This is the first in a series of articles discussing various diet trends that have become popular in recent years, and whether the science supports their claims.
The alkaline diet has gained popularity in recent years, most likely due to a combination of celebrity advocates, scientific language, and an increasing interest in healthy living. But is it all it’s cracked out to be?
The alkaline diet is based on the premise that the body functions best in a slightly alkaline state, and that illness is due to acidity in the body. Some advocates even go so far as to claim that disease cannot live in an alkaline environment, and therefore if you have a disease (yes, that includes cancer!) it’s because your body is acidic. Sound a little far-fetched? Well that’s because it is, and here’s why.
Before we get into the nitty-gritty of these claims, we need to clarify some basic high school science. In chemistry, pH measures how acidic or how alkaline/basic a substance is. pH stands for “particles/power of hydrogen”, and measures the concentration of hydrogen (H+) ions. An acid has a low pH (or high concentration of hydrogen ions) and an alkaline/base has a high pH. To put this into perspective, water is neutral and has a pH of 7, fizzy soft drinks have a pH of around 3 (very acidic), and baking soda has a pH of around 9 (slightly alkaline). For the sake of argument, alkaline and basic mean pretty much the same thing, but calling it the “basic diet” obviously doesn’t have the same ring to it!
Proponents of the alkaline diet say that what we eat and drink affects the pH of our bodies, including the blood. As the body is in a naturally alkaline state – the pH of your blood is 7.4 – they say we need to eat an abundance of alkaline-forming foods (namely fruits and vegetables), and avoid acid-forming foods (mainly meat and dairy).
The problem with this is that various parts of your body have a different pH. The stomach is highly acidic with a pH of around 2, the pH of your mouth is around 6 (the optimum pH for the enzyme amylase which kicks off the digestion process), and, as I said earlier, your blood has a pH of 7.4 (slightly alkaline). All foods that leave your stomach are acidic, and then enter the intestines where the stomach acids are neutralised by the pancreas. So even if you drink a litre of fizzy drink the end result in the intestines is alkaline. On top of that your blood pH never changes, as it’s highly regulated by a sophisticated buffer system. If your blood pH really was acidic, you would be dead, not merely unwell. Certain foods can leave end-products called ash that can make your urine acidic or alkaline, as it is the only part of your body affected by food. But the urine in your bladder is technically external, and therefore urine has no relation to body pH whatsoever.
Ok, you may argue, but your body neutralises any acid-ash using nutrients from your body, particularly phosphate ions which come from your bones, so if you overwork the phosphorous buffer system surely it has negative health effects? Well…yes, if you eat no vegetables and live off junk food for years, but surely that goes without saying? On top of that, several recent meta-analyses have found no link between acid-ash from dietary sources and osteoporosis. So the alkaline diet doesn’t even help prevent osteoporosis, and it creates restrictions on your diet which can actually create health issues if you’re not prepared.
Finally, I want to debunk this ridiculous saying that advocates fall back on, namely that cancer cannot grow in an acidic environment, and therefore if your body is alkaline you cannot get cancer. While cancer tissue does grow in an acidic environment, it’s the cancer that creates the environment, not the environment that creates the cancer. So eating alkaline won’t help – sorry! On top of that, anything that discourages individuals from life-saving conventional medicine should never be encouraged, ever.
But despite the glaring scientific flaws and ridiculous claims made by the alkaline diet, it has one advantage: it encourages people to eat more fruits and vegetables, which is never a bad thing. But it’s a shame that it relies on pseudoscience to get there.
Rather than worrying about acid and alkaline foods as their own “food groups”, if you simply eat a decent amount of fruits and vegetables (5 a day springs to mind), you have nothing to worry about. Quite frankly, anyone who says you can change the pH of your blood needs to be immediately directed to a high school chemistry classroom.
I was NEVER a fan of the alkaline diet because I couldn’t eat peanuts! UM I need my peanut butter XD but I do like its message about balancing digestion and blood stability!
Could you please clarify what you mean when you say “blood stability”?
These posts are interesting! Keep it up
Sorry, but the stomach is not meant to be highly acidic. You are starting with a false premise. The idea that HCL is produced for digestion came about in Germany 1952 and the experiments were conducted badly.
The purpose of the stomach is to create sodium bicarbonate. The body takes sodium, water and carbon dioxide from the blood and makes sodium bicarbonate for the purposes of raising the pH of food to 8.4 so that it can be absorbed in the small intestine. BUT, for every molecule of bicarb created, an equal amount of HCL is made….as a waste product. HCL never comes in contact with food, if falls away to the gastric pits….the bicarb, produced by the cover cells in the stomach, splashes over the food to alkalize it. The studies in Germany looked at the stomach after the mix of food and bicarb had exited the duodenum and so all the were registering was the HCL wastes.
The stomach does NOT digest food. This is why meat ferments, not digests – hence why the bathroom stinks, especially if its cooked meat combined with carbs. Digestion takes place in the mouth, and salivary glands produce bicarb to assist in alkalizing the food before it is passed over to the stomach. Chew well or use a blender, either way food must be liquefied if it is to be digested.
If you don’t believe an alkaline diet works, try drinking alkaline water and eating zero carbs and increasing healthy overt fats like avos – and you will feel and distinct difference in your mental and physical energy and clarity.
you will also be able to monitor dramatic changes in urine and salive pH.
Good effort with the article, false premise from the start never helps…..better luck next time 🙂
Thanks for your comment, however I have to correct you. You say the stomach is not meant to be highly acidic, yet the stomach’s natural pH lies between 1-5. When you eat it releases HCl (as you said) and the pH drops down to 1 or 2. This is not to digest the food but so that proteases can function in their ideal environment. Afterwards your stomach returns to its “resting pH” of 4 or 5. So saying the stomach is not meant to be acidic just doesn’t make sense – it’s always acidic! I never said the stomach digests food or that HCl is produced for digestion, so please don’t put words in my mouth.
The pH of food is raised after it leaves the stomach, as first the proteases in the stomach have to act at a low pH, and then in the intestines (and duodenum) serine proteases and so on act on the food at a higher pH and break everything down further.
As I said in the article, saliva and urine pH is NO indicator of your body’s pH (which barely changes), so measuring it doesn’t tell you anything useful about the state of your body, only what’s come out.
As I also said, an “alkaline diet” is often beneficial for individuals as it encourages them to eat more fruits and vegetables, which is always a good thing! The problem I have is that proponents of this diet use incorrect science and even pseudoscience to promote this diet, when a simple “eat more vegetables” would suffice. I have no false premise, I have been entirely scientifically accurate, and the vast majority of the scientific community stands behind me on this for a reason – I can provide plenty of evidence. Also alkaline water? Really? Citation please. Ditto for zero carb diets being a healthy long-term solution. Anecdotes just won’t do, I’m a scientist.
I have only just read both your articles now, but I just want to thank you for going for it and posting stuff like this! Even if it is “controversial”, it seems to me that’s just a nice way of saying that people want to continue to be ignorant. It’s so difficult to blend science and “wellness”, when they should pretty much be overlapping at this point. I hope you post more stuff like this!
Also, love watching you kick ass with facts when you get backlash. Well done 😄👊
Thank you so much for this lovely comment, it honestly means the world to me 🙂 I will definitely continue to post and kick ass 😉 and always open to topic suggestions!