The Animal Protein Cancer Connection

The dietary advice given to cancer patients is at best painfully ignorant and at worst potentially deadly.

Cancer patients are routinely told by their doctors and nutritionists to eat whatever they want and are often sent home with suggestions to consume high-calorie junk food like ice cream and milkshakes. In addition, there are a number of cancer diet books with meat-based recipes despite countless published studies demonstrating how eating animal products (meat, dairy, eggs) can cause and promote cancer growth.

An eighteen year study following 6,000 middle-aged people (ages 50-65) found that those who ate a high protein diet (20% of calories from animal protein) had a 75 percent increased risk of death and a four hundred percent increased risk of dying from cancer than those who ate a low-protein diet (less than 10% of calories from animal protein). This four-fold risk of cancer death from consuming too much animal protein is comparable to the four-fold risk of cancer death from smoking. And again, that was found in people eating 20% of calories from animal protein.

The study also found that people over 65 who ate moderate amounts of animal protein did not have as high a risk, presumably because as we age it is more difficult for our bodies to synthesize protein. People in the study who ate high amounts of plant protein did not have an increase in risk.

Let’s start with the animal products that are known cancer causers.

In 2015, after reviewing 800 scientific studies, the International Agency for Research on Cancer (IARC) classified processed meats including bacon, sausage, ham, hot dogs, deli meats, corned beef, canned meat, and jerky as Group 1 carcinogens (Source, Source). That means there is sufficient evidence that these foods directly cause colorectal cancer, and may also cause stomach cancer. Eating just 1.75 ounces (50 grams) of processed meat each day—that’s about two strips of bacon—increases your risk of colorectal cancer by 18 percent (Source).  And your risk increases with the amount of meat consumed.

Red meat (beef, pork, lamb, etc.) is classified as a Group 2A carcinogen, which means the current body of evidence indicates that it is a probable cause of cancer. A separate meta-analysis associated the consumption of red meat and processed meat with an increased risk of colorectal, esophageal, liver, lung, and pancreatic cancers (Source).

Another notable study found that middle-aged Americans ages 50 to 65 who reported eating a high-protein diet with more than 20 percent of calories coming from animal protein were four times more likely to die of cancer or diabetes and twice as likely to die of any other cause over the next 18 years. But those who ate a plant-based diet did not have any increase in risk (Source).

In addition to processed meat and red meat being potential cancer causes, here are ten ways eating animal products can contribute to cancer.

Saturated fat
A diet high in animal protein­–meat, dairy, eggs–is also high in saturated fat. A diet high in saturated fat has been found to increase your risk of lung, and intestinal cancers. It also increases a man’s risk of prostate cancer and a woman’s risk of post-menopausal breast cancer and death. Palmitic acid in animal foods (and palm oil) may be the biggest instigator. There is no association of increased cancer risk from saturated fat found in plant food such as nuts, seeds, avocados and olives.

Dietary cholesterol has been associated with an increased risk of many cancers including stomach, colorectal, breast, lung, pancreatic, kidney, bladder, and non-Hodgkin’s lymphoma. Cholesterol metabolites support cancer progression and suppress immune responses. Studies have shown that manipulating cholesterol metabolism inhibits tumor growth, reshapes the immunological landscape, and reinvigorates anti-tumor immune function (Source). Cholesterol is not found in plant food, only in animal food, and eggs are the highest source. The simplest way to eliminate excess cancer-fueling, immune-suppressing cholesterol in your body is to stop eating animal food. Your liver makes all the cholesterol your body needs.

Insulin-like growth factor-1 (IGF-1) is a hormone that speeds up cell division and is directly linked to uncontrolled cancer growth. Elevated levels of IGF-1 can promote cancer in humans, specifically breast, prostate, pancreatic and colon cancer (Source). IGF-1 stimulates tumors to grow and helps cancers cells spread to other parts of the body. IGF-1 levels increase when you eat animal protein and/or refined sugar. One remarkable study found that after just 12 days on a whole-foods plant-based diet plus daily exercise, the blood of breast cancer patients was found to have significantly lower levels of IGF-1 and increased cancer-stopping power (Source).

Many human cancer cells, including colorectal, breast, ovarian, melanoma, and even leukemia, are dependent on an amino acid called methionine, which is one of nine amino acids not made by the body (Source, Source). Fruits contain little to no methionine. Vegetables, nuts, and whole grains have small amounts. Beans have the most methionine in the plant kingdom, however, milk, eggs, and red meat have over twice the methionine as beans. Chicken and fish have five to seven times more. The easiest way to keep your methionine levels low and deprive cancer cells of this essential amino acid is to eat little to no animal food.

mTOR is an essential protein that functions as a master regulator of cellular growth and proliferation (Source). The amino acid leucine is the greatest stimulator of mTOR. Fruits and vegetables have low levels of leucine. Grains and beans have more, but animal products have the highest levels of leucine by far. Meat, fish, eggs, and dairy have 2-4 times more leucine than beans, up to fifteen times more leucine than vegetables, and up to 75 times more leucine than fruit. The highest source of leucine is dairy, specifically whey protein, which has 75% more than beef.

Protein restriction reduces mTOR signaling, stimulates autophagy (that’s cellular housecleaning), and reduces cancer-promoting growth hormone IGF-1 (Source). Limiting the TOR-activating amino acid leucine in your diet naturally down-regulates mTOR, but there are a number of special compounds in plants that also inhibit mTOR. Diets emphasizing plants, especially cruciferous vegetables, not only decrease leucine-dependent mTORC1 activation but provide natural plant-derived inhibitors of mTOR. (Source)

Plant compounds that may inhibit mTOR directly or indirectly include DIM in cruciferous vegetables, EGCG in green tea, genistein in soy, curcumin in turmeric root, and resveratrol in grapes, blueberries, cranberries, apples, plums, pistachios, and peanuts (Source).

The flavonoid fisetin also targets mTOR. Fisetin is found in fruits and vegetables, especially onions strawberries, blueberries, mangoes, and the skin of cucumbers (Source).

Flavonoid fisetin also targets mTOR. Fisetin is found in fruits and vegetables, especially onions strawberries, blueberries, mangoes, and the skin of cucumbers (Source).

Heme Iron
Heme iron is a highly absorbable form of iron found in meat—especially red meat, organ meat, and shellfish—but not found in plant food. Dietary iron is necessary for the formation of healthy blood cells, but excess iron causes oxidative damage, DNA damage, and can catalyze the formation of cancer-causing N-nitroso compounds. Excess dietary iron has been linked to an increased risk of esophageal, stomach, colorectal, and breast cancer (Source, Source, Source). Excess iron accumulates in your liver, heart, and pancreas eventually resulting in iron toxicity because your body has no way of ridding itself of excess iron except through blood loss (women do this every month until menopause). Non-heme iron is a much safer form of iron found in plant foods, especially in legumes, sesame seeds, pumpkin seeds, spinach, Swiss chard, quinoa, and dried apricots. And unlike the highly absorbable heme iron animal food, plant-based iron absorption is naturally regulated. Humans absorb more iron from plant food when we need it and less when we don’t. 

N-glycolylneuriminic acid (Neu5Gc) is a unique sugar molecule found only in animal food, especially red meat, organ meat, and some dairy products, which increases the risk of tumor formation in humans. Neu5Gc does not occur in humans and your immune system treats this molecule as a foreign invader and produces antibodies in response to it, which increases inflammation in your body. Neu5Gc has been associated with inflammatory diseases including cancer, cardiovascular disease, and some bacterial infections (SourceSource).

Choline, Carnitine and TMAO
Trimethylamine N-Oxide is an inflammatory metabolite produced by gut bacteria from choline and L-carnitine. The highest source of L-carnitine is red meat followed by pork, milk, and chicken. Red meat has 2-5 times more carnitine than pork and 4-10 times more than chicken.  Your body can also produce L-carnitine from lysine and methionine. The highest amounts of choline are found in meat, eggs, poultry, milk, and refined grains, in that order, with meat having nearly twice the level of choline as refined grains. Higher levels of TMAO increases your risk of heart attack stroke and death. Higher levels of TMAO in the body are also associated with increased
“bad” trimethylamine-producing bacteria in the gut (like Fusobacterium, Prevotella, and Lachnospiraceae) and with the development of heart disease, diabetes, and cancer, especially colorectal cancer. One study found that women with the highest levels of TMAO had triple the risk of colorectal cancer. TMAO is also associated with increased risk of breast and prostate cancer. Vegetarians and vegans have markedly reduced synthetic capacity to make TMAO from L-carnitine and have lower TMAO plasma levels than meat eaters. (Source, SourceSource, Source,Source, Source, Source)

Phosphate (Phosphorus)
High dietary phosphate is associated with an increased risk of breast cancer in middle-aged women. One key finding is that exposure to greater than 1,800 mg of phosphate per day increased the relative risk of breast cancer incidence by 2.30 compared to the those with the lowest phosphate intake.

The gastrointestinal bioavailability of phosphorus derived from dairy and meat (40-60%) is higher than phosphorus bound to phytate in whole grains (20–50%). [Phytates do not leach minerals from your body. They prevent the absorption of excess potentially harmful minerals like iron and phosphorus.] Phosphate additives used in processed food have even higher absorption rates (90–100%). Recent studies have also found a correlation between tumorigenesis and phosphate toxicity, occurring due to dysregulated phosphate metabolism in the body. (Source) Phosphoric acid, commonly used in sodas, is also linked to kidney stones. (Source)

HCA and PACs
As if all of those problematic compounds weren’t enough, cooking meat creates mutagenic compounds called heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). These are cancer-causing chemicals formed when amino acids and creatine in muscle or organ meat and/or fatty meats are cooked at high temperatures, as in barbecuing, baking, pan frying, charring, or grilling over an open flame. HCAs and PAHs are linked to various cancers, including kidney, colorectal, lung, prostate, and pancreatic cancer. (Source)(Source)(Source)

These compounds are not produced when vegetables are cooked.

One large study found that people with the highest consumption of meat cooked at high temperatures had a 70 percent greater risk of pancreatic cancer compared to those with the lowest consumption of well-done meats. (Source)

Fried bacon and fried fish have the highest concentrations of HCAs and PACs, about five times more than beef and chicken. Interestingly, chicken cooked without the skin has been found to have twice the levels of mutagens as chicken cooked with the skin on. (Source) (Source)

Grilling specifically contributes to the carcinogenicity of meat. Wood smoke contains numerous toxins and volatile organic compounds including cancer causers benzene and formaldehyde. When you cook over a wood fire (or smoke in a smoker) you infuse these carcinogens into the meat (or vegetables) and then you eat them. Charcoal smoke contains many of the same toxins as wood. Cooking with charcoal also doubles the amount of polycyclic aromatic hydrocarbons in meat compared to cooking over gas (Source). Gas fumes aren’t 100% safe either. Always turn the ventilation hood on when cooking on a gas stove.

But haven’t humans been eating animals for thousands of years?
Yes, but not at the excessive levels we do today. Thanks to factory farming, we are eating meat and dairy at every meal. This seems normal, but it is unprecedented in human history, as are our rates of chronic diseases like cancer, heart disease, and diabetes. There are still many parts of the world where cancer rates are very low. For example, the rate of colon cancer is 50 times lower in native Africans than in African Americans. Researchers credit the native Africans’ extraordinarily low rates of colon cancer to an absence of “aggressive dietary factors,” namely animal protein and fat. (Source)

What about grass-fed, organic, wild meats and wild-caught fish?
Those forms are certainly better than factory-farmed animal food. When it comes to eating animal products, think in terms of quality and quantity. I suggest high quality, low quantity. According to the National Geographic Blue Zones Project, the healthiest longest-living people groups around the world eat 95% plant-based on average. This equates to eating animal products somewhere between a few times per week to a few times per month. That is considered to be a safe level of consumption for the prevention of many chronic dietary diseases. There are zero studies showing long life and exceptional health eating high animal protein or carnivore diets.

How much protein do you need?
Unless you are a professional athlete or competitive bodybuilder, you need far less protein than the meat, dairy, egg, and protein supplement industries have lead you to believe. Humans need 0.8 grams of protein per kilogram (2.2 lbs) of body weight.

Here’s how many grams of protein you need per day based on your weight, assuming you are in a healthy weight range (BMI under 25):

100lbs – 36 grams
125 lbs – 45 grams
150 lbs – 55 grams
175 lbs – 64 grams
200 lbs – 74 grams

To calculate your daily protein requirement, divide your weight by 2.2, then multiply by 0.8.

Believe me, it is easy to achieve adequate protein intake eating three meals per day of whole plant foods.

If you are trying to heal active cancer, I suggest applying the precautionary principle and drastically reducing your consumption of animal products as well as processed foods to zero or near zero. Think in terms of risk reduction. When you reduce or eliminate the animal products in your diet and replace them with whole plant foods from the earth, you not only reduce the levels of cancer causers and cancer promoters found in animal food, but you also increase the levels of thousands of anticancer compounds in your body from plant food. That’s why a whole food plant-based diet (preferably organic) is the optimal anticancer diet.

I created a coaching program called SQUARE ONE to teach you exactly how I and many others have healed cancer against the odds with evidence-based anticancer nutrition and natural non-toxic therapies.  If you are serious about healing or prevention, the SQUARE ONE Program is for you. 

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