6.4) Food Taste and Preference

Our genetics can influence our preference for certain foods and our ability to taste foods. Food and taste preferences are encoded in our genetic makeup. By finding out which tastes and preferences you are predisposed to, you can better understand why you are attracted to certain foods and make better decisions about your diet that are suited for your genetic type.

This section includes:

  • Preference to consume normal amounts of caffeine.
  • Preference for carbohydrates, proteins and fats.
  • Ability to taste bitter, salty and sweet foods.
  • Ability to respond normally to nicotine.

A variation in any of the above tests might make it more or less likely for you to consume a specific type of food. By being aware of possible eating patterns, you can be more proactive in weight management, disease prevention and greater overall health and energy.  If you have a predisposition to crave sweet foods, avoid them or eat healthier options such as fruit. If you are unable to detect certain flavors, use that knowledge to ensure you do not unknowingly consume them in excess.

6.4.1 Caffeine Preference

Your preference to consume a normal amount of caffeine

Caffeine is a stimulant present in coffee, some teas, carbonated beverages and energy drinks. Caffeine is metabolized in the liver. The resulting metabolites travel to other organs, affecting their function. For example, caffeine metabolites bind to receptors in the brain, causing arousal and interaction with neurotransmitters. This leads to caffeine’s signature effect of warding off drowsiness and increasing alertness.

Individuals with variations in this panel are likely to consume more caffeine per day than those who do not have variations in this panel. Research into caffeine’s impact on long-term health has provided both positive and negative results. These include an increased risk of bladder cancer with excessive coffee consumption (> 5 cups/day), and a decreased overall risk of cancer, cardiovascular disease, and type 2 diabetes with moderate consumption (2 cups/day).

Short term negative effects include dehydration, diarrhea, hypertension, sleep and anxiety disorders. Short term positive effects include improved cognitive function.

Regardless of your genetic type, consuming more than 400mg of caffeine a day can have detrimental side effects. 

If you have variations in this panel, you may want to consider the following to improve your health:

  • Be conscious about the amount of caffeine you are consuming in a day.
  • Try coffee alternatives such a green tea, black tea or matcha.

Some examples of genes that have been associated with caffeine consumption are:

AHR: Is involved in the detection of xenobiotics found in roasted coffee and the regulation of caffeine metabolism. Variation is associated with habitual caffeine consumption.

CYP1A1: Involved in the metabolic activation of aromatic hydrocarbons.

6.4.2 Carbohydrate Preference

Your preference to consume a normal amount of carbohydrates

Carbohydrates are an essential part of our diet. Variations in this gene panel may be associated with increased intake of dietary carbohydrates, which can lead to an increased tendency to gain weight, particularly abdominal fat, and lower success rates with weight loss regimens. Genetic variations have been associated with both higher body composition and macronutrient intake, suggesting that it may influence eating behavior. It was also associated with increased energy intake from carbohydrates, mainly because of a higher consumption of mono and disaccharides and a higher glycemic load in the diet.

If you have variations in this panel, you may want to consider the following to improve your health:

  • Monitor your carbohydrate intake to ensure you are not overconsuming.
  • Increase strength activity to better metabolize carbohydrates, help regulate blood sugar levels, and reduce the risk of diabetes.

An example of a gene that has been associated with carbohydrate preference is:

TUB: Encodes a protein highly expressed in the hypothalamus. Linked to increased BMI, obesity, insulin-resistance and neurosensory deficits. Also associated with glycemic load, total macronutrient and carbohydrate intake.

6.4.3 Fat Preference

Your preference to consume a normal amount of fats

Variations in this gene panel may be associated with increased snacking and intake of dietary fats including total fat, saturated fat, and monounsaturated fat. This can lead to an increased tendency to gain weight, particularly abdominal fat, and lower success rates with weight loss regimens. Variations can cause an increased drive to eat, resistance to the effects of circulating insulin and weight gain from a young age. It is associated with regulation of weight and could be important for weight problems and diabetes.

If you have variations in this panel, you may want to consider the following to improve your health:

  • Monitor your fat intake.
  • Watch your tendency for snacking and what foods you select.
  • Consult a health care professional to help develop a health program right for you, especially if you are experiencing weight problems.

Some examples of genes that have been associated with fat consumption are:

ADRB3: Breaks down stored fats for energy consumption. Dissipates excess energy through heat production in adipose tissue, where the majority of body fat is stored. Variation is associated with onset of type 2 diabetes, visceral fat accumulation, insulin resistance, increased energy intake and preference for protein and fat.

SH2B1: Expressed particularly in the hypothalamus, a crucial center for energy balance and regulation of food intake. Variations can disrupt hormonal signaling and are associated with obesity, increased snacking and fat intake. This variation is also associated with type 2 diabetes independently of BMI.

6.4.4 Protein Preference

Your preference to consume a normal amount of protein

Variations in this gene panel may be associated with increased intake of dietary protein, an increased tendency to gain weight, and lower success rates with weight loss regimens. People with variations show a high energy intake and preferences for proteins and lipids including fatty acids and cholesterol, they eat more fish and meat.

If you have variations in this panel, you may want to consider the following to improve your health:

  • Monitor your protein intake.
  • If you are trying to increase muscle growth and repair, consider proteins such as lean beef, skinless chicken, fish, cottage cheese, protein powders, tofu, dark leafy greens, legumes, nuts and seeds.
  • If you are trying to lose weight decrease your animal protein consumption, or be conscious of choosing only recommended, healthy protein sources. Increase vegetarian protein consumption.

An example of a gene that has been associated with protein preference is:

ADRB3: Breaks down stored fats for energy consumption. Dissipates excess energy through heat production in adipose tissue, where the majority of body fat is stored. Variation is associated with onset of type 2 diabetes, visceral fat accumulation, insulin resistance, increased energy intake and preference for protein and fat.

6.4.5 Bitter Taste

Your ability to taste bitter flavors and foods

People have varied abilities to perceive the bitter taste of both 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC) present in foods such as dark beer, coffee, dark chocolate, cabbage and broccoli. The genes in this panel facilitate signals to the bitter taste receptors.

Variations in these genes contribute to decreased sensitivity to bitter-tasting foods and drinks. Studies indicate that variations may also lead to decreased sensitivity to compounds in tobacco. If you are unable to detect certain flavors you may be more likely to unknowingly consume them in excess or to not be as interested in them.

If you have variations in this panel, you may want to consider the following to improve your health:

  • Monitor your intake of bitter foods such as bitter chocolate, dark beer and salts as you may be inclined to eat more to satisfy cravings.
  • Avoid smoking, as you may not be as sensitive to the taste which could contribute to excessive smoking and addiction.

An example of a gene that has been associated with bitter taste is:

TAS2R38: Facilitates sensitivity to bitter taste through 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC).

6.4.6 Salt Taste

Your ability to taste salt and salty foods

Table salt, made up of sodium and chloride, is found in high quantities in pre-packaged and fast foods. We respond favorably to its taste and it is useful in the preservation of food. However, an increased intake of sodium can lead to high blood pressure which has many negative health effects.

Taste is one of the primary determinants of food intake. Variation in an individual’s ability to taste salt might partially explain the variation observed in sodium intake.

Salty taste is unique in that increasing salt concentration transforms an appetitive stimulus into a powerfully aversive one. If you ingest too much salt, your body recruits the sour and bitter aversive taste sensors, thus preventing its potentially detrimental effects on health.

If you have variations in this panel, you may want to consider the following to improve your health:

  • Moderate your salt intake if you have high blood pressure. 
  • Rather than adding salt, introduce alternative flavoring techniques and fresh ingredients.
  • Avoid processed foods, which tend to be high in salt.
  • Exercise regularly to decrease the effect that sodium has on blood pressure.

Some examples of genes that have been associated with ability to taste salt are:

SCNN1B: Plays an essential role in electrolyte and blood pressure homeostasis, but also in airway surface liquid homeostasis, which is important for proper clearance of mucus. It controls the reabsorption of sodium in kidney, colon, lung and sweat glands. Also plays a role in taste perception.

TRPV1: Activated by a wide variety of physical and chemical stimuli. Best known for providing detection and regulation of body temperature, as well as a sensation of scalding heat and pain. Variations play a role in a person’s ability to taste salt.

6.4.7 Sweet Taste

Your ability to taste sweet flavors and foods

Sweet taste sensitivity is facilitated by taste receptors found in the taste buds, situated near the back of the tongue and the roof of the mouth. When we eat and drink, these receptors initiate a cascade of signaling reactions in the body’s cells. The message is relayed to the hypothalamus of the brain, where sweet taste is recognized, and cellular responses are activated.

The receptors recognize natural sugars more easily than artificial substitutes.

Variations in these genes can result in impacts on taste receptors that may decrease your ability to taste sweetness. This can lead to an increase in sugar consumption to satisfy a sugar craving or lack of interest in sweet foods as they are less rewarding.

If you have a mutation in this panel, you may want to consider the following to improve your health:

  • Be aware of your consumption of sweet foods and desserts as you may be inclined to eat more to satisfy sweet cravings.

An example of a gene that has been associated with sweet taste is:

TAS1R2: Facilitates the ability to taste sugars.

6.4.8 Smoking Behaviour

Your ability to respond normally to nicotine

Smoking is a risk factor for most of the diseases that lead in human mortality rates. Smoking behaviour and nicotine dependence are influenced by genetics. While environmental factors play a strong role in the initiation of smoking, the heritability of smoking persistence, smoking quantity and nicotine dependence is high in most twin studies. Variations within these genes are associated with the smoking initiation, number of cigarettes smoked per day, nicotine dependence, and smoking-related diseases such as lung cancer, peripheral arterial disease, and chronic obstructive pulmonary disease.

If you have variations in this panel, you may want to consider the following to improve your health:

  • If you don’t smoke, don’t start. You are at higher risk of dependence and addiction.
  • If you do smoke, make every effort to quit or reduce smoking to preserve your health.
  • Contact your health care provider if you need assistance in quitting smoking.

Some examples of genes that have been associated with response to nicotine are:

BDNF: Expressed at high levels in the prefrontal cortex and hippocampus, which are brain regions implicated in the cognitive-enhancing effects of nicotine. Genetic variation could alter the reward effects of nicotine through modulation of dopamine reward circuits and could contribute to nicotine’s effects to promote continued use after initial exposure.

CHRNA3: Is a nicotinic acetylcholine receptor, a neuron receptor protein that responds to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs that mimic nicotine. They are found in the central nervous system of humans, and also play important roles in the peripheral nervous system.