Low Purine Diet
by Sue Kira, Naturopath & Clinical Nutritionist
What are purines?
Purines are chemicals that are either made in the body or are found in foods that we eat. When the body breaks down (metabolises) purines you get uric acid as a by-product that is normally easily excreted by the blood by sending it through the kidneys and then out via urine.
For some people, this uric acid doesn’t clear very well, and the result can be an increase in uric acid levels which causes hyperuricemia (too much uric acid).
This leads to an increase in uric acid crystals that can build up around joints and create a painful condition known as gout or gouty arthritis. This build-up can also lead to uric acid type kidney stones. Commonly, kidney stones are made from calcium, but 5% of kidney stones can be attributed to uric acid crystals.
Purines are not all bad news
Purines do have positive effects for our body. Everything has its function in our body and purines are part of our DNA building blocks (the genetic stuff that makes our cells). Researchers have recently discovered that purines have a role in maintaining a healthy cardiovascular system, healthy digestive system, our inflammatory responses, and aiding the absorption of nutrients from food.
Why avoid purines?
If you suffer from gout, have problems clearing stones from kidney issues, have chronic inflammation from conditions such as Ross River Virus (RRV), or other infections that create inflammation, then a low purine diet may be helpful.
All foods contain some purines, but some are higher than others. Previously, when someone was told they needed to go onto a low purine diet, they removed many foods including certain vegetables, grains, and protein foods.
New research shows that plant-based foods are the least problematic of the high purine foods because of their high fibre content.
The foods that are the most aggravating are the organ meats, red meats, seafoods (especially shellfish), meat extracts, yeast extracts and alcohol.
Vitamin C has been shown to help reduce uric acid levels and lower the risk of getting gout.
Most vitamin C comes from fruits and vegetables rather than animal proteins. Generally, the higher the ratio of plant foods you consume over animal proteins, then the better off you will be, particularly if you have an issue with uric acid and purines and of course the associated gout, kidney stones, infections, or inflammation.
For those suffering from gout, kidney stones or inflammatory conditions, it is important to seek medical support – and a Low Purine Diet (see below) may also be very supportive for these conditions.
Purines and Food
High purine foods to avoid
While a small amount of these foods may be fine for your body, the less you have the better. Rheumatologists recommend avoiding the following foods:
- Shellfish & Seafood such as anchovies, sardines, tuna, mackerel
- Red meat, including beef, lamb, kangaroo, venison, pork, bacon
- Organ meats, including heart, liver, brains etc (even from white meats)
- Yeast – breads, yeast extracts, meat extracts and yeast fermented foods
Moderately high purine foods to limit
Limit to less than 5oz/140g per day (approx 3/4 cup) to keep purine and uric acid levels down:
- Duck, goose, or other wild type birds (pheasant, quail etc)
Other foods/substances to avoid
These do not necessarily contain purines, but they can increase uric acid, lower the clearance of purines, or increase inflammation in the body, to aggravate conditions like gout, kidneys or inflammatory conditions:
- Refined carbohydrates: breads, cakes, lollies/sweets/candies, pasta
- Alcohol: beer, wine, liquor, and spirits (alcohol disrupts the excretion of uric acid plus some contain purines)
- Anything with sugar: fruit juice, soda/soft-drinks (increases inflammation more than purines do). High levels of fructose can increase uric acid levels
Better food choices for a lower purine diet
- Legumes, such as lentils and beans (moderate amounts to reduce acidity). Limit to 2 times per week
- Whole grains/seeds like brown rice and quinoa (moderate amounts)
- Sweet potatoes and normal potatoes (moderate amounts)
- Most other vegetables are totally fine. Peas, dark leafy greens, asparagus, mushrooms, and cauliflower are said to contain high levels of purines, but the fibre content helps to clear them from the body before absorption. However if your condition is bad, best to limit.
- Chicken (less than 1 cup per day). Most animal protein is high, but chicken is about the lowest
- Eggs (same as chicken). 1-2 eggs per day is fine provided you don’t also have lots of chicken or other purine rich foods
- White fish has the lowest purines in the seafood section
- Nuts, seeds, and nut/seed butters/spreads/pastes are good sources of protein with lower purine levels. Eat moderate amounts to reduce acidity levels.
- Most fruits are fine, including apples, avocado, bananas, berries, stone fruit, pineapples, melons, rhubarb
Before you commence your diet, see your medical or health care professional for qualified guidance about what foods and supplements are best for your body. While on the diet do not stop any medications or supplements previously prescribed unless advised otherwise by your medical or health care professional.
During the early stages of a new diet, you may experience symptoms such as fatigue, headaches, or body aches, which may occur because your body is detoxifying. However, if you are unsure about a symptom at any time, check immediately with your medical or health care professional.