Did you know that your sense of taste can actually affect your health, food choices, and your lifespan?
The Story of the Fly
A recent article reported on findings on this subject from researchers from the University of Michigan, Wayne State University, and Friedrich Miescher Institute for Biomedical research in Switzerland in a study involving flies. The researchers found that by suppressing the little critters’ ability to taste its food, regardless of how much it ate, had an effect on their lifespan. Survival was negatively related to the flies’ ability to distinguish bitter taste, whereas, sweet perception was beneficial. Interestingly, they found that flies that couldn’t taste water lived up to 43% longer than other flies.
How did researchers come up with these conclusions? They manipulated the Drosophilia melanogaster (fruit flies) gustatory system and looked at how different taste sensors altered their bug subjects’ metabolic processes. This lack of water sensor was found to increase a hormone that promoted survival. The researchers felt these results suggested that sensory perception can alter physiological adjustments. In other words, the fruit flies may have made up for the apparent lack of nutrients by boosting a feedback mechanism in hormone signaling to make the water-haters survive.
Hence, the addition of the role of taste combines with the continual saga that also started with the fly– the effect of caloric restriction on lifespan. The belief: lifespan will be extended due to exercising metabolic compensation by eating less.
Now a Major Caveat to Consider:
The above study reminded me what I learned from my training with the Institute for Functional Medicine, specifically with a highlight on Dr. Stone’s presentation and how it translates to Homo sapiens (humans).
The Story of Humans: How Smell and Taste Differs Among Humans & Why It’s Important
Why don’t you eat that rotten tomato? You may have learned the hard way through experience or your genetic history spared you the disgust.
A 2010 study demonstrated that our sensory systems of taste and smell are vital to determine if a food is harmful or helpful. Furthermore, they report that everyone differs in their ability to determine good verses bad in regard to taste preference. Specifically, genetic variants in taste perception in individuals could determine if one likes bitter foods or sugary treats. The abstract reads:
Genetic studies in humans and experimental animals strongly suggest that the liking of sugar and fat is influenced by genotype; likewise, the abilities to detect bitterness and the malodors of rotting food are highly variable among individuals. Understanding the exact genes and genetic differences that affect food intake may provide important clues in obesity treatment by allowing caregivers to tailor dietary recommendations to the chemosensory landscape of each person.
Geek Out Alert: More on SNPs and the Sense of Taste
How cool is this article above? Those who like sweet may have a variant in the gene T1R1-3 hanging out on their tongues. Similar SNPs (single nucleotide polymorphism) on your tongue can determine one’s liking of the other taste qualities of bitter, salty, umami, sour, and fat. Furthermore, a taste receptor sensitive to calcium (Tas1r3) has been found in mice and there is a possibility that the same receptor is in humans.
Translation to my clients: Don’t like bitters such as green leafy veggies? Your poor liver may need some help and we may have to work with your sense of taste to find ways to get them into your diet and modulate those taste receptors.
Click here to read how the food industry is trumping our taste buds and how you can stop the insult!
If You Have a Change in Smell or Taste, You May Have a Deficiency in Nutrients
What about if you have an aversion to various foods that you know would be beneficial to your body that grows over time? It could be your body doesn’t have what it needs to digest that food. Nutrients that should be considered with an alteration of smell or taste include: Vitamin A, Niacin, Riboflavin, Pyridoxine, Pantothenic acid, Folic acid, Vitamin E, copper, iodine, iron, and zinc.
Furthermore, these nutrient deficiencies could alter your appetite, further decreasing the very foods you need to build back up your health!
For example, I see this with a lot of my clients who have lost the taste for meat. They “just don’t like it anymore.” To me, this could signal a zinc or a mineral deficiency that is needed to form the stomach enzyme, hydrochloric acid (HCL). HCL functions in the breakdown of protein in the stomach.
Back to the Fly
If we bring this back to the fly comparison, it would make sense. If the body doesn’t have the ability to break down protein, why would it want to eat it? Still, protein is needed for healing, hormone synthesis, and brain health.
You Gotta Symptom-You Need Nutrients to Heal, But Which Ones?
Unless you live in a perfectly non-toxic environment, serene, non-stressed-out state, eat all organic and pure foods, drink pure water, have emotional support, healthy relationships, and financial security, your body is up against a lot and needs support.
You either need support to cleanse or build back up the body. Which supplements do you need to use to do this?
With my clients, I correlate their symptoms and history and review their medications, which can cause deficiencies, to determine what nutrients they may be lacking. I also consider the foods that they are overeating that can create deficiencies. Sugar is a main culprit.
Common examples of medications that rob the body of vitamins and minerals include diuretics (water pills), blood pressure medications, blood sugar lowering drugs, acid blockers, birth control pills, and hormone medications. Dr. Carla Hass has a wonderful book on this, and I have a fancy nutrient-drug interaction program I can look at when my clients list their medications at our first consultation.
Blood Sugar, Medication, and Loss of Sensation Linked to Nutrient Deficiency
Here’s an example of the triad of a condition (high blood sugar), a medication adding to the deficiency (metformin) relating to a symptom, and the symptom (peripheral neuropathy).
70% of diabetics have some smell and taste dysfunction and have a higher rate of peripheral neuropathy (loss of sensation in the hands and feet). They may crave lots of sugar and cut down on good, quality meat protein, the highest foods in vitamin B12. This person may then be prescribed the drug Glucophage (Metformin).Metformin depletes vitamin B12. To complete the circle, low B12 is related to peripheral neuropathy.
What to Do- Test
In this example, if someone is on Metformin, has a diminished sense of taste or smell, and is diabetic, it’s important to evaluate B12 status. Even if nerve sensation is intact, it could prevent an issue down the road. A conventional lab test of blood cell indices can signify a B12 or folic acid deficiency. For example, the mean corpuscular volume (MCV) of red blood cell indices panel may be elevated. This is not specific, however, as other things such as hypothyroidism can also affect MCV values.
Therefore, methylmalonic acid (MMA) and holotranscobalamin II (holo-TC) are better functional markers for B12 status. MMA is more readily available and if elevated, it suggests a B12 deficiency. This is because it is converted to succinic acid via an active-B12 dependent enzyme. Homocysteine levels and health history, such as a vegan diet history and environmental exposure, can also be considered. To discover more information on B12, check out this article by Chris Kresser. He goes into good detail in how to determine a deficiency and other symptoms that occur when someone is lacking B12.
Putting It All Together
1. Taste and smell are related to our ability to choose between helpful and harmful foods.
2. We have genetic variances in our taste receptors which can predispose some people to crave more of certain foods and dislike others.
3. Nutrient deficiencies can cause diminished taste and medications, stress, and dietary restrictions can further contribute to the same nutrient deficiencies. This perpetuates diminished taste and can cause many symptoms.
4. Other factors such as oral health (mercury, metal, and gum inflammation) also have an effect on taste.
5. The food industry may be profiting by manipulating our taste, making us crave more food. Read more here.
Citrus Oil Benefits
The benefits of therapeutic citrus essential oils include: mood enhancement, acting as a non-toxic cleaner, deodorizer, and vegetable/fruit cleanser.
M. J. Waterson, B. Y. Chung, Z. M. Harvanek, I. Ostojic, J. Alcedo, S. D. Pletcher. Water sensor ppk28 modulates Drosophila lifespan and physiology through AKH signaling. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1315461111
University of Michigan Health System. Taste test: Could sense of taste affect length of life? ScienceDaily. Accessed May 22, 2014.
Reed DR, Knaapila A: Genetics of Taste and Smell: Poisons and Pleasures. ProgMol Biol Trans Sci: 2010:94:213?40
Reed, D, Tanaka, T, McDaniela, A. Diverse Tastes: Genetics of Sweet and Bitter Perception. Physiol Behav. Jun 30, 2006; 88(3): 215–226. doi: 10.1016/j.physbeh.2006.05.033
Saxena, S, Houstan, M, Stone, D. Institute for Functional Medicine: Cardiometabolic Advanced Practice Module. 2014.
Images courtesy of istockphotos: istockphoto.com