Alkaline water. pH test strips. Green powders sold on the promise of a more alkaline body. The idea behind all of them is that your internal chemistry has drifted off balance, and that the right drink or powder will put it back.
Here is a number that tells you how wrong that picture is. Your whole bloodstream holds about four grams of sugar. That is less than a teaspoon, spread through around five litres of blood. Eat a bowl of pasta or drink a can of cola and the body still brings it back to roughly four grams, every time, without asking you. It does this whether or not you have bought the powder.
It does the same with acid, with heat and with water. Your chemistry does not drift. It is defended, every second of your life.
So the useful question is not whether your body is "out of balance". It is how hard it has to work to stay in balance, and what you do every day that makes that work harder or easier.
The numbers your body defends
In 1854 Claude Bernard, in Paris, began writing about the milieu intérieur, the internal environment that bathes every cell. He summed it up in one line: "The stability of the internal environment is the condition for the free and independent life." Freedom, it turns out, is a chemistry problem. You can walk out into a frost or a heatwave, skip lunch or eat a feast, because the inside of you stays the same.
In 1926 the American Walter Cannon gave the idea a name: homeostasis, from the Greek for "staying the same".
A handful of numbers matter most. Blood pH is held in a narrow band around 7.4. Blood sugar stays near those four grams. Core temperature sits close to 37 °C. And the water and salt in your blood stay steady too, which is why your kidneys filter about 180 litres of fluid a day and hand almost all of it back, letting only a litre or two leave as urine.
You cannot shift most of these numbers by eating. What you can shift is how much work it takes to hold them.
pH: what the strips miss
The fast system and the slow one. Every breath out is a small act of acid removal. Carbon dioxide forms an acid in the blood, and the lungs clear it in seconds, breathing faster or slower as needed. The kidneys work more slowly, sending surplus acid out in urine through the day. Chemical buffers in the blood soak up the rest in the meantime.
Blood is protected. Urine shows the work. A pH strip dipped in urine does change with what you eat, because the kidneys are getting rid of the acid. That is the system doing its job, not a sign that your blood has turned. Blood pH that moves far out of its band is a medical emergency, which is exactly why the body never lets food push it there. If a salad could change your blood pH, you would need an ambulance, not a recipe.
The bone claim, tested. The "acid-ash" idea says that a more acid diet, with protein and grains, makes the body pull calcium out of bone to neutralise it. It sounds plausible, because a more acid diet does raise the calcium in urine. But when the best balance tests were pooled, the extra calcium in urine did not mean calcium lost from the body, and a marker of bone breakdown did not move either. The authors' verdict: promoting an alkaline diet to prevent calcium loss "is not justified". That is about as blunt as a review of the evidence gets. A wider review, of 55 sets of findings, found no causal link between diet acid load and osteoporosis, and no mechanism that works at the body's real pH.
What more protein did. Across 16 controlled tests and 20 long-term follow-ups of adults, higher protein intake went with slightly better bone density in the lower spine, not worse. And across 28 controlled tests in 1,358 healthy adults, higher-protein diets did not change kidney function compared with normal or lower-protein ones. Meat, fish and eggs are not the acid villains the alkaline story makes them. The steak can stay. Why People Fail at Weight Loss (And How to Succeed) has why protein comes first for weight, too.
Alkaline water and cancer. One review searched 8,278 citations for any evidence that an acid or alkaline diet, or alkaline water, affects cancer. Only one was good enough to include, and it found no link with bladder cancer. The review found no tests at all of alkaline diets or water as a treatment.
Ketosis is not acidosis. On low-carb, keto or carnivore eating, or during a fast, the liver turns fat into ketones, and blood ketones rise to somewhere around 0.5 to 3 millimoles per litre. Ketones are acids, and the body handles them like any other: acid balance holds. Ketoacidosis is a different thing, an uncontrolled flood of ketones, mostly from a complete lack of insulin in diabetes, and it is an emergency. How to Fix Blood Sugar Spikes Naturally, linked below, has the caution for anyone on medicine that lowers blood sugar: cutting carbs can push it too low.
When it is different. With kidney disease, acid balance becomes a real medical issue, and it is managed by the people treating the kidneys. If you have kidney disease, heart failure or an abnormal heart rhythm, or take medicines that affect potassium or blood pressure, treat electrolyte powders and high-potassium foods as part of your treatment, not as wellness products.
Minerals: the bank and the till
Calcium is defended too. An adult carries about a kilogram of it, and 99% sits in the skeleton. The small amount in the blood is held steady by hormones that move calcium in and out of that bank as needed. So a normal blood calcium tells you the till is full, not how much is left in the bank.
Magnesium works the same way, with even less on show. Of about 25 grams in the body, half or more is in bone, most of the rest is in muscle and other tissue, and only about 1% is in the blood. That is why a normal blood level can hide a shortfall. If cramps, poor sleep or tiredness keep coming back, a magnesium test is worth having, as long as you know what the number can and cannot show.
Blood sugar: four grams
Those four grams are the reason sugar is hard work. Drink a can of cola and roughly ten teaspoons of sugar arrive at once in a bloodstream built to hold about one. The pancreas releases insulin to push it into the cells, the liver takes in what it can, and the muscles take the rest. The system copes, meal after meal, and the coping is the work. Your pancreas does not get weekends off.
Starchy food does the same more slowly. Bread, pasta, rice and cereal all end up as glucose. How to Fix Blood Sugar Spikes Naturally, linked below, has how low-carb, keto and carnivore eating flatten the spikes, and the ten-minute habit after a meal. If you want to watch your own numbers, a shows them before a meal and after it.
Cola carries a second load. The Hidden Cost of Your Daily Sugary Drink has the 1,413 women whose hip bones were 3.7% less dense if they drank cola every day, a pattern that showed with diet cola too and not with other fizzy drinks. Phosphoric acid and caffeine are the likeliest suspects.
Water: 180 litres
Those 180 litres a day are filtered whether you drink or not. What changes is how hard the kidneys have to work to keep the blood the same. Short of water, they concentrate the urine and hold on to every drop, and the dark colour is the sign. Your pee is the cheapest test kit you own.
Heat raises the stakes. Sweating is how the body holds its temperature, and at its fastest an adult can lose 2 to 4 litres an hour that way, all of which has to be drunk back. Sweat carries salt as well as water, so on a long, hot, sweaty day plain water is only half of it. put the salt back without the sugar, unless you are in one of the groups named in the pH section, in which case check with the people treating you first.
Make water your main drink, and keep a where you can see it. Fizzy drinks, energy drinks and sweetened coffees bring water too, but they bring sugar with it, and in cola's case phosphoric acid. 7 Fun and Tasty Ways to Stay Hydrated Without the Boredom has how much you need, the pale-yellow check, and the 199 people with a first kidney stone: five years on, 12 of the 99 who drank more water had had another, against 27 of the 100 who did not.
Water can be overdone too, and that is a load of its own. The same article has the 2002 Boston Marathon, where 13% of the runners tested at the finish had too little sodium in their blood. The ones most at risk had gained weight during the race, by drinking more than they sweated out. Thirst is a better guide than a target.
Temperature: 37, then 36.8
In the 19th century, Carl Wunderlich in Germany set normal body temperature at 37 °C, or 98.6 °F. The figure stuck. It is now thought to be closer to 36.8.
The body may have changed, not just the thermometer. Records from 23,710 Union Army veterans of the American Civil War, measured between 1860 and 1940, from 15,301 Americans in the early 1970s, and from 150,280 patients between 2007 and 2017 showed average body temperature falling by 0.03 °C for every decade of birth. The authors' best explanation is less chronic inflammation. When 37 °C was set, life expectancy was 38, and tuberculosis, syphilis and gum disease were common. A body with less to fight runs a little cooler. Progress, measured in fractions of a degree.
The body can move this number on purpose. In a fever, the brain raises its own temperature target to fight an infection. The chills and shivering are the body heating itself up to the new setting, and the sweat comes when the target drops back again. Even then, it is defending a number. It has just chosen a different one.
The everyday loads
The defended numbers hold. The cost of holding them is set by what you do every day.
Short sleep. How to Start Taking Care of Yourself Today: Why Your Body Can't Wait has the nine healthy people who slept four hours instead of seven and a half for one night, and were about a quarter less sensitive to insulin the next day. The four grams take more holding after a bad night.
Sleep apnoea. When breathing stops and starts through the night, carbon dioxide builds up between breaths, and the body spends the night correcting it. Loud snoring with pauses, gasping or waking unrefreshed is worth getting checked.
Alcohol. The liver drops other work to clear it, and it pushes the kidneys to let water go. Less of it, less often, lightens both.
Stress and breathing. A decade before he named homeostasis, Walter Cannon described its emergency override, "the necessities of fighting or flight": heart rate up, breathing up, sugar released into the blood. Useful for a few minutes. Kept on for weeks, it is one more load the steady state has to carry. A stressed body also tends to breathe fast and shallow, and sometimes clears too much carbon dioxide rather than too little, which is what brings on the tingling and light-headedness of a panic. Slow breathing with the belly, a longer breath out than in, settles it.
How long it should have to
The body maintains its blood pH without help. It holds its sugar, its heat and its water too, every second, whatever you eat, for as long as you are alive. No strip, powder or special water is needed for any of it.
What it does need is a fair workload. Fewer sugar floods, enough water, enough sleep, less alcohol, a calmer breath: none of it changes the numbers, because the numbers are already defended. It changes how hard the defending has to be. You cannot win an argument with your chemistry. You can stop picking fights with it.
That matters more with every decade. The defences that hold these numbers get slower with age, and the compensating can hide a problem for a long time before it shows.
The body is resilient. It compensates for a great deal. The question is how long it should have to.
Swap your next sweet drink for a glass of water, and give the four grams one less flood to deal with.
Wondering which signs are worth a test? 12 Signs Your Body Is Trying to Tell You Something Important — tiredness that sleep does not fix, thirst that never lets up, and the test to ask for with each.
Want the four grams to have an easier time? How to Fix Blood Sugar Spikes Naturally — low-carb, keto and carnivore, the order you eat in, the walk after a meal, and what one short night does.
Know someone with a cupboard full of alkaline water and pH strips? Send them this, and let the money they save go on a good steak.
Disclaimer: This article is general information. For advice about your own health, talk to a qualified health professional. If you have kidney disease or heart failure, or take medicines that affect potassium or blood pressure, check before using electrolyte products.
Affiliate Disclosure: This article contains affiliate links. As an Amazon Associate, All For Life earns from qualifying purchases, at no extra cost to you. We only link to products we would recommend without the commission.
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