Preference for Fatty Foods: The Genetic Influence

The Flavorful Role of Fat

Unraveling the science behind the preference for fatty foods.

For a long time, taste has been classified into five basic categories: sweet, sour, salty, bitter, and umami.

Fat was traditionally not considered a flavor in this model because it doesn’t have a unique taste that we can perceive on its own.

Instead, fat was known to enhance other flavors by carrying fat-soluble compounds that contribute to aroma and taste, and by providing texture and mouthfeel.

However, recent research suggests that fat could be considered a sixth taste known as ‘oleogustus.’ The term oleogustus comes from the Latin “oleo” (for oily or fatty) and “gustus” (for taste).

This is based on the finding that our tongues may have specific receptors that can detect fatty acids, the building blocks of fat.

A study published in the journal “Chemical Senses” in 2015 found that people can identify fatty acids as a distinct taste sensation separate from the other five basic tastes.

In this study, participants could recognize and distinguish varying levels of fatty acids mixed into otherwise tasteless solutions.

However, it’s important to note that the sensation described as oleogustus is not the creamy, rich experience we usually associate with eating fatty foods.

Instead, the taste of pure fat, such as free fatty acids, is often described as bitter or sour.

The pleasant taste experience associated with fat usually comes from how it interacts with other flavors and their texture.

Despite these findings, fat’s status as a distinct taste is still debated among scientists, and more research is needed to fully understand the role of fat as a potential sixth taste.

Why Fat Appeals to our Palate?

Our fondness for fat likely has roots in our evolutionary past. Fat is a dense source of calories, providing more than twice as many calories per gram as protein or carbohydrates.

For our ancient ancestors, foods high in fat were valuable for survival in times of scarcity because they provided sustained energy.

Over time, we’ve evolved to find fatty foods highly palatable, partly because they trigger the release of feel-good chemicals in the brain, such as dopamine.

Evolution’s Role in Fat Consumption

In the context of human evolution, fat consumption has been a critical aspect of survival.

Understanding why this is the case requires us to look back at our early ancestors and their dietary needs.

Our prehistoric ancestors lived in environments where food was often scarce and unpredictable.

In these settings, the ability to consume and store energy efficiently was a significant survival advantage.

Fats, which provide more than twice as many calories per gram as proteins or carbohydrates, were an extremely valuable resource in this respect.

Consuming a diet rich in fats meant that our ancestors could glean a large number of calories from a relatively small amount of food, providing them with the energy needed to survive and reproduce.

The immense health benefits of fats

Beyond their caloric content, fats also played a crucial role in other aspects of human health and development.

Core body temperature

For instance, fats are essential for maintaining the body’s core temperature and protecting vital organs.

Absorption of other nutrients

They also contribute to the structure and function of cell membranes and are necessary for the absorption of fat-soluble vitamins, such as vitamins A, D, E, and K.

Crucially, certain types of fats, known as essential fatty acids, cannot be synthesized by the body and must be obtained through the diet.

Brain Function

These include omega-3 and omega-6 fatty acids, which play critical roles in brain function and development, inflammatory response, and other physiological processes.

Fats also had a role in early human brain development.

The human brain is composed of nearly 60% fat, and specific types of fats, particularly polyunsaturated fatty acids like DHA, are crucial for its development and function.

Early humans eating a diet rich in these types of fats could have supported larger, more complex brains.

Section Summary

Therefore, the consumption of fats was not only a matter of survival for our ancestors but also contributed to the physical and cognitive development that characterizes our species. These evolutionary pressures likely shaped our physiological responses to fat, including our ability to efficiently store excess energy as body fat and our perception of fatty foods as being highly palatable.

Genetic Factors in Fat Preference

Our genetic makeup plays a crucial role in determining our individual food preferences, including our inclination toward fatty foods.

This predisposition can be traced to specific variations in our DNA, particularly in the form of single nucleotide polymorphisms (SNPs), which are individual differences in the genetic code at specific locations on our genes.

Several genes have been linked with a preference for high-fat foods. Here are a few examples:

CD36 Gene

The CD36 gene is responsible for encoding a protein found on the surface of many cell types in the body.

This protein plays a crucial role in fat taste perception by participating in the detection and signaling of dietary fats.

Certain variants of the CD36 gene have been associated with a higher sensitivity to the taste of fat, which in turn could influence a preference for fatty foods.

Check your AncestryDNA, 23andMe raw data for the CD36 gene family variants

FTO Gene

The FTO gene is strongly linked to body mass index (BMI) and obesity.

Variants of the FTO gene have been found to be associated with a preference for high-fat foods and a higher overall energy intake.

However, the exact mechanisms by which FTO influences dietary habits and weight are still under investigation.

Check your AncestryDNA, 23andMe raw data for the FTO gene family variants

MC4R Gene

The Melanocortin 4 Receptor (MC4R) gene is another gene implicated in obesity.

Variants of the MC4R gene are associated with increased hunger and a preference for high-fat foods.

Check your AncestryDNA, 23andMe raw data for the MC4R gene family variants

TAS2R38 Gene

This gene is associated with the perception of bitter taste.

Some research suggests that individuals with certain variations of this gene may have a reduced sensitivity to bitter tastes, which could increase their preference for fatty foods.

Check your AncestryDNA, 23andMe raw data for the TAS2R38 gene family variants

Section Summary

While these genetic influences can predispose an individual towards a preference for fatty foods, it’s important to note that genes are not destiny. Other factors such as our environment, upbringing, cultural influences, and personal experiences with food also play a significant role in shaping our dietary preferences and habits.

Additionally, healthy dietary habits and lifestyle changes can often mitigate genetic risk.

The SNP table with risk alleles of genetic variants influencing fat preference

Gene	SNP ID	Risk Allele	Effect
CD36	rs1761667	G	Variants may increase sensitivity to fat taste, increasing fat intake
FTO	rs9939609	A	Variants associated with higher BMI and a preference for high-fat foods
MC4R	rs17782313	C	Variants linked to increased hunger and preference for high-fat foods
TAS2R38	rs713598	G	Variants may decrease sensitivity to bitter taste, increasing fat intake

Fat Consumption: Adverse Effects

While dietary fat is an essential part of a healthy diet, consuming too much fat, particularly the wrong types, can have several adverse effects on your health.

These effects largely depend on the type of fat consumed, with saturated and trans fats generally linked to negative health impacts.

Here are a few possible adverse effects of excessive fat consumption:

1. Cardiovascular Disease: High intake of saturated and trans fats can lead to elevated levels of low-density lipoprotein (LDL) cholesterol, commonly referred to as “bad” cholesterol. This can lead to the buildup of plaques in the arteries, a condition known as atherosclerosis, which can increase the risk of heart disease and stroke.
2. Obesity: All fats, regardless of type, are calorie-dense, meaning they provide a high number of calories per gram. Consuming too much fat can contribute to a calorie surplus, which over time can lead to weight gain and obesity.
3. Type 2 Diabetes: Obesity, often resulting from excessive fat and calorie intake, is a significant risk factor for developing type 2 diabetes. Moreover, diets high in trans fats and saturated fats have been linked to an increased risk of type 2 diabetes.
4. Liver Disease: Overconsumption of fat, especially in the form of unhealthy processed foods, can lead to non-alcoholic fatty liver disease (NAFLD). NAFLD is a condition in which excess fat builds up in the liver cells, which can lead to liver damage over time.
5. Certain Types of Cancer: A diet high in fat has been associated with an increased risk of developing certain types of cancer, including breast, colon, and prostate cancer.

To minimize these risks, it’s crucial to maintain a balanced diet.

That includes a moderate amount of fats, focusing on healthier unsaturated fats and omega-3 fatty acids, while limiting saturated and trans fats.

Consuming Fats The Healthy Way

Consuming fats is a necessary part of our diet. Fats provide us with energy, support cell growth, and help protect our organs.

They also assist in nutrient absorption and hormone production.

However, it is essential to choose the right types of fats and consume them in moderation to maintain a balanced diet.

Here are some tips for a healthy approach to consuming fats:

Prioritize Unsaturated Fats

Unsaturated fats, including monounsaturated and polyunsaturated fats, are considered “good” fats.

They can help reduce bad cholesterol levels and provide essential fatty acids that your body needs.

Foods rich in these fats include avocados, nuts, and seeds, fish like salmon and mackerel, and oils such as olive, canola, and flaxseed oil.

Limit Saturated Fats

While not as harmful as trans fats, saturated fats can raise your cholesterol levels if eaten in excess and may increase your risk of heart disease.

These fats are typically found in red meat, full-fat dairy products, and many processed foods.

Avoid Trans Fats

Trans fats are considered the worst type of fat you can eat.

They not only raise your bad (LDL) cholesterol but also lower your good (HDL) cholesterol.

This can increase your risk of cardiovascular disease.

Trans fats are often found in processed foods, baked goods, and fried foods.

Always check food labels to avoid products with “partially hydrogenated oils,” a source of trans fats.

Balance Fat Intake with Total Caloric Need

Even healthy fats are high in calories.

Therefore, it’s crucial to balance fat intake with your total caloric needs.

The dietary guidelines suggest that fats should make up 20-35% of your total daily calorie intake.

Consider Omega-3 Fatty Acids

Omega-3 fatty acids are a type of polyunsaturated fat that is particularly beneficial to heart health.

Foods high in Omega-3 include fatty fish, flaxseeds, chia seeds, and walnuts.

Cooking Methods

Opt for healthier cooking methods that use less fat, such as grilling, baking, steaming, or roasting.

If you are using fat to cook, opt for “good” oils like olive or canola.

Be Mindful of Hidden Fats

Many processed foods, including some labeled as “low fat,” have hidden fats.

Always check the nutritional information on food packaging.

Section Summary

Remember, it’s not just the quantity of fat that matters, but the type of fat you eat.

By replacing unhealthy fats with healthier ones and consuming them in moderation, you can enjoy the benefits of fat without negatively affecting your health.

Takeaways

While fat is not officially recognized as a taste, it significantly influences flavor perception and has been a crucial component of the human diet for evolutionary reasons.

Genetic factors also contribute to our preference for fatty foods. However, excessive consumption of certain types of fats can lead to health issues.

Therefore, it’s important to consume fats mindfully, focusing on unsaturated fats and controlling portion sizes.

References

1. Stewart, J. E., Newman, L. P., & Keast, R. S. (2011). Oral sensitivity to oleic acid is associated with fat intake and body mass index. Clinical Nutrition, 30(6), 838–844. doi:10.1016/j.clnu.2011.06.007
2. Keller, K. L., Liang, L. C., Sakimura, J., May, D., van Belle, C., Breen, C., . . . Chung, W. K. (2012). Common variants in the CD36 gene are associated with oral fat perception, fat preferences, and obesity in African Americans. Obesity, 20(5), 1066–1073. doi:10.1038/oby.2011.374
3. American Heart Association. (2020). Dietary Fats. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/dietary-fats
4. Genetic Home Reference. (2019). FTO gene. U.S. National Library of Medicine. https://ghr.nlm.nih.gov/gene/FTO
5. Stewart, J. E., Feinle-Bisset, C., Golding, M., Delahunty, C., Clifton, P. M., & Keast, R. S. (2010). Oral sensitivity to fatty acids, food consumption and BMI in human subjects. British Journal of Nutrition, 104(1), 145-152.
6. Keller, K. L., Liang, L. C., Sakimura, J., May, D., van Belle, C., Breen, C., . . . Chung, W. K. (2012). Common variants in the CD36 gene are associated with oral fat perception, fat preferences, and obesity in African Americans. Obesity, 20(5), 1066–1073.
7. Qi, L., Kraft, P., Hunter, D. J., & Hu, F. B. (2008). The common obesity variant near MC4R gene is associated with higher intakes of total energy and dietary fat, weight change and diabetes risk in women. Human Molecular Genetics, 17(22), 3502-3508.
8. Hayes, J. E., Feeney, E. L., & Nolden, A. A. (2015). Do polymorphisms in chemosensory genes matter for human ingestive behavior?. Food Quality and Preference, 40, 202-216.