Which is more acidic, lemon or potato?: Demystifying Dietary pH for a Balanced Plate

October 13, 2025 •

4 min read

The pH scale, which measures acidity and alkalinity, plays a significant role in understanding food chemistry, with pure water at a neutral pH of 7. So, when it comes to the kitchen, which is more acidic, lemon or potato? While one is clearly more acidic, a food's initial pH isn't the whole story for your body.

Quick Summary

This article explains the raw pH levels of lemons and potatoes and compares their distinct nutritional profiles. It clarifies how the body tightly regulates its internal pH, making dietary pH less impactful than popular myths suggest. The focus should be on a balanced intake for optimum nutrition.

Key Points

Lemon is more acidic: In its raw state, a lemon's pH (around 2.0-2.6) is significantly lower than a potato's (around 5.6-6.0).
Body pH is stable: Your body has powerful mechanisms to regulate blood pH, and eating acidic or alkaline foods does not alter this delicate balance.
Dietary pH vs. PRAL: While raw lemons are acidic, their post-digestion metabolic effect (PRAL) is alkalizing, a trait also shared by potatoes.
Lemons are rich in Vitamin C: This citrus fruit is a potent source of vitamin C and antioxidants, supporting immune health.
Potatoes offer energy and potassium: Potatoes are excellent sources of complex carbohydrates, potassium, and fiber, and they also contain vitamin C.
Overall dietary balance is key: Focus on consuming a diverse range of nutrient-dense, whole foods rather than obsessing over the individual pH of single ingredients.

The Science of pH: Understanding Acidity in Food

To determine which is more acidic, lemon or potato, one must first understand the pH scale. This scale runs from 0 to 14, where a pH below 7 is acidic and a pH above 7 is alkaline (or basic). A lower number indicates a higher level of acidity. The acidity of a food comes from its chemical composition, specifically the concentration of free hydrogen ions. This raw, or initial, pH is a key characteristic of many foods.

Lemon vs. Potato: The Raw Acidity Revealed

When tested for their raw pH, the results are quite distinct:

Lemon: Due to its high concentration of citric acid, fresh lemon juice typically has a pH ranging from 2.0 to 2.6. This places it squarely in the highly acidic category, comparable to vinegar or even soda.
Potato: A raw potato, by contrast, is much less acidic. Its pH value generally falls in the mildly acidic range of 5.6 to 6.0. This difference is immediately noticeable to the taste buds, with the sharp sourness of a lemon contrasting with the mild, earthy flavor of a potato.

The Misconception of Dietary pH and Body Acidity

One of the most persistent myths in nutrition is that eating certain foods can alter the body's blood pH. Proponents of the 'alkaline diet' suggest that an acidic diet can cause disease and that consuming more alkaline foods can 'rebalance' the body's pH. This idea is not supported by scientific evidence. The human body is remarkably efficient at regulating its blood pH within a very narrow, slightly alkaline range of 7.35 to 7.45. If your diet could drastically change your blood pH, it would signal a serious underlying health condition, not a dietary issue. The kidneys and lungs work constantly to maintain this balance. While diet can affect the pH of your urine as the body excretes metabolic waste, this does not influence your systemic pH.

Lemons vs. Potatoes: Beyond the pH Scale

Instead of focusing on raw acidity, it's more beneficial to look at the overall nutritional contribution of each food. Both lemons and potatoes offer unique health benefits and play different roles in a balanced diet.

The Zesty Power of Lemons

Lemons are renowned for their high vitamin C content, which acts as a powerful antioxidant and is crucial for immune function and collagen production. The citric acid in lemons can also aid in digestion and help with mineral absorption. Although the fruit is initially acidic, when metabolized, the mineral content, particularly potassium, has an alkalizing effect on the body, though it won't change blood pH.

Key nutritional highlights of lemons:

Excellent source of vitamin C.
Rich in antioxidants.
Supports immune health.
May aid mineral absorption.

The Earthy Goodness of Potatoes

Potatoes are often unfairly maligned, but they are a fantastic source of energy and essential nutrients. They provide complex carbohydrates, fiber (especially in the skin), and are a notable source of potassium. Surprisingly, potatoes also contain vitamin C, and historically, they were a crucial source of this vitamin to prevent scurvy. The potential renal acid load (PRAL), which measures the acid load food generates after digestion, shows potatoes as having an alkalizing effect on the body, contrary to their mildly acidic raw pH.

Key nutritional highlights of potatoes:

Good source of carbohydrates for energy.
High in potassium.
Contains vitamin C and fiber.
Has an alkalizing effect on the body post-digestion.

Comparison Table: Lemon vs. Potato


Feature	Lemon	Potato
Raw pH	Highly Acidic (2.0-2.6)	Mildly Acidic (5.6-6.0)
Primary Nutrient	Vitamin C, Antioxidants	Carbohydrates, Potassium
Dietary Role	Flavoring, Garnish, Enhancer	Starchy Vegetable, Energy Source
Effect on Body PRAL	Alkalizing (despite raw acidity)	Alkalizing (despite raw acidity)
Best Use	Juices, dressings, seasoning	Roasting, boiling, mashing, baking

Practical Ways to Incorporate Lemons and Potatoes into Your Diet

Instead of worrying about their raw pH, focus on how these foods can complement each other and contribute to a healthy, balanced diet.

For Flavor and Zest: Add a squeeze of lemon juice to roasted potatoes to cut through the richness and add a bright, fresh flavor. This can also help prevent potatoes from browning.
For Nutrient Balance: Pair nutrient-dense potatoes with a lemon and herb vinaigrette for a delicious and well-rounded side dish. The potassium in potatoes and vitamin C from lemons work together synergistically.
For a Hearty Meal: Create a sheet pan meal with roasted potatoes, lemon wedges, and a protein source like chicken or fish. This combines complex carbohydrates, vitamins, and protein for a complete meal.

The True Lesson for Nutrition Diet

Ultimately, a healthy eating pattern is about dietary diversity and balance, not manipulating your internal pH by favoring specific foods. Both lemons and potatoes are nutritious in their own right. Lemons offer powerful antioxidants and vitamin C, while potatoes provide essential carbohydrates and minerals. The key is to incorporate a wide variety of whole, unprocessed foods into your meals.

For more information on the alkaline diet myth and the body's natural pH regulation, consider exploring reliable resources like this Healthline article. It provides a comprehensive, evidence-based review that clarifies the scientific facts behind this common dietary trend. By understanding that your body handles its own pH, you can focus on building a sustainable diet rich in a variety of fruits, vegetables, and other wholesome ingredients for long-term health.

Conclusion

In conclusion, the lemon is significantly more acidic than the potato in its raw state, with a much lower pH level. However, for healthy individuals, this fact is largely irrelevant to internal body pH regulation. Both foods, when incorporated into a balanced diet, offer distinct and valuable nutritional benefits. By moving past the superficial measure of a food's initial acidity and focusing on the nutrient profile, one can make more informed and healthier dietary choices.

Frequently Asked Questions

No, your body has very effective and complex systems, involving your kidneys and lungs, to keep your blood's pH level in a very narrow and healthy range, regardless of the foods you eat.

A raw potato has a mildly acidic pH, typically ranging from 5.6 to 6.0. This is considerably higher (less acidic) than a lemon.

No, lemons are a healthy food, offering high doses of vitamin C and antioxidants. While the high acid content can potentially damage tooth enamel, it does not negatively impact overall body pH.

The alkaline diet is based on the unproven theory that food can change your body's pH. Science shows that your body regulates its pH, and diet has no significant effect on your blood's acidity levels.

A food's raw acidity is measured on a pH scale. While lemons are clearly acidic in taste and raw pH, the metabolic effect on the body is often different. A food's Potential Renal Acid Load (PRAL) is a better indicator of its post-digestion effect.

Potatoes are a good source of complex carbohydrates, potassium, and vitamin C. They also contain dietary fiber, especially when the skin is eaten.

Yes, pairing lemons and potatoes is a common and delicious practice in many cuisines, particularly Mediterranean cooking. The acidity of the lemon complements the starchiness of the potato, creating a balanced flavor.