Can Your Eat Beef on Low Carb Diet

1. What is "red meat"
2. Benefits
3. Potential harm
4. Cancer
5. Heart disease
6. Insulin resistant conditions
7. Gout
8. Red meat evidence
9. Mortality
10. Healthy choices
11. Summary

Is red meat healthy, harmful, or neutral? Should you enjoy it freely on your healthy diet or limit your consumption?

Depending on which expert you ask, these questions may receive very different answers.

Has a strong link between red meat and heart disease, cancer, or other diseases been established? Will consuming it on a regular basis shorten your life or put you at risk of health problems?

Here is our guide to what we currently know about red meat, so you can make an informed decision about whether to include it – and how much – in your own diet.

Disclaimer: Many health and nutrition experts consider red meat to be potentially dangerous when it comes to long-term health. A careful analysis of the science shows that there is room for debate given the quality of evidence on which current conventional wisdom is based.

We recognize that many of the studies cited have both pro- and anti-meat funding biases. While the funding source does not invalidate the data, it does question its strength. That is one of the many reasons detailed in this guide why the evidence is not as strong as we would like on either side of the argument.

This guide is our attempt to summarize current scientific evidence. It is written for adults who are concerned about meat intake and health.

Discuss any lifestyle changes with your doctor. Full disclaimer

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What is red meat?

Red meat comes from mammals. When raw, it usually appears dark red because it contains a lot of myoglobin, the iron-rich protein that stores oxygen in animal muscle. The red meat category includes beef, pork, lamb, veal, goat, bison, venison, and other game.¹

Red meat can be fresh or processed. Fresh red meat is exactly what it sounds like: meat that contains no additives, requires refrigeration, and needs to be consumed within a few days, after roasting, grilling, stewing, etc.

Processed red meat is a broader term referring to meat that's been modified by salting, curing, smoking, canning, or treating with preservatives. Popular types include bacon, salami, sausage, hot dogs, and jerky.

Some processed meats contain salt as their sole additive, whereas others may include sugar, starch, other fillers, and chemicals such as nitrites.

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Benefits of eating red meat

Animal foods are an important part of our evolutionary past, having likely played a critical role in our development as a species.² They have even been credited with allowing us to develop the large, complex brains that are unique to humans, although evolutionary science like this is imprecise at best.³ Indeed, we may be genetically wired to enjoy the flavor and texture of meat.

In addition to being tasty and filling, red meat provides many nutritional benefits:

• High-quality protein: A 100-gram (3.5-ounce) serving of red meat contains about 20-25 grams of protein, depending how fatty it is (leaner cuts have more protein). Like eggs, dairy, and other animal products, red meat provides protein that is considered complete, meaning it contains all nine essential amino acids in the amounts your body needs.⁴ Learn more about protein:

  

  Protein on a low-carb or keto diet

  Guide Along with fat and carbohydrates, protein is one of the three macronutrients ("macros") found in food, and it plays unique and important roles in the body. Here's a guide to everything you need to know about protein on a low-carb or keto lifestyle.

• Several vitamins and minerals: Red meat is an excellent source of many important micronutrients, including vitamin B12, niacin, selenium, zinc and potassium.
• Heme iron: All types of red meat are rich in heme iron, which your body absorbs more easily than the non-heme form of iron found in plants.⁵ Consuming red meat on a regular basis may help increase your iron stores and prevent iron-deficiency anemia.⁶
• May help preserve muscle: It's an unfortunate fact that we usually lose muscle as we age due to hormonal and other physiological changes. In one study, older women who ate red meat in combination with resistance training achieved greater gains in lean muscle and strength than the resistance-training-only group.⁷ Similar improvements have been shown in studies of young and middle-aged men who consumed beef and triathletes who took beef-based supplements, when compared to men of similar age who ate lacto-ovo vegetarian diets or took whey-based supplements during strength training.⁸
• May help prevent frailty: In a study of older women, consuming higher amounts of animal protein, including red meat, was linked to a decreased risk of weakness, loss of strength and other changes that often occur with aging.⁹

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What does the research show with respect to meat's potential harm?

Over the past several years, news media have reported on studies showing an association between eating a lot of red meat and increased risks of cancer and heart disease. Some articles have even stated that meat is flat-out "killing us."

But how strong are these associations, especially when considering all available types of studies? Let's take a look at the research on red meat and disease risk to date and assess the strength of the evidence.

Red meat and cancer

In October 2015, the International Agency for Research on Cancer (IARC) issued a press release classifying processed meat as "carcinogenic" and red meat as "probably carcinogenic" in humans. While the epidemiological studies reviewed by the committee suggest an association, other studies question the strength of the association.

Cancers other than colorectal

In large reviews and meta-analyses of observational studies, researchers have found inconsistent results. One very large meta-analysis found that the absolute effects of red meat on cancer risk are extremely low, with the certainty of evidence being low to very low.¹⁰ While some have shown no association of red meat and cancer risk, others have shown a positive association with gastric, esophageal, breast, and prostate cancer.¹¹

For those that did show an association, the hazard ratios were quite small, in the range of 1.06 to 1.4. In comparison, cigarette smoking has a hazard ratio greater than 20 for being associated with cancer.¹² Therefore, although these observational studies can suggest an association between red meat and cancer, the very low hazard ratios weaken the assertion that red meat causes cancer.

Colorectal cancer

Colorectal cancer is by far the most common type of cancer studied regarding its relationship to red meat. Here, studies have shown a more consistent association.¹³ However, once again the association is very weak with hazard ratios mostly below 1.4. While this does not invalidate the data, the weak hazard ratios do raise the question of what it is, exactly, about meat that may increase risk.¹⁴

In some studies, the association with colorectal cancer has been attributed to heterocyclic amines (HCAs) and other potentially harmful compounds that form when meat is cooked at high temperatures.¹⁵ Therefore, it seems reasonable to infer that limiting high-temperature cooking of red meat could mitigate the very small risk of colorectal cancer.

The heme iron found in red meat has also been suggested to play a causative role in colorectal cancer, based on findings in animal studies and some epidemiological studies in humans.¹⁶

However, other studies have failed to show a connection between ingesting HCAs and heme iron with developing colorectal cancer.¹⁷

While many observational trials suggest red meat is associated with colon cancer, some researchers point out that other lifestyle factors could influence those results. With low hazard ratios, it's difficult to completely exclude that high sugar consumption, alcohol intake, smoking, decreased physical activity, lack of vegetable intake or other factors impacted the results.¹⁸

In contrast to the large amount of observational research available, very little experimental research on red meat consumption and colon cancer exists, at least in humans.

However, we do want to highlight one particular clinical trial that suggests green leafy vegetables may mitigate the presumably very low risk of colon cancer from red meat. The evidence is short-term, uses surrogate endpoints, and requires larger confirmatory trials, but at the same time is encouraging for demonstrating a potentially protective effect.¹⁹

Looking at other human clinical trial data, one study in people with precancerous colon polyps found that cutting back on red meat over a four-year period did not decrease the risk of polyp recurrence.²⁰ In addition, a systematic review of RCTs comparing lower vs. higher red meat consumption found the overall quality of evidence to be low or very-low, and the authors concluded there is no meaningful increase in cancer with higher red meat consumption.²¹

While there are compelling mechanistic data to explain how compounds in red meat or produced by the cooking of meat could cause colorectal cancer, it's important to remember that plausible mechanisms are not sufficient to prove a causal relationship.²²

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Red meat and heart disease

Many observational studies show a relationship between eating meat and the risk for heart disease, stroke and heart disease deaths.²³

One large review failed to find a consistent and definitive relationship between red meat and increased risk of ischemic heart disease (also known as coronary artery disease).²⁴ But other large reviews found evidence for an increased risk of heart disease and all-cause mortality, albeit extremely small.²⁵

Still other reviews of the literature show a link with processed meat but not minimally processed red meat.²⁶

Recognizing that trying to link red meat to cardiovascular events requires studying very large numbers of subjects for long periods, many investigators choose to focus instead on surrogate endpoints.

One meta-analysis of randomized controlled trials (considered the strongest, highest-quality evidence) showed that eating three or more servings of red meat per week had no adverse effects on CVD risk factors like cholesterol, triglyceride or blood pressure values.²⁷

A 2019 review of RCTs and cohort studies used the GRADE technique to assign a level of quality to studies comparing more vs less red meat intake. They found no meaningful increased cardiovascular risk from higher red meat consumption.²⁸

Part of the problem is separating the effects of red meat from the effects of other dietary and lifestyle factors. The evidence suggests that those eating meat as part of a high-carb and high-fat Western diet tend to be less healthy at baseline than those choosing not to eat meat.²⁹

Investigators try to control for unhealthy behaviors, but it's really hard to do that. This leads to weak statistical relationships and fairly uncertain conclusions. Perhaps the best we can say is, if you are unhealthy at baseline and eating a standard Western diet, then the data suggest red meat consumption is associated with heart disease risk.

But what if you aren't eating a standard Western diet? What if you aren't unhealthy at baseline? Here, the data are much sparser regarding the role of red meat in heart disease.

A user guide to saturated fat

Guide This guide explains what is known about saturated fat, discusses the scientific evidence about its role in health, and explores whether we should be concerned about how much we eat it.

In addition to looking at surrogate endpoints like cholesterol, investigators have also looked at the tendency of red meat to raise blood levels of TMAO (trimethylamine-N-oxide), which some studies show correlates with increased heart disease risk.³⁰ Yet, what's often not mentioned is that eating many other foods — including fish — also raises TMAO.³¹ Further, the production of TMAO is dependent on gut microbiota, not just the consumption of red meat.³²

As we have written about the inconclusive evidence for a relationship between TMAO and CVD, questions remain regarding the role of TMAO as an independent risk marker or causative factor for coronary disease.

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Red meat and insulin-resistant conditions

Some studies suggest that eating red meat on a regular basis may increase the risk of diabetes and other conditions characterized by insulin resistance.

• Diabetes: Several large reviews of observational studies have found weak associations between frequent red meat and processed meat consumption and diabetes risk.³³ Once again, however, we need to consider this association between meat and diabetes risk in a real-world context: it is possible that many of these study subjects were also eating high-carbohydrate diets and low-quality foods. It is critical to note that randomized controlled trials have shown impressive improvement in diabetes with unlimited animal food sources, including red meat.³⁴ This appears to make it less likely that meat itself leads to diabetes; rather, the risk may more likely be due to a combination of foods that tend to be high in both fat and carbohydrates, as well as other poor lifestyle habits.
• Obesity and metabolic syndrome: A 2014 systematic review of observational studies showed a weak relationship between red meat and obesity but a much stronger one between red meat and large waist size.³⁵ But once again, that is far from proving causation.

  Another trial, an analysis of data from the PREDIMED trial — a large study exploring health-related effects of the Mediterranean diet — found similar results. ³⁶

On the other hand, a well-controlled trial in overweight and obese people found that including 500 grams (17.6 ounces or approximately three 6-ounce servings) of lean red meat per week as part of a Mediterranean diet resulted in equal weight loss and reduction in metabolic risk factors compared to following the same basic diet but eating much less red meat.³⁷

And a meta-analysis of 24 RCTs found no differences in glycemic control, insulin sensitivity, or inflammatory markers among metabolically healthy people, comparing those whose average red meat intake was less than 0.5 servings (35 grams) per day to those who consumed more than 0.5 servings per day.³⁸

How can we interpret these data? For those eating a standard Western diet with high carbohydrates and high fat, red meat consumption is likely associated with insulin resistance and metabolic syndrome. However, other studies show that low-carb diets that include red meat successfully treat type 2 diabetes and insulin resistance.³⁹

Therefore, we come back to the concept that the overall content of the diet may be more important than the specific intake of red meat.

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Red meat and gout

Gout, one of the most acutely painful joint conditions, is characterized by high levels of uric acid in the blood (hyperuricemia). People with gout are often advised to strictly limit the amount of red meat they eat.

However, a systematic review of 19 observational studies found that consuming red meat intake was only weakly associated with gout and elevated uric acid levels, whereas alcohol and fructose intake were found to have stronger correlations with each of these conditions.⁴⁰

Read more about gout and low-carb diets here.

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Red meat and all-cause mortality

Multiple epidemiologic studies have shown a weak association between meat consumption and increased risk of premature death. However, once again these studies have low hazard ratios consistently under 1.4, and they are subject to healthy user bias and other weaknesses of nutritional epidemiology studies.⁴¹

Given that the correlation between red meat intake and all-cause mortality is consistently weak, it's not surprising that the some of the largest cohort studies and meta-analyses have demonstrated just a tiny increased risk regarding red meat intake and all-cause mortality.⁴²

What's more, a 2013 review of dietary habits among Asians not only found no association of increased risk of death among red meat eaters but also a slightly decreased risk of CVD mortality in men and cancer mortality in women who reported the highest intakes of meat.⁴³

Just as with the risk for cancer and heart disease, what else is eaten with the red meat likely plays a significant role as do other health habits. For instance, one study tried to control for these factors and recruited "health conscious" participants. They found no mortality difference between meat eaters and vegetarians.⁴⁴

Nonetheless, we can't dismiss the data associating red meat with mortality. If someone fits the common subject profile in many of the epidemiologic studies – eating 40-50% carbohydrates, overweight, metabolically unhealthy – then that person may have a slightly higher risk of premature death if eating red meat. Is it the meat or is it other unhealthy lifestyle choices? That remains to be proven.

We also need to ask: what happens when someone lowers their carbohydrates, loses weight, reverses metabolic disease, and improves their overall lifestyle? In that situation, we do not have incriminating evidence against red meat.

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Source: https://www.dietdoctor.com/low-carb/red-meat

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