Alkaline Diet: Everything You Need to Know

Are you considering starting an alkaline diet? We're going to tell you everything you need to know about this feeding method so that you're clear if it's really beneficial.

Written and verified by el nutricionista Saúl Sánchez.

Last update: 30 June, 2023

The alkaline diet became trendy a few years ago due to its supposed health benefits. It was proposed that through this feeding method, it was possible to reduce the incidence of several complex diseases, including cancer.

The truth is that nutrition experts have debated the supposed positive effects of this diet. Below, we’ll show you what the scientific evidence says. However, remember that healthy eating is based on variety, and the alkaline diet doesn’t meet that requirement.

Previous physiological concepts

The body tends toward a state of constant equilibrium, this is what’s called homeostasis. Stability is sought in all biochemical parameters. When any alteration occurs, a series of processes are generated that try to correct the imbalance to return to the usual state. If it’s achieved, it can be said that the body’s in a state of health.

However, not all parameters have the same level of flexibility. For example, blood glucose levels can change significantly in the short term without posing a real health risk. Moreover, it can be decisive to achieve a certain sports performance. It’s true that once the stimulus has passed, it goes back to calm.

For their part, other parameters don’t enjoy such wide ranges of mobility. One of them is the acid-base balance, marked by pH. This parameter oscillates in the blood between 7.35 and 7.45, that is, it undergoes a very small variation. In the event that these limits are exceeded, the consequences for the body can be devastating.

It’s true that other tissues or fluids in the body have greater flexibility in terms of acid-base balance. For example, the pH of the urine can vary more depending on the diet, the intake of dietary supplements, and even the consumption of drugs. Be that as it may, it always stays within ranges within which it’s considered normal.

The liver, kidneys, and lungs, among other organs, are responsible for preserving this stable biochemical parameter. The first two organs purify existing toxins within the body and allow their excretion through urine and feces. In addition, they have endocrine functions and intervene in metabolism, so their physiology is complex.

What is the alkaline diet based on?

The alkaline diet is based on its ability to influence blood pH through the intake of certain foods. It has been suggested that the consumption of products considered “basic” (high pH values) causes an alteration in the internal environment that generates health benefits. From here, the incidence of many complex diseases could be reduced.

However, it’s not possible in practice to vary blood pH levels without harmful consequences for human health.

Only a change in the acid-base balance of the urine would be feasible. On the other hand, although it’s true that some diseases such as cancer are characterized by creating an acidic environment around them, it hasn’t been proven that an influence on pH levels causes protection against them.

To all this, we must add that the organs of the human body responsible for homeostasis do their job really well. There’s no need to support their function other than with the approach of a healthy diet that ensures that the requirements of essential nutrients are covered. It’s also advisable to limit the intake of toxins as much as possible.

Foods allowed in the alkaline diet

Despite the fact that the principles of the alkaline diet contradict the explained physiology, it’s true that this feeding method can generate benefits for the body. According to research published in the Iran Journal of Kidney Diseases, a reduction in kidney problems can be experienced from its implementation.

However, this isn’t produced by the influence of foods on the acid-base balance, but by their quality. The alkaline diet considers foods with basic pH to be fresh products such as vegetables, fruits, legumes, and fish. At the same time, it categorizes ultra-processed meats, red meats, fried meats, battered meats, etc. as acidic.

In short, staple foods would be considered healthy in almost any eating method, while poor quality food falls into the group of acidic products. Under this premise, if we try to emphasize the consumption of the foods of the first group, we’ll be generating a significant benefit for the body.

For example, eating large amounts of fruits and vegetables is associated with a lower risk of death from any cause. This is evidenced by a study published in the International Journal of Epidemiology. On the other hand, a low presence of additives, trans fats, and simple sugars is widely considered positive. All these elements are related to a higher incidence of disease.

Acidic foods and staple foods

The alkaline diet distinguishes between acidic foods and basic or alkaline foods. We’re going to show you which foods are included in each group so that you know how to differentiate them.

• Alkalines foods: Cucumbers, spinach, broccoli, cabbage, grapefruit, avocado, beets, garlic, celery, ginger, aubergine, beans, lettuce, tomato, onion, artichoke, asparagus, carrot, potato, buckwheat, quinoa, lentils, almonds, and oil of extra virgin olive.
• Neutral foods: Chickpeas, seitan, melon, watermelon, cashews, walnuts, hazelnuts, apples, peach, bananas, grapes, oranges, rice, and pasta.
• Acidic foods: Red meat, eggs, seafood, dairy, mushrooms, chocolate, coffee, tea, and alcohol.

Most of the foods considered alkaline are green leafy vegetables. This type of diet greatly emphasizes the importance of including these products in the usual diet. However, it must be taken into account that red vegetables are characterized by a higher concentration of antioxidant compounds.

Likewise, most of the products with high protein and calcium content are restricted in this type of diet. It may be that there are deficits in both nutrients, which would negatively condition the state of health in the medium and long term. Although some of the allowed vegetables have proteins in them, they’re elements of low biological value.

The effects of the alkaline diet on the body

The alkaline diet can’t influence the acid-base balance of the blood or cells. Only the pH of the urine can be slightly altered, something that, in practice, doesn’t generate striking results. This doesn’t mean that this feeding method isn’t considered positive for health if it’s carried out with certain criteria.

It’s essential to include a large amount of fresh foods in the diet, making the presence of these predominate over industrial ultra-processed foods. However, it’s also necessary to ensure that protein requirements are covered, something that’s not always carried out in the context of an alkaline diet. Keep in mind that many types of meat are considered acidic.

As stated by research published in the Annals of Nutrition & Metabolism, at least a daily intake of 0.8 grams of protein per kilogram of weight is required in sedentary people. When you exercise, these needs can even triple. If they’re not covered, you can experience a negative change in body composition and a loss of strength.

In addition, it must be taken into account that half of the proteins consumed daily must be of high biological value. This means that they must come from food of animal origin. These nutrients are characterized by containing all the essential amino acids and by presenting a good level of digestibility.

However, the alkaline diet doesn’t always fulfill this premise. Especially when the ingestion of detox juices and green smoothies is emphasized instead of the main meals, with a goal of weight loss. In these cases, great care must be taken, as nutritional deficits could be experienced that negatively affect the state of health.

How to plan an alkaline diet correctly?

To be able to plan an alkaline diet that really generates positive effects, the first thing that must be guaranteed is protein intake. It’s important to include more fish than eggs and meat in the weekly schedule. Within the latter, meat from free-range, grass-fed birds and animals should be prioritized. This ensures a higher content of omega-3 fatty acids.

From here, you’ll need to determine the number of meals that will be made throughout the day. For example, it’s possible to include an intermittent fasting protocol in your diet. This has shown positive effects on body composition and on the efficiency of metabolism. Thanks to fasting periods, autophagy is promoted, a key process in the prevention of complex diseases.

At this point, the next step has to do with determining the daily energy intake. If you’re not overweight, you’ll need to ensure a caloric balance in order to keep your body composition stable. Otherwise, an increase in fat tissue or the catabolism of lean mass could be caused. Both scenarios are considered counterproductive.

The next step has to do with including lots of fresh vegetables in your diet routines. Now, as much as possible, avoid the consumption of green juices. When fruits and vegetables are crushed, a good part of the fiber inside them is destroyed, thus losing the positive effects in terms of digestive health.

Likewise, ingesting simple sugars through a liquid medium lacking in fiber causes a significant increase in blood glucose levels. As a result, pancreatic inflammation and a phenomenon known as insulin resistance, the precursor to type 2 diabetes, are promoted. When it comes to ingesting carbohydrates, it’s always necessary to guarantee the presence of fiber in the meal.

Cooking methods

Choosing the right cooking methods in the context of an alkaline diet is essential. The most fatty and aggressive methods can cause a particular food to change category and come to be considered acidic. This is basically due to the genesis of trans-fatty acids and other waste compounds, such as acrylamide.

It should be noted that the best alternatives for preparing food are a skillet, oven, steam, and cooking with water. They’re the most respectful of products and don’t cause alterations in their lipid profile. Of course, in the case of baked goods, you have to avoid reaching temperatures above 350 or 400 degrees Fahrenheit.

At the same time, when cooking, it’s always necessary to use extra virgin olive oil instead of other fatty elements. This has the ability to better withstand temperature rises. Even so, it shouldn’t be abused but rather, always used in very moderate amounts.

It’s advisable to include certain raw foods in your diet. Different cooking mechanisms can cause alterations or losses of essential nutrients. An example would be that of water-soluble vitamins when cooking with water. However, when the food is eaten raw, all its benefits are taken advantage of.

Is it necessary to include supplements?

On many occasions, the consumption of supplements is proposed in the context of an alkaline diet to reinforce its beneficial effects on health. The truth is that a well-planned diet doesn’t initially require dietary supplements. However, there are some products that can help improve aspects related to well-being.

For example, if protein intake isn’t correct, the inclusion of a vegetable protein supplement can help avoid deficits. This has a very simple digestion thanks to the presence of proteolytic enzymes in the product itself. Likewise, it’s a nutrient of high biological value, as amino acid deficiencies are overcome through technological processes.

At the same time, it’s possible to consume other supplements that help to modulate inflammatory states. One of the most effective is omega-3. This fatty acid present in oily fish and in extra virgin olive oil has been shown to be able to help prevent the development of cardiovascular diseases. They act by preventing the aggregation of lipoproteins at the arterial level, limiting the risk of atherosclerosis.

Even if you experience a stressful situation, you can still take melatonin. This neurohormone is secreted in the pineal gland naturally and is responsible for regulating sleep and wake cycles. Its exogenous contribution allows you to experience a deeper sleep with fewer interruptions, as well as a reduction in anxiety levels.

Liquids in the alkaline diet

Another aspect to mention is that of the liquids that are included in the alkaline diet. In general, the best tool to ensure good hydration status is mineral water. If it’s slightly cool, gastric emptying is expedited, thus reducing the risk of causing stomach discomfort.

It has been suggested that alkaline water, with a modified pH, could have certain health benefits. The truth is that there’s no evidence that this version is able to help prevent disease or improve parameters related to the proper functioning of the body.

In fact, a study has been published in the journal Scientific Reports as the influence of alkaline water on the microbiota was analyzed, and no significant alterations were found. For this reason, the inclusion of this type of liquid in the usual diet is of no great interest. Also, keep in mind that it’s more difficult to find than normal mineral water and more expensive.

What’s decisive is the limitation of the consumption of sugary soft drinks and alcohol. Both elements are considered acidic, but besides this, it’s more than proven that they generate alterations in the state of health in the medium term. Soft drinks can increase the risk of developing diabetes due to their impact on metabolism.

For its part, alcohol is a toxic substance regardless of the dose consumed. It generates liver, kidney, and cardiovascular problems. It can even affect the quality of rest and hormonal balance. For this reason, its restriction at the dietary level is recommended. Even moderate consumption is unsafe.

The alkaline diet: A very restrictive eating method

The alkaline diet is characterized by being a feeding method that excludes a large part of the products of regular consumption in almost any diet. For this reason, the risk of presenting deficits that condition the state of health in the medium term increases. As a general rule, its implementation isn’t recommended.

This doesn’t mean that, if it’s implemented correctly, with certain modifications and the supervision of a professional, positive results can’t be experienced. However, these won’t be generated by an effect on the pH of the body, but rather thanks to a higher intake of vegetables and a lower consumption of industrial ultra-processed products.