Alkaline Diet:
“Your body is too acidic,” I was told by the “nutrition expert” at my local health food store. “You need to start drinking alkaline water or put these drops into your water in order to increase the pH level and alkalize your body.” My mother-in-law, a health- nut agreed. She also told me to start following an “alkaline diet” which emphasized fruits and vegetables and decreased grains, dairy and proteins. How could I function on primarily vegetables and fruit? I wasn’t sure, but what did I have to lose? My body felt awful and I was looking for anything to make me feel better. Did this dietary shift work? Yes and no. I liked the taste of the alkaline water, so I drank more than I would have otherwise. Increasing fruits and vegetables has never hurt anyone (that I know of ☺), however, the decrease of proteins, dairy and grains really limited the nutrients I was getting.
Did it help “alkalize” my blood? No. Let’s dig into why.
There are some truths to these beliefs. When you consume certain types of foods, they leave either alkaline ash or acid. The type is determined by the relative content of acid-forming components such as phosphate and sulfur, and alkalis such as calcium, magnesium, and potassium. The foods that are associated with being “acidic” are grains, dairy and animal products. Fruits and vegetables are “alkali forming.
Foods that are considered “neutral” include fats, sugars, and starches are neutral. This is because they don’t contain protein, sulfur, or minerals. Consuming these types of foods might have immediate impact on the pH level of urine, however, this is not indicative of pH levels in blood.
Your urine’s pH will reflect a number of metabolic, digestive, and other processes. Despite claims, there is minimal convincing scientific evidence to demonstrate that your urine’s pH has any correlation with your risk of medical conditions like osteoporosis or cancer, or any of the other medical conditions that advocate claim are the result of “excess acidity.”
Alkaline vs. Acid
Some acid is beneficial
Our different organ systems all having varying pH levels designed for their unique function. The stomach has the highest pH, which is actually beneficial. We need stomach acid to properly digest food. However, even in the stomach, the layer just outside the epithelium is quite basic to prevent mucosal injury (natural protection mechanism!). Our skin is also quite acidic. This functions as an acid mantle (protective barrier) to the environment against microbial overgrowth. The pH level actually exists on a gradient and is highest at its outer layer where most protection is needed (pH 4) and lowest at the basal layer (pH 6.9). I find that pretty amazing. You’ll also find high pH levels in the vagina (around 4.7). This serves to protect the female body from microbial overgrowth.
What about our blood pH levels?
It has been said that we can change the pH of our blood by changing the foods we eat, and that acidic blood causes disease while alkaline blood prevents it. Our bodies are well designed. Unless there is a serious underlying medical issue, such as chronic renal insufficiency, in which the kidney function is compromised, the body tightly regulates the pH of our blood and extracellular fluid. We cannot influence our blood pH by changing our diet. That is what our kidneys are for.
Our natural acid-base regulator: Kidneys
According to the American Physiological Society Journal, it is true that foods in the diet may contain various acids and alkalis that, when absorbed via the gastrointestinal tract, contribute to the net acid/alkali load to the body. They agree that in a healthy individual consuming a “typical Western diet,” there is a net addition of acid to the body. They refer to this acid as “net endogenous acid production (NEAP)” and explain that the accumulation of this acid results in an equivalent loss of HCO3− (base), which must then be replaced. However, the kidneys excrete acid and, in the process, generate HCO3−. “Therefore, the systemic acid-base balance is maintained when renal net acid excretion (RNAE) equals NEAP.”
In plain English, this means that our kidneys are able to produce enough acid or base in order to maintain homeostasis (balance) in the body. Our blood’s pH is 7.4 which slightly alkaline(aka: basic). Enzymes that facilitate chemical reactions in the cells work only in a narrow range of pH. Any significant shifts in pH (below about 7 or over 7.7) would result in death. However, as explained above, the blood circulates throughout the body constantly, and therefore compensates any changes in pH in any of our organs such as our muscles during intense exercise or an whole grain piece of toast with cheese and a glass of milk. ☺
Functional medical practitioner, Chris Kresser, gave an excellent description of the body system. He explains that the kidneys are well prepared to deal with ‘acid ash.’ When we consume grains, protein and dairy the acids produced are quickly buffered by bicarbonate ions in the blood. This reaction produces carbon dioxide, which is exhaled through the lungs, and salts, which are excreted by the kidneys. The kidneys produce ‘new’ bicarbonate ions during the excretion process, which return to the blood to replace the bicarbonate that was used to buffer the acid at the start. This creates a continuous, sustainable cycle in which the body is able to maintain the pH of the blood, with no involvement from the bones whatsoever.
Will an acid-heavy vs. alkaline diet increase risk of osteoporosis?
Some proponents of an alkaline diet suggest that in order to keep blood pH constant, the body pulls minerals from our bones to neutralize any excess acid that is produced from our diet. This belief is referred to as “acid-ash hypothesis of osteoporosis.” This leads some to believe that consumption of a “typical Western diet” will result in the body leaching calcium from bone deposits to maintain balance.
The Journal in Environmental and Public Health stated that, “Measurement of pH of the urine (reviewed in a recent study with two morning specimens done over a five-year span) did not predict bone fractures or loss of bone mineral density.” The same journal article concluded that, “there is no substantial evidence that alkaline diets improve bone health or protect from osteoporosis.” You can be confident in the body’s natural balancing mechanisms. Excluding chronic renal failure, regardless of what you eat (a steak or a green smoothie) or what your urine pH is, you can rest assured that your blood pH is hovering around a comfortable 7.4.
What should I eat/drink then?
If you are already a fan of alkaline water, there is no need to stop. Staying hydrated is essential for optimal health. If you like the taste of alkaline water and it makes you feel better; naturally, you’ll drink more water and stay more hydrated. Aim for ½ of your body weight in oz of water per day, or 8 to 10 cups to get you started. Consuming “alkaline foods” such as fruits and vegetables is essential to a balanced diet, as both provide vitamins, minerals, fiber and water. However, protein provides amino acids, iron, B-Vitamins and whole grains provide fiber, manganese, phosphorous and other nutrients.
If you have health concerns and check your urinary pH, remember that urinary pH changes throughout the day depending of the types of foods you eat. Following a “pH balanced” diet, and taking pH manipulative supplements has no demonstrated relationship to one’s risk of osteoporosis, cancer, or other serious illness. Instead, follow the dietary advice of balance that I always advocate! Consume plenty of fruits and vegetables, sufficient amounts of protein, and whole grains. If osteoporosis is of concern, prioritize vitamin D and lots of calcium-rich foods. Good sources of calcium include dairy, dark leafy greens, chia seeds and sardines. Vitamin D sources include fatty fish (salmon, tuna, sardines), liver (if you dare), egg yolks and cheese.
Eating well is your best defense against disease, as there is no evidence to suggest that your urine’s pH correlates with osteoporosis, or your risk for diseases like cancer.
References:
http://advan.physiology.org/content/33/4/275.full
http://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.26.11.1113
http://chriskresser.com/the-ph-myth-part-1/
http://www.latimes.com/health/la-he-alkaline-water-20160701-snap-story.html
