Nutritionists from the University of Maryland Medical System regularly contribute a guest post to The Baltimore Sun's health blog Picture of Health (baltimoresun.com/pictureofhealth), which is reprinted here. The latest post is from Shanti Lewis, a registered dietitian.
The benefits of eating less meat? Decreased cancer risk, improving heart health, helping the environment, weight management and financial benefits are just a few.
Helping your diet
It may seem obvious that exchanging a hamburger for a black bean burger is an easy way to cut fat and calories out of your meal. A recent study based on a large European population in the American Journal of Clinical Nutrition found that consumption of what is equivalent to 250 grams of red meat, poultry or processed meat per day, regardless of overall calorie intake, can lead to an approximately 5-pound weight gain over the course of five years. There was a statistical significance between meat consumption and weight gain when factoring in overall caloric intake, gender, body mass index and physical activity. This study implies that a decrease in meat consumption can lead to improved weight management.
Limiting cancer risk
Numerous studies have linked red meat and processed meat consumption with the increased risk of colorectal, pancreatic, gastric and prostate cancer. A study of more than 900,000 women published in the Archives of Internal Medicine found that the more red meat or processed meat consumed by women in their 20s, 30s and 40s, the higher their risk for developing breast cancer. Those women who ate more than 11/2 servings a day of beef, lamb or pork were found to have twice the risk of hormone-receptor-positive breast cancer compared to those who ate less than three servings per week.
One possible theory as to why red meat can increase the risk for cancer is that the higher levels of fat found in certain meats may increase levels of certain hormones, such as estrogen and progesterone, that may promote cancer. In addition, substances, such as heterocyclic amines and polycyclic aromatic hydrocarbons, found when meat is cooked at high temperatures, have been found to be carcinogenic in animal studies. Another theory is that the growth hormones fed to cows by farmers may contribute to breast cancer risk if women consume diets containing lots of red meat.
The water and soil needed to grow feed for cows to produce beef and milk, along with the number of animals needed to feed humans, causes a substantial amount of damage to the environment. When crops do not receive enough rainfall, fuel is required from groundwater systems to help produce sufficient water for crops that will be used to create feed for these animals.
In addition, more dangerous greenhouse gases, such as carbon dioxide, methane and nitrous gases, are released into the air from raising cattle and dairy cows than from all cars on the road and industry today according to the U.N. Food and Agricultural Organization 2006 report.
Initially, experts agreed that limiting red meat was associated with lowering saturated fat and cholesterol in the diet. A recent study showed that women who ate two or more servings of red meat per day versus half a serving had an almost a 30 percent higher risk of heart disease. A recent 2013 study from the Cleveland Clinic suggests that carnitine found in meat or choline found in eggs mixed with gut bacteria produce a substance called Trimethylamine-N-oxide (TMAO) that may play a role in accelerating the hardening of arteries.
Saving animals, money
While regulations govern animal raising in the United States, billions of chickens, pigs, cows, ducks and sheep are slaughtered each year for human ingestion. Sometimes, these animals suffer cruel slaughter techniques and are confined to cages, crates and pens for most of their lives.
The Humane Society promotes a campaign called "Meatless Mondays" that suggests 1.4 billion animals could be spared each year if Americans could cut out meat for one day per week. One of the benefits of opting for meat-less meals a few times per week is that it will save you money. There are more costs associated with producing meat, including land, fertilizer and oil, than there are for other types of food. As a result, there are substantially higher prices for meats than for vegetarian options. In this tight economy, limiting your meat intake will help limit your food costs.
First, limit your red meat to two 3- to 4-ounce portions per week and avoid processed meats as much as possible, along with considering adding some meat-free days into your week. Second, consider using fish, poultry, lower-sodium soy products, nuts and beans to replace red meat. While there needs to be additional research linking carnitine and choline to the progression of atherosclerosis, one should avoid choline, lecithin or carnitine supplements unless recommended by a health care provider. In addition, make sure that you practice safe grilling techniques to avoid the ingestion of herterocyclic amines that have been linked with cancer.