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As we have learned over the years with dietary fat, not all fat is created equal. Certain types nourish us, while other types may promote inflammation and chronic disease. Similarly, all body fat is not created equal. Research has found that activating and maintaining brown fat can have anti-aging benefits and protective effects against many chronic illnesses, metabolic diseases and inflammation.

The body fat that we typically think of as being unhealthy, or a nuisance that we want to get rid of, is “white fat” or white adipose tissue. This type of fat can be thought of as inactive storage, as it stores excess energy and calories we consume and can lead to obesity. Brown fat, or brown adipose tissue, on the other hand, can be thought of as “active” fat as it can burn calories and enhance our metabolic rate.

“As we age, the amounts of brown fat in our body drastically decrease, and we gain almost exclusively white fat for the remainder of our lives.”

We are all born with brown fat found mostly around the neck, chest and shoulders. Interestingly, babies are unable to shiver, which is a human adaptation that increases the amount of heat in our bodies. Consequently, this brown fat is a mechanism that keeps infants warm by essentially acting as an automatic, built in heater. Brown fat can also be found in most hibernating animals. As we age, the amount of brown fat in our body drastically decreases, and we gain almost exclusively white fat for the remainder of our lives. This decline in brown fat functioning increases the likelihood of developing metabolic disorders.

“The food we eat and a modern lifestyle that favors inactivity and inhibits stress management can play a large role in the production of white fat and the subsequent onset of obesity.”

Many of today’s chronic illnesses are associated with increased rates of systemic inflammation, which may be caused by or enhanced by growing stores of white fat in the body. As discussed in this blog many times, the food we eat and a modern lifestyle that favors inactivity and increases chronic stress (allostatic load) can play a large role in the production of white fat and the subsequent onset of obesity. Growing rates of obesity are a major risk factor for the ongoing chronic non-transmissible disease epidemic in the form of an increased risk for the development of a variety of diseases including heart disease, stroke, type-2 diabetes, early cognitive decline and even certain types of cancer.

Consequently, increasing levels of brown fat in the body may be the key to promote healthy longevity and improving health span. Scientists are now looking for mechanisms that promote the development of brown fat in the body well as possible mechanisms that can convert white fat to brown fat in a process referred to as “browning”.

There are currently a number of medications that may be able to flip the switch that triggers the production of brown fat. Thiazolidinediones medications, which are used to manage insulin resistance, may promote the so-called browning of white fat, however results are inconclusive. And just as with all medications, there are numerous side effects associated with these drugs such as weight gain and fluid retention, both of which may exacerbate inflammation.

“Exposing the body to cold temperatures […] has been shown to stimulate the production of brown fat.”

There is evidence that the stimulation of brown fat can also be triggered by consuming certain foods and behaviors. Exposing the body to cold temperatures, for example, has been shown to stimulate the production of brown fat “via an indirect pathway mediated by the sympathetic nervous system”. Research suggests that just 2 hours of cold exposure daily at temperatures below 66 degrees Fahrenheit is enough to convert white fat to brown. Extreme heat, such as from a sauna, may have a similar impact.

Exercise has also been shown to activate a switch that converts white fat to brown fat through the production of the hormone irisin. Increased irisin levels play an important role in insulin sensitivity by facilitating glucose uptake. Resistance training and high intensity interval training have been shown to induce the highest levels of irisin, therefore, promoting the best outcomes.

“Certain compounds in food may also play a role in converting white fat to brown fat and enhancing metabolic fitness.”

Certain compounds in food may also play a role in converting white fat to brown fat and enhancing metabolic fitness. Polyphenol containing plant-derived compounds such as turmeric, green tea, chili peppers, fish oil, resveratrol, berberine, and cinnamon have all been shown to play a role in the browning of fat cells. Green tea contains the powerful polyphenol compound EGCG which, in animal studies, induced genes related to the browning of fat. Resveratrol, another plant derived polyphenol, has also been shown in animal studies to increase brown adipose tissue.

Finding mechanisms that increase levels of brown fat in our bodies may have profound implications for our general health and the growing rates of chronic diseases. And while current medical interventions may not be accessible or thoroughly beneficial for most, comprehensive lifestyle changes such as cold and heat exposure, exercising and eating more “fat browning” foods as discussed previously are simple strategies that can improve metabolic health.