Do taste buds become less sensitive as you get older?

Question

I've heard it explained that your taste buds become duller as you get older and that is why I can now eat things like carrots and mushrooms that I used to think tasted like garbage.

Is it true that as you get older your taste buds become duller?

Answer 1

The earliest results I've found is from The Effect Of Age On Taste Sensitivity from 1959:

Over-all taste sensitivity. Figure 1 summarizes the course of development and decline of over-all taste sensitivity (mean of 4 taste thresholds expressed in standard scores). [..]

The abstract in Taste Perception with Age: Generic or Specific Losses in Threshold Sensitivity to the Five Basic Tastes? from 2001:

Detection thresholds for NaCl, KCl, sucrose, aspartame, acetic acid, citric acid, caffeine, quinine HCl, monosodium glutamate (MSG) and inosine 5′-monophosphate (IMP) were assessed in 21 young (19–33 years) and 21 elderly (60–75 years) persons by taking the average of six ascending two-alternative forced choice tests. A significant overall effect was found for age, but not for gender. However, an interaction effect of age and gender was found. The older men were less sensitive than the young men and women for acetic acid, sucrose, citric acid, sodium and potassium chloride and IMP. To detect the compound dissolved in water they needed a 1.32 (aspartame) to 5.70 times (IMP) higher concentration than the younger subjects. A significant decline in thresholds with replication was shown. The age effect found could be attributed predominantly to a generic taste loss.

The results in Influences of Aging on Taste Perception and Oral Somatic Sensation goes on to investigate what it is that has changed:

Significant age-associated deterioration was observed in taste but not somatic sensations such as touch and burning pain in the tongue, showing that aging affects taste perception and oral somatic sensations differently. This suggests that decreased taste perception of foods in elderly people may be caused primarily by perceptual loss of taste among oral sensations.

Substance and tongue-region specific loss in basic taste-quality identification in elderly adults from 2007 has nice summary in the introduction, but I don't have access to the journal so I can't add or look at the references for the claims:

It is well documented that a decrease in taste function typically accompanies normal aging. (for review see [4]), which may partly be attributed to reduction in the density of taste buds [5] and papillae.

This seem to suggest that our perception of taste signals degrade with age, but that our taste buds don't lose sensitivity (unless I'm misinterpreting the meaning of "somatic") we do however lose the amount of them we have with time. So the answer to your question is no our taste buds don't become less sensitive (as far as I can tell), but they might as well have from the perspective of the elderly.

Answer 2

From Care 2

Like all the other cells in the body, those special sensory cells that make up the taste buds eventually wear out. As we age, the taste buds begin to disappear from the sides and roof of the mouth, leaving taste buds mostly on our tongue. The remaining taste buds eventually become less sensitive. Smoking and eating scalding liquids can damage them further. Our sense of smell also decreases as we get older, and smell and taste are intimately linked.

Another article even goes deeper on the matter Phil Lempert :

As we become adults our sense of taste remains at roughly the same level, although our taste buds do get abuse - especially from smoking or scalding the tongue with hot beverages that dulls them.

It is true that some people are born with poor senses of taste or smell, but most lose them after an injury or illness. Loss of the sense of smell can result from polyps in the nasal cavities, sinus infections, hormonal disturbances, or dental problems. Loss of smell and taste also can be caused by exposure to certain chemicals such as insecticides or pesticides and by some medicines.

Scientists also tell us that as we get older, the olfactory bulb in the brain responsible for processing smell becomes smaller. In addition, the patch of receptors in our nose that sends information to the brain begins to thin and spread out, and may be less effective at capturing scents.

Getting older means that smells become more blunt and difficult to distinguish. As a result, our ability to taste food diminishes. As we said before, we are really only able to distinguish four tastes- salty, sweet, sour and bitter. The sense of smell enhances taste and provides those thousands of nuances that help us identify a flavor. As these senses diminish, food tastes blander.

Medical professionals remind us that some common illnesses like allergies and nasal infections as well as some diseases can effect tast.

The site MedLine Plus has very interesting informationon taste buds and aging (source)

The number of taste buds decreases beginning at about age 40 to 50 in women and at 50 to 60 in men. Each remaining taste bud also begins to atrophy (lose mass). The sensitivity to the four taste sensations does not seem to decrease until after age 60, if at all. If taste sensation is lost, usually salty and sweet tastes are lost first, with bitter and sour tastes lasting slightly longer.

The sense of smell may diminish, especially after age 70. This may be related to loss of nerve endings in the nose.

Studies about the cause of decreased sense of taste and smell with aging have conflicting results. Some studies have indicated that normal aging by itself produces very little change in taste and smell. Rather, changes may be related to diseases, smoking, and environmental exposures over a lifetime.