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Red meat is commonly red when raw and a dark color after it is cooked.
White meat, is pale in color before and after cooking.
Red meat is defined as any meat that has more of the protein myoglobin than white meat.
Observational studies suggest higher consumption of redmeat and processed meat and is associated with a higher risk of diabetes, cardiovascular disease and certain cancers.
The increased risk of incident atherosclerotic cardiovascular disease (ASCVD) associated with red meat consumption is mediated in part by microbiota-generated metabolites of L-carnitine and choline that are abundant in red meat.
White meat is defined as non-dark meat from fish or chicken, excluding the leg or thigh.
Some types of meat, such as pork, is classified as white meat under the common or gastronomic definition, but as red meat under the nutritional definition.
Concentration of myoglobin by percentage.
Chicken breast 0.005%, White meat
Chicken thigh 0.18 – 0.20% Dark meat
Turkey thigh 0.25 – 0.30% Dark meat
Pork 0.10 – 0.30% Red meat
Veal 0.10 – 0.30% Red meat
Beef 0.40 – 1.00% Red meat
Old beef 1.50 – 2.00% Red meat
Red meats contain more myoglobin than fish or white meat, but not necessarily dark meat from chicken.
The gastronomic definition of meat from adult or game mammals, including beef, horse meat, mutton, venison, boar, and hare is considered red meat.
While meat from young mammals, such as rabbit, veal, lamb is considered to be white meat by culinary definition.
Most poultry is white meat, but duck and goose are red meats
Most cuts of pork are red, but others are white, gastronomically.
All pork is considered red in nutritional studies.
Large amounts of iron, creatine, minerals such as zinc and phosphorus, and B-vitamins: (niacin, vitamin B12, thiamin and riboflavin), are contained in red meat.
Red meat is a source of lipoic acid, and contains small amounts of vitamin D.
It is encouraged to avoid processed meat and limit red meat consumption to twice a week because of links to heart disease, diabetes, and colon cancer.
Meta-analyses show that redmeat and processed meat are associated with an increased risk of diabetes.
To replace these meats it recommends consuming fish, poultry, beans or nuts.
It is recommend eating at least 8 oz (227 grams) of fish each week.
The increased mortality associated with red meat may be increased with certain cooking methods.
There is a correlation between the consumption of processed red meat and several kinds of cancer: lung, esophageal, liver, pancreatic, and colon cancer.
Processed meats such as bacon, ham, hot dogs, sausages are felt to be carcinogenic to humans.
WHO – processed meats such as hotdogs, bacon, and sausages have been classified as carcinogenic to humans for colorectal cancer, and unprocessed meats, such as beef and pork are probably carcinogenic.
However, other studies do not support significant links between meat consumption and various cancers.
A meta-analysis found that there were no significant differences between vegetarians and nonvegetarians in mortality from stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer.
A meta-analysis found no association of colorectal cancer with consumption of animal fat or protein, and the EPIC-Oxford study found a lower rate of colorectal cancer amount red meat eaters.
The European Prospective Investigation into Cancer and Nutrition (EPIC) found that association between esophageal cancer risk and total and processed meat intake was not statistically significant.
Consumption of red meat does not seem to be associated with cardiovascular disease risk factors like total cholesterol, LDL, HDL, triglycerides, ratio of TC to HDL and blood pressure.
Red meat consumption is associated with higher fasting glucose, insulin concentrations, and increased cardiovascular mortality.
Replacing processed or processed red meat with fish
leads to reduced atherosclerosis and vascular occlusion.
Replacing processed or processed red meat with fish, but has no impact on rates of total ischemic strokes.
Replacing unprocessed red meat with poultry in Asian men is associated with reduced cardiovascular disease.
Increased unprocessed red meat consumption is associated with a decreased risk of demyelinating neurologic disease.
Studies that differentiate between processed and fresh red meat have failed to find a link between unprocessed red meat consumption and heart disease.
A meta-analysis involving around one million people who ate meat found that only processed meat had an adverse risk in relation to coronary heart disease.
The differences in salt and preservatives, rather than fats, might explain the higher risk of heart disease and diabetes seen with processed meats, but not with unprocessed red meats.
Suggested mechanisms of why red meat consumption might be risk factor for cardiovascular disease include: its impact on serum cholesterol, that it contains arachidonic acid, heme iron,homocysteine, and its high saturated fat content.
A study of 84,000 women 26 years, found that those with the highest intake of unprocessed red meat, have a 13% increased risk of CHD.
In a Harvard study published in 2012, it was found that one serving (? 42 g/day) of unprocessed meat a day resulted in an increased risk of mortality of 13%, and likewise, processed meat 20% (ratios are indicative of cancer and cardiovascular).
But, there was no statistical significance between the risk of unprocessed and processed red meats factors in the occurrence of CVD.
Unprocessed red meat intake is associated with an increased risk of type II diabetes, but the link is weaker and less certain than the link between processed red meat and diabetes.
Substitutions of one serving of nuts, low-fat dairy, and whole grains per day for one serving of red meat per day is associated with a 16-35% lower risk of type 2 diabetes.
A meta-analysis found an increased risk of gastric cancer with higher consumption of red or processed meat.
Red meat itself contains certain factors that potentially can produce carcinogens like N-nitroso compounds.
Health Professionals Follow-up Study: Participants 43 272 men without cardiovascular disease or cancer at baseline, 1 023 872 person years of follow-up, 4456 incident CHD events were documented of which 1860 were fatal.
Red meat intake were each associated with a modestly higher risk of CHD: hazard ratio for one serving per day increment: 1.12 for total red meat, 1.11 for unprocessed red meat, and 1.15 for processed red meat.
Compared with red meat, the intake of one serving per day of combined plant protein sources: nuts, legumes, and soy was associated with a lower risk of CHD compared with total red meat, compared with unprocessed red meat, and compared with processed red meat.
Substitutions of whole grains and dairy products for total red meat and eggs for processed red meat were also associated with lower CHD risk.
Substituting high quality plant foods such as legumes, nuts, or soy for red meat might reduce the risk of CHD.
Substituting whole grains and dairy products for total red meat, and eggs for processed red meat, might also reduce this risk.
The International Agency for Research on Cancer concluded that red meat is probably carcinogenic and reported that for each additional 100g of red meat consumed per day, the risk of colorectal cancer increased by 17%.
The International Agency for Research on Cancer found that in the UK, 56 out of 1000 people who eat the lowest amount of red meat will develop colorectal cancer (5.6%) while 66 out of 1000 high-red meat eaters will develop colorectal cancer (6.6%).
A literature review in 2016 reported that for 100g or more per day of red meat consumed, the risk increased 11% for each of stroke and for breast cancer, 15% for cardiovascular mortality, 17% for colorectal cancer, and 19% for advanced prostate cancer.
Processed meat attempts to enhance flavor or improve preservation of meat by salting, curing, fermentation, smoking, or other processes.
Process meats include bacon, ham, salami, pepperoni, hot dogs, and some sausages which contain nitrates and nitrites that can be converted by the human body into nitrosamines that can be carcinogenic.
Nitrosamines cause mutation in the colorectal cell line, thereby causing tumorigenesis and eventually leading to cancer.
The International Agency for Research on Cancer, based on a review of 800 studies over 20 years, concluded that processed meat is definitely carcinogenic and found that for each additional 50g of processed meat consumed per day, the risk of colorectal cancer increased by 18% .
It also found that there appeared to be an increase in gastric cancer but this was not as clear a result.
A 2016 literature review found that for the each additional 50g per day of processed meat consumed, the risk increased 4% for total prostate cancer, 8% for cancer mortality, 9% for breast cancer, 18% for colorectal cancer, 19% for pancreatic cancer, 13% for stroke, 24% for cardiovascular mortality and 32% for diabetes.
Cooking meat at a high temperature or smoking meat produces carcinogenic polycyclic aromatic hydrocarbon compounds and heterocyclic amines.
Marinating fresh lean red meat and cooking it at a low temperature likely will reduce the production of carcinogenic compounds and thereby lower the risk of colorectal cancer.
Eating more red meat is associated with higher risk of death from cardiovascular disease, respiratory disease and neurodegenerative disease.
Consuming red and processed meat increases the risk for type 2 diabetes, cardiovascular disease and certain cancers.
The risk remains for all participants regardless of age, physical activity, dietary quality, smoking or alcohol.
The life-shortening effect of red meat may be due to increased cholesterol, iron, preservatives and cancer-causing compounds that are produced when meat is cooked at high temperatures.
Red meat has been tied to certain bacteria in the gut that might increase the odds for atherosclerosis.
Eating more plant foods and fewer foods from animals helps to reduce the risk of many chronic diseases and mortality.
Bradley Johnston from McMaster University, produced four meta-analyses examining the impact of red and processed meat consumption on overall mortality, cardiovascular disease, and cancer.
The meta-analysis of eight observational cohort studies of at least 1000 patients each that linked red or processed meat consumption with all-cause mortality:
a reduction in red meat consumption of three servings per week was associated with a 7% reduction in mortality rate.
However, the only randomized controlled trial in the above meta-analysis that had mortality data was the Women’s Health Study.
The Women’s Health Study randomized about 50,000 women to a low-fat or regular diet: The low-fat group did cut back on their red meat consumption, but there was no difference in cardiovascular disease or cancer mortality.
In a study examining the effect of the Dietary Approaches to Stop Hypertension (DASH) diet containing lean red meat on measures of body composition and muscle strength in a cohort of obese adults 65 and older.
Each consumed 1800 kcal/day for 12 weeks under controlled feeding conditions.
The study diet included daily intakes of 126 g of meat.
Measures of body composition and muscle strength were obtained.
Breakfast, lunch, and dinner were provided every day for 12 weeks, and equal portions of meat were distributed at each meal.
From baseline to study end, total body weight decreased by 6.3%, body fat percentage decreased by 2.5% and absolute fat mass decreased by 4.4 kg.
DASH diet has the potential to be a tool to preserve muscle strength while reducing fat mass in obese older adults.
In the elderly an accumulation of fat mass occurs simultaneously with reduced muscle mass and strength leading to metabolic dysregulation, resulting in accelerated disease onset and increased mortality.
Maintaining muscle mass and strength while reducing fat mass accumulation are vital to maintaining mobility and reducing disease risk in the elderly.
Diet quality and dietary protein intake are vital for maintaining body composition and muscle mass, as well as improving physical performance
Malnutrition in dietary protein intake is a major cause of reduced muscle mass, strength, and function in older adults.
The current recommended dietary allowance (RDA) for protein for adults is 0.8 g/kg/day, which averages to ~50 g/d (56 g/d for men; 46 g/d for women) for average weight sedentary adults.
Consuming less than the protein RDA results in significant declines in muscle mass, strength, and function in older populations.
To preserve muscle mass and strength, older adults should consume at least 1.1�1.3 g/kg of protein daily.
The Dietary Approaches to Stop Hypertension (DASH) dietary pattern improves health status in various diverse and at-risk populations resulting in improved heart health, maintained cognitive function, and reductions in metabolic diseases such as diabetes, metabolic syndrome, and nonalcoholic fatty liver disease.
The primary protein recommendations of the DASH diet are poultry and fish, and it is recommended to decrease red meats from the diet.
Lean red meat incorporated into a DASH-like diet does not exacerbate cardiovascular health indices in adults.
Lean red meat can be included in the DASH diet without negative effects on heart health.
In all participants, body weight decreased by 6.3% from baseline to study end.
BMI decreased from baseline from 32.0 to study end, 30.1.
Waist decreased from baseline (101 cm) to study end (96.3 cm).
The hip decreased from baseline (115 cm) to study end (111 cm); body fat percentage decreased from baseline (37.2%) to study end (34.7%).
Daily meat as a part of the DASH diet was associated with preserved handgrip strength, a significantly increased strength-to-weight ratio, and increased resting energy expenditure in adults 65 and older.
In the present study diet intakes, total body weight was significantly reduced by 6.3% (p < 0.001) at a rate of 0.5 kg (1.1 lb) per week as a result of consumption of the study diet over the course of 12 weeks.
The 0.5 kg per week of weight loss follows CDC recommendation of gradual and steady weight loss of 1-2 lbs per week for long-term success
More studies are required to determine body fat levels that define obese phenotypes in males and females and determine the relationships of such levels with poor health outcomes.
The accumulation of abdominal body fat is the hallmark of the obese phenotype in older adults.
Abdominal fat accumulation is the primary contributing factor to the development of obesity-related chronic diseases afflicting this population and promotes the onset of sarcopenia and osteopenia
DASH diet may be a potential method to improve body composition that may in turn lead to obesity management and reduce disease risk in obese older adults.
Systolic and diastolic blood pressure were drastically reduced with the Dash diet.
Controlling for weight loss did not alter the beneficial drop in blood pressure.
The study supports the effectiveness of the DASH diet to lower blood pressure in obese adults with hypertension.
The study diet consumed by all participants contained foods that provided daily average dietary intakes of 1895 mg of sodium, 585 mg of magnesium, 4395 mg of potassium, and 1187 mg of calcium, and all participants consumed a daily multivitamin/multimineral supplement that provided an additional 50 mg of magnesium, 80 mg of potassium, and 220 mg of calcium.
Muscle strength is considered the most reliable measure of muscle function in older adults, superseding the role of muscle mass.
Grip strength is a dominant predictor of poor health outcomes in older adults such as poor quality of life, increased hospitalizations, reduced functional capabilities, and death.
Despite the loss in total body mass, grip strength was well preserved in all participants, with an increase observed in females.
In all participants, there is an increase in relative body strength.
The body mass decreased over time, grip strength increased during the study period, indicating strength-to-weight ratio was significantly improved.
Reduced walking mobility and activities of daily living in obese older adults is due in part to poor strength-to-weight ratio, which may increase the risk of falls and subsequent mobility disability.
By improving the strength to weight ratio, older obese patients will be able to perform activities of daily living, including walking and stair climbing at a lower percentage of their strength capacity.
Grip strength alone serves as a dominant predictor of poor health outcomes in older adults, gait and sit/stand serve as additional indicators of physical performance and strength.
Gait is a measure of physical performance that has been shown to be a predictor for adverse outcomes related to sarcopenia such as falls, cognitive impairment, disability, and mortality.
Sitting and standing requires strength and endurance and serves as a proxy for leg muscle strength.
In this Dash diet study gait and balance was well preserved and sit/stand increased over the course of 12 weeks.
The study demonstrated that total body energy expenditure was well maintained, and the total body energy expenditure was moderately associated with skeletal muscle mass.
The per kg of body fat and muscle mass, energy expenditure was increased, even though the total amount of muscle mass and body weight were reduced.
Suggests that the DASH diet coupled with high-quality protein from lean red meat increases the efficiency to maintain muscle strength and energy expenditure.
Measures of muscular strength, muscle function, and resting energy expenditure were maintained or increased as a result of consuming daily intakes of 126 g of high-quality meat as a part of the study diet.
These findings suggest an improved health status over time.
In addition to dietary protein intake, micronutrients provided by the study diet and the supplement, such as vitamin D, vitamin B12, and iron may have also played a role in the outcomes related to muscle strength.
DASH dietary patterns can be an effective tool to reduce body fat and manage obese phenotypes in adults 65 and older.
Daily intakes of high-quality protein consumed throughout the day aids in the maintenance of strength, performance, and total body energy expenditure.
This study supports the recommendation that older adults should consume protein above the current RDA, and suggests the consumption of at least 126 g of high-quality protein per day as a part of a healthy dietary pattern to maintain muscle strength and performance.
The risks of unprocessed red meats are not ameliorated by eating more fruits and vegetables.
High consumption of red meat has been implicated in a greater risk of developing colon cancer, breast cancer, heart disease, diabetes, and an overall greater risk of death from any cause.
Higher intake of fruits and vegetables reduces the risk of breast cancer, reducing the levels of inflammation in the body, and reducing risk of heart disease, among many other benefits.
Swedish Mammography Cohort, included nearly 35,000 women, and the Cohort of Swedish Men, which included just over 40,000 men, responded to a dietary questionnaire to analyze both their red meat intake as well as their consumption of fruits and vegetables.
Red meat intake was broken out into processed meats such as hot dogs, bacon, salami, sausages, and ham, and unprocessed meats such as fresh or minced pork or beef.
For men, the more red meat they ate, the more likely they were to develop diabetes.
For both women and men, those who ate the most red meat had a 21% greater risk of all-cause mortality than those who ate the least.
Higher risk did not change by how many servings of fruits and vegetables people ate, however.
Processed meats compared with unprocessed meats account for the majority of the risk.
Higher intakes of unprocessed meats were only associated with a slightly greater risk of death when they looked the very highest levels of consumption.
The highest levels of total red meat consumption, both processed and unprocessed, suggested a 29% increased risk of death from cardiovascular disease.
Because people who eat more red meat did not necessarily consume fewer fruits and vegetables than those who eat less red meat, eating more red meat does not necessarily indicate a less healthy diet.
The examination of the relation between total, processed, and unprocessed red meat and risk of CHD in the large prospective Health Professionals Follow-up Study cohort with repeated measures of diet during 30 years of follow-up.
Those with higher total red meat consumption were more likely to smoke, consume alcohol, have diabetes, use aspirin, had higher intakes of total energy and trans fatty acids, were less physically active and less likely to have hypercholesterolemia or a family history of cardiovascular diseases, lower intakes of multivitamins, fruit, vegetables, and cereal fiber compared with those in the lower fifths of total red meat intake.
Similar distributions were observed with processed and unprocessed red meat consumption.
Higher intakes of total red meat, unprocessed red meat, and processed red meat were each positively associated with higher risk of CHD
For an increment of one serving per day, total red meat was associated with a 12% higher risk of CHD: Similar associations were observed for unprocessed and processed red meat.
Compared with intakes of total, unprocessed, or processed red meat, intakes of nuts, legumes, soy, and combined plant protein sources (nuts, legumes, and soy) were associated with a significantly lower risk of CHD.
Intake of high fat dairy products, low fat dairy products, and whole grains were also associated with a lower CHD risk compared with intake of total, unprocessed, and processed red meat.
Egg intake is additionally associated with a lower CHD risk compared with intake of processed red meat.
Milk, yogurt, and cheese were each associated with a 10% to 22% lower risk of CHD compared with red meat.
In this prospective cohort study of men with at least 30 years of follow-up, greater intakes of total, unprocessed, and processed red meat were associated with a higher risk of CHD, independent of other dietary and non-dietary cardiovascular disease risk factors.
Compared with intake of total, unprocessed, or processed red meat, intake of high quality plant based protein foods such as nuts, legumes, and soy in addition to whole grains and dairy products were each associated with a lower risk of CHD.
Substituting nuts and plant based proteins for total red meat is associated with a lower CHD risk among those older but not younger than 65 years.
In a California Seventh Day Adventists study of 25 153 people daily meat consumption was associated with a 70%, among men, and 37%, among women, higher risk of fatal ischemic heart disease.
In six prospective US cohort studies, an additional two servings per week of unprocessed red meat was associated with a 3% greater risk of cardiovascular diseases.
Participants who consumed two servings per week of processed meat were also at a 7% higher risk of CVD compared with non-consumers.
In a meta-analysis study of 17 prospective cohorts, one serving per day of total red meat was associated with a 19% higher risk of cardiovascular disease mortality, and this risk was mostly associated with processed red meat.
In the above mega-analysis unprocessed red meat was associated with higher cardiovascular disease mortality among the US populations only.
In a recent prospective meta-analysis of a reduction of three servings per week of unprocessed and processed red meat was each associated with a lower risk of all cause and cardiovascular disease mortality and a lower risk of myocardial infarction.
A higher intake of total red meat was statistically significantly associated with an increased risk of CHD among 84 136 women of the Nurses’ Health Study.
A study of 409 885 men and women in nine European countries showed that the risk of ischemic heart disease was 19% greater for every 100 g/day increment in the intake of total and processed red meat.
Substituting 100 kcal/d of fatty fish, yogurt, cheese, or eggs for 100 kcal/d of red and processed meat is associated with a 15-24% lower risk of ischemic heart disease.
Consumption of red meat is associated with increased blood levels of low density lipoprotein cholesterol compared with consumption of plant based protein sources, consistent with the high saturated fat and cholesterol content of red meat.
Nuts, legumes, and whole grains were each shown to be more effective in reducing low density lipoprotein cholesterol compared with red meat.
Red meat is low in polyunsaturated fat, and reduction of risk of CHD by replacement of saturated fat with polyunsaturated fat has been supported by both observational cohort studies and randomized trials.
Dietary heme iron found in red meat has been associated with myocardial infarction and fatal CHD in many studies.
Excessive iron intake might catalyze several cellular reactions involved in the production of reactive oxygen species, increasing the levels of oxidative stress.
L-carnitine, which is relatively high in red meat, might be metabolized by intestinal microbiota into proatherogenic compounds, promoting atherosclerosis.
Sialic acid N-glycolylneuraminic acid in red meat has been hypothesized to generate a proinflammatory, atherogenic state.
The high sodium content of processed meats is likely to increase the risk of CHD by increasing blood pressure and vascular resistance.
The intake of high quality plant based protein foods such as nuts, legumes, and soy is associated with a lower risk of CHD compared with intake of red meat.
Food replacement with high quality plant food reduces the amounts of saturated fats, cholesterol, and heme iron, but also increases the intake of unsaturated fat, fiber, antioxidants, polyphenols, and many constituents that could reduce the risk of CHD.
Intake of dark meat fish was inversely associated with CHD risk compared with intake of red meat.
Other fish intake was positively associated with CHD risk, possibly because this food group also included processed breaded fish, fish cakes, fish pieces, and fish sticks.
Associations with CHD among women of the Nurses’ Health Study and the associations of red meat consumption with all cause, cardiovascular disease, and cancer mortality were also similar among participants of the Nurses’ Health Study and Health Professionals Follow-Up Study.
The greater intakes of total, unprocessed, and processed red meat Re associated with a higher risk of CHD.
Compared with total, unprocessed, or processed red meat, other dietary components such as soy, nuts, and legumes were associated with a lower risk of CHD.
These findings are consistent with the effects of these foods on low density lipoprotein cholesterol levels and support a health benefit of limiting red meat consumption and replacement with plant protein sources.
Substituting whole grains or dairy products for total red meat and substituting eggs for processed red meat were also associated with a lower CHD risk.