dilation and blood flow to the arms also improved, but in an uncontrolled pilot study. Subjects drank 16 ounces of a cranberry drink that was 54% cranberry juice daily. Authors of the study point out that the flavonoids in plant foods have multiple benefits. Flavonoids are plant pigments that that have anti-inflammatory, anti-microbial and anti-cancer activities. In the case of cranberries, the heart benefits are added to known anti-bacterial benefits. A recent study that looked at daily cranberry pills compared to antibiotics to prevent bladder infections in women. Those taking the antibiotic (Bactrim) had the fewest bladder infections, although the cranberry pills were also effective. However, women taking the antibiotic developed resistance to Bactrim and other antibiotics. Cranberries are believed to be helpful by preventing bacteria from sticking to the walls of the bladder and urethra and multiplying.

Rather than taking cranberry pills, it is probably better to drink the whole juice on a daily basis, for heart health (if you have narrowed arteries), or to prevent frequent bladder infections. Note – people on Coumadin should not drink cranberry juice without talking to their doctor – it can increase the risk of bleeding. For all other interested people, I suggest looking for an unsweetened cranberry concentrate, which you can usually find in health food stores. Mix it with water, add a little apple juice for sweetener or put it in your shake. Some people love its sour taste. Fall is coming, and whole cranberries will be in the market soon!
Sadja Greenwood, MD MPH back issues on this blog