Salty vs. Sweet Taste Preference - Is it Genetic in Humans and Horses?

An exciting new discovery by EtalonDx geneticists Laura Patterson Rosa, DVM, PhD and Samatha Brooks, PhD found that some of the genes correlated to Equine Metabolic Syndrome and obesity are related to horse’s perception of smell and taste! That means that our horses’ weight gain and ultimately EMS may be due to a preference for sweet foods embedded in their DNA.

“We all know horses with specific flavor preferences, especially for treats, and perhaps it is their perception of individual foods that is altering their feeding behavior and putting them at risk for EMS. It was extremely interesting to see sensation genes correlated to EMS and obesity.” said Dr. Patterson Rosa.

This may explain why one pony may need to be muzzled during the spring months when grass is lush, while another horse doesn’t care to seek out the sweetest blade of sugary grass. The first pony might actually genetically prefer the sweet taste more than other horses. Researchers hypothesize that natural variations in these genes might lead to horses preferring sweeter/sugary feeds, or that it may cause a lack of distinction and indiscriminate feeding behavior, ultimately contributing to overeating and obesity.

This discovery isn’t all that new. In fact, there has been extensive research in humans correlating taste preference to genetics!

Taste preferences in humans are influenced by different factors including genetics, culture, repeated exposures and role models such as parents and siblings, and taste preferences change over time. Sweet tastes are preferred by newborns and bitter tastes are disliked by infants. In general humans are born with a biological predisposition to prefer sweet and to avoid bitter foods such as green leafy vegetables. It has been hypothesized that this predisposition evolved to attract children to energy-dense foods while discouraging the consumption of toxins. There are at least 25 known genes in the bitter taste receptor family in humans. “Sweet” perception involves at least 3 genes, and others have been identified for sour and salty foods.

This news helps us to better understand what causes Equine Metabolic Syndrome in horses and how to prevent it. Understanding that obesity is a key element of EMS and managing the weight of the horse is key. Approximately two-thirds of horses are obese, according to a U.K. study. Obesity is common in horses for the same reason it is in people. “We don’t participate in physical labor the way we did 100 years ago, and we have improved diets that are designed to meet all of our needs,” said Dr. Brooks. “Also, we have easily accessible, and tasty, junk food and treats. This all contributes to problems with obesity and maintaining our blood sugar, for both horses and humans.”

References:

Barlow LA. Progress and renewal in gustation: new insights into taste bud development. Dev Camb Engl. 2015;142(21):3620-3629. doi:10.1242/dev.120394

Forestell CA. Flavor Perception and Preference Development in Human Infants. Ann Nutr Metab. 2017;70 Suppl 3:17-25. doi:10.1159/000478759

Fry Vennerod FF, Nicklaus S, Lien N, Almli VL. The development of basic taste sensitivity and preferences in children. Appetite. 2018;127:130-137. doi:10.1016/j.appet.2018.04.027