It’s also possible that inflammation could trigger numerous reactions that cause other problems. “It’s basically a chemistry issue,” says Dr. Trence. “It’s a chemistry that turns on a whole cascade of events that are very detrimental to the inside of a blood vessel as well as to the immune system.”
The role of diet in inflammation
How much does what you eat have to do with it? Possibly quite a bit, which is both good and bad news. First, the bad news: Some foods cause inflammation, and some people are more susceptible to inflammation than others.
Back in 2000, Dr. Dandona and his team found that people who ingested 75 grams of glucose, the standard amount used in an oral glucose tolerance test to determine if someone has diabetes, had an inflammatory reaction to the glucose. “We saw oxidative stress; oxidative stress and inflammation are back-to-back things that happen together. You form a whole lot more free radicals when you’ve taken that amount of glucose.” (Free radicals are the unstable, highly energized molecules that cause oxidative damage to body cells and tissues.)
Next they put saturated fat to the test, using cream as the source. “Again, we saw the same oxidative stress with increased levels of free radicals being formed,” says Dr. Dandona. But since humans don’t generally take meals of solely glucose or cream, they decided to see what happens after a person eats a meal of mixed macronutrients: in this case, a small McDonald’s meal that topped out at 900 calories. The findings were not encouraging for fans of fast food.
“We showed that a small McDonald’s meal resulted in inflammation and oxidative stress at a cellular, molecular level,” says Dr. Dandona. The markers Dr. Dandona and his team used to establish the presence of inflammation and oxidative stress are the same ones the body produces when it is seriously hurt. “In the cells, we look at nuclear factor kB (NF-kappa B), which is the orchestrator of inflammation. When we get infections, it is NF-kappa B that gets stimulated,” he explains. “We were shocked to find that what infections do, food does, too.” Disturbingly, the post-meal inflammatory reaction did not resolve quickly — study subjects still showed signs of inflammation five hours after eating.
Dr. Dandona’s research also found that people with obesity who already had a basic level of inflammation and oxidative stress had a worse reaction than people of normal weight when challenged with a fast-food meal. “Sure enough, they start from higher levels of inflammation, they achieve a much higher level, and the inflammation is much more prolonged.” The oxidative and inflammatory stress observed with meals probably contributes to atherosclerosis, heart attack, and stroke.
Now the good news: Some foods may protect against inflammation. Dr. Dandona and his team tested a portion of orange juice containing 300 calories against an amount of glucose containing 300 calories and found that while the glucose caused inflammation, the orange juice did not, despite the fact that it, too, is pure carbohydrate.
Their next experiment investigated what happened when subjects drank orange juice with a small McDonald’s meal. “And guess what: Orange juice neutralizes inflammation. To me, that is one of the most amazing findings in the field of nutrition today,” says Dr. Dandona. “On the one hand you have all these terrible things that cause inflammation, but if you take a certain amount of orange juice, it balances things off. That’s really remarkable.”
Part of the reason orange juice and glucose have a different impact on inflammation may be due to the nature of the type of carbohydrate: The sugar in orange juice is half fructose, and fructose is noninflammatory. But what would cause it to be anti-inflammatory? “The secret is probably in agents called flavonoids, which are what gives orange juice its yellow color,” says Dr. Dandona. “And two major flavonoids are hesperetin and naringenin, which have shown in the test tube to suppress free-radical formation and to be anti-inflammatory. Chances are that the secret is in these flavonoids.”