Brown Fat, Fat You Want!
Brown Adipose Tissue (aka BAT) & Beige Fat
I’ve mentioned brown fat in the midst of other topics but never offered it as a topic in and of itself. With the likes of Wim Hof talking of his cold immersions, some people now may have heard of brown fat thanks to his popularity.
Brown fat is fat you want!
White adipose tissue (WAT) or white fat is the fat most of us think about when we hear the word body fat. It is just a storage tank for fuel (and hormones), it is not metabolically active. We easily get too much white fat when we live very comfortable lives, eat sweets or processed foods, and don’t move enough.
Whereas brown fat is metabolically active, it stores even more energy than white fat, yet it gobbles up calories and glucose (sugar) and actually helps with blood sugar regulation. It also helps to burn up your white fat. It is actually brown, because it is packed with iron-rich mitochondria that make it brown.
People who have higher levels of brown fat have lower risk of developing type 2 diabetes, obesity, hypertension, heart failure, and heart disease in general — and have an easier time regulating their weight.
We are born with higher levels of brown fat — infants have about 5% brown fat, stored in a specific place, around our shoulders and neck and upper spine, and some around the kidneys. Over time we seem to lose this, more than we used to, so lifestyles may be a factor.
Brown fat increases thermogenesis — our body making heat without shivering. One of the reasons infants and children have more brown fat is because they have a harder time keeping their bodies warm.
In a 150 lb. individual who is mostly lean with about 20-30 lbs. fat will have only 2-3 ounces of brown fat. But 2 ounces of brown fat can burn 300-500 calories per day! (Yes “they” are working to find a pill to increase brown fat.)
While brown fat we are born with, called constitutive brown fat, can diminish with age (for some more than others), our body can also convert white fat to brown fat under the right circumstances — this is called “the browning of white fat”, and is referred to as “recruitable” fat. This recruitable type of fat is found in muscles and white fat throughout your body.
Then there is beige fat … Beige fat seems to be a third type of fat that is stored in pea sized deposits in adipose tissue around the body. This type of fat is different from brown and white fat, but it is more similar to brown fat in that it can burn calories, however it is not always as active. Some studies report that beige fat is the “recruitable” fat — the fat we convert to brown fat, and other studies list it as a 3rd type of fat.
How do we turn our recruitable fat or beige fat into brown fat??
Cold … Cold seems to be one of the best ways, exposing your body to cool or cold temperatures helps to stimulate the recruitment. How cold and how long? This has been my question for a decade! According to a study in 2015 from Diabetes Journal, exposing yourself to 66o for 2 hours each day stimulated the recruitment of brown fat.
Ref: https://diabetes.diabetesjournals.org/content/diabetes/64/7/2346.full.pdf
According to Wim Hof, 10 minutes of a cold shower or ice bath are adequate to support your production of brown fat.
It seems more recently in history adults have less brown fat than they used to, this could be a result of our comfy lives. In the old days we were not quite so warm and comfy all winter long, and had to do chores outside just for survival that are not necessary today.
Exercising in the cold may be a “warm” way to get your cold exposure, I say warm because you will build heat while exercising which would make the cold less uncomfortable.
Turning down the temperature in your house to around 65o during for periods of the day in the winter could be another strategy. One study I saw had volunteers in a 60o room for 6 hours per day for 10 days, the participants saw a big increase in brown fat and blood sugar control just after 10 days.
I’ve said for many years, something I learned from my yoga teacher -always end your shower cold. Which I do, when I still lived in PA that was a challenge in the winter … it was a quick shot of cold! Living in Maui the water is not as cold and it is easier to maintain a cold shower longer — it’s almost pleasant. Perhaps the water does not need to be sooo cold, if you live in a climate that gets cold you might not have to have the water too far below 66o to get the benefits.
Also a quick jaunt outside barefoot and barely dressed may be helpful too. I used take the short jaunt to the compost bin and back in my barefoot and pajamas all winter long. It’s not as bad as you may think. I learned from a very dear friend many years ago to “let the cold blow through you, don’t try to resist it”, that advice has helped so much. You accept the cold, become 1 with it.
On the flip side, I’d love to find data that sauna and heat exposure could also be a route. There are so many benefits to saunas, I have a hunch it may too help to create brown fat and increase thermogenesis.
Exercise
Beige fat can become more like brown fat in the presence of exercise, our skeletal muscles release a hormone called irisin during exercise, which some say is what converts beige fat to brown fat.
Ref: https://hms.harvard.edu/news/beige-fat-cells-could-help-fight-obesity
Caloric Restriction
A 20% reduction in calories has shown to increase brown fat and reduce white fat. Perhaps pick a season or time of year to reduce your caloric intake for a short period of time, try skipping one meal each day and eating 1-2 meals per day. Spring is a nice time of year to do that. Also time restricted eating might be helpful here, restrict your eating “window” to 6-8 hours per day — and not too close to bed time, so all your food is eaten in that window of time each day.
Interestingly enough, another study showed an increase in brown fat with increased calories, however increased calories day after day will lead to more white fat than brown fat. The increase in brown fat after increasing calories was most likely due to cycling out of caloric restriction and increasing to a normal caloric intake.
And conversely, day after day of restricting calories will leave you gaunt and low energy, its cycling in and out of caloric restriction that is most beneficial. Just like old times when we cycled through periods of feast and famine.
Foods 🙂 There are certain foods that increase brown fat as well
Fruits and herbs can build brown fat if you eat the skin. The natural wax in apple skins (not the applied wax that is sometimes applied in the production cycle) and other fruits is rich in ursolic acid which has been shown to boost brown fat.
Herbs have ursolic acid too! Specifically tulsi, basil, rosemary, lavender, and peppermint, all popular Lamiaceae family plants we love and can grown in our own yards. Ursolic acid in and of itself seems to have many of the same benefits as brown fat.
Curcumin in turmeric has also been shown to increase brown fat by boosting the energy production of mitochondria, remember brown fat is rich in mitochondria.
Compounds in capsaicin found in cayenne peppers, catechins in green tea, resveratrol in grape skins, and omega3 fatty acids – specifically from fish increased brown fat production.
Sleep & Melatonin
And lastly melatonin supplementation in individuals who were low in melatonin help support increasing brown fat. I would like to theorize that sleep could do the same thing! While the study did not look at sleep, the individuals in the study were melatonin deficient, which means they were not sleeping well. This is more and more prevalent in the aging, due to light at night exposure and the use of some drugs like beta-blocking drugs.
Ref: https://pubmed.ncbi.nlm.nih.gov/30765337/
I’ve spoken many times about the importance of sleep and melatonin! Here is yet another reason to make sure you are not melatonin deficient.
Sleeping in a cool room
Night sleep hours is another good time to reduce your heat, perhaps sleeping in a cool room — 65o or less could increase your brown fat while you sleep.
And here we are again … looking at common lifestyle factors that improve our health and well being:
- Exercise
- Eating fruits and vegetables with skins, and herbs too
- Get good sleep and keep your melatonin levels up
- Don’t live life too comfy … get out in the cold every now and then.