BodySense Blog

Calcium tied to lower cancer risk in older people

     

CHICAGO – A study in nearly half a million older men and women bolsters evidence that diets rich in calcium may help protect against some cancers. The benefits were mostly associated with foods high in calcium, rather than calcium tablets.

Previous studies have produced conflicting results. The new research involved food questionnaires from participants and a follow-up check of records for cancer cases during the subsequent seven years. This research method is less rigorous than some previous but smaller studies.

But because of its huge size — 492,810 people and more than 50,000 cancers — the new study presents powerful evidence favoring the idea that calcium may somehow keep cells from becoming cancerous, said University of North Carolina nutrition expert John Anderson, who was not involved in the study.

The study was run jointly by the National Institutes of Health and AARP. The results appear in Monday's Archives of Internal Medicine.

National Cancer Institute researcher Yikyung Park, the study's lead author, called the results strong but said more studies are needed to confirm the findings.

Duke University nutrition researcher Denise Snyder said the results support the idea that food rather than supplements is the best source for nutrients.

Participants were AARP members aged 50 to 71 who began the study in the mid-1990s. A total of 36,965 men and 16,605 women were later diagnosed with cancer. There were more than 10 different kinds of cancer, the most common being prostate, breast, lung and colorectal.

Compared with people who got little calcium, those who consumed the most had the lowest chances of getting colon cancer. Those in that highest category got on average 1,530 milligrams a day among men and 1,881 milligrams daily among women. The recommended amount for older people is 1,200 milligrams, and getting much more than that didn't result in any greater protection. Adults can get that amount from four cups of milk or calcium-fortified orange juice.

Men who got the most calcium from food were about 30 percent less likely to get cancer of the esophagus, about 20 percent less likely to get head and neck cancer and 16 percent less likely to get colon cancer, when compared to men who got low amounts of calcium.

Among women, those who got the most food-based calcium were 28 percent less likely to get colon cancer than low-calcium women.

In men, calcium supplements only seemed to help protect against colon cancer; for women, supplements meant a lower risk for liver cancer, which is rare.

Some previous studies have linked diets high in calcium with prostate cancer but the current study found no such risk.

Adults who ate the most calcium also tended to be healthier overall than the others.

Northwestern University preventive medicine instructor Patricia Sheean called the results impressive. But she noted that all those in the study, AARP members, may have been healthier and wealthier than the general U.S. population so it's not clear if the results would apply to the wider population.

By LINDSEY TANNER, AP Medical Writer

Preventing Cancer Part 2: Supplements

We all need essential fatty acids for optimum health, but most Americans consume far too many omega-6 fatty acids (mainly from vegetable oils), and not enough omega-3 fatty acids (found in oily fish, walnuts and freshly ground flaxseed). This imbalance can lead to an increased risk of heart disease, inflammatory conditions, cancer and other health concerns.

While eating several servings of oily fish (I prefer wild Alaskan salmon and sardines) per week is a start, you may want to take fish oil supplements, especially if you don't enjoy fish. Available in liquid or capsule forms, fish oil is effective at helping to reduce blood pressure, is beneficial to the nervous system, and can even help alleviate mild to moderate depression. Omega-3 fatty acids may also help support the health of breast tissue by maintaining healthy breast cells, a positive note for women with a family history of breast cancer. Look for capsules or oil that are certified free of contaminants, and begin with small daily doses, building up to the recommended amount.

DrWeil.com

More Amazing News About Vitamin D

We’ve been hearing a lot about vitamin D recently. In addition to its contribution to bone health, it seems to prevent some types of cancer and protect against multiple sclerosis and rheumatoid arthritis. Now, a vitamin D researcher at the University of California, Riverside, has noted that “D” also affects insulin secretion and regulation, heart and blood pressure regulation, muscle strength and brain activity. Writing in the August 2008 issue of the American Journal of Clinical Nutrition, Anthony Norman, distinguished professor emeritus of biochemistry and biomedical sciences, says that cells in 36 organs respond biologically to vitamin D. He notes that a deficiency of “D” can affect all of those organs including bone marrow, breast, colon, intestine, kidney, lung, prostate, retina, skin, stomach and uterus. Norman recommends an average daily intake of 2,000 IU of vitamin D for all adults, a dosage some other experts have suggested. The current RDA is 200 IU for adults up to the age of 50, 400 IU for those ages 51 to 70 and 600 for those over 70. My current recommendation for supplementation is 1,000 IU.

DrWeil.com

Breast Cancer: Six Signs to Look For

Do you know the signs and symptoms that might indicate breast cancer? While personal and family histories of breast cancer and lifestyle habits (including diet, exercise and how you handle stress), can all affect breast-cancer risk, learning to recognize the signs of breast cancer may save your life - early diagnosis is key to treatment and recovery. Performing a monthly self-examination is still recommended by many health professionals, as is having a yearly exam performed by your doctor. In addition, the National Cancer Institute suggests keeping an eye out for the following signs:

1. A lump or thickening in or near the breast or in the underarm area
2. A change in the size or shape of the breast
3. Nipple discharge or tenderness
4. An inverted nipple
5. Ridges or pitting on the breast (resembling an orange peel)
6. A change in the look or feel of the breast, areola or nipple (such as temperature, swelling, redness or a scaly feel)

If you are experiencing any of these symptoms, see your doctor for a diagnosis and possible treatment. If you are over 40, talk to your doctor about mammograms.

DrWeil.com

7 Diet Tips to Help Prevent Cancer

A healthy diet can help the body in its efforts to heal itself, and in some cases, particular foods can strengthen the immune system and lessen the risks of serious illness. To help reduce your risk of some types of cancer, try the following:

1. Avoid polyunsaturated vegetable oils, margarine, vegetable shortening, all partially hydrogenated oils, and all foods that might contain trans-fatty acids (such as deep-fried foods).
2. Increase omega-3 fatty acids by eating more cold water oily fish, freshly ground flaxseeds, and walnuts.
3. Reduce consumption of animal foods and try to replace them with vegetable proteins such as whole soy products.
4. Use hormone-free, organically produced products whenever possible.
5. Eat plenty of fresh fruits and vegetables.
6. Eat shiitake, enokitake, maitake, and oyster mushrooms frequently.
7. Drink green tea daily.

DrWeil.com

Five Ways to Prevent Prostate Cancer

Prostate cancer is the second most common cause of cancer deaths in men. Scientists have estimated that lifestyle factors account for about 75 percent of advanced prostate cancer cases. Of all the environmental factors, diet appears to be the most influential. So what can you do about prostate cancer? Try the following:

1. Watch your diet. Avoid a diet high in red meat, saturated fat and dairy products, all of which may increase the risk for prostate cancer. Instead, eat more tomatoes, especially tomatoes in sauces - they contain lycopene, a carotenoid linked to a lower risk of prostate cancer. Also include whole soy foods, which contain genistein, an isoflavone that helps normalize hormone levels; fish, which may lower the risk of prostate cancer; and fiber, which influences the elimination of hormones such as testosterone and estrogen.
2. Drink green tea. Lab studies indicate that an antioxidant compound in green tea called EGCG kills prostate cancer. Another compound in green tea blocks the actions of an enzyme that promotes prostate cancer.
3. Exercise. Regular aerobic exercise is associated with a reduced risk of prostate cancer.
4. Take a multivitamin that includes vitamin D and antioxidants, especially selenium.
5. Have regular screenings. Rectal exams can provide early detection of problems with the prostate gland.

DrWeil.com

Bisphenol A exposure linked to cardiovascular disease, diabetes

Exposure to bisphenol A (BPA), a chemical used in the resins that line food and beverage containers and in the production of polycarbonate plastics, appears to increase the risk of cardiovascular disease and diabetes, according to epidemiologic findings reported in the Journal of the American Medical Association for September 17.

In the study, each standard deviation increase in urinary BPA levels, a proxy for BPA exposure, increased the risks of cardiovascular disease and diabetes by 39% each.

Findings from animal studies have raised concerns that low-level exposure to BPA may have a harmful in humans, senior author Dr. David Melzer, from Peninsula Medical School in Exeter, UK, and colleagues explain.

Most research has focused on the estrogenic activity of the chemical, but there is evidence that BPA may cause damage through other mechanisms, including disruption of pancreatic beta-cell function and obesity-promoting effects. Initially, it was believed that there was a safe threshold for exposure, but recent reports have questioned this.

The present study involved a cross-sectional analysis of data from the National Health and Nutrition Examination Survey 2003-2005. Included were 1455 subjects, between 18 and 74 years of age, who had urinary BPA levels measured.

As noted, higher urinary levels of BPA were associated with elevated risks of both cardiovascular disease (p = 0.001) and diabetes (p < 0.001). By contrast, BPA exposure did not appear to have an effect on the occurrence of other common diseases, including arthritis, cancer, liver disease, respiratory disease, stroke, or thyroid disease.

An increase in urinary BPA was also associated with abnormal levels of two liver enzymes. For each standard deviation increase in BPA levels, the likelihood of an abnormal level for gamma-glutamyltransferase and alkaline phosphatase rose by 29% (p < 0.001) and 48% (p = 0.002), respectively.

The current research supports animal data, but "independent replication and follow-up studies are needed to confirm these findings and to provide evidence on whether the associations are causal," the research team notes.

In an accompanying editorial, Dr. Frederick S. vom Saal from the University of Missouri, Columbia, and Dr. John Peterson Myers from Environmental Health Science in Charlottesville, Virginia, comment that this research "should stimulate further studies and reevaluation of the basic assumptions in chemical risk assessments that led to US Food and Drug Administration assurances that BPA is safe."

The editorialists add that the results "also heighten incentives for green chemistry (a new field based on collaboration between biologists and chemists to develop biologically inert chemicals for use in products) to find cost-effective replacements for BPA applications contributing to widespread human exposures."

JAMA 2008;300:1303-1310,1353-1355.

Reuters

Five Ways to Help Prevent Lung Cancer

Along with making positive lifestyle choices (such as not smoking), following a healthy diet may play a significant role in reducing the risk of developing lung cancer. Keep your lungs in top shape by following these healthy dietary tips:

1. Add more natural antioxidants. Apples, tomatoes and oranges are especially helpful in nourishing the lungs.
2. Add carrots, yellow squash and dark, leafy greens for their lung-protective carotenoids.
3. Drink plenty of water to help flush out toxins and keep nasal passages moist.
4. Eat whole soy foods - the phytoestrogens they contain may have protective effects throughout the body.
5. Keep in mind that antioxidants and carotenoids from foods are your best source. While supplemental mixed carotenoids may offer some benefit, you should avoid taking isolated beta-carotene, especially if you are, or were, a smoker - higher doses may actually increase the risk of lung cancer.

DrWeil.com

Study shows how broccoli fights cancer

Just a few more portions of broccoli each week may protect men from prostate cancer, British researchers reported on Wednesday.

The researchers believe a chemical in the food sparks hundreds of genetic changes, activating some genes that fight cancer and switching off others that fuel tumors, said Richard Mithen, a biologist at Britain's Institute of Food Research.

There is plenty of evidence linking a healthy diet rich in fruits and vegetables to reduced cancer risk. But the study published in the Public Library of Science journal PLoS One is the first human trial investigating the potential biological mechanism at work, Mithen added in a telephone interview.

"Everybody says eat your vegetables but nobody can tell us why," said Mithen, who led the study. "Our study shows why vegetables are good."

Prostate cancer is the second-leading cancer killer of men after lung cancer. Each year, some 680,000 men worldwide are diagnosed with the disease and about 220,000 will die from it.

Mithen and colleagues split into two groups 24 men with pre-cancerous lesions that increase prostate cancer risk and had them eat four extra servings of either broccoli or peas each week for a year.

The researchers also took tissue samples over the course of the study and found that men who ate broccoli showed hundreds of changes in genes known to play a role in fighting cancer.

The benefit would likely be the same in other cruciferous vegetables that contain a compound called isothiocyanate, including brussel sprouts, cauliflower, cabbage, rocket or arugula, watercress and horseradish, they added.

Broccoli, however, has a particularly powerful type of the compound called sulforaphane, which the researchers think gives the green vegetable an extra cancer-fighting kick, Mithen said.

"When people get cancer some genes are switched off and some are switched on," he said. "What broccoli seems to be doing is switching on genes which prevent cancer developing and switching off other ones that help it spread."

The broccoli eaters showed about 400 to 500 of the positive genetic changes with men carrying a gene called GSTM1 enjoying the most benefit. About half the population have the gene, Mithen said.

The researchers did not track the men long enough to see who got cancer but said the findings bolster the idea that just a few more vegetable portions each week can make a big difference.

It is also likely that these vegetables work the same way in other parts of the body and probably protect people against a whole range of cancers, Mithen added.

"You don't need a huge change in your diet," he said. "Just a few more portions makes a big difference."

Reuters

Combo Therapy Knocks Out Melanoma Tumors

Chemotherapy may be more effective on melanoma tumors if a protein frequently found in the growth can first be disabled, a new study reports.

Researchers at the Duke Comprehensive Cancer Center found the drug ADH-1, which makes it difficult for cells to properly bind to one another, helped chemotherapy completely destroy the tumors in twice as many patients than with chemo alone. Sixteen people with regionally advanced melanoma, in which the cancerous growths appear and spread mainly on the limbs, participated in the pilot study.

"Eight of the patients in the study had complete responses to therapy, meaning their tumors completely disappeared," study lead investigator Dr. Georgia Beasley, a medical student at Duke, said in a prepared statement. "This is very encouraging, and we look forward to continuing this study and then eventually moving on to a phase III trial."

Without ADH-1, patients generally have complete responses about 25 percent to 35 percent of the time.

"When chemotherapy was applied to the tumor in this weakened state, it was much more effective compared to conventional therapy alone," study senior investigator Dr. Douglas Tyler, a surgeon at Duke and the Durham Veterans Affairs Medical Center, said in a prepared statement.

The researchers were expected to present their findings Sunday at the American Society of Clinical Oncology annual meeting, in Chicago.

"These early results really speak to the importance of developing combination therapies," Beasley said. "Earlier animal results showed that using ADH-1 alone was not an effective treatment, but in combination with chemotherapy, the results, both pre-clinically and clinically, have been very exciting."

Malignant melanoma is increasing at a rate faster than any other cancer -- 60,000 new cases are expected to be diagnosed this year in the United States alone. When the growths spread beyond the primary site, the disease is rarely curable, and treatment is limited.

Health Day