What acidic foods should you avoid?

Acidification of the body: why are we more exposed?

The concept of acidification of the body refers to the notion of acid-alkaline balance, itself linked to our blood pH value.

This numerical measurement, ranging from 0 to 14, assesses the acid load in our blood: below 7, it is acidic; around 7, it is neutral; above 7, it is basic or alkaline.

For our bodies to function properly, our blood pH should be slightly alkaline (between 7.35 and 7.45) (1). Natural buffer systems limit variations in pH by neutralising fluctuations in H⁺ ions. This is mainly maintained by the lungs and kidneys, with secondary assistance from the liver and muscles (2).

However, our natural buffer systems (the lungs and kidneys) are under greater strain as a result of the way we live today. Our modern diet, for example, favours meat and ultra-processed products to the detriment of plant-based ones. Other contributing factors include excessive alcohol consumption, chronic stress, a sedentary lifestyle and advancing age. This functional overload can have metabolic consequences, such as increased acid excretion by the kidneys or mineral imbalances. This could contribute to a metabolic state sometimes described as chronic low-grade acidosis (3-4).

What are the risks of chronic acidosis?

A number of researchers and naturopaths are currently considering chronic acidosis as a serious possibility to explain the resurgence of certain chronic disorders and conditions, ranging from heartburn and acid reflux to muscle and joint pain and various inflammations, as well as certain renal and cardiovascular dysfunctions (such as high blood pressure) (5).

Excessive acid load is also thought to increase the risk of osteoporosis (6). Why would this be? To counteract an excessive acid load, our bodies are forced to draw alkalinising substances such as citrates and bicarbonates directly from our bones. However, these substances are bound to calcium ions, forcing us to draw on our calcium reserves and consequently reduce our bone density.

The list of acidic foods

The acidifying or alkalinising potential of a food can be roughly estimated using its PRAL (Potential Renal Acid Load) index (7).

It can be interpreted simply: foods with a positive PRAL are acidic, while those with a negative PRAL are alkaline. The further the score is from zero, the more pronounced the effect. For example, cucumber has a PRAL index of -5 (it is alkalinising) while cooked beef has a PRAL index of +14 (it is acidifying).

We can quickly see that certain food groups have a more marked acidifying effect.

Salt (and salted products)

Table salt and all products containing it, such as cold meats, bread, cheese, crisps and ready-made meals, are thought to acidify the body and hasten the loss of bone calcium (8).

We are therefore strongly advised to add less salt to our dishes (and especially not to re-salt them routinely) and to limit all sources of 'hidden salt', as already recommended by health authorities as part of their efforts to prevent cardiovascular disease.

Meat products

While meat products provide good quality protein, their sulphur-containing amino acids are converted into acidifying sulphuric acid (9).

For example, a fried egg has a PRAL index of +7.9, prawns +10.1, ham +12.2 and veal escalope +18.7. Without eliminating them completely, it is advisable to restrict yourself to one portion a day when you are trying to deacidify your body.

Having trouble reducing your meat intake? At least try to redress the balance by boosting your intake of alkaline minerals (magnesium, calcium and potassium in particular) and/or by relying on plant extracts such as ginger, the flagship rhizome of Ayurvedic medicine with a PRAL index of less than -6 (all combined in the synergistic Alkaline Formula, which also contains various promising compounds for regulating acid-base balance, such as liquorice root, which supports digestion and metabolic health) (10-12).

Cheeses

With a PRAL index of around +20 on average (and up to +34 for Parmesan!), cheeses are among the most acidifying foods available (13).

Here again, a portion of 30 to 40g a day is reasonable, with a preference for those that have the least impact on acid-base balance, such as Camembert, Saint-Nectaire or Roquefort (around +13).

Milk and yoghurts, on the other hand, have a fairly neutral effect and are therefore to be preferred.

Some cereals

The starchy foods family also includes some acidifying agents.

While rice and pasta have a PRAL index fairly close to neutral, those of bread products, spelt, rye and oat flakes are higher.

It would be better to replace them more often with legumes, which have little or no effect on our body's acid load.

Some seeds and nuts

Despite their richness in alkalising minerals (particularly magnesium), some oily seeds and nuts tend to increase the body's acid load because of their high protein content (14).

This is the case with cashew nuts, Brazil nuts and sunflower seeds. And if they're roasted, it's even worse. Notably, only the hazelnut and the macadamia nut are alkalising.

To boost your plant protein intake without affecting your acidity levels, why not turn to Spirulina? It's a remineralising micro-alga that is a source of magnesium, calcium and potassium (the Spirulina supplement comes from drastically controlled aquaculture, which guarantees safe supplementation, unlike other sources contaminated with pollutants and heavy metals) (15).

Soft drinks

Soft drinks (particularly cola-based drinks) contain phosphoric acid, a particularly acidifying agent.

While it's best to stick to tap water, which is generally in a neutral pH range, alkaline waters (such as SuperWater, with a high sodium chloride and hydroxide content) are a useful addition to hydration as part of an acid-alkaline rebalancing programme (16).

But beware: a food with an acidic taste is not necessarily acidifying... and vice versa! The best example is citrus fruit (lemon, orange, grapefruit) which, despite their acidic flavour, are actually alkalinising.

What basic foods should I choose?

Fruit and vegetables are the mainstays of an alkalinising diet (17). And with good reason: they are packed with potassium, which has a strong alkalizing effect. Among the most beneficial are bananas, green leafy vegetables, celery and dried apricots.

Another good idea is to sprinkle spices (turmeric, cinnamon, etc.) and fresh herbs (thyme, parsley, etc.) over your dishes, or drink green tea instead of coffee (18-19).

To find out more, take a look at our detailed article on the subject: What are the best basic foods?