Red Meat Consumption

By Bonnie Jenkins, Advanced Natural Medicine

There’s nothing my husband likes better than a big, juicy steak. And, I know he isn’t alone. But, if you’re a woman, you just might want to rethink what’s for dinner. A major new study analysis suggests that eating too much red meat can raise the risk of breast and colorectal cancer.

Red Alert

The newest large-scale study, the Nurses Health Study II, followed more than 90,000 pre-menopausal women for 12 years. Red meat consumption across time showed no relation to overall breast cancer risk. But, when researchers conducted an analysis of only the breast cancers fueled by the hormones estrogen and progesterone, they found a definite link to red meat consumption.

After adjusting for established risk factors, including weight, alcohol consumption and dietary intakes of fruit, vegetables and dairy foods, the researchers found that women who reported eating more than one and a half servings of red meat a day had almost twice the risk of developing hormone receptor positive cancer compared with women who reported eating three servings or less of red meat per week.

A Rare Suggestion

So what is it about beef and breast cancer? Studies suggest one reason for the increased cancer risk relates to the heterocyclic amines (HCAs) that form when red meat is cooked at high temperatures – think frying and grilling – and HCAs bond to estrogen receptors and create estrogen-like effects.

A recent population-based, case-control study of more than 3,000 postmenopausal women found that those who ate the most grilled or barbecued and smoked meats over a lifetime had a significantly higher risk of developing breast cancer. And the news was even worse for the women who ate few fruits and vegetables.

And some women who eat well-done beef may be at more risk than others. Like many carcinogens, HCAs have to be activated before they can damage our DNA and pose cancer risk. People whose genes cause HCAs to activate quickly could be at more risk of breast cancer than those whose genes lead to slower activation. But since it’s essentially impossible to determine how your genes react to HCAs, it’s better to err on the side of caution. If you must have the occasional steak, make sure it’s rare or medium-rare.

Not convinced? Here’s another reason to avoid red meat. While red and white meats both form HCAs when cooked at high temperatures, red meat is higher in easily absorbed heme iron. Laboratory studies suggest that heme iron may increase colon cancer risk by damaging the colon lining and increasing the growth of precancerous cells. Several population studies also link higher heme consumption with greater colon cancer risk. This particular form of iron can also interact with estrogen to enhance the initial development of breast tumors.

Fat Chance

The link between red meat and breast cancer may also relate to its fat content. Several studies link higher fat intake with higher levels of estrogen. It also impacts insulin levels. While most of us think of this hormone in terms of blood sugar, it turns out that insulin can also convert to estrogen in the body. Higher saturated fat consumption seems to raise levels of insulin, a hormone that may promote development of breast cancer regardless of estrogen sensitivity.

So, does that mean you have to banish beef from your diet? Most nutritionists say no, but they caution that it’s important to limit the amount you eat to two to three times a week at most.

One Last Thing ...

While beef itself can up the risk of breast cancer, American women have even more to worry about. Cattle in the United States are routinely given synthetic growth hormones to quickly fatten them up, which increases the profit margin of major beef producers. But a growing number of studies show that this hormone-laced beef poses a health risk to consumers. The reason is simple: Many types of breast cancer grow more quickly when exposed to estrogen. The longer the exposure to high levels of the hormone, the greater the breast cancer risk.

In one study, researchers at Ohio State University mixed beef from hormone-treated cows with human breast cancer cells and saw "significant" cancer cell growth – in some cases at levels 30 times lower than the government says is safe.

In other research, scientists examined the environmental effects of synthetic hormones that leach into water from cattle feedlots. The study, funded by the European Union (which bans beef hormones), found serious damage to the reproductive systems of fish downstream from a Nebraska feedlot.

If you don’t want to completely eliminate beef from your diet, opt for organic beef. Available in full-service health food stores and even some supermarkets, organic beef is raised on organic feed without added hormones. Look for lean cuts to avoid unnecessary saturated fat and make sure you don’t eat more than three ounces at any one time because more definitely isn’t better when it comes to beef, even if it is organic.

This Just In ...

Last month, a study in the Annals of Internal Medicine announced that the popular arthritis supplement, chondroitin, doesn’t do a thing to relieve joint pain. But before you toss your supplements you need to know that, while the researchers initially reviewed 20 studies using the compound, they ultimately based its conclusion on only three studies.

So was the study flawed? You bet! While the other 17 trials reported large benefits for chondroitin, the three trials they chose didn’t report a significant benefit to those taking the supplement. The researchers also didn’t look at chondroitin’s effect in people with mild to moderate osteoarthritis. Nevertheless, the new study concluded that doctors should stop recommending chondroitin to their patients with osteoarthritis of the knee or hip.

Another problem with this meta-analysis is that the researchers didn’t review studies that used a combination of chondroitin and glucosamine – the way most people take the nutrient. But just last year, the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) reported that the combination supplement actually did decrease knee pain associated with moderate-to-sever osteoarthritis – and it reduced the pain significantly.

But before you start thinking that chondroitin is just a natural pain reliever, you should know that this compound is actually a major constituent of cartilage. Chondroitin also helps to attract and hold fluid, which is a vital part of joint structure and function.

Taking chondroitin sulfate in supplemental form acts like an anti-inflammatory to reduce pain and improve joint function. It may also have a direct impact on the structure of your joints. Research shows that chondroitin promotes the structural integrity of affected joints by stimulating cartilage formation.

Of course, none of this information was even mentioned in this new study which, by the way, was funded by the drug giant Merck. So the next time you hear rumors that certain supplements are ineffective (or even dangerous!) do your homework. You just might be surprised as who’s doing the talking.

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References:

Collins K. “Breast cancer another reason to limit beef.” MSNBC. 3/16/07 .

Leeb BF, Petera P, Neumann K. “Results of a multicenter study of chondroitin sulfate (Condrosulf) use in arthroses of the finger, knee and hip joints” Wiener medizinische Wochenschrift.1996;146:609-614.

Reichenbach S, Sterchi R, Scherer M, et al. “Meta-analysis: Chondroitin for Osteoarthritis of the Knee or Hip.” Annals of Internal Medicine. 2007;146:580-590.

Steck SE, Gaudet MM, Eng SM, et al. “Cooked meat and risk of breast cancer-lifetime versus recent dietary intake.” Epidemiology. 2007;18:373-382

Updike MS, Sawdy JC, Wang LS, et al. “Primary cultured human breast epithelial cells up-regulate protein disulfide isomerase in response to zeranol.” Anticancer Research. 2007;27:407-410.