Is Canned Tuna Acidic or Alkalie? A Dietitian Explains Food pH

If you’ve looked into an alkaline diet before, you may have come across conflicting information about whether foods like canned tuna are acidic, alkaline or neutral Proponents of alkaline diets claim that eating more alkaline foods can improve health and wellbeing But what does the science actually say?

As a dietitian, I’m often asked if certain foods are alkaline or acidic While the idea of an alkaline diet is popular right now, the truth is a little more nuanced In this article, I’ll break down what gives foods their pH, look at common misconceptions about canned tuna’s acidity, and explain why focusing on an overall balanced diet is best.

Alkaline vs Acidic Foods Explained

To understand if a food is acidic or alkaline, we need to look at its pH value. The pH scale ranges from 0-14, with 0-6 being acidic, 7 neutral, and 8-14 alkaline.

But surprisingly, the pH of a food outside the body does not directly correlate with its pH inside the body Once metabolized, many acidic foods produce alkaline byproducts Likewise, some alkaline foods leave acidic ash.

For example, foods like lemons and vinegar taste quite acidic. But during digestion they go through metabolic changes and do not make the blood more acidic. The kidneys tightly regulate blood pH between 7.35-7.45 regardless of diet.

So while a food’s pH before eating provides some insight, it does not give the full picture. Let’s explore what factors contribute to a food’s acidity or alkalinity.

What Makes a Food Acidic or Alkaline?

Several factors impact whether a food is acidic or alkaline-forming in the body:

Sulfur-Containing Amino Acids: All proteins contain amino acids, some of which form sulfuric acid during metabolism. This can make them acidic.

Phosphoric Acid: Found in carbonated drinks like soda. Very acidic and not metabolized.

Organic Acids: Naturally occurring acids found in fruits and vinegar, like citric acid and acetic acid. Metabolized differently than dietary mineral acids.

PRAL Score: Estimates a food’s acid load based on nutritional content. Positive PRAL = acidic. Negative PRAL = alkaline.

Mineral Content: Foods containing chlorine, sulfur, and phosphorus tend to be more acidic. Foods with magnesium, potassium, and calcium tend to be more alkaline.

Is Canned Tuna Acidic or Alkaline Forming?

When looking strictly at a PRAL acid/alkaline food chart, tuna is considered an alkaline food. Its PRAL score is -18.8, giving it a net alkaline effect on the body.

However, as a high protein food, tuna also contains amino acids that metabolize into acids. The sulfur-containing amino acids cysteine and methionine are more prevalent in tuna than less acidic amino acids.

Tuna is also relatively low in alkaline minerals like magnesium and calcium compared to plant foods. Though it provides some potassium, phosphorus, and selenium.

For these reasons, some experts consider tuna to be mildly acidic forming in the body. Though not nearly as acidic as foods like cheese, grains, meat, and fish with higher fat content.

Overall, tuna’s pH altering effects are likely negligible for most people eating a varied diet. Focusing too heavily on individual foods misses the bigger picture.

An Alkaline Diet is Not Proven to Benefit Health

Proponents of alkaline diets claim that eating primarily alkaline foods can raise blood pH and produce benefits like:

• Strengthening bones
• Reducing muscle wasting
• Increasing growth hormone
• Improving cardiovascular health
• Preventing cancer

However, the science to back these purported benefits is currently lacking. Studies demonstrate our bodies tightly regulate pH balance regardless of diet.

Urine pH can become more alkaline with an alkaline diet. But reports of health benefits are primarily anecdotal. More research is needed on potential mechanisms.

For now, there is no solid evidence that alkaline diets can alter blood pH or provide significant health advantages. The greatest benefits seem to stem from increasing intake of fruits, vegetables, legumes, nuts and reducing processed foods.

A Healthy, Balanced Diet is Most Important

Rather than fixating on individual acidic or alkaline foods, the healthiest approach is to follow an overall nutritious diet. Guidelines recommend focusing on:

1. Including a Wide Variety of Nutrient-Dense Foods

Aim for lots of different fruits, vegetables, legumes, nuts, seeds, whole grains, lean proteins, and healthy fats from foods like olive oil, avocado, and fatty fish.

2. Limiting Ultra-Processed Foods

Cut down on fast food, sweets, refined grains, and sugary drinks. These provide excess sodium, sugar, unhealthy fats, and few nutrients.

3. Staying Adequately Hydrated

Drink enough water and unsweetened beverages to avoid dehydration and constipation. Certain medications and health conditions can also alter acid-base balance.

4. Being Physically Active

Regular exercise provides alkalizing benefits by reducing calcium excretion and protein breakdown. Aim for 150 minutes per week of moderate activity.

5. Supporting Your Microbiome

A healthy gut microbiome promotes optimal pH balance. Eat probiotic foods like yogurt, kefir, kimchi, kombucha, and fermented pickles.

By following these evidence-based guidelines, you can help support acid-base equilibrium without needing to micromanage individual food pH values.

Healthy Ways to Enjoy Canned Tuna

If you’d like to include canned tuna as part of a balanced diet, here are some tasty ways to eat it:

• Create a Niçoise salad with tuna, green beans, potatoes, olives, and vinaigrette.

• Make a poke bowl with tuna, brown rice, edamame, cucumber, seaweed salad, and ginger dressing.

• Stuff a baked sweet potato with tuna salad made with yogurt and celery.

• Mix tuna with chickpeas and veggies for a tuna salad sandwich or wrap.

• Add tuna to a leafy green salad and top with lemon juice and olive oil.

• Stir tuna and white beans into tomato sauce and whole wheat pasta.

• Grill or pan-sear tuna steaks and serve with roasted asparagus.

Be sure to pair tuna with plenty of antioxidant-rich fruits, veggies, beans, nuts, seeds, and whole grains. Avoid adding high-sodium, acidic ingredients like mayonnaise.

The Bottom Line

While considered alkaline on some food charts, tuna contains amino acids that generate acids during metabolism. However, for most people eating a balanced diet, tuna’s pH effects are negligible. Rigidly adhering to an alkaline diet is not essential for health. Focus instead on overall diet quality, variety, and moderation.