How? New research indicates that adipose tissue is not simply a passive reservoir for surplus calories. Instead, fat cells are active players in a dynamic physiological communication system—and scientists are discovering that certain nutrients can modify these signals in ways that may aid weight-loss efforts.

Who’s in Charge?

Researchers have shown that fat cells secrete a host of bioactive peptides collectively known as adipokines (or adipocytokines) that affect blood pressure, blood sugar, blood lipids (cholesterol), and inflammation, as well as the formation of certain hormones. To ensure their survival (and ours, in evolutionary terms), fat cells communicate with other fat cells, muscle cells, and even the brain. In fact, new studies indicate that your brain may not control your fat, but rather that your fat controls your brain. Currently, scientists are taking aim at a dozen or so adipokine targets; two crucial ones are leptin and adiponectin.

Target 1: Leptin

A hormone released by fat cells that acts on the central nervous system, specifically the hypothalamus, leptin suppresses appetite and increases energy expenditure. Excessive leptin in the blood is a hallmark of obesity. Leptin also links fat cells to the reproductive system and is thought to play a role in whether adequate energy reserves are present for normal reproductive functioning. In short, leptin might help shut down ovulation in women who are too lean. In vitro and animal studies suggest that elevated plasma leptin levels promote vascular inflammation, oxidative stress, and negative changes in cholesterol levels. These actions may contribute to the pathogenesis of high blood pressure and heart disease. Although more studies are needed, supplementation with fish oil appears to help normalize leptin levels.

Target 2: Adiponectin

Plasma adiponectin concentrations are low in obese animals and in humans with Type 2 diabetes. Adiponectin is inversely related to obesity and inflammation—as we gain weight, our levels of adiponectin decrease, and vice versa. In muscle, adiponectin stimulates glucose use and fat oxidation and improves insulin sensitivity—all good things. This adipokine inhibits the vascular inflammatory process and possibly atherosclerosis. In other words, adiponectin has antidiabetic, anti-inflammatory, and antiatherogenic effects. Consuming fruits high in anthocyanins (elderberries, grapes, blueberries, blackberries) or the equivalent in supplement form is a prudent way to increase adiponectin levels.

The Bottom Line

As fat cells shrink and enlarge, they secrete bioactive chemicals that affect energy balance, the metabolism of glucose and fat, cardiovascular function, reproductive function, and immunity. Until researchers pinpoint which nutrients in foods can amplify the effects of beneficial adipokines and minimize the effects of those that make us sick, one thing is certain: Supplementing with high-quality fish oil and fruit extracts is a great way to improve overall health, regardless of body weight.