The Alkaline diet has been gaining a lot of attention over the last few years and evidence shows that it can be an integral part of enjoying a healthy lifestyle. There’s a lot of information out there, but we think it’s best to hear it coming from someone who really knows their stuff. Our expert nutritionist, Lucy-Ann is here to take a look at alkali diets in a brilliant two-part feature! First up – What are acidic and alkaline diets?
The “Alkaline Diet” and the theory that a diet high in “acidic” foods is a major cause of disease has existed for some time. It has certainly become a popular concept in nutrition and in the lay literature.
A high plant based diet (rich in fruits, vegetables, nuts, seeds & wholegrains) is thought to enhance health due to its “alkaline nature”, and in particular playing a key role in optimum bone health, as well as being effective in the treatment of diseases such as diabetes, heart disease and even cancer. Diets high in fruits and vegetables have, amongst many positive elements, a greater potassium (one of several alkalising minerals) and lower "acidic" content than diets rich in animal protein, fat and sodium. It is largely this that lends itself to the proposed better state of health.
Studies and research
The alkaline diet theory has led to a number of studies (originating mainly in the area of bone health) that manipulated diets to enhance potassium and "alkaline" content to assess the effects this has on bone health. Although an acidic diet featuring a high protein intake appears to be associated with an increase in calcium loss from the body, studies revealed that this doesn’t automatically equate to a decrease in bone density. Similarly, intervention studies giving “alkaline diets” or using supplements such as potassium citrate or potassium bicarbonate have not consistently shown a bone health benefit.
However, more recent, up-to-date research does show that high dietary acid load or highly acidic diets increases the risk of diabetes. A large prospective study with 60,000 women revealed that a high intake of fruits and vegetables such as peaches, apples, pears, bananas and even lemons and oranges effectively reduces dietary acid load, protecting women from developing type 2 diabetes. Women consuming high-acid diets (including meat, sweetened beverages and coffee) appeared to be at an increased risk of developing the disease, irrespective of having other known risk factors for diabetes. This is really the first large study of its kind and paves the way for the promotion of diets with a low acid load for the prevention of diabetes. This ground-breaking work was published in 2013 in Diabetologia, the journal of the European Association for the Study of Diabetes.
A quick low-down on acid and alkaline foods…
The foods we eat are either, predominantly, acid or alkaline. Foods create an acid or alkaline “residue” or “ash” and can have an impact (albeit small) on the blood, urine and tissues of the body after digestion. These “acid and alkaline” classifications do not refer to how food tastes on the palate however! It refers to the chemical nature of the food’s ash residues. Even though many fruits may taste acid, this is not chemical in action. The acid taste on the tongue is due to organic acids in the fruits, like malic, tartaric and citric acid, which are actually converted in the body and can have an alkalising benefit (e.g. lemons, limes, oranges and pineapples).
The residue “ash” relates to the specific mineral content of the food. If the food is rich in alkaline minerals - calcium, potassium, magnesium, iron, sodium and manganese - the pH will be alkaline. If the food is composed mainly of acid minerals such as phosphorus, chlorine, sulphur, silicon, iodine and fluorine it will render acidic.
High mineral foods and therefore a high “alkaline diet” may consequently help, and contribute to controlling the acid and alkaline balance in the body. However, it is important to understand that it’s mainly our kidneys (as well as the body's other regulatory mechanisms of breathing, digestion, circulation, and hormone production) that keep a tight control on the pH of the blood, adjusting the body's acid-base balance to maintain proper pH.
Diet certainly does impact on the pH or “acidity” of the blood, and scientists have shown that in some people (possibly those with impaired renal/kidney function), when dietary acid loads are high (for example with many typical Western diets), our in-built mechanisms can be overwhelmed, and not always able to effectively “re-alkalise” the blood. However, to what extent this affects overall health is still something scientists are pondering, as well as trying to fully understand the mechanisms involved, as well the long-term effects of high acid diets. Suffice to say, however, a high vegetable/fruit-based diet (i.e. highly alkaline) is still one of the best approaches to good health, and certainly supports, and assists the body’s systems to re-alkalise when necessary. A high alkaline diet is certainly one that we support here at Nakd!
The most valuable foods for a healthy body, and a state of long-term wellbeing, are those that generate the least amount of acidic waste products and the highest amount of acid-neutralising by-products. Acidity (or acidosis) is common in our society, due to a high intake of cooked, processed foods and fast foods, and relatively low intake of fruit and vegetables. This causes an acid state in the tissues, lymph and blood, and is thought to be a strong cause of pain and disease - especially joint and tissue pain. An overly acid state reduces the amount of oxygen that the cells can receive. When a cell is oxygen deprived, all kinds of serious health problems may be created, including cancer. Cancerous cells are acidic. Healthy cells are alkaline, and many believe that an “alkaline diet” is important in the treatment of cancer.
Remember that the body includes a number of organ systems that are very adept at neutralising and eliminating excess acid in most people. Having said that, there is of course a limit to how much “acid” even a healthy individual can cope with. Modern-day diets are extremely acidic, and it’s important to minimise acid-producing factors, such as smoking, and even stress and negative emotions. Stressful situations and negative emotions like anger, hate, depression, and jealousy can be acid producing in the body; while positive emotions such as happiness, kindness, and love, help build a healthy, alkaline environment. Strenuous exercise is also “acid-generating”, so too much exercise can have a negative impact on an already acidic system.
So there’s the science, but which foods are best? Check out part 2 which has some great ideas on what you can eat!