Considering all it does for us, body fat gets a bad rap. Fat, or adipose tissue, is essential for storing energy, protecting our internal organs, helping to regulate body temperature, and participating in the production of many hormones.
However, body fat is not always the same. The most common type is called white fat, or white adipose tissue, and its main function is to store calories for energy. But there is also a second kind of fat, called brown fat, or brown adipose tissue (BAT), which exists in small amounts in all adults and whose simple function is to keep us warm when we are cold. White fat can sometimes turn into brown fat, and at this stage it is sometimes referred to as beige fat.
In recent years, scientists have discovered that brown fat may have an even greater health role in terms of weight loss, diabetes, and even heart health. This article will tell you everything you need to know about what brown fat is, what it does, and how it affects your health.
What is brown fat?
Health researchers have become interested in brown fat because of its apparent role in calorie burning and thermogenesis, which is the process by which the body generates heat. Brown fat tissue contains many more mitochondria, the part of the cell responsible for energy production, than white fat tissue. This may be the reason why brown fat is more abundant in babies and hibernating mammals. Adults have much lower amounts, usually located in the neck, around the shoulder blades and kidneys, and along the spinal cord. Due to brown fat’s ability to burn calories, researchers have studied its role in fighting obesity.
Brown fat or white fat: what’s the difference?
White fat is the type of fat most of us are familiar with, it’s what the body stores for energy, but it can lead to obesity when not used. Most fats in an adult’s body are white fats. Brown fat is mainly found in babies and hibernating mammals, to help with temperature regulation.
The two greases differ not only in their function and color, but also in their structure. White fat cells have large lipid droplets for storing energy, while brown fat has smaller droplets and tons of mitochondria. Often referred to as the “powerhouses” of the cell, the mitochondria produce energy and are activated by cold to burn calories and kick-start thermogenesis. Mitochondria are also rich in iron, which gives brown fat its color.
What are the potential health benefits of brown fat?
Research on brown fat is relatively new and most of it is preliminary or has only involved animals or small groups of humans (less than 50), so it needs more research. Here’s what we currently know about brown fat and the following conditions:
Weight loss and metabolism
It is believed that when brown fat is activated (in other words, when its mitochondria are signaled to burn calories and produce heat), it can absorb and use compounds called branched-chain amino acids (BCAAs) . Previous research in rodents and humans has linked high BCAA levels to obesity, insulin resistance and type 2 diabetes, suggesting that lowering these levels may improve These conditions.
Although further research is needed to determine the relationship between brown fat activation via cold exposure and BCAA levels in humans, a small study published in Nature in 2019 examined its effects on levels. of BCAAs from 33 healthy young men, and found that two hours of cold exposure led to lower BCAA levels in those who already had high brown fat activity. Another study published the same year in Autophagy found that the thyroid hormones thyroxine (T4) and triiodothyronine (T3) activated brown fat and thermogenesis in mice, without the need for exposure to cold. This is a promising future avenue of research, to link the treatment of obesity and metabolic diseases to the direct effect of T3 on the activation of brown fat. When brown fat is activated, more calories are burned for energy, leading to better insulin sensitivity and appetite regulation. »
Diabetes
Unlike white fat, brown fat is a metabolically active tissue: It burns glucose as fuel. And there is early evidence that brown fat can significantly influence metabolic health. A small study published in April 2022 in The Journal of Nuclear Medicine recruited 34 college students and activated their brown fat by lowering their core body temperature. A correlation has been found between brown fat and metabolic disorders such as diabetes. Researchers believe that a high level of brown fat activation may be an early warning sign that an individual might be developing diabetes, although more rigorous research is needed.
heart disease
A study published in Nature Medicine in 2021 found a correlation between the presence of brown fat in a person’s body and their risk of cardiometabolic disease. Specifically, the study found that people with more easily detectable brown fat (using positron emission tomography) had a lower risk of abnormal cholesterol, coronary heart disease, hypertension, and heart failure. congestive.
How to activate brown fat
Humans tend to have the most brown fat in childhood, and we lose a lot of it as we get older. But if brown fat has health benefits, is there a way to increase the amount?
It is generally accepted that an adult cannot actively increase the amount of brown fat that he inherently possesses. But while brown fat cannot be created, there is some evidence that the brown fat we have can be activated, and white fat can potentially be oxidized. Again, the research is still in its infancy, but it appears that certain conditions can activate brown fat by signaling its mitochondria to burn calories and produce heat. Here is what is currently known about how the following factors contribute to brown fat activation:
Diet
A review of studies published in Frontiers in Physiology in 2019 looked at the effects of certain foods on thermogenesis, the heating process that activates brown fat. The review largely included studies done on rats, but found that the spices turmeric and curcumin, foods containing resveratrol (like wine), green tea, and spicy foods containing capsaicin can activate the thermogenesis and/or trigger fat oxidation, which is the browning of white fat.
Further research is needed to verify the effectiveness of these ingredients on BAT in humans, particularly because the doses required for some of them (e.g. resveratrol) to achieve results may be unrealistically high. Additionally, an analysis published in Frontiers in Neuroscience in 2021 found that caffeine evokes BAT thermogenesis in rodents, but its effect on BAT thermogenesis in humans remains unclear.
Supplements
Various previous research conducted on rodents has shown that certain herbal dietary supplements, including kudzu flower oil, ginseng, quercetin (a plant flavonoid found in many fruits and vegetables), propolis and oleuropein (a compound found in green olives) activated thermogenesis or oxidized white fat in rodents. However, the results are not directly transferable to humans and further research is needed.
Exercise
Increasing your workouts won’t create more brown fat outright, but it might oxidize existing white fat into what researchers call beige fat. There is a correlation between the level of physical activity you do and better overall body fat distribution, including the amount of brown fat. Managing your overall body fat by working towards healthy weight goals will improve your overall fat distribution. Recent studies demonstrate that exercise shifts the body from storing white fat to storing beige fat, although it is not known if beige fat is directly beneficial metabolically or if it is is an adaptive response.
Cryotherapy
Taking a polar dip in an ice bath or cryotherapy chamber can activate your brown fat by triggering thermogenesis, according to a study published in the Journal of Obesity in 2018. But taking a brisk walk in the winter can work just as well. Adjusting your body to cold temperatures by taking a walk outside or taking the occasional cold shower may help.
Summary
While the possibility of harnessing the power of brown fat in humans for weight loss and other health benefits holds promise, scientists haven’t quite figured it out yet. The majority of existing studies on the subject have been done on animals, and more research is needed to determine how to effectively activate brown fat in humans.
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