Keto's Long-Term Effects: Is It Safe Or Not?

The ketogenic, or keto, diet has become increasingly popular in recent years, with many people adopting it for weight loss and diabetes management. However, there are concerns about its long-term health effects, and some experts warn that it could be dangerous. The keto diet is typically very low in carbohydrates, modest in protein, and high in fat. It involves drastically reducing carbohydrate intake and replacing those calories with fat, which puts the body into a state of ketosis, where it burns fat for fuel instead of glucose. While this can lead to initial weight loss, the diet may also have negative long-term health consequences.

Keto may cause vitamin or mineral deficiencies

The keto diet is a high-fat, moderate-protein, and low-carbohydrate eating pattern. It is extremely strict and difficult to maintain. The diet typically reduces total carbohydrate intake to less than 50 grams a day, with some people consuming less than 20 grams. Keto dieters are encouraged to derive 70-80% of their daily caloric intake from fat, 10-20% from protein, and 5-10% from carbohydrates.

The keto diet can lead to vitamin and mineral deficiencies due to its restrictive nature and the types of food it eliminates. Here are some of the deficiencies that may occur:

Thiamin (Vitamin B1)

Thiamin is important for neurological health, heart health, and metabolism. A thiamin deficiency can lead to serious health problems such as beriberi and Wernicke-Korsakoff syndrome, which affect breathing, eye movements, heart function, alertness, and mental abilities. The keto diet may be low in thiamin due to the reduced consumption of high-carbohydrate foods like fruits, vegetables, grains, and legumes.

Folate (Vitamin B9)

Folate is critical for life and plays a crucial role in methylation, a process that keeps our cells functioning. It also regulates neurotransmitters that control our urges and sense of contentment. The keto diet may lead to a folate deficiency as it restricts carbohydrates, and many plants and leafy greens are good sources of folate.

Biotin (Vitamin B7)

Biotin is important for hair, skin, and nail health. It is also necessary for embryonic growth during pregnancy. The keto diet may cause a biotin deficiency as it is used up in the processing of fatty acids. Additionally, biotin is found in some keto-friendly foods like liver, egg yolks, meat, and avocados, but the high-fat content of the diet may reduce its absorption.

Vitamin A, Vitamin D, and Vitamin E

These fat-soluble vitamins play essential roles in maintaining health. Vitamin A is important for vision, immune function, and cell growth. Vitamin D is crucial for bone health, muscle function, and nerve communication. Vitamin E acts as a biological antioxidant, protecting cells from damage. The keto diet may lead to deficiencies in these vitamins due to the reduced consumption of vitamin-rich foods like fruits, vegetables, and plant oils.

Selenium

Selenium is a mineral with antioxidant properties that boost immunity, support thyroid function, and protect heart health. The keto diet may cause a selenium deficiency as high-fat foods tend to be low in selenium. Additionally, the keto diet's restriction of carbohydrates and its effects on nutrient absorption can further contribute to this deficiency.

Calcium, Magnesium, Iron, and Potassium

The keto diet may also lead to deficiencies in these essential minerals. Calcium is important for bone and teeth health, blood vessel function, and nerve communication. Magnesium is crucial for energy production and the proper functioning of nerve cells and the brain. Iron is necessary for energy production and the formation of red blood cells. Potassium helps balance fluids, maintain blood pressure, and support nerve and muscle function. The keto diet's restriction of calcium-rich and magnesium-rich foods, such as fruits, vegetables, and grains, can lead to deficiencies in these minerals. Additionally, the diet's impact on insulin levels and urine pH can affect the absorption and excretion of these minerals.

It could be bad for your heart

The keto diet has gained traction over the last decade, with many people adopting it for weight loss and diabetes management. However, there are concerns about its long-term health implications, particularly for the heart.

The keto diet is a high-fat, low-carbohydrate, and moderate-protein eating pattern. It involves drastically reducing carbohydrate intake to less than 50 grams per day, with some people consuming less than 20 grams. This means cutting out fruits, starchy vegetables, grains, beans, and lentils, and instead consuming high amounts of animal products, such as red meat, fish, and eggs.

This shift in diet can have a detrimental impact on heart health. A study published in the Journal of the American College of Cardiology found that people on low-carb diets are more likely to develop atrial fibrillation (AFib), which increases the risk of blood clots, stroke, and heart failure. Additionally, a study of CrossFit athletes who followed a keto diet for 12 weeks experienced a 35% increase in "bad cholesterol" (LDL-C), which is linked to cardiovascular risk due to its contribution to arterial plaques.

The restriction of nutrient-rich fruits, vegetables, and whole grains on the keto diet can lead to deficiencies in vitamins and minerals, including thiamin, folate, vitamin A, vitamin E, vitamin B6, calcium, magnesium, iron, and potassium. These deficiencies can have a range of negative health impacts, including constipation, heart palpitations, and extreme fatigue, which are symptoms of potassium deficiency.

The keto diet's emphasis on animal products can also increase the risk of heart disease. Neal Barnard, MD, FACC, and co-author of a study on keto diets, states that while a cat can eat meat every day without having a heart attack, humans who eat meat for a week will often see their cholesterol levels rise, increasing the risk of heart disease.

Furthermore, the keto diet's restriction of carbohydrates can lead to a more acidic state in the body, which may limit its ability to perform at peak levels. This could be detrimental to heart health, especially for athletes or individuals with active lifestyles.

In conclusion, while the keto diet may offer short-term benefits, such as weight loss, it could be detrimental to heart health in the long term. It is important to consult with a healthcare professional before starting any restrictive diet like keto to ensure it is safe and appropriate for your individual needs and health status.

It may damage blood vessels

The ketogenic diet has been linked to an increased risk of damaging blood vessels. Researchers from the University of British Columbia found that indulging in a high-sugar treat while on a high-fat, low-carb diet can damage blood vessels. The study, published in Nutrients in 2019, found that a "cheat day" on the ketogenic diet can have long-term consequences for blood vessel health.

Senior author Jonathan Little, an associate professor in the School of Health and Exercise Sciences, expressed concern that those on a keto diet may be undoing the positive impacts on their blood vessels if they suddenly consume a high-sugar treat. He warned that ketogenic dieters should not take a break from the diet, as it could negatively affect their blood vessels.

The potential damage to blood vessels is linked to the body's state of ketosis, which is characterised by higher levels of acidity. This increased acidity may limit the body's ability to perform at peak levels and could be a factor in damaging blood vessels.

Furthermore, the keto diet's restriction of carbohydrates can lead to a lack of fibre, which is essential for healthy intestinal function, nutrient absorption, and immune function. This fibre deficiency could also contribute to blood vessel damage over time.

In addition, the keto diet's emphasis on animal products and limitation of nutrient-rich vegetables, fruits, and whole grains can result in vitamin and mineral deficiencies. These deficiencies can have a detrimental effect on overall health, including blood vessel health.

While the keto diet may offer short-term benefits, such as weight loss, the potential long-term consequences on blood vessel health should be carefully considered. The damage to blood vessels could lead to an increased risk of cardiovascular disease and other health issues. Therefore, it is essential to consult a healthcare professional before starting any restrictive diet like keto to ensure it is safe and suitable for your individual needs.

It can be difficult to maintain

The keto diet is extremely strict and can be difficult to maintain. It requires a person to eat 75% of their calories from fat, 5% from carbohydrates, and 15% from protein. This means cutting back on carbohydrates to 50 grams a day or less, which can be challenging and may result in a person cutting back on important sources of vitamins and minerals, such as fruits and vegetables.

The keto diet is also likely to lead to a general nutrient imbalance, with deficiencies in thiamin, folate, vitamin A, vitamin E, vitamin B6, calcium, magnesium, iron, and potassium. These deficiencies can lead to a host of frustrating daily health issues. For example, common symptoms of potassium deficiency, or hypokalemia, include constipation, heart palpitations, and extreme fatigue. Magnesium deficiency leads to fatigue, muscle twitches and cramps, apathy, and high blood pressure.

The keto diet is also low in fiber, which is important for healthy intestinal function, nutrient absorption, and immune function. It can be challenging for people to get enough fiber while on the keto diet, as whole grains are a significant source of this nutrient. A lack of fiber can lead to digestive problems such as constipation or chronic diarrhea.

Additionally, the keto diet can be challenging to maintain due to its restrictive nature, with over 50% of people failing to adhere to the diet in many medical studies. It can be difficult to follow the diet correctly, and even a small deviation can lead to weight regain. This can be frustrating and lead to a higher risk of early death.

Furthermore, the keto diet can be socially isolating, as it may be challenging to find keto-friendly options when eating out or socializing with others. The diet can also be expensive, as keto-compliant foods like red meats and nuts can be costly.

Overall, while the keto diet may offer some potential benefits, it can be challenging to maintain due to its strict and restrictive nature, the potential for nutrient deficiencies, the difficulty of long-term adherence, and the risk of social isolation and increased expenses.

It may affect athletic performance

While the keto diet has been linked to weight loss, some researchers are concerned that athletes may be compromising their strength and fitness. A 2019 study published in the Journal of Sports Medicine and Physical Fitness found that participants performed worse on high-intensity cycling and running tasks after four days on a ketogenic diet compared to those who had spent four days on a high-carb diet.

The body is in a more acidic state when it is in ketosis, which may limit its ability to perform at peak levels. While keto can help athletes lose weight, which can be beneficial for speed and endurance, Edward Weiss, PhD, associate professor of nutrition and dietetics at Saint Louis University, has expressed concern that the benefits of weight loss could be cancelled out by reductions in performance.

Some elite athletes thrive on a keto diet, but others do not. High-intensity activities, such as Crossfit, HIIT, and obstacle races, as well as longer efforts, such as marathons, will require extra glucose for energy. Adding back carbs in a ratio that supports an athlete's exercise regimen may be the answer.

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