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The carnivore diet is more popular than ever. As opposed to a traditional varied diet, this restrictive way of eating excludes all plants, relying entirely on animal-based foods like meat, fish, dairy, and eggs.
Advocates say that by cutting out vegetables and grains and returning to a more primitive diet, you can lose weight, think straight, and feel better. However, research into this new diet has given rise to concerns about its long-term effects, and in particular, its life-shortening consequences.
This article explores seven ways in which the carnivore diet can accelerate aging and reduce longevity, from increasing your risk of heart disease to damaging your kidneys.1. Increased Risk of Cardiovascular Disease
One way in which the carnivore diet can accelerate aging is by increasing the risk of age-related diseases, such as cardiovascular disease (CVD). CVD includes heart attacks and strokes, but also a wide range of other issues like high blood pressure, arrhythmia, and more, all of which can be very serious—and potentially shorten your life. Heart attacks, for example, reduce life expectancy by more than 16 years (1).
A meta-analysis published in eBioMedicine—an important tool that combines data from multiple studies—found that high consumption of red meat tends to increase the risk of CVD mortality.
This is mainly due to the high levels of saturated fat and cholesterol that come from red and processed meats. Consuming these in large amounts contributes to higher cholesterol levels in the blood, which, over time, can lead to blocked arteries and heart disease. The diet can also cause excess levels of other potentially harmful substances, like heme iron, salt, and phosphate, which can further strain the heart.
As well as excess animal protein being identified as a cause of cardiovascular disease, a lack of plant protein is bad too. Plant-based foods contain important nutrients and compounds that help protect the heart through reducing inflammation and getting rid of cholesterol. Research has shown that whereas diets rich in animal protein cause higher risk of death from CVD, diets rich in plant protein cause lower rates, suggesting that a balanced diet rich in plant sources is crucial for long-term heart health (2).
2. Accelerated Cellular Aging
The carnivore diet can also accelerate cellular aging: the decline of physiological functions in cells and body tissues. This happens naturally and gradually as we age, but evidence shows that a diet consisting only of animal products can speed up this process significantly.
It does this in several interrelated ways: through its activation of the mTOR pathway, through reducing autophagy, and through shortening telomeres.
Cellular aging has a huge impact on health and longevity, affecting everything from organ function to injury recovery. It can even be seen with the naked eye through its effect on skin health, much like how alcohol ages the skin.
The mTOR Pathway
The mTOR pathway is what determines whether your cells will grow, divide, or repair themselves. Which choice your cells make depends in part on what you eat. Diets low in protein (or only high in plant-based proteins) shut down the mTOR pathway, while diets high in certain amino acids from animal protein–BCAAs–keep the pathway constantly switched on, stopping your cells from being recycled in a process called autophagy.
Autophagy
Cell death is a natural bodily function, but all the different parts of a cell aren’t simply left to die. They’re recycled and converted into energy through a process called autophagy, mediated by compounds called polyamides, including spermidine.
Damaged proteins and organelles of cells are broken down into smaller components like amino acids and sugars, which can be used as energy, or to make new parts for the cell. Autophagy is essential because it keeps cells working optimally; perhaps unsurprisingly, then, reduced autophagy has been linked to negative effects like liver damage and insulin resistance. By inhibiting this vital process, the carnivore diet may contribute to metabolic diseases, worsen overall cellular health, and reduce lifespan (2).
Autophagy in particular contributes to anti-aging effects like the reduction of wrinkles and the overall look of healthy skin. The best longevity supplements trigger this process to protect the skin and prevent both visible and invisible aging.
Telomere Shortening
Another key factor in aging is telomere shortening. Telomeres are protective caps on the ends of chromosomes, and they play a critical role in maintaining the stability of DNA. Each time a cell divides, its telomeres shorten; when they become too short, the cell can no longer divide and eventually dies, contributing to the aging process.
Studies have shown that diets high in red and processed meats are associated with shorter telomere length, whereas diets rich in plant-based foods like legumes, nuts, and fruits are linked to longer telomeres. This suggests that the carnivore diet, with its reliance on animal products, may accelerate the aging process by shortening telomeres more rapidly (3).
3. Compromised Gut Health
Other impacts that a carnivore diet has on the body are far more straightforward. Meat, fish, eggs, dairy, cheese and yogurt may all contain lots of calories and protein, but they don’t contain any dietary fiber. Fiber is essential for a healthy digestive system because it regulates bowel movements. Getting no fiber at all causes digestion to slow down, causing uncomfortable symptoms such as stomach pain, constipation, and wind.
Fiber is also food for gut bacteria, which use it to produce short-chain fatty acids that help maintain gut lining and gut health. And more generally, cutting out food sources leads to a reduced variety in gut bacteria. Diets high in red meat can particularly promote the growth of bacteria like Streptococcus bovis, Fusobacterium, Clostridium, and Helicobacter pylori. These bacteria thrive in the gut when exposed to high levels of heme iron, which is abundant in red meat.
Over time, an imbalance in gut bacteria can damage the intestinal lining and increase inflammation, further raising the risk of gastrointestinal issues and even serious diseases like colorectal cancer, reducing lifespan. A diet rich in plant proteins, by contrast, ensures that the body has a greater variety of gut bacteria that prevents these issues (4).
High-fat and high-protein carnivore diets can also alter the structure of lactase-producing bacteria in the intestines, causing diarrhea (5).
4. Nutrient Deficiencies
As with any imbalanced diet, the carnivore diet can cause nutrient deficiencies. Plants are a source of various vitamins and minerals that are not found in useful amounts in animal products. As a result, following the carnivore diet may put you at risk of serious health issues that get worse over time, potentially shortening your life.
Vitamin C
Perhaps the most concerning deficiency is in vitamin C, which is vital for all sorts of bodily processes: immune function, collagen synthesis, and skin health. A lack of vitamin C famously causes scurvy, which leads to symptoms such as fatigue, swollen gums, joint pain, and anemia—and can even be life-threatening (6).
Even if the deficiency isn’t severe enough to cause scurvy, it can accelerate the growth of wrinkles, cause bruising, and exacerbate dryness in the skin. This happens because vitamin C is an important ingredient in collagen production (7).
There are animal products that are good sources of vitamin C, like liver meat. But people don’t often eat these, so a carnivore diet without them (and without supplementation) could cause these issues.
Folate
The absence of dietary folate can also be a major concern. Folate is needed for DNA synthesis and cell division–as in the mTOR pathway and autophagy described above. More generally, a deficiency in folate can lead to anemia and negatively affect brain health, too. It is especially important for women of childbearing age, as adequate folate levels are required for fetal development during pregnancy.
Minerals
While animal products can be a good source of minerals, removing plants from your diet puts significant limitations on the variety of foods you can eat, and a varied diet is the best way to get all the minerals you need. Many plants are good sources of minerals like potassium and magnesium which are important for all sorts of reasons; carnivore diets can be deficient in these minerals and others if they rely on only one or two types of meat.
Without getting enough of these minerals, individuals on the carnivore diet will experience weakened immune function, increased risk of chronic diseases, a decline in overall health, and reduced lifespan.
5. Increased Cancer Risk
Cancer is one of the most serious potentially lifespan-limiting health issues that can be caused by a carnivore diet. Research indicates that people aged 50-65 who consume higher levels of protein, like in the carnivore diet, face significantly increased risks of all-cause and cancer-related mortality. Participants in the study’s high-protein intake group had a 74% increase in their risk of all-cause mortality and were over four times more likely to die from cancer than the low-protein group (2).
It’s not just a high-protein diet that raises your risk of cancer. People following carnivore diets typically eat a lot of red meat, which is classified by the World Health Organization as “probably carcinogenic to humans”. Studies show a notable link between eating red meat, such as beef, pork, and lamb, and developing colorectal cancer; the evidence for processed meat is even stronger (8).
A potential explanation is the high level of heme iron in red meat. Heme iron damages cells and DNA by creating free radicals, and over time, this can result in cancer-causing DNA mutations. It also contributes to poor skin health and signs of aging (9).
In addition, plants contain cancer-fighting phytochemicals which can’t be found in meat. These compounds, such as flavonoids, carotenoids, and polyphenols protect cells and DNA from damage, and reduce inflammation. Studies have found that dietary phytochemicals play a significant role in cancer prevention—and can even destroy cancer cells (10).
If you’re concerned about DNA damage from your diet, consider NMN and resveratrol supplements. Resveratrol and NMN activate sirtuins which upregulate the production of NAD+, a molecule that is essential for DNA repair, metabolism, energy production, and more.
6. Impaired Cognitive Function
A carnivore diet can also age the brain. Consuming processed red meat, such as bacon or bologna, is linked to a higher risk of dementia. In fact, eating just a quarter serving of processed meat a day—about two servings a week—has been associated with a significantly increased likelihood of developing dementia compared to those who consume far less (11).
This may be because many animal-based foods lack certain brain-protective nutrients found in plant-based foods. Antioxidants, which are abundant in fruits, vegetables, and whole grains, help reduce cell damage in the brain, which can slow cognitive aging.
Plus, processed red meats are thought to promote inflammation, which can increase the risk of neurodegenerative diseases. Chronic inflammation in the brain has been strongly linked to cognitive decline and conditions such as Alzheimer’s disease.
This combination of nutrient deficiency and inflammation suggests that long-term adherence to a carnivore diet may impair brain health, contributing to faster cognitive decline.
7. Kidney Stress and Damage
Last but certainly not least, a carnivore diet can accelerate aging by putting significant strain on your kidneys.
When more protein is eaten than is needed, the kidneys need to work harder to get rid of protein-derived nitrogen. The volume and weight of your kidneys increases as a result. This isn’t harmful in the short term, but over time, an increase in kidney size can cause permanent damage. While any diet can be excessively high in protein, you’re much more likely to get more than you need from a carnivore diet than a varied diet.
Another risk factor is the formation of kidney stones. High levels of animal-derived protein can lead to kidney stone formation due to higher concentrations of calcium and uric acid in the urine.
Unless rectified, chronic inflammation and kidney stones will lead to reduced kidney function, and can even cause chronic kidney disease (CKD). CKD is a life-threatening progressive condition in which the kidneys eventually fail, requiring dialysis or even a transplant. A diet high in animal protein can both cause CKD and make it much worse if its early signs are already present (12).
CKD is one of the major conditions associated with accelerated aging, specifically premature vascular aging, muscle wasting, osteoporosis, frailty, and stiffening of the arteries. It also significantly decreases life expectancy (13)(14).
Conclusion
In summary, despite its supposed benefits, there are many ways in which the carnivore diet can accelerate aging—and potentially even shorten your life. A diet of all animal products and no plants can increase your risk of heart disease, cancer, kidney disease, cognitive decline, nutrient deficiencies, and premature cellular aging.
Instead of following an extremely restrictive diet, a balanced approach is best for overall health and longevity. Even so, it’s always recommended to consult with a healthcare professional before making any dietary changes.