New guidelines on nutrition, calcium, and colon cancer

Today’s article deals with the most recent dietary guidelines — an updated food pyramid focusing on older adults, the latest word on the safety of calcium supplements, and new guidelines in the detection of colon cancer. These new developments represent the latest advances in nutrition, osteoporosis treatment, and colorectal cancer screening.

New Food Guidelines For Older Adults

The food guide called “MyPyramid,” is considered the gold standard of nutrition for people of all ages. This was discussed extensively in a previous issue of this column. With its emphasis on high-fiber, low-fat foods, MyPyramid promotes optimal nutrition for everyone. But adults over 70 have unique nutritional needs not met by the 2005 MyPyramid, according to experts. In particular, they may not be getting enough nutrition for their caloric intake, according to the Modified MyPyramid for Older Adults published in a recent issue of the Journal of Nutrition, which stresses the importance of “nutrient-dense” foods in the over-70 population.

The modified version of the MyPyramid is easier to use than the original. In fact, it may be useful to a much wider age range than simply those 70 and over. “The information in the updated pyramid is as applicable to a 50-year-old person as it is for those 70 and over,” says Alice Lichtenstein, DSc, of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston. “People age at different rates, and they shouldn’t worry about what nutrition decisions kick in at 50, 60, 70, or beyond. Following these new recommendations is about optimizing food choices that give you the best chance for aging in a healthy way.”

Here are some of the more important recommendations, represented by images in the Modified MyPyramid (see diagram).

• Whole, enriched, and fortified grains and cereals such as brown rice and 100-percent whole wheat bread — 6 to 9 ounces a day.

• Vegetables — 2.5 to 3.6 cups per day; brightly colored, such as carrots and broccoli.

• Fruits — 2 cups per day; deep-colored, such as berries and melon.

• Low- and non-fat dairy products such as yogurt and low-lactose milk — 3 cups per day.

• Dried beans, nuts, fish, poultry, lean meat, and eggs — 5.5 to 6.5 ounces per day.

• Liquid vegetable oils and soft spreads low in saturated and trans fat — 6 to 8 teaspoons per day.

• 12-16 cups (8 ozs.) of fluid daily (8 from water) from all food and beverage sources combined.

• Daily physical activity such as walking, housework, and yard work.

Most nutrients should come from food, but as people age, it is sometimes difficult to get adequate amounts from food alone. Consider taking supplemental forms of calcium, vitamin D, and vitamin B12, which are vital for continued good health. The foundations of good health, as depicted in the pyramid, are physical activity and fluids. Physical activity keeps us fit and flexible, preserves and increases strength and, ultimately, helps us retain physical independence. Fluids are important to older adults because compromised homeostatic mechanisms, such as loss of the thirst sensation, can result in dehydration.

The Latest On Calcium Supplement Safety

You take calcium supplements to protect your bones and prevent fractures, but a recent study suggests they might be damaging to your heart. The study, published recently in the British Medical Journal (BMJ), found that healthy menopausal women (average age of 74) who took elemental calcium citrate supplements daily were significantly more likely to have a heart attack than women who didn’t take calcium. The authors say the supplements raise blood calcium levels, potentially leading to calcium deposits in the arteries that can block blood flow. “The findings suggest that the very elderly may have an increase in heart attack when taking this formulation of calcium,” says Erica C. Jones, MD of the Weill Cornell Medical College in New York City. “It is not clear if this is true for younger postmenopausal women, or if the women take different forms of calcium.”

Before you panic and toss out your calcium supplements, there are a few caveats. First, the study was relatively small and not all participants followed the regimen. Second, there is evidence from previous studies that calcium might actually protect against heart disease by increasing the ratio of HDL (“good”) cholesterol to LDL (“bad”) cholesterol, lowering blood pressure, and decreasing fat absorption. And third, the study group was a narrow demographic (older and white, primarily), and those results might not apply to a broader population. In addition, the Women’s Health Initiative (WHI) study, which included 36,000 postmenopausal women, found no difference in cardiovascular events between calcium supplement users and non-users. In that study, the women were younger — ages 50 to 79 — and took calcium carbonate.

The BMJ study shouldn’t change your decision to take calcium supplements if you have no major risk factors for heart disease, especially if you are at risk for osteoporosis. Dr. Jones says, “On the other hand, if you have a normal bone density and a significant cardiovascular risk, you should discuss with your doctor whether taking supplemental calcium is necessary.” When taking calcium, Dr. Jones suggests using calcium carbonate (the type used in the WHI study) instead of calcium citrate used in the current study. Get at least 1,200 milligrams of calcium daily combined with 800 International Units of vitamin D. Vitamin D is absolutely essential in aiding the absorption and utilization of calcium in the body and preventing osteoporosis.

More Options For Catching Colon Cancer

If you’re age 50 or older, it is recommended that you be screened for colorectal cancer. However, studies show that less than half of people in this age group have ever had a colonoscopy (the gold standard screening method), perhaps because they’re hesitant to undergo the uncomfortable procedure. So researchers are studying blood tests and genetic testing, as well as imaging technologies, that may gauge your risk of colorectal cancer and offer hope for a non-invasive way to detect the disease. In March last year, the American Cancer Society and other medical organizations released new guidelines, which recognize some of these newer methods as screening options.

In January 2008, researchers reported that a test for a blood protein — colon cancer-specific antigen-2 — was 91-percent accurate at detecting colorectal cancer and polyps that are likely to become cancerous. The test was also 80-percent accurate in identifying people without colorectal cancer or high-risk polyps. The findings must still be confirmed in larger studies, but some scientists already feel we are “on the threshold of something really exciting” as far as colon cancer screening is concerned.

Meanwhile, one non-invasive screening method already in use is the fecal occult blood test. Experts also continue to evaluate a newer approach, the fecal DNA test, which checks for genetic abnormalities from colorectal cancer shed in the stool. Another newer screening method already in use — CT colonography (virtual colonoscopy) — scans the bowel to search for colorectal polyps.

The new guidelines recommend the following screening options and intervals for everyone 50 and older at average risk of colorectal cancer. Higher-risk individuals should talk with their doctors about appropriate screening options and intervals.

Here are the tests for polyps and colon cancer:

• Colonoscopy every 10 years.

• Flexible sigmoidoscopy (endoscopic exam of the lower third of the colon) every five years.*

• Double-contrast barium enema every five years.*

• Computed tomography (CT) colonography every five years.*

Stool tests primarily for colon cancer:

• Annual fecal occult blood test.*

• Annual fecal immunochemical test.*

• Fecal DNA test (interval uncertain).*

*A follow-up colonoscopy is needed if any of these tests returns a positive result.

Early detection through screening is the best way to prevent colorectal cancer. Which one of the above tests you choose will depend on your preferences, resources, and discussions with your doctor.

The bottom line? Get some form of regular screening — it can save your life!