Tom Brady says the secret to his success includes avoiding mushrooms, tomatoes and eggplants. The New England Patriots quarterback also limits dairy, gluten, white sugar, white flour, processed sweets, condiments, alcohol and salt.
Instead, Brady eats mostly fresh, local and organic fruit and vegetables, according to his new book, "The TB12 Method: How to Achieve a Lifetime of Sustained Peak Performance." His staples also include wild fish and free-range, hormone-free meat, along with whole grains, nuts and products from his line of snacks and protein bars.
A major motivator for his choices about food as well as about exercise, hydration, sleepwear and mental training, he writes — in sweeping statements without references or citations — is to fight inflammation and help his body absorb nutrients.
"The type of nutrition regimen you choose will either promote or reduce inflammation," he writes. (That explains his avoidance of mushrooms and nightshades, which some people consider inflammatory.) "If I know my body will experience inflammation every Sunday during the season, the last thing I want to do is stack on more inflammation on top of it — not if I want to feel great every time I take the field."
Could food choices actually lower inflammation and make the rest of us as strong and healthy as Brady, who has won five Super Bowls and is still starting as quarterback at age 40?
Science has yet to connect those dots, experts say, and there are reasons to be skeptical. Despite a growing body of evidence linking inflammation with a variety of illnesses, inflammation isn't always bad. And even though the literature on food and inflammation is suggestive, the details remain murky.
"I think everyone wishes that there was one secret or a couple of secrets for making dietary changes and improving health outcomes," says Laura Cappelli, a rheumatologist at the Johns Hopkins School of Medicine in Baltimore. "It's not that simple."
Inflammation is a useful immune-system reaction that helps fight infections. Inflammation also follows injuries and athletic exertion, like the kind Brady endures every football Sunday, leading to muscle soreness and, eventually, stronger muscles. But chronic inflammation has been linked to such illnesses as heart disease, Alzheimer's, cancer and autoimmune conditions including arthritis.
That link has fueled the appealing idea that dietary choices might fight inflammation and reduce symptoms of disease or help us avoid getting ill altogether.
In theory, the concept of eating to reduce inflammation makes sense, says Cappelli, especially as research builds about the influence of gut microbes on the immune system. And, to be fair, there is some evidence to back up parts of Brady's diet.
In many ways, his meal plan resembles the Mediterranean diet, which has been linked with lower rates of heart disease and death from all causes. Like Brady's diet, the Mediterranean diet is plant-based. Less restrictive than Brady's diet, it also emphasizes fish and whole grains over red meat and butter, and it has been associated with reduced risks of cancer, Alzheimer's and Parkinson's disease.
Inflammation may even have something to do with the Mediterranean diet's benefits, according to studies that have found lower levels of inflammation-related compounds in the blood of people who follow that kind of eating plan.
But science is far less clear about which foods matter or why — despite Brady's confident yet vague statements about the relative benefits of "alkalizing" foods over "acidifying" foods.
Nutrition is difficult to study, Cappelli says. The only definitive way to link foods with health outcomes would be with expensive, long-term studies that randomly assign large numbers of people to eat specifically designated menus in highly controlled environments. Studies more often look for associations in people's recollections of what they eat.
Meanwhile, nobody eats in a vacuum. Sleep, exercise, stress, genetics and other factors can get in the way of interpreting nutrition findings. And scientists have yet to come to consensus about the most reliable and meaningful markers of inflammation.
Websites and books that promote anti-inflammation diets, including Brady's, tend to mention some key foods, though a deeper look often reveals mixed results and lingering unknowns.
Omega-3 fatty acids are a good example. Abundant in certain fish, omega-3s get Brady's thumbs-up as "natural anti-inflammatories."
Although he mentions no specific studies, that reputation has emerged from research linking fish and omega-3 supplements with lower risks of heart disease as well as less pain and a reduced need for anti-inflammatory medications in people with rheumatoid arthritis.
But other studies have failed to connect omega-3s with positive results, Cappelli says. And many questions remain about whether benefits come solely from omega-3s or from interactions among nutrients in certain foods.
The same kinds of complexities surround other foods and food components that often get linked with inflammation, including turmeric, cherry juice, resveratrol and gluten.
"We might find one study that says something, but can you find another to back it up? Not usually," says Katherine Zeratsky, a registered dietitian and nutritionist at the Mayo Clinic in Rochester, Minn. "I don't mean to imply it's bad science. It's science that doesn't necessarily have the rigor behind it to say this is an absolute conclusion."
Brady's restrictive advice could even backfire for some people. Strict diets tend to fail, Zeratsky says. And some of the foods he avoids are full of vitamins and antioxidants. One recent study found lower levels of 12 inflammatory markers in people who ate more anthocyanins (found in eggplants, blueberries and other purple foods) and lower levels of two inflammatory markers in people who ate more flavonols (in cherry tomatoes, apples, cherries and other foods).
(The recipes in Brady's book actually include tomatoes, peppers and potatoes, which he says are okay on occasion.)
It's worth thinking twice before taking advice from celebrities, says Steven Hoffman, scientific director of the Canadian Institute of Health Research's Institute of Population & Public Health.
In a review of published research, he and colleagues discovered a web of psychological processes that make people vulnerable to the influence of famous people, who often impart a "golden glow" on the products they support. With so many choices available, this halo effect can help people make decisions.
Celebrity declarations about health can also spread harmful or misleading information, Hoffman says. Actress Jenny McCarthy, for example, made influential statements against vaccines as a cause of autism, even though a study purporting to show such a link has been debunked. Also, Gwyneth Paltrow's popular website has come under fire for promoting unsupported and potentially dangerous advice, such as inserting jade eggs into the vagina. And Angelina Jolie's double mastectomy has been linked to a spike in preventive breast-cancer surgeries even though the practice remains controversial and can lead to complications.
As for Brady's eating plan, it's impossible to know whether his diet will be beneficial for other people or even whether it helps him. As a professional athlete, he is probably exceptional in a variety of ways. And his experience is an anecdote, not an experiment.
"It's crazy to think," Hoffman says, "that in societies like ours, where most people have access to primary-care providers, that we would instead take health advice from famous people who often don't know what they're talking about and certainly don't know our health contexts."