Why is fat so tasty?
Most animals, including humans, prefer high-fat food to low-fat food. Fatty foods are very palatable though the fatty acids, which make these foods fatty, are tasteless. On the other hand, sweet, sour, salty, or bitter foods are recognized by the corresponding receptors of the taste buds. The receptors then send information to the brain areas responsible for positive or negative sensations called hedonic or aversive. But how the tasteless fatty acids manage to make fatty foods so tasty?
Recently, it was suggested that long-chain fatty acids attaching to their specific transporter in the tongue. These long-chain fatty acids are recognized on the tongue, and then neuropeptides and neurotransmitters such as the famous “reward chemical” beta-endorphin is released in the brain.
Source: J Nutr Sci Vitaminol (Tokyo). 2007 Feb;53(1):1-4.
Message: Avoid meals that are high in both fats and carbs
Most animals, including humans, prefer high-fat food to low-fat food. Fatty foods are very palatable though the fatty acids, which make these foods fatty, are tasteless. On the other hand, sweet, sour, salty, or bitter foods are recognized by the corresponding receptors of the taste buds. The receptors then send information to the brain areas responsible for positive or negative sensations called hedonic or aversive. But how the tasteless fatty acids manage to make fatty foods so tasty?
Recently, it was suggested that long-chain fatty acids can attache to their specific spots on the tongue and be recognized by specific transporters; the brain receives the signal and releases (along with many neuropeptides and neurotransmitters) the famous “reward chemical” beta-endorphin (1)
Another story is, what metabolic consequences these process have comparing with well known effects of the sweet taste of carbohydrates. Turns out that without carbs, fat fails to be fattening. This is exactly what happens on the ketogenic diet having well known neuro-protective and metabo-protective effects (2).
Sources
- J Nutr Sci Vitaminol (Tokyo). 2007 Feb;53(1):1-4.
- Frontiers in Neuroenergetics, 2011, 3:8.
It has been suggested that nutrition may play a role in age-related hearing loss and that it may be associated with poor micronutrient status. For example, Vitamin B-12 or folate deficiencies may negatively influence blood flow to the cochlea, leading to age-related hearing loss. Australian researchers showed that people with hearing loss were more likely to be exposed to workplace noise, be a current smoker, have a doctor-diagnosed history of stroke or type 2 diabetes, and to have Vitamin B-12 (1).
In Finland, two groups of 40-59-year olds were studied, 1) one on a diet high in saturated animal fats, 2) the other on a diet high in polyunsaturated fats. After 5 years of follow up, blood vessel condition was better in the group 2 and the participants hearing ability was also significantly better in all frequencies. After that, the diets in the two groups were reversed. Four years after the diet reversal the hearing in the now low-fat group was improved and the hearing in the now high-fat group was deteriorating. The authors concluded that a diet high in polyunsaturated fats may stop, if not reverse, hearing loss (2).
In a recent Dutch study, 720 participants 50–70 years of age without hearing loss were tested for levels of polyunsaturated fats, very long-chain n-3 PUFA in their plasma. In high sound frequencies, there was no correlation of hearing acuity and PUFA concentrations in plasma. However, in the low frequencies, the higher PUFA levels corresponded to better hearing abilities. The authors found their results “encouraging, but requirig confirmation from future studies.” (3)
Serum Homocysteine and Folate Concentrations Are Associated with Prevalent Age-Related Hearing Loss. Journal of Nutrition, Vol. 140, No. 8, 1469-1474, Aug, 2010
DIETARY PREVENTION OF HEARING LOSS. Acta Otolaryng 70: 242-247, 1970
PLASMA VERY LONG-CHAIN N-3 POLYUNSATURATED FATTY ACIDS AND AGE-RELATED HEARING LOSS IN OLDER ADULTS. THE JOURNAL OF NUTRITION, HEALTH & AGING Volume 14, Number 5, 347-351, 200
It has been suggested that nutrition may play a role in age-related hearing loss and that it may be associated with poor micronutrient status. For example, Vitamin B-12 or folate deficiencies may negatively influence blood flow to the cochlea, leading to age-related hearing loss. Australian researchers showed that people with hearing loss were more likely to be exposed to workplace noise, be a current smoker, have a doctor-diagnosed history of stroke or type 2 diabetes, and to have Vitamin B-12 (1).
In Finland, two groups of 40-59-year olds were studied, 1) one on a diet high in saturated animal fats, 2) the other on a diet high in polyunsaturated fats. After 5 years of follow up, blood vessel condition was better in the group 2 and the participants hearing ability was also significantly better in all frequencies. After that, the diets in the two groups were reversed. Four years after the diet reversal the hearing in the now low-fat group was improved and the hearing in the now high-fat group was deteriorating. The authors concluded that a diet high in polyunsaturated fats may stop, if not reverse, hearing loss (2).
In a recent Dutch study, 720 participants 50–70 years of age without hearing loss were tested for levels of polyunsaturated fats, very long-chain n-3 PUFA in their plasma. In high sound frequencies, there was no correlation of hearing acuity and PUFA concentrations in plasma. However, in the low frequencies, the higher PUFA levels corresponded to better hearing abilities. The authors found their results “encouraging, but requirig confirmation from future studies.” (3)
- Serum Homocysteine and Folate Concentrations Are Associated with Prevalent Age-Related Hearing Loss. Journal of Nutrition, Vol. 140, No. 8, 1469-1474, Aug, 2010
- DIETARY PREVENTION OF HEARING LOSS. Acta Otolaryng 70: 242-247, 1970
- PLASMA VERY LONG-CHAIN N-3 POLYUNSATURATED FATTY ACIDS AND AGE-RELATED HEARING LOSS IN OLDER ADULTS. THE JOURNAL OF NUTRITION, HEALTH & AGING Volume 14, Number 5, 347-351, 200
Neuroscientist Daeyeol Lee of Yale University registered activity of single neurons in the human volunteers’ brain (amygdala) while images of junk food were presented. About 31 % of all registered neurons were increasing their activity in a predictable way as the individual value of a food increased though there were other neurons in the same region, which activity declined as the value of a food increased (J Neuroscience, January 5 , 2011).
Interestingly, the amygdala is a region that is traditionally associated with memory of emotions, mostly fear and aversive reactions including immobility, tachycardia, increased respiration, and stress-hormone release (“Cytoarchitectonic mapping of the human amygdala, hippocampal region and entorhinal cortex: intersubject variability and probability maps”. Anat Embryol (2005) 210 (5-6): 343–52). However, it’s been shown to participate in the process of Pavlovian conditioning with food as a positive reinforcement (Nature 2005, 439 (7078): 865–870)
