Different WFPB Strokes for Different WFPB Folks

 Individual variability plays a role in determining the ease of transition to a whole food plant based diet (WFPB).  There is pretty much a limitless amount of variables that affect an individual’s food acceptance.  Some that come to mind include: age, ethnic background, religious beliefs, family background, personality traits, thoughts about nutrition, fitness goals, emotional health and medical history.

 The work of researchers like Beverly J Tepper, a food science professor at Rutgers University, may eventually reveal that the most important variable affecting a person’s ability to switch to healthier eating habits is found in his/her genes.  Specifically in genes affecting taste sensitivity.

 Tepper became interested in this idea after learning about a colleague’s study that found that people who were really sensitive to the bitter compound called 6-n-propylthiouracil (otherwise known as PROP) also, for some reason, gave higher creaminess ratings to dairy products than those who could not taste PROP.

 Tepper decided to divide test subjects into PROP non-tasters, medium tasters, and particularly “super-tasters.” (Statistically, about 25 percent of Caucasians are non-tasters; 50 percent medium tasters and 25 percent super-tasters.)  She then gave them high-fat and low-fat versions of salad dressings to taste.  As predicted, the non-tasters liked the high-fat dressings better.

 Subsequent work by Tepper and others has pointed to a host of taste tendencies that separate tasters from non-tasters.

 Tepper states “We recognized that PROP tasters not only taste the bitterness of PROP and the bitterness of other compounds more, but they perceive sweetness more; they perceive the textural aspects of dairy products more; they perceive hotness—like chili pepper—more,” Tepper said. “It’s a whole range of sensory characteristics that they seem to be more sensitive to”

 Super-tasters seem to pick up on food nuances.  Super-tasters tend to use lots of adjectives when describing foods.  Non-tasters seem to use a handful of words to describe what they eat.  Tepper explains that “they clearly know what they like, but they have difficulty describing it.”

 Tepper decided to see if PROP taster status has an effect on weight.

 Two years ago, Tepper found that women in their 40s who were super-tasters were 20 percent thinner than non-tasters. The super-tasters appeared to eat less overall, be it bitter vegetables or fatty foods. The super-tasters had a body-mass index of 23.5; the medium tasters had an average of 26.6, and the non-tasters nearly 30. (A BMI of 30 or above is considered obese.) So far, she has only seen body-weight correlations to PROP status in women, not men.

Tepper acknowledges that there are plenty of exceptions to the rule.  She counts herself as an exception.  She is a super-taster as she states that the PROP containing filter paper blows the back of her head off when placed on her tongue.  Although she is a super-taster, she likes all foods that she theoretically should hate.  Tepper readily admits that it’s not just taste genetics that influence people’s behavior and food preferences.  She states that “there are so many other factors.  We can’t just forget about all of them.”

One significant factor or variable is a person’s willingness to try new foods, otherwise known as food adventurousness.  This is a trait that can vary greatly among individuals.

Tepper has found that super-tasters who are not food adventurous are the ones who hate everything.  Tepper believes her food adventurousness explains her varied food preferences.

Another important factor is the ability to fight food urges, otherwise known as “resistant eating”.  People’s self control, especially if they are concerned about nutrition or their weight, seems to override PROP taster status.

John Hayes, an assistant professor of food science at Penn State College of Agricultural Sciences, was aware that previous research has suggested that supertasters need less fat and sugar to satisfy their taste buds (and food cravings),

Hayes and his colleagues suspected that the same would hold true for salt as well.

To confirm their suspicion, they taste-tested various off-the-shelf foods on 87 people, roughly a third of whom were super-tasters. The others were a mix of non-tasters and “medium” tasters.

 The participants tried samples of Campbell’s chicken broth with varying amounts of salt added, pretzel sticks, and shots of soy sauce. They were also asked to compare Lay’s potato chips and Cracker Barrel cheddar cheese with equivalent low-sodium store brands.

 Hayes and his colleagues were surprised to discover that the supertasters liked more salt rather than less, even though they were more sensitive to it. But after the researchers analyzed the data in more detail, they realized that salt plays a role in tastes besides saltiness.

 For instance, salt helps cancel out bitterness, one of the sensations that super -tasters experience in Technicolor. This may explain why the super-tasters in the study perceived the low-sodium cheddar cheese to be twice as bitter as the Cracker Barrel, and liked it far less than the other study participants did.

“They needed the salt to block the bitterness of the cheese,” Hayes explains.

 The study findings could have implications for the highly publicized efforts to cut the nation’s salt intake.

The Food and Drug Administration is considering limiting the amount of sodium in packaged foods, the main source of sodium in our diet. And some food companies — such as Kraft (maker of Cracker Barrel) and PepsiCo (the maker of Lay’s) — have pledged to voluntarily reduce the amount of sodium in their products.

Hayes’s study suggests that super-tasters may have a harder time than most with a lower-sodium food supply. Super-tasters tend to like salty foods better and consume more of them, the study found.

 Keri Gans, R.D., a spokesperson for the Academy of Nutrition and Dietetics, suggests that super-tasters try adding spices to their food instead of salt to compensate for reduced sodium.

“They could be using pepper, fresh garlic, basil, dill, oregano. Maybe they could add a few red pepper flakes,” Gans says. “If they’re taste sensitive, why not try to encourage people to enhance their food with natural herbs and spices as opposed to salt?”

 Tepper, Hayes and other PROP researchers are looking at several ways that this one genetic proclivity may affect public health. At least one study has found that heavy smokers are significantly more likely to be non-tasters than tasters, who appear more sensitive to the irritation of smoke and the bitterness of nicotine. Similarly, tasters perceive more bitterness and irritation from ethyl alcohol, and research has found that tasters consume fewer alcoholic beverages per year than non-tasters. Tepper stresses that more work needs to be done in both areas, and that if there is a PROP connection, it would only be a risk factor, not a genetic mandate.

 My take on the research

 I’m not sure how helpful PROP taster status research can be for folks transitioning to a WFPB diet.  I agree with Dr. Tepper that PROP taster status is just one of many variables that can affect an individual’s food preferences.  As a dietitian, it helps me to understand why some people, who have been following a WFPB diet for years, still crave salty, crunchy snacks – while others crave foods laden with sugar and fat.  I expect cravings of these foods when people are in the early stages of their transition.  As Dr. Doug Lisle and Dr. Alan Goldhamer explain in their book “The Pleasure Trap”, people will essentially feel withdrawal symptoms soon after they begin following a WFPB diet.  This period of withdrawal can last up to a few months, but once conquered, I expect food cravings for calorically concentrated foods (fat/salt, fat/sugar) to diminish.  This is probably true for medium – tasters.  But perhaps it’s not so simple for super-tasters and non-tasters.

 As a dietitian, having the knowledge of the different PROP taster statuses can help me to identify potential super-tasters and non-tasters and make sure that: 

  •  Super-tasters, who are not food adventurers, learn the importance of using herbs and spices rather than salt to hide bitter flavors in vegetables.
  • Non-tasters learn the importance of herbs and spices to flavor food to replace sugar and fat.

 Some super-tasters and non-tasters may wonder why they seem to crave foods that WFPB family members and friends don’t seem to crave. Knowing that the answer may lie in their genetically predetermined taste sensitivity could  alleviate any perceived guilt or sense of failure.

 It’s important to remember that science supports a WFPB diet as ideal for human health.  Individual variability will require tweaks  to a WFPB diet so that it satisfies the specific needs and desires of  the individual.  Individual variability does NOT require  the abandonment of a WFPB diet.

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