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Although excess body fat might contribute to the development of certain diseases, fat is not inherently bad or unhealthy. It is required for health and has important roles, including providing the body with energy, fat-soluble vitamin absorption, cell membrane structure, molecule signaling, body heat, and more.

Different types of fat, or adipose tissue, exist in the body. Each one has a distinct and vital function. One type of fat stores energy when the body requires additional food, such as during a fast. The other is ready to burn energy to make heat when the body becomes cold. Adipocytes, or fat cells, also play a crucial role in the regulation of appetite, glucose, and energy balance through secreting adipokines, or messengers, such as leptin and adiponectin.

Some adipose tissue is protective against obesity and metabolic diseases, so it is considered the healthier fat. However, adipose tissue is complex and more colorful than previously thought. New research demonstrates that there might be a way to switch fat to the healthier type, a process known as “beiging.” While losing fat was once the focus for optimal health, transforming fat for better health may be more beneficial.

Types of Adipose Tissue

For decades, it was presumed that there were two main categories of adipose tissue: white adipose tissue (WAT) and brown adipose tissue (BAT). BAT is generally considered healthier as it is involved in thermogenesis, or burning calories to make heat. It is protective against obesity and contains a higher number of mitochondria. WAT is an endocrine organ tightly regulated and contains subcutaneous and visceral fats. It stores excess calories and generally exists in the stomach area and subcutaneously, which serves as a protective layer for the intestinal tract. It is often associated with diseases, including diabetes and cardiovascular disease.

However, there is some evidence that WAT is not fully understood. One study found that metabolically unhealthy obese individuals had a lower expression of remodeling enzymes and more cross-linking and adhesion proteins than metabolically healthy lean individuals. The findings suggest that healthy adipose tissue is more likely to remodel and adapt dynamically. Subcutaneous fat versus visceral fat may be more adaptable to changing conditions in the body.

While much of the discussion has focused on WAT and BAT, research has discovered a third type of adipose tissue: beige. It is a blending of the two types of adipose tissues with a distinct gene expression. Beige adipose tissue has a low basal expression of white fat cells but still will respond to the cyclic adenosine monophosphate (AMP) stimulation as needed. This feature suggests that the cells can switch between storage and creating energy, depending on the body’s needs.

Beige adipose tissue arises when brown-like cells accumulate in WAT, which happens more often in subcutaneous adipose tissue than visceral fat tissue. The addition of brown cells increases the capacity to burn calories through thermogenesis. Other benefits of beige include lower blood glucose, higher resting energy expenditure, and lower body weight. Specific components of these cells provide them with unique characteristics, including PR domain containing 16 (PRDM16), which is like a switch that differentiates the BAT. The cells also express the genes for uncoupling protein 1 (UCP1), typically reserved for brown adipocytes and associated with mitochondrial cells, which is where energy production occurs. Generally, the more mitochondria in a cell, the more energy it can burn.

There are ways to boost beiging to combat obesity and obesity-related diseases. For example, consuming polyphenols, caffeine, capsinoids, carotenoids, and omega-3 fatty acids has influenced beiging. Specific foods and herbs, such as soy, onion, cinnamon, mint, ginseng, Coptis chinesis, chili peppers, tea, thyme, and magnolia officinalis, may support BAT and beige activation. As a bonus, many of these recommendations have multiple health-boosting benefits beyond converting adipose tissue. However, hypermetabolic conditions (e.g., burns, inflammation, cancer), being cold, calorie restriction, and hormones affect gene expression involved in beiging.

Exercise

Exercise provides numerous health benefits, including reducing stress, facilitating weight loss, and increasing strength. Recent research has found that exercise, especially aerobic and resistance training, prevents extracellular matrix expansion. Extracellular matrix expansion and remodeling could result in more adipose tissue, inflammation, and metabolic dysfunction. By preventing this expansion and remodeling, exercise supports healthy adipose tissue.

Another way exercise might provide benefits, especially in terms of weight loss, is by instigating beiging. Specifically, exercise increases UCP1 expression. This effect suggests that physical activity increases the number of mitochondria and the expression of the marker for UCP1, which is typically associated with brown adipocytes. As more mitochondria enter the white tissue, more beige cells arise.

Another reason exercise promotes the development of beige adipose tissue is due to an increase in irisin. Irisin is a hormone that increases fat loss, glucose tolerance, and energy expenditure. Irisin levels are directly related to muscle mass. In an older study using murine cells, differentiated cells were incubated with irisin alongside a control group that was not. Irisin led to upregulations of the markers for BAT in the WAT, including UCP1 and PCG1A. The researchers also performed the study on live mice and found similar results. A recent human study found that exercise significantly increased irisin and decreased insulin resistance in overweight or obese pregnant women. Additionally, the researchers found that beiging genes were expressed more in the exercise group than the controls. These studies suggest that exercise fights obesity, type 2 diabetes, and cardiovascular disease by reducing the number and size of fat cells and switching at least some WAT to the healthier beige variety.

Environment

Another way to stimulate the production of beige adipose tissue is through the environment, including social activities and temperature extremes. One mouse study found that enriched living conditions (i.e., housing in which social interactions, learning, and activities are prioritized) improved insulin sensitivity, glucose metabolism, and anti-inflammatory processes while eating a high-fat diet. Researchers also found that more beiging occurred, and the metabolic imbalances caused by a high-fat diet were reversed or restored. Another study confirmed that enriched living environments could support weight loss, reduce anxiety, and improve memory.

Environmental exposures have become a burgeoning area of research due to reported benefits to adipose tissue, mood, and immunity. Similar to exercise-induced beiging, cold exposure seems to upregulate UCP1. Research suggests cold exposure may improve glucose metabolism and insulin sensitivity and increase beiging. However, more human studies are required to understand how cold therapy might support human health. Heat exposure could also be a valuable tool in the beiging of adipose tissue, but this mechanism has not yet been fully studied.

Capsaicin

Capsaicin has a reputation for assisting in weight loss, possibly due to its ability to facilitate thermogenesis and beiging. Regarding the beiging properties of food ingredients, capsaicin is one of the best studied, including in human studies.

Capsaicin is the component of hot red peppers that gives them their spicy properties. A closely related particle is capsinoids found in the less-spicy red peppers. Both can enhance fat oxidation and increase energy expenditure for weight loss. One way they do this is through BAT. A study found that capsaicin directly increased beiging through upregulated UCP1 expression, mitochondrial biogenesis, and energy consumption rates. Other studies have identified that capsaicin and capsinoids activate BAT, increasing beiging in WAT.

Omega-3 fatty acids

Omega-3 fatty acids are often touted as anti-inflammatory and health-promoting, and they may boost the conversion of WAT into beige or brown. One mouse study found that the anti-inflammatory effects of consuming the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased fatty acid oxidation, decreased adipogenesis, and reduced the inflammatory response caused by adipose tissue. Additionally, although mice were fed a similar high-fat, calorically dense diet, the mice supplemented with EPA and DHA experienced a delay in weight gain.

An older human cell study found that, after treating fully differentiated human white adipose subcutaneous tissue cells of women who were overweight with 100– 200 uM of EPA for 24 hours, there were alterations in the mRNA expressions of the genes suggestive of beiging. There was an increase in the number of mitochondria and the gene expressions for fatty acid oxidation, which burns fat as energy. There was also an induction of specific genes of beige, including PRDM16 and UCP1, as well as expression of specific markers for beige cells.

Vitamin A

Vitamin A is a fat-soluble vitamin whose metabolites, such as retinoic acid and other retinoids, play a key role in the differentiation of tissues and cells around the body. The body stores excess vitamin A and its metabolites in the liver and adipose tissue, and it might do more than simply lodge in the depot of adipose tissue. A specific metabolite, all-trans-retinoic acid (ATRA), has been shown to stimulate beiging. In an older study, cells treated with ATRA had an increased number of mitochondria and UCP1 expression. The researchers also studied the effects of ATRA on mice. A group of mice consumed feed with 5 IU of vitamin A per kilocalorie, and six of the mice received subcutaneous amounts of ATRA at levels of 50 mg/kg of body weight per day (this would be equivalent to 0.375 grams in a 165-pound person, which is relatively high). Despite not reaching statistical significance, there was a definite increase in mitochondrial gene expression in the treated mice’s WAT. This study looked at a specific metabolite of vitamin A rather than vitamin A. However, it does suggest that beiging could be another possible benefit of consuming sufficient vitamin A in the diet, although more research is needed to confirm the exact dose. A more recent study confirmed these results, showing that ATRA treatment stimulates UCP1 expression in a dose-dependent manner. Additionally, ATRA contributed to adipocyte apoptosis and reduced adipogenesis.

Alpha-lipoic acid (ALA)

ALA is an important antioxidant naturally produced by the body, which supports mitochondrial health. It has anti-obesity properties, possibly due to its beiging effect on the body. An older study looked at the effects of subcutaneous adipocytes treated with ALA at doses of 100 and 250 uM over 24 hours. After treatment, the cells had increased mitochondria numbers and markers of brown adipocytes.

Resveratrol

As with many of the above, consuming resveratrol increased the markers of brown adipocytes, including UCP1 and PRDM16, in WAT. In a study on female mice consuming a high-fat diet, researchers gave one group 0.1 percent resveratrol in their feed, and the control group did not have any resveratrol. The researchers also performed a similar experiment on cultured cells. Their findings pointed to the beiging of the WATs based on the increased markers. Newer research supports this finding; however, it may be essential to consider resveratrol potency and therapeutic dosing for the effects to be observed.

Curcumin

Curcumin is considered a “browning agent” with numerous health benefits, thanks to its anti-inflammatory and health-promoting properties. An older mouse study found that curcumin supplementation while consuming a high-fat diet augmented lipogenesis and reduced adipocyte inflammation, which may help combat obesity. Another study found that curcumin combined with physical activity benefited fat loss.

Curcumin has been found to promote thermogenesis. In one study, curcumin increased the number of mitochondria in the WAT and the ability of the cells to augment lipolysis. Additionally, there was increased expression of UCP1 and other specific markers of BAT. This finding suggests it converts the WAT into the more fat-burning and healthier beige or BAT. Curcumin’s fat-fighting benefits do not stop simply at converting white to brown tissue to beige or brown; it has the potential to inhibit the genesis of adipose tissue as another way to help combat obesity.

Berberine

The herb berberine has many health benefits, including helping prevent and treat diabetes. One reason for its efficacy in weight regulation and diabetes prevention might stem from its effects on beiging white adipocytes. A study on db/db mice, which are a variety that has impaired glucose tolerance and marked obesity, treated one group of mice with berberine. This group lost weight despite no significant difference in caloric intake. The berberine reduced the size of the white adipose cells and activated AMPK, increasing the energy production of adipocytes. There was also an increased number of mitochondria, suggesting beiging.

Green tea

Tea contains polyphenols called catechins, which may activate beiging. One catechin, epigallocatechin gallate (EGCG) has been found to activate beiging through the expression of UCP1. Animal studies showed a higher expression of the genes involved in BAT activation, leading to increased AMPK phosphorylation and beiging.

Another study assessed the thermogenic effects of green tea catechins on humans. Researchers found that caffeinated green tea catechins consumption increased overall energy expenditure related to BAT activation. The results observed are similar to the effects of cold-induced thermogenesis. However, more human studies are required to understand the necessary dose to enhance beiging.

Raspberries

Raspberries contain phytonutrients with beneficial effects on lipid metabolism, oxidative stress, and inflammation. Additionally, raspberry consumption may increase AMPK activation, thus supporting beiging. One mouse study found that raspberry consumption increases thermogenesis and beiging, mediated by AMPK. More human studies are required to understand if raspberries may be a therapeutic approach for preventing metabolic diseases.

Final Word

Beiging is still a relatively new area of research, and much of the studies are in the in vitro and animal trial phase. However, promising results demonstrate numerous ways in which individuals may be able to increase the number of brown and beige fat cells in the body. This includes exercising, consuming a healthy diet, and having a healthy gut microbiome.

While losing fat has become a mainstream, popular culture focus, it’s important to remember that fat is important in the human body. Rather than try to lose fat, it may be more beneficial to transform fat to help support health. Consult with a healthcare practitioner or dietitian/nutritionist before changing the diet or supplementing with any of the above nutrients or herbs for a personalized approach, especially if taking medication(s) or experiencing a health condition.