Red meat and nutrition

Red meat is long established as an important dietary source of protein and essential nutrients including iron, zinc and vitamin B12. Meat is defined in food preparation as the edible flesh of domesticated animals. Meats are composed of muscle, connective tissue, fat and bone.

Basically, there are two types of meat –red meat and white meat. Red meat is commonly considered to include beef, pork, lamb and game. The flesh of poultry, including chicken, turkey and duck is termed ‘white meat.’

The chemical composition of meat varies to a large degree. The lean component of red meat is an excellent source of high biological value protein, vitamin B12, niacin, vitamin B6, iron, zinc and phosphorus. Red meat also rich with long-chain omega-3 polyunsaturated fats, riboflavin, pantothenic acid, selenium and, possibly, also vitamin D.

Meat may contain 45-70% water, 15-20% protein and anywhere from 5 to 40% fats depending on the cut and trim.

Red meat is low in total fat, saturated fatty acids – SFAs and salt, whereas untrimmed meat is higher in both total fat and saturated fatty acids, processed meat is generally higher in salt and fat and often contains other components such as nitrites which are added during processing. Saturated fats promote less oxidation, and therefore less rancidity.

Red meat also contains relatively low levels of PUFA. The main PUFA in red meat are the essential fatty acids, linoleic (n-6) and α-linoleic acid (n-3). When consumed, the body can convert α-linoleic acid into the long-chain beneficial n-3 fatty acids EPA and DHA.

Meat is principally composed of protein which provides 17kJ/4kcal of energy per gram, but also contains fat in varying amounts providing 37kJ/9kcal of energy per gram.

The protein is highly digestible, around 94% compared with the digestibility of 78% in beans and 86% in whole wheat. Protein from meat provides all essential amino acids (lysine, threonine, methionine, phenylalanine, tryptophan, leucine, isoleucine, valine) and has no limiting amino acids. Protein is needed for growth, maintenance and repair of the body.

Red meat contains on average 20–24 g protein per 100 g (when raw) and can therefore be considered a high source of protein.

The three types of protein in meats are myofibril, stromal protein and sarcoplasmic protein.

Muscle is approximately 75 percent of water and 20 percent protein with a remaining 5 percent representing a combination of fat, carbohydrate and minerals.
Red meat and nutrition

Red Meat and Breast Cancer

A hypothesis has been advanced that links red meat consumption to the induction of carcinogenesis through it’s highly bio-avaolable, iron content, growth promoting hormone used in animal production, carcinogenic heterocyclic amines fomed in cooking and its specific fatty acid content.

Research on heterocyclic amines has shown that they can move through the human body and become localized ro breast tissue, where they can act metabolically driving canceorus cell growth.

Women who ate more than 1½ servings of red meat per day were almost twice as likely to develop hormone-related breast cancer as those who ate fewer than three portions per week, one study found.

In the UK women’s Cohort study, which enrolled 35,371 participants, women with the highest total meat consumption (poultry, red meat and processed meat) had the highest risk of both premenopausal and postmenopausal breast cancer.

In Italian study, the risk of developing breast cancer was significant only when women consumed more than seven portions of meat a week.

Studies of other types of cancer, such as pancreatic have noticed as much as a 50 percent increased cancer risk when comparing study participants who ate most grilled, fried or otherwise well done meat to participants who at the least.

Women should be advised to decrease their red meat consumption to three or fewer times per week and to avoid processed meats.
Red meat and breast cancer