Berries burn fat? Well, not exactly, but some interesting studies in vitro (petrie dishes) and rats do show compounds in berries to have some interesting effects. Before I get into the research, it is important to not let the language of hype persuade us. Until a high berries diet is compared to a equal calorie non-berry diet, this is all just speculation, but I found it interesting just the same. The story of berries gives some insight into the informational nature of food. Food is not just calories, but it has the potential to send direct communication to our genes. Berries MAY be doing just that.
It turns out that the anthocyanin (pronounced AN-THO-SIGH-AN-INS), a type of plant chemical found in berries, may have some impact on fat metabolism. If you are accustomed to thinking about food from strictly a caloric standpoint, you may suspect berries have this action because they are low in calories. However, food is much more than simple caloric mathematics.
Food has both direct and indirect hormonal effects on the body. Berries might work through mechanisms associated with the release of insulin and direct manipulation of metabolism. First, berries are what is known as a low glycemic index (GI) food. Glycemic Index is a term used to describe how fast a particular food will raise blood sugar levels. This is important for fat loss because high blood sugar gives rise to the release of large amounts of insulin. Since insulin is a fat storing hormone, the body is unable to burn fat when it is around in significant quantities. Berries, having a low GI effect, cause only a slight rise in blood sugar, and minimize the amount of insulin discharged. This makes berries an ideal addition to a fat burning diet.
A second useful mechanism comes from chemicals in the berries themselves. Berry anthocyanins appear to act directly on physiology, and affect major biochemical switches for fat metabolism. Research published in the January 2008 issue of the Journal of Agricultural and Food Chemistry, showed berries are able to turn on an enzyme called AMP Kinase. This enzyme is the “master fuel switch” in muscle and fat cells telling them to increase their use of fat for energy. This is the enzyme switch involved with fat burning exercise as well. These anthocyanins also modulate the expression of several hormonal compounds released from fat, including adiponectin and IL-6, furthering the potential on metabolism.
Two other studies in the same month, of the same Journal, confirmed a protective affect against an obesity producing diet in rats fed an anthocyanin rich diet. One of the articles points out the use of berries is an important biochemical modulator, one that has been consumed by native humans for thousands of years, making them perfectly suited to human genetics. In native American cultures, berries were used to protect against diabetes, decrease inflammation, fight infection, and provide valuable nutrition.
The exact mechanism of how the berry compounds are influencing these enzyme systems is not yet known, but my guess is there is an epigenetic component. Epigenetics refers to the manipulation of genes through interaction with their protein coats determining whether the gene is actually expressed or not. The prefix “epi” means above, so epigenetics is literally above the genes. Many people, including healthcare practitioners, are unaware that the “reading” of genes are not controlled by the genes themselves, but by biochemical signals induced by the lifestyle we choose.
Many other food compounds have been shown to act in this way. This information on berries is a reminder that food is more than calories, but a source of information for the body. The effects of food and the compounds within it are vastly more complex than simple calorie models of metabolism. They also have huge power once you understand your choices drastically influence your genetic expression and metabolic outcome.
To take advantage of the natural compounds in berries, I usually have my clients incorporate 1-3 cups of organic mixed berries into their diet daily. When this is not possible, I recommend a concentrated powdered berry and fruit product derived from organic berries and other fruits. Buying berries frozen is ideal as they can be consumed throughout the year. Obviously consuming berries in pies or with added sugar will negate the effects, so they should be consumed by themselves without added starch or sugar.
So, can berries really help with fat loss? Any effect they might have is likely marginal and would be washed out by the hormonal impact of other foods. But, as part of the natural health and fat loss lifestyle, they are low in sugar, high in fiber and very high in potentially beneficial compounds. Even though berries are probably making little impact on your fat burning, they are certainly a healthy and fat loss friendly addition to a overall fat loss program.