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The Physicians Committee

No Debate: Soy is Beneficial to Health

March 2, 2016   Dr. Neal Barnard   ,

There’s no debate: Soy is beneficial to your health. Soy products have been shown beneficial for lung cancer prevention and survival, prostate cancer prevention, heart health and diabetes, bone health, inflammation, and hot flashes, among other conditions.  

Soy is also beneficial in reducing breast cancer risk and in breast cancer survival. Xiao Ou Shu, M.D., M.P.H., Ph.D., who established the Shanghai Breast Cancer Survival Study, a cohort of more than 5,000 breast cancer survivors and who has also led several other epidemiological studies on soy food and breast cancer risk, will discuss the influence of soy food consumption on breast cancer risk and survival at this summer’s International Conference on Nutrition in Medicine.

Below, Dr. Shu answers a few questions about soy products and breast cancer survival that she will cover in depth at the conference.


Please describe your study.

We have applied both cohort and case-control study designs in our research. For the former, we followed up one group of women who were initially free of breast cancer for a risk association investigation or who were newly diagnosed with breast cancer for survival research. The risk of breast cancer or recurrence/death was compared for women who had high soy food consumption versus those with a low intake.

Study participants for case-control study are a group of breast cancer patients and healthy control. We measured the risk association by comparing the soy food consumption of breast cancer patients to that of healthy women.

Why are scientists looking at soy products in relation to breast cancer survival?

Estrogen plays a central role in breast cancer development and progression. Soy foods not only have an antiestrogen effect but also have antiproliferation, antioxidation, and many other anticancer properties. Both laboratory and epidemiological studies have shown that soy food and soy components can reduce breast cancer recurrence and increase survival rates. Evidence is quite consistent that soy food consumption at the level of the traditional Asian diet is associated with a reduced breast cancer risk. Epidemiological research on soy food consumption has not shown any soy product to be more beneficial than others.

How does general nutrition and lifestyle impact breast cancer?

Vegetables and a diet enriched with antioxidants are also beneficial to breast cancer survivors. Red meat and a high fat diet, on the other hand, should be avoided. Low physical activity, obesity, diabetes, and likely chronic inflammation also play an important role in breast cancer development and prognosis.


Gut Bacteria: The Good, the Bad, and the Ugly

February 22, 2016   Dr. Neal Barnard   ,

Three Tips to Create a Set of Disease-Fighting Microbes

This is a guest blog by Physicians Committee associate director of diabetes nutrition education Meghan Jardine, M.S., M.B.A, R.D.N., C.D.E.

The bacteria living in our gut performs many functions, such as controlling metabolism, immune function, and maybe even our thoughts and moods.  How can these tiny cells be so powerful in controlling human health? It depends on the types of bugs living in us and what we feed them.

To cultivate a set of disease-fighting versus disease-spreading microbes, move plant-based foods like vegetables, especially leafy greens, legumes (beans, peas, lentils), and whole grains to the center of your plate.  Avoid meat and other high-fat, animal-based foods.

If you’re not sure where to start, follow this three-step plan for a thriving microbiome:


Step 1: Eat More Vegetables. When it comes to championing optimal health and slashing the risk for disease, dark leafy green vegetables take home the gold.  A new study finds that the sugar (sulfoquinovose) in leafy greens such as spinach, kale, and watercress feed healthy bacteria that live in our digestive tracts, or gut. This bacteria flourishes and crowds out unhealthful varieties, while secreting bactericides that kill off harmful bacteria. Plus, good habits pay off. A 2015 study from RUSH University shows older adults who eat at least two servings of leafy greens each day reduce their risk for dementia.

Step 2: Add Beans to Your Diet. Beans, a member of the legume family, are a dieter’s best friend, since they are rich in fiber, leaving us feeling full, with just 115 calories per 1/2-cup serving. Legumes also have an amazing effect on our gut bacteria. The fiber in beans is not digested in the small intestine.  When it gets to the large intestine beneficial bacteria are waiting. They ferment the fiber and release short chain fatty acids (SCFA), which provide all kinds of benefits. SCFA help our body absorb essential minerals (calcium, zinc, magnesium), increase satiety (improving weight loss), decrease inflammation, reduce the risk of colon cancer, prevent and treat diabetes, and may even reduce the risk of asthma.

Step 3: Avoid meat, dairy, eggs, and fatty foods, which are high in calories and associated with insulin resistance. This can lead to type 2 diabetes and other forms of chronic disease.  Here’s how it works:

Animal products promote the growth of detrimental bacteria and result in the release of toxic chemicals that are harmful to our health. Like carbohydrates, proteins are fermented by the bacteria living in the large intestine. Fermentation of protein causes a release of toxic metabolites (ammonia, phenolic compounds, and amines) that promote the formation of tumors (colon cancer), and increase the risk of inflammatory bowel disease, ulcerative colitis, schizophrenia, and liver problems. Animal protein from meat, eggs, and dairy products are metabolized in the gut and once absorbed into the body to release a metabolite (trimethylamine-N-oxide), which has been linked to cardiovascular disease.

Fats are mostly absorbed in the small intestine. Studies have demonstrated that fat in the diet reduces the production of those beneficial short chain fatty acids by inhibiting the growth of healthy bacteria. Fats also need bile to be digested and absorbed. Bile is secreted from the liver into the small intestines. So now the bacteria also have to metabolize this bile and that causes a growth of “bile-tolerant” bacteria. Bile-tolerant bacteria have been associated with inflammatory bowel disease, higher levels of inflammatory factors in the blood, and may also increase the risk of liver cancer.

The good news is we have 40 trillion bacteria living inside our body. With a few modifications it’s easy to create a new biological system to enable our body to focus on larger tasks, like climbing Mount Everest or helping our children with their science project, instead of constantly combating pathogens.

Partner these tips with gut-friendly pre- and probiotics to give your body the fuel it needs to succeed.

Meghan Jardine, M.S., M.B.A., R.D., L.D., C.D.E., is the associate director of diabetes nutrition education for the Physicians Committee for Responsible Medicine, and works to develop programs to educate physicians, health care professionals, and the public about nutrition as preventive medicine.

For more on gut bacteria, Ms. Jardine will be speaking about the microbiome’s role in diabetes at the International Conference on Nutrition in Medicine in Washington, D.C., this summer. Join us



Eat Your Way to a Good Night’s Sleep

February 19, 2016   Dr. Neal Barnard   ,

According to a new study, 1 in 3 Americans are chronically sleep deprived. And we’re paying for it—not just by dozing off and yawning throughout the day, but through our overall health.

When we sleep, our brains act like a road crew that comes out at night to fill in potholes and repave roads before the morning rush hour. Our bodies need sleep to rest and recharge. Without a sufficient amount of sleep—seven to eight hours for most people—we increase our risk for developing serious health problems. Sleep deprivation has been tied to obesity, elevated blood pressure, and Alzheimer’s disease.

Cutting caffeine, reducing alcohol intake, staying active during the day, and maintaining a consistent schedule can all set the tone for a good night’s sleep. But evidence suggests that diet may play a role, too.


One recent study found that diets rich in fiber and low in saturated fat can lead to deeper, more restorative sleep. It’s not uncommon for people who have improved their diets to report that they feel energized during the day and sleep better at night. Last year, when Jere Downs traded in greasy burgers and fries for green smoothies and chickpea sandwiches on a 22-day vegan challenge, she reported that her “sleep is deep and uninterrupted. My eyes pop open at 6 a.m.”

So what makes plant-based foods so beneficial for sleep? Complex carbohydrates stimulate the release of serotonin—a neurotransmitter that calms your brain and helps you sleep. So building your dinner around starchy foods, like pasta, rice, and potatoes, will help you doze off and stay asleep through the night.

While many people believe that high-protein meals are key to getting a good night’s rest, the opposite is true. High-protein foods block the brain’s ability to produce serotonin. Because high-protein foods contain more amino acids, tryptophan—the amino acid that eventually turns into serotonin—is crowded out of the brain. As a result, high-protein foods will leave you feeling alert.

High-protein plant-based foods, like tofu, beans, and lentils, are very nutritious. But if you’re having trouble sleeping, try eating these foods earlier in the day. You’ll feel more alert during the day, while favoring carbohydrates later on can help you rest at night.

For more on diet and sleep, watch my appearance on The Ellen Show:



White Lies? Five Milk Myths Debunked

February 11, 2016   Dr. Neal Barnard   ,

Last month, a study was called into question for suggesting that chocolate milk could be beneficial for teens recovering from concussions. Not surprisingly, the study was funded by the dairy industry. For decades, milk marketers have been spreading misleading information about the supposed health benefits of dairy products.


Thanks to these marketing campaigns, milk myths abound in our culture. But science doesn’t support them. Let’s take a look at five common claims about dairy products:

Myth 1: Milk builds strong bones.

The dairy and bone health link is one of the most pervasive milk myths. One large-scale Harvard study followed 72,000 women for two decades and found no evidence that drinking milk can prevent bone fractures or osteoporosis. Another study of more than 96,000 people found that the more milk men consumed as teenagers, the more bone fractures they experience as adults. Similarly, another study found that adolescent girls who consumed the most calcium, mostly in the form of dairy products, were at greater risk for stress fractures than those consuming less calcium.

Myth 2: Drinking milk can help you lose weight.

While advertisers would like you to believe that drinking milk can slim you down, studies consistently show that dairy products offer zero benefits for weight control. One major study even found that dairy products might lead to weight gain. In 2005, the Physicians Committee petitioned the FTC to put an immediate end to the dairy industry’s misleading campaigns about milk and weight control. In response, the government no longer allows advertising campaigns to claim that dairy products lead to weight loss.


Myth 3: Milk is “nature’s perfect food.”

Cow’s milk might be ideal for growing baby cows, but it’s far from a perfect food for humans. More than 60 percent of people are lactose intolerant, which can lead to uncomfortable symptoms like cramping, diarrhea, and bloating. Regular consumption of dairy products has also been linked to prostate cancer, lung cancer, breast cancer, and ovarian cancer.

Myth 4: Kids need milk to be healthy.

After babies are weaned from breast milk or formula, they do not need any type of milk to be healthy. Milk consumption during childhood has even been linked to colic and type 1 diabetes. Another study found no evidence that low-fat milk plays any role in preventing childhood obesity.

Myth 5: Milk is heart-healthy.

Milk and other dairy products are the top sources of artery-clogging saturated fat in the American diet. Milk products also contain dietary cholesterol. Diets high in fat, saturated fat, and cholesterol increase the risk of heart disease, which remains America’s top killer.



The Negative Calorie Effect

February 8, 2016   Dr. Neal Barnard   ,

Are there “negative-calorie” foods—foods that burn more calories than they provide? Some Web sites would like you to believe that celery, carrots, or beets fit that bill. But the fact is, none of these foods actually burns more calories than it provides.

And you don’t need them. Scientific studies show that there is actually something better: foods that give you the energy and nutrition you need, while helping you trim away excess weight.


Let me describe a study conducted by our research team that showed the remarkable power certain foods have. Our participants were women who had been wrestling with weight problems for years. Many reported that their metabolisms seemed very slow. One said, “When I was young I could eat anything, but nowadays I gain weight just by looking at food!”

And it’s true: for many people, metabolism does slow over time. We know that because we can measure it. Arriving at our laboratory early in the morning, we fitted each participant with a special device that sampled the air she inhaled and exhaled. With some simple calculations that told us her calorie-burning speed.

Once her metabolism was measured, each participant then ate breakfast. Immediately, her metabolism picked up. As she absorbed the nutrients from the foods she ate, her metabolism rose and stayed higher than it had been for several hours. That’s normal.

But then, each participant began a low-fat plant-based diet. No meat, no dairy, no eggs, and keeping oils to a minimum. Fourteen weeks later, the participants came back to the laboratory and had their metabolisms measured again. And we found that the average after-meal metabolism was now 16 percent higher than before. That might not sound like much. But if you get that extra boost three times a day, the calorie burning adds up. In other words, a low-fat plant-based gives you a weight-control edge.

You can think of this as a “negative-calorie effect.” It does not mean that foods have no calories, or less than zero calories. Rather, it is a “calorie-subtracting” effect. The foods you eat have calories and healthful nutrients, and some of those calories power your body, while others are simply lost as body heat.

Watch Dr. Barnard discuss the link between diet and metabolism on The Dr. Oz Show: http://www.doctoroz.com/episode/negative-calorie-foods-why-people-think-they-can-chew-their-way-thin.


For extra credit, tweet photos of your favorite plant-based meals to @PCRM with #PlantBasedRx and let us know what you think.  



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