This page about pH and gout last reviewed or updated on 19 May 2012
On this website's pH for gout pages we saw that if your body is in a more alkaline condition, as recorded by a higher pH number on the pH scale of 0 - 14, it is in a more favourable (favorable) state to excrete uric acid. (See the links below to go to the first of the pH and gout pages. The others are linked from that page).
One body pH you can measure yourself is the pH of urine.
In a study in Japan in 2010 (1), by eating a more alkaline diet than their regular diet, 26 healthy young women significantly raised the amount of uric acid they excreted. And in a short time, only five days. On the other hand, a more acidic diet inhibited the excretion of uric acid in urine, again after five days.
So how much was excreted?
The participants didn't have to achieve such a big rise in urine pH to get a much larger percentage rise in uric acid excretion. The rise in uric acid excretion was from 302 mg* a day at pH 5.9 to 413 mg*** per day at pH 6.5. That's an excretion increase of nearly 37% from a rise in urine pH of about 0.6 (on the pH scale), compared to the uric acid excretion and urine pH of a participant's average daily diet for the preceding month.
And what did the acid gout diet do? Acidic urine <i> inhibited </i> uric acid excretion.
And this occurred despite not drinking huge amounts of water or alkaline water or taking alkaline supplements. There was just, as the researchers said, "free access to mineral water."
How good were these results? The results were good enough for the researchers to propose the more alkaline diet for the prevention of hyperuricaemia (hyperuricemia) i.e. high uric acid above around 7.0 mg/dL (0.416 mmol/L).
Not all roses Unfortunately there was a snag. Although the measured amount of excreted uric acid (UA) rose considerably, any resulting fall in serum (blood) uric acid was not measured. (Or if it was, the results were not published). Blood serum or plasma are the UA levels used to measure progress, or the lack of it, in dealing with gout. So we don't know if it fell in line with the additional excretion, which is what we would have hoped.
FOODS EATEN - ACIDITY, ALKALINITY AND PURINES
The intention in this study was not to lose weight by eating a low calorie or a restricted carbohydrate diet. The diet focused on the acid/alkaline amount in foods and also measured the diets' purine content. Both the more acid, and the more alkaline diet, delivered around 2,200 calories per day, which isn't a low calorie diet.
Protein amounts in the diets however, were a measured factor, because protein tends to be acidic. The more acid diet consisted of 102 grams of protein a day and the more alkaline diet, 60 protein grams per day. The more acid diet was calculated to deliver 533 mg per day of purines; the alkaline 306 mg of purines per day. The acid load of the acid diet was calculated as 19,458 mg/day; the alkaline diet's acid load was 8,039 mg/day. Alcohol content appears to have been only amounts used in cooking in both diets.
306 mg/day is quite a low purine diet. Not surprising, because the more alkaline foods for gout diet was weighted towards fruit and vegetables which are lower in purines than meats and fish. This alkaline diet might have been expected to be associated with less uric acid excretion because less purines were consumed. This was not so. Although fewer purines were consumed on the more alkaline diet, more uric acid was removed. This is a strong suggestion that alkaline urine is good at excreting more uric acid.
The foods consumed If you want to see a complete list of foods and amounts eaten daily (from which the recipes were prepared) they are published in the appendix to the study. The study is an open access document and can be read or downloaded free, courtesy of the Nutrition Journal:
Click this: “Urine alkalization facilitates uric acid excretion.” For the foods eaten on both diets, scroll to the appendix.
Although the foods were among those popularly eaten in Japan, most of them, as ingredients, are common elsewhere. So if you used these foods as a basis for recipes of an alkaline foods for gout diet you would be able to construct meals from them since you'll be familiar with most. To learn of the acidity/alkalinity of other foods,
The diets' fructose consumption This was not measured but it was probably low enough. i.e. below 25 grams of fructose a day. Note that honey is high in fructose, and that high intake of fructose is though by many to raise uric acid. A little honey was eaten on the alkali diet (21 grams per day which delivers about 8 grams of fructose) but you could always avoid honey or build say 8 grams into a daily fructose allowance.
MORE ENCOURAGING RESULTS FROM THE STUDY
Did it take long to reach urine pH 6.5 on the more alkaline diet, and urine pH 5.9 on the more acidic diet? No. Just three days. The effect of diet on urine pH is very quick.
Did it take long for the uric acid excreted to rise? Again no. The uric acid in the urine was measured after five days. Thus just two days after the urine pH targets were reached. Only a few days had been required to raise uric acid excretion by 37%.
WHAT ARE THE pH FOR GOUT LESSONS FROM THIS?
I think this study has given us useful and practical knowledge about pH and gout. Here are some of my conclusions. They are not based on studies, but logical outcomes as a result of what's been learnt in this pH and gout study.
* If your low purine diet doesn't appear to be working, or working very well, to lower blood uric acid, it might be because the foods you are eating are too acidic. This would also be true of any diet that aims at weight loss to lower blood uric acid.
* It is quite easy and quick to make your urine alkaline. And you can get a booster from prescribed (RX) potassium citrate which will also alkalise (alkalize) urine.
* If kidney stones are at risk of developing, and there is about a 20%+ risk of them in gout sufferers with acidic urine, you can use a more alkaline diet to alkalise (alkalize) urine.
* Some people think that the confusion surrounding the precise acidity or alkalinity of certain foods makes an alkaline foods for gout diet too uncertain. This study showed that this isn't so, with the caveat that blood uric acid was not measured. For example 120 grams (4.23 ounces) per day of tomatoes were eaten on the alkaline diet. Tomatoes are a "confusion" food - they have been called alkaline and acidic. Here they seem to have had an alkaline effect, because excreted uric acid rose.
***Average amount per day for the last 3 days.
(1) Aya Kanbara, Masayuki Hakoda, Issei Seyama Urine alkalization facilitates uric acid excretion Nutrition Journal 2010. 9:45