Purines are a category of molecules found in various food and beverage commodities but which are also produced by the destruction of some cells in our body. Some foods, such as beer or seafood, contain them in quite high concentrations. Those who have difficulty expelling them in the form of urine, that is to say, those who suffer from hyperuricemia or gout, should therefore limit their consumption of these foods. We talk about this topic with Professor Carlo Selmi, rheumatologist and clinical immunologist at Humanitas.
Constituent elements of living beings
The name “purine” refers to a specific type of molecule found in the DNA and RNA of cells and can therefore be said to be in the list of constituent elements of all living beings.
In the human body purines can be divided into two categories: endogenous purines produced by the body and exogenous purines that enter the body through food. The exogenous purines, introduced with food, are metabolized by the liver, which decomposes them and produces a waste product called uric acid. Uric acid is released into the bloodstream and is finally filtered by the kidneys and excreted in the urine.
When uric acid is too high
If uric acid accumulates in the blood, a condition called hyperuricemia occurs. In some people hyperuricemia can cause kidney stones or lead to an inflammatory condition of the joints called gout. However, a high level of uric acid may not lead to a specific symptomatology in everyone.
People with hyperuricemia should eat foods with low concentrations of purines and avoid those that contain a high percentage of purines. Food and drink that inhibit the body’s ability to metabolize purines, such as alcohol and saturated fats, should be restricted or avoided altogether. In addition, people on a low-purine diet should drink plenty of water to promote renal excretion of uric acid and thus reduce blood concentrations.
Foods containing high, moderate or low purine concentrations
Among those with high concentrations are: the innards (such as liver, brain and kidneys of beef), as well as game meat with a high percentage of fat including deer.
It also includes foods containing saturated fats that tend to inhibit the body’s ability to metabolize purines including beef, pork, lamb, fish and poultry and seafood (in particular scallops and other shellfish, or blue fish such as anchovies, sardines, herring and mackerel). The list also includes foods and drinks made from corn syrup with a high fructose content, such as carbonated drinks and everything that contains yeast or yeast extract and sauces and particularly rich in fats.
On the other hand, a medium concentration of purines is contained in some green leafy vegetables, including asparagus, spinach, mushrooms, peas and cauliflower. Meat from beef, pork, lamb, fish and poultry. Wine, wheat bran and wheat germ, dried beans, lentils and peas, oatmeal, fruit juices (without corn syrup) and all meat soups.
Finally, most of the green leafy vegetables, carrots and tomatoes, and condiments containing oils, spices and vinegar have a low concentration. Rice, pasta, bread, potatoes and popcorn and walnut products also have a lower concentration. Finally, milk products (with the exception of buffalo milk), eggs, in particular egg whites, tea, coffee and all fruit. More good news, a study suggests that eating cherries can reduce the risk of gout.