Whether you’ve got a cabinet full of pH strips or this is the first you’re hearing of it, the alkaline diet (also called the alkaline ash diet or the acid-ash diet) has been a part of the posh set since the Spice Girl herself tweeted about it in 2013.
The diet focuses on maintaining optimal body pH (more on this later) by limiting acid-inducing foods and drinks such as caffeine and alcohol, meat and dairy, and anything processed or fried, and replacing it with alkaline-inducing substances like raw veggies, low-glycemic fruits, and green smoothies galore. By ingesting foods that maintain proper pH rather than stressing your body to self-correct its pH level, the diet claims to reduce inflammation, boost immunity, and improve overall health (including shedding some pounds and avoiding diseases like osteoporosis and cancer).
This all sounds well and good, but shifting from meat and potatoes to quinoa and kale is not for everyone. So before changing up your diet, let’s take a closer look.
The Diet Breakdown
As you might remember from chemistry class, every substance has a pH that falls on a scale from zero to 14. The closer to zero, the more acidic a substance is; seven is neutral, and as a substance climbs toward 14, the more alkaline (or basic) it becomes. Normal and healthy blood pH is between 7.35 and 7.45, with the body working to maintain this through respiration, urination, and mineral depletion.
The theory goes that consuming acid-inducing foods and drinks creates an unhealthy cellular environment and sends distress signals throughout the body, leading to colds, outbreaks, and inflammation. It’s suggested this continual acid-dumping via food can create chronic disease such as arthritis, osteoporosis, and cancer. Proponents say you can think of it like a sliding scale—the more you eat and drink your way left, the more work your body must do to get back to normal. And making your body work really hard day in and day out will ultimately take its toll.
So basically (yup, that’s a pH joke), supporters claim that ditching the steak and brewskie and opting for the leafy green smoothie will keep the internal pH scale shifted rightward and the body unstressed, leading to more energy and greater overall health.
And to see if you’re on track, devotees suggest testing the pH of your second pee of the day with easy-to-purchase litmus paper strips. Somewhere between 6.8 and 7.5 is ideal for what famed practitioner Kris Carr calls “optimum sparkle.”
Does the Science Stack Up?
Well, er, kind of. Now bear with us for a second.
There are studies suggesting alkalizing has positive effects such as promoting strong bones and muscles, preventing kidney stones, reducing chronic diseases such as hypertension and stroke, and reducing the risk of type 2 diabetes The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health? Schwalfenberg, G.K. Journal of Environmental and Public Health, 2012; 727630. Diet-induced acidosis: is it real and clinically relevant? Pizzorno, J., Frassetto, L.A., Katzinger, J. The British Journal of Nutrition, 2010; 103(8): 1185-1194. Dietary acid load and risk of type 2 diabetes: the E3N-EPIC cohort study. Fagherazzi, G., Vilier, A., Bonnet, F, et al. Diabetologia, 2014; 57(2): 313-320.. It’s also been suggested to have the potential to improve cardiovascular health as well as memory and cognition The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health? Schwalfenberg, G.K. Journal of Environmental and Public Health, 2012; 727630..
But don’t drop dough for a juicer just yet. The above support rests on mild evidence, and with respect to the alkaline diet’s most fundamental claim—that what you eat can affect your pH enough to thwart off cancer and osteoporosis—the science is lacking. For one, there are no human studies supporting the alkaline diet for the prevention or treatment of cancer, only test-tube and animal findings examining the effects Investigating Mechanisms of Alkalinization for Reducing Primary Breast Tumor Invasion. Robey, I.F., Nesbit, L.A. BioMed Research International, Published online Jul 10, 2013.. And when it comes to bone health, other studies lie in stark contrast to the above claim, saying that acidic foods such as meat and dairy will not promote osteoporosis Phosphate decreases urine calcium and increases calcium balance: A meta-analysis of the osteoporosis acid-ash diet hypothesis. Fenton, T.R, Lyon, A.W., Eliasziw, M, et al. Nutrition Journal, Published online Sep 15, 2009. Low urine pH and acid excretion do not predict bone fractures or the loss of bone mineral density: a prospective cohort study. Fenton, T.R., Eliasziw, M., Tough, S.C, et al. BMC Musculoskeletal Disorders, Published online May 10, 2010. Meta-analysis of the effect of the acid-ash hypothesis of osteoporosis on calcium balance. Fenton, T.R., Lyon, A.W., Eliasziw, M, et al. Journal of Bone and Mineral Research, 2009; 24(11): 1835-1840..
So benefits, maybe. But how about harms? There are no studies to suggest that an alkaline diet is bad for you, but some experts warn that being too restrictive could cause your protein The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health? Schwalfenberg, G.K. Journal of Environmental and Public Health, 2012; 727630. Does a high dietary acid content cause bone loss, and can bone loss be prevented with an alkaline diet? Hanley, D.A., Whiting, S.J. Journal of Clinical Densitometry, 2013; 16(4): 420-425. and calcium intake to drop. Still, as any vegetarian can tell you, obtaining meat-free protein ain't really no big thang if you know what to eat, and leafy greens provide what some experts suggest is a superior source of all-important calcium.
Skeptics believe people feel better on the diet simply because they’re eating more fruits and vegetables and less processed foods, not because they’re altering their internal pH—any benefit of that doesn't have enough scientific support Does a high dietary acid content cause bone loss, and can bone loss be prevented with an alkaline diet? Hanley, D.A., Whiting, S.J. Journal of Clinical Densitometry, 2013; 16(4): 420-425.. The nutrient-rich foods touted by alkalizers are, unsurprisingly, going to make you feel way better than greasy burger and fries, but that’s something we’ve known for years The Standard American Diet and its relationship to the health status of Americans. Grotto, D., Zied, E. Nutrition in Clinical Practice, 2010; 25(6): 603-612..
So Where Does That Leave You?
Informed enough to holster that shot of wheatgrass, unless you happen to love the taste or you want to try whatever superfood is currently on Gwyneth Paltrow’s radar. After all, nobody’s going to argue that replacing cola with kale is an unhealthy swap. But if you simply couldn’t fathom a week without cheese (and honestly, we don’t blame you), know that it’s OK. The most important takeaway is knowing the effects different foods can have on your body and striving to stock your kitchen toward alkalinity. So keep that in mind as you grocery shop or hit the farmer’s market—there’s no need to create dietary stress unnecessarily.