Four of these tastes are sweet, salt, bitter and sour: Those that many of us learned as children. The taste for salt and sweet generate positive, pleasure-like responses that encourage the intake of these foods, while the bitter and sour tastes tend to lead to aversion and a general dislike. It is very likely that these tastes were developed to help us eat foods that were safe and beneficial, while avoiding foods that might contain toxins or poisons.
There is also a fifth taste originally identified by a Japanese researcher in the early 1900s. The taste was called umami, or the savory taste, generated by a specific amino acid known as glutamate. The flavor can also be markedly enhanced by certain purine-rich substances known as AMP and IMP.
Many of us love umami foods, examples of which include rich meat sauces and gravies, organ meats, shellfish, anchovies, blue cheese, and beer. The umami flavor is especially high when meat is cured, smoked, dried, aged, boiled or cooked, allowing the release of glutamate and nucleotides from the meat. This is why gravies and rich simmering sauces contain a lot of umami. One major source of glutamate are tomatoes, while beer is especially rich in nucleotides due to the presence of brewer’s yeast. Some people add tomato juice to beer to make red beer, or mix cocktails such as Bloody Marys that contain alcohol and tomato juice. Glutamate can also be added to foods as monosodium glutamate (MSG) to enhance taste. For many who write about umami, it is considered wonderful, and umami foods are often viewed as healthy and safe.
How are Umami Foods Linked to Uric Acid?
However, there is increasing evidence that the umami taste was aimed at eating foods that might increase uric acid levels1. In fact, when glutamate is ingested, some of it is used to produce uric acid2. Glutamate levels are also uniquely elevated in the blood of subjects with gout3. Foods rich in glutamate, such as tomatoes, are also associated with increased risk for gout4.
Likewise, purine-rich foods that increase the risk for gout are almost always rich in umami1. Organ meats, such as liver, are rich in purine-rich substances such as AMP and IMP that are broken down to uric acid. The same is true for processed red meats, shellfish and beer (which is rich in brewer’s yeast). Blue cheese is blue because of the yeast that is rich in AMP and IMP. Interestingly, it is not the protein content, or even the overall purine content, but rather the amount of AMP and IMP that appear to be important in the umami taste and the risk for gout.
Why Do We Have a Taste for Foods that Increase our Risk for Gout?
It has been known for a long time that uric acid levels are high in people with obesity and diabetes, and these conditions are also associated with gout. At one time, most people also believed that being overweight might increase the risk for gout, but more recent studies suggest that high uric acid levels are what may increase the risk for obesity. Indeed, recent studies in laboratory animals show that feeding animals umami foods can lead to the development of obesity5. Adding uric acid to drinking water can further increase the risk for obesity in animals fed glutamate. What is more, when the production of uric acid is blocked, the animals tend to gain less weight from umami foods.
Therefore, we believe that the umami taste developed alongside the other four in order to help us identify foods that can break down into uric acid. This way, humans of the distant past could maximize the ability to increase body fat1. Having some fat was likely a survival advantage millions of years ago, especially during times when food was less available. However, in modern society where foods rich in sugar, salt and umami are readily available, we are no longer trying to prevent starvation. Instead, the ingestion of these foods are increasing our risk for obesity and diabetes. It is interesting that uric acid and glutamate are the No. 1 and No. 2 most common blood markers that have been linked with obesity6.
What Umami Foods Should We Avoid if We Have Gout?
In many respects, umami foods are the same foods we are told contain purines and can increase the risk for gout. The primary foods are: organ meats (liver), shellfish (especially shrimp, crab, lobster), fish (especially anchovies, mackerel, herring) 7, meats (especially processed red meats) and beer8. Most purine-rich vegetables tend not to increase the risk for gout7, with the exception of tomatoes (especially cooked or dried) 4. Blue cheese and gorgonzola cheese that are rich in yeast may also increase our risk for an attack of gout. However, while all of these foods can increase risk, the recommendation is not abstinence but rather, moderation.
Are There Foods that can Reduce the Risk for Gout?
There are also foods that can reduce the risk for gout. One highly recommended way is to stay well hydrated by drinking a lot of water. Coffee, in particular, also contains substances that can lower uric acid, and drinking five cups a day is associated with both reduced risk for gout and reduced risk for diabetes 9. Vitamin C also may reduce the risk for high blood pressure, obesity and gout. Dairy foods, especially skim milk and cheese, may also have protective effects 7. Certain nutraceuticals, such as quercetin, may also reduce the risk for gout.
Richard J Johnson MD is a physician and researcher who has studied uric acid for over 25 years and is a board member of the Gout Education Society. He is also author of “Nature Wants Us to Be Fat” (Benbella books, 2022) that discusses the role of fructose and uric acid in the epidemics of obesity and diabetes. Check out his website: DrRichardJohnson.com
References
1. Johnson RJ, Nakagawa T, Sanchez-Lozada LG, et al. Umami: the taste that drives purine intake. J Rheumatol. 2013;40(11): 1794-1796.
2. Feigelson M, Feigelson P. Relationships between hepatic enzyme induction, glutamate formation, and purine nucleotide biosynthesis in glucocorticoid action. J Biol Chem. 1966;241(24): 5819-5826.
3. Gutman AB, Yu TF. Hyperglutamatemia in primary gout. Am J Med. 1973;54(6): 713-724.
4. Flynn TJ, Cadzow M, Dalbeth N, et al. Positive association of tomato consumption with serum urate: support for tomato consumption as an anecdotal trigger of gout flares. BMC Musculoskelet Disord. 2015;16: 196.
5. Andres-Hernando A, Cicerchi C, Kuwabara M, et al. Umami-Induced Obesity and Metabolic Syndrome is Mediated by Nucleotide Degradation and Uric acid Generation. Nature Metabolism. 2021;in press.
6. Cirulli ET, Guo L, Leon Swisher C, et al. Profound Perturbation of the Metabolome in Obesity Is Associated with Health Risk. Cell Metab. 2019;29(2): 488-500 e482.
7. Choi HK, Atkinson K, Karlson EW, Willett W, Curhan G. Purine-rich foods, dairy and protein intake, and the risk of gout in men. N Engl J Med. 2004;350(11): 1093-1103.
8. Major TJ, Topless RK, Dalbeth N, Merriman TR. Evaluation of the diet wide contribution to serum urate levels: meta-analysis of population based cohorts. BMJ. 2018;363: k3951.
9. Choi HK, Curhan G. Coffee, tea, and caffeine consumption and serum uric acid level: the third national health and nutrition examination survey. Arthritis Rheum. 2007;57(5): 816-821.
