In medical school I learnt that we have four senses of taste: sweet, sour, salty, and bitter.
Several years ago a fifth sense, umami, was officially added to this list. Umami is stimulated by glutamate (as in MSG) and apparently allows us to taste protein (as in meat, sea food, or cheese).
Now, Jessica Stewart and colleagues from Deakin University in Australia show that a sixth sense, i.e. the ability to orally “sense” the fat content of foods may explain differences in fat preferences (British Journal of Nutrition).
Indeed, previous studies in animals have suggested that oral hypersensitivity to fatty acids (the building blocks of fat) are associated with decreased fat intake and body weight.
In the current study, the investigators first examined the taste thresholds for different types of fatty acids (olate, linolate, and laurate) in 31 normal weight subjects and classified them as hypo- or hypersensitive. Subjects also completed a fat ranking task using custard containing varying amounts (0, 2, 6 and 10 %) of fat.
Hypersensitive subjects reported lower energy and fat intakes, had an increased ability to rank the custards based on fat content and also had a lower BMI levels.
These data suggest that the increased ability to detect nutritional fat may result in lower energy and fat intake, which in turn may result in lower body weights.
Obviously, the idea here is that people who are less sensitive to fat are likely to need more fat in their foods to get that same level of enjoyment as people with more sensitive fat receptors. Because of fat’s high caloric content, this means that they may in the end also end up with more calories, and thus, weight gain.
I can think of a number of interesting questions that these findings may prompt:
1) Is the increased ability to taste fat genetic or are changes in fat-sensitivity determined by habitual fat intake (gustatory plasticity)?
2) Does weight loss affect people’s ability to taste fat (resulting in them searching out fattier foods when on a diet)?
3) Does going on a low fat-diet increase fat sensitivity thereby allowing people to get the same pleasure out of low-fat foods?
4) Can we develop artificial compounds that can stimulate the fat receptors thereby mimicking a higher fat content of foods (like we do with artificial sweeteners)?
Lots of interesting questions, which may not only explain why some people derive more pleasure from fatty foods than others but also open new possibilities for the food industry to manipulate the taste of foods (hopefully to our benefit).
I’d love to hear from my readers regarding their thoughts on “tasting” fat.
AMS
Edmonton, Alberta
In The News
March 9th, 2010 at 7:23 am
Very nice observations Doc.Tasting fat is all in your mind, I think. Most of us just love to eat and for any good reason also. If we only knew what all these “good tasting” foods where doing to our inside’s it think many of us would eat “smarter?”
Eating for the right reasons is so important.
Having a junk food day, eating what you want, when you want will turn your stomach upside down. Doing this will make you ask what should you do.
Learning about foods and reading from experts like you is worth it’s weight in gold for your life.
Thank you for being there for us all.
Pierre William Trudel
March 9th, 2010 at 7:46 am
Rereading my own post, I would like to amend the last statement. It is of course not that people with lower fat sensitivity derive more pleasure from fat - it is just that they probably need fattier foods to perceive the same pleasure as people who are more sensitive to fat.
The study does not actually examine or talk about the reward or pleasure of eating fat - that is a different topic altogether.
AMS
March 9th, 2010 at 8:21 am
A personal comment on “gustatory plasticity”:
I have gradually switched from cream in my coffee to milk, to 2%, to skim milk.
Cream in coffee now seems oily to me - yuck.
I think fat is like sugar and salt - you get used to high levels - very gustatorially plastic.
March 9th, 2010 at 10:10 am
I believe fat preference is acquired. There is a great deal of research (especially with children) that suggests people tend to prefer the foods they are most exposed to. I would be willing to hypothesize that changing one’s dieting would change one’s food preferences as well (how much? Not sure, but it would certainly be interesting to find out).
March 9th, 2010 at 5:35 pm
I went on a very-low-fat diet in 1991 and stayed on it for years. I lost 40 pounds “effortlessly”, was 21, in good shape and basically felt fine on it. I’m not sure I stopped liking the taste of fatty foods, like good cheese or olives or chocolate, but I certainly adjusted to the taste of low-fat foods, and high-fat foods made me feel noticeably heavy. I remember going on a 3-day backpacking trip where I ate a lot of oatmeal, dried fruit, dried beans, and then stopping at a fast food place. I had a regular cup of chili - beef and cheese, but nothing ridiculous - and had to upchuck an hour later.
March 9th, 2010 at 8:07 pm
This read is really interesting to me. After looking at thousands of diets over the years I can truly say the one nutrient that is never below recommended levels is fat. Fats are very satisfying and satiate hunger effectively, which is why low fat diets are difficult to stick to. I believe we will learn much more about this sixth sense in the coming years, and I truly hope that fast food and processed food companies will require a greater degree of accountability as to their ingredients, particularly the crowd pleasing fat.
March 11th, 2010 at 7:43 am
[...] interesting questions brought up by Dr. Sharma’s musings** on these findings: 1) Is the increased ability to taste fat genetic or are changes in [...]
June 21st, 2010 at 6:27 am
I went on a low fat diet once, and after a few days the slimy slithery quality of fatty foods was repulsive and used that experience to give up milk in tea and give up chips (fries) pretty much permanently. I eat chips very rarely now. But I am back onto a normal fat diet.
I tried those pills that stop you digesting all the fat. The best things about them is realising just how much fat you do eat. So they can help you change your regular diet. It helped me anyway.