Healthy Food & Healthy Living by Dr. Ayala

The dos and don'ts of colorectal cancer prevention

Cancer of the colon and rectum are the third most common cancer in the world, accounting for 10 percent of cancer overall. Colorectal cancer is correlated with industrialization and is more common in higher income countries. In fact, a rise in its incidence usually coincides with the spread the western diet and lifestyle – Japan, Singapore and Eastern European countries experienced a doubling of colorectal cancer rates in the last few decades – therefore nutrition and lifestyle have always seemed to play a big part in increasing the risk for this often deadly disease.

The World Cancer Research Fund is a non-profit that funds scientific research on cancer prevention and promotes healthy living. A new authoritative report from its Continuous Update Project reviewed the current research papers (hundreds of them), weighed the evidence, and came out with an analysis of what we can all do about reducing our risk of colorectal cancer.

Reducing risk, increasing protection

The expert panel found convincing, consistent and cumulative evidence for several modifiable factors:

Probably protect against colon cancer:

• physical activity

• foods containing dietary fiber – the data is about fiber contained in food naturally, not fiber supplemented to food or in supplements

• garlic, milk, and calcium – evidence not as strong as the factors mentioned above, but still quite convincing

Probably increase risk of colon cancer:

• consumption of red meat and processed meat – this is a dose-response relationship, the more red/processed meat the higher the risk

• alcoholic drinks (by men and probably by women)

• body fatness and abdominal fatness – abundant and consistent evidence that obesity, and especially increased belly fat, are a serious risk factor

For other factors the panel found that the evidence is limited and only suggestive of a cancer causing effect:

Maybe protective foods:

• non-starchy vegetables
• fruits
• foods containing vitamin D

Maybe risky foods:

• Foods containing iron
• cheese
• foods containing animal fats
• foods containing added sugars

A plant based diet for cancer prevention

Although cancer is a disease caused by many factors – genetic predisposition and environmental exposures to name just a few – experts agree that many cases of cancer can be prevented. Scientists estimate that by eating healthy, being physically active and maintaining a healthy weight we can prevent about a third of the most common cancers.

What is healthy eating? This report, like many others points toward a more plant centered diet as the best description of what eating well is at its essence.

There is no compelling evidence to convince even me (full disclosure: I am a lifelong vegetarian) that meat in moderation causes cancer or any other disease, but there’s no doubt that half a pound of meat a day – which is what the average American eats – is way too much.

The highly processed food and fast food diet (which can easily be called the fiber-less diet) is definitely the riskiest way to eat when it comes to colorectal cancer, and it plays a role in numerous other ailments, too.

This weekend marks the official beginning of barbeque season, so how about a few more veggies on that skewer?

Dr. Ayala

Reposted as part of Food Renegate's Fight Back Fridays--go join the food fight!

Sampling our way into healthy eating

Here’s something every food maker knows: Sampling drives trial. Sampling also drives sales. Giving future consumers a taste of the product is perhaps the most honest of marketing tools (let the food speak for itself!) and the most effective way to engage and impress target audiences.

And those little samples taste so good! There’s nothing like that first bite, the first burst of flavor! That’s why the appetizer tastes so good and the entrée is so often disappointing; that’s why we love tapas bars. The sample is also valued because it’s free — we all love free stuff, no matter how small, and no matter how much money we have.

So why not try sampling healthy offerings to kids as a way to encourage them to select a new healthy dish?

As I’ve note in a previous post, I think it’s about time we applied the methods the food and beverage industries have been studying and perfected for decades to improve kids’ choices in the school cafeteria -- and at home.

Would sampling of healthy alternatives work?

I was glad to find a new study in the journal Appetite that took this idea and conducted a controlled test of the effect of healthy food samples on young people’s choices.

The study enrolled 197 Dutch 17-25 year-olds, and was performed in 5 college lunch cafeterias, in which 4 new, recently launched but unbranded products were introduced: Low fat bread spread, low fat cheese, fruit juice and a fruit and veggie juice.

(For those of you not impressed by the “healthy choices” in this study: I hear you and see your point. But arguing whether low fat margarine and cheese and fruit juices are “healthy” would distract us from the study’s main point, so let’s move on.)

For the experimental group, bite- or sip-sizes samples were placed in front of the new product. The cheese and low fat margarine were spread on a small piece of bread. A sign indicated these were free samples.

The control group was not exposed to samples.

For both the control and the experimental groups, the buffet products were identified by name, but nutritional information, such as caloric content, wasn’t mentioned.

Samples did drive choice of the new products. In fact, the new offered food was selected instead of the traditional full fat offering 15 percent more often when a sample was tried.

Try it at home, try it at school

A few ideas you can suggest to your lunch ladies:

• Place tiny trial size offerings in front of a new healthy dish: This way kids have a “no-risk” way of trying it. Even if the kid ends up going with the old familiar offering, at least he tried – every exposure opens the palate and mind a little bit!

• If you have a cafeteria line offer samples of the healthy stuff to sweeten the wait (a volunteer can do that): I’m sure those will be appreciated!

• Make it cool and catchy to try. Jamie Oliver gave out “I tried something NEW” in his Jamie Oliver’s Food Revolution.

Try at home:

• Offer a dinner preview: If you have parts of dinner ready well before dinner time – I’ll admire you for that – offer a bite of what’s to come as a sample when your kids come home from school. Mine usually arrive ravenous -- they’ll devour whatever I put on the counter.

• Create compelling samples: If hummus isn’t the subject of craving at your home, it might look much more exciting on a freshly toasted sliver of pita, garnished with a slice of cucumber, with a dark kalamata olive on the side for color contrast. I’m sure you have some great ideas on how to combine the tried and true with the unfamiliar.

• Offer samples to the hungry: Hunger is the best flavor enhancer!

• Some of my favorite sample containers: endive leaves, halved mini bell peppers, Chinese ceramic soup spoons, and ok, I’ll have to admit to this one: scoops baked tortilla chips – whatever you put in that scoop shaped chip will be devoured!

Please share your sampling stories!

Dr. Ayala

Reposted as part of Food Renegate's Fight Back Fridays--go join the food fight!

When do kids develop food preferences? New study and 5 practical tips

Research shows that although there’s a natural attraction to sweetness and saltiness, taste preference has much to do with exposure, especially early exposure. Infants usually accept whatever they’re fed, and that’s why kids around the world reflect the culinary traditions of their parents. In some cultures kids will eat spicy, sour and even bitter foods, while in others kids have a narrower range, and stick with sweet fat and salty.

When do babies develop flavor preferences?

The window of maximum plasticity in flavor openness probably occurs very early on. Studies suggest that babies whose mothers ate certain foods during pregnancy or breastfeeding tended to like these same foods later on (the flavor of foods is reflected in amniotic fluid and in breast milk, therefore the baby is exposed to mom’s flavor preferences).

A new study from the Monell Center in Philadelphia, published in The American Journal of Clinical Nutrition, tried to figure out the time frame of that sensitive period – the time in which baby’s mind and palate are open and accepting to new flavors – by an interesting experiment.

The study recruited about 70 babies whose parents selected to formula feed, and assigned them to either ordinary cow-milk based formula (Enfamil), or hydrolyzed protein formula (Nutramigen) at different ages and for varying periods of time.

Now, I don’t know if you’ve tried baby formulas, but I have. Mostly out of curiosity, I’ve tasted lots of the (vegetarian) food stuffs designed for babies. I mean no offense, and this is of course just my personal opinion, but infant formulas have a unique appeal to babies only – I doubt any adult would add this milk to his morning coffee. But even more astoundingly weird tasting are the hydrolyzed protein formulas. These are the formulas that use amino acids instead of whole proteins, and are given to babies with serious allergies and intolerances. Let’s just say that they have a distinct taste and smell and are a little bitter and sour. In fact, most babies older than 4 months will outright reject the hydrolyzed protein formulas unless they’ve been exposed to it in the first months of life.

The researchers in this study, led by Julie Mennella, found that exposing babies to hydrolyzed protein formulas for 1 month was enough to make the baby open to its taste at the age of 7.5 months. Exposure to hydrolyzed protein formulas for 7 months, as opposed to 3 or 1 month, made babies more accepting of the formula, suggesting that the dose and duration of exposure matter, but what mattered most was timing.

Exposing babies to the unusual flavor was most effective when it occurred really early, and the babies accepted hydrolyzed protein formulas better at 1.5 months and 2.5 months than at 3.5 months. At 3.5 to 4 months the flavor acceptance window seemed to close and the babies just refused the Nutramigen!

Not all is lost

Although it’s easiest to introduce new flavor during the maximum acceptance window, it’s never too late to expand your kid’s palate and broaden their interest in healthy food. As we know, young kids will absorb a new language quickly if immersed in it – grammar, accent and all – while older kids and adults will have to put in more of an effort. But I think learning to enjoy new, healthy flavors is always possible, just like it’s always possible to acquire a new language – it will just take more work, and perhaps a dedicated tutor.

Five tips for developing kids’ healthy flavor preferences

• Eat well as a mom-to-be: If mom eats her fruits and veggies, baby is exposed to their flavor in-utero, a double win!

• Breastfeed if you can: Breast milk is the ideal baby food for so many reasons. When it comes to flavor development remember that unlike formula, which is uniform, no two breast milk meals are the same, as breast milk reflects mom’s diet; therefore a breastfed baby is exposed to more flavors than a baby who is formula fed. Studies show that breastfeeding may facilitate the acceptance of new foods in childhood.

• Stay away from the sweet-salty-fatty trap: Babies and kids have a natural affinity to sweet and salt. Our job as parents is to expose our young ones to what’s good and healthy, not to what they’ll surely eat. Do your kids a favor and don’t create an expectation that all food should be sweet – expecting the usual sweet –salt-fat trifecta is a preference that can lead to a poor diet and obesity.

• Expose young kids to a variety of healthy foods: Let them experience many flavors and textures, especially in their first two years of life.

• Repeat exposures: Many studies show that repeated exposure works. Even if a vegetable is initially disliked it’s worth persisting at least eight times – kids do change their mind.

Early exposure matters, but it’s never too late to move to healthier eating habits and develop a fondness of wholesome, plant-based foods!

Dr. Ayala

Reposted as part of Food Renegate's Fight Back Fridays--go join the food fight!

Should parents restrict unhealthy food?

We want what’s best for our kids, therefore we want them to eat well, but what is the best way to influence our kids’ eating habits?

I believe in the importance of good parental role-modeling regarding food choices; We have to watch what and how we eat not only for our own well-being, but because our kids are watching!

I also believe that we as parents have the right and the duty to decide what goes into our pantry and on our table.

But when it comes to the issue of control over kids’ food intake it gets a little more complicated. Well-meaning parents, consciously or not, often participate in some form of pressure or restriction to further reinforce what they see as good eating habits.

I devoted a previous post to the issue of pressuring kids to eat healthy — pressure includes common practices, such as prizes and coercion tactics — not cruel torture. I concluded that pressure is counterproductive, and is more likely to lead to decreased consumption of the target food (aside from fostering an overall unpleasant experience).

But what about restricting foods you perceive as unhealthy? Could prohibiting certain unhealthy foods from kids benefit their diet?

I’m sure most of you already have an opinion about the wisdom and fairness of such tactics, but I pulled out a few studies to see if we can look at this topic in a more evidence-based way before we get to that.

There are several studies showing a correlation between parents’ restrictions on food and overweight and obesity; the more restrictions on food intake the higher the body-weight. In these studies one can argue that parents restricted food because the kid was getting chubby, and not the other way round. That’s why I’ll discuss two studies that actually perform an experiment, and don’t just look at associated findings. Both studies were lead by Esther Jansen, a clinical psychology researcher and both were published in the research journal Appetite.

In the first study, 74 kids aged 5-6 years were recruited from six elementary schools in the Netherlands, Germany and Belgium. The researchers set out to test whether prohibiting snack foods elevates their desirability and consumption. The snack food was M&M’s of the red and yellow variety, and crisps (chips in American), also in red and yellow. The snacks did not differ in taste, only in color (yeah, that red doesn’t come from strawberries or cherries; it’s just color).

The kids were randomly assigned to either a prohibition group, or a no-prohibition (control) group. Each kid was tested individually and answered questions about taste, satiety and desirability of the snacks.

Four bowls were filled with measured amounts of the snacks. In the first phase of the experiment, the kids were left alone with the four bowls for five minutes, in which the prohibition group was instructed not to eat red snacks, and the control group kids could eat whatever they wanted. The bowls were then taken away and measured. The level of desire for the snacks was assessed between the two phases of the tasting experience. In the second phase, both groups of kids had five minutes in privacy in which they could eat whatever they wanted from the four replaced and measured bowls of snacks.

The desire to eat the forbidden red snack increased after the prohibition even though this prohibition lasted only five minutes. Kids that were forbidden the red snack also ate relatively more of it in the second phase once they could.

This raised an interesting possibility: If restriction creates desirability, can restriction be used for positive purposes? Can we make healthy foods more attractive by forbidding them?

That’s exactly what the researchers set out to test in the second experiment. Seventy kids, aged 5-7 years were divided into three groups. This experiment followed much the same protocol of the previous one, but the four foods tested this time were pineapple pieces, banana slices, M&Ms and fruitgums. In the first phase, one group was prohibited to eat from the two fruit bowls, the second group was prohibited to eat from the two candy bowls, and the control group could eat whatever they wanted. In the second phase, all kids could eat whatever they pleased.

And the results? Kids in both the fruit-banned group and the candy-banned group ate more of the forbidden food during the second phase of the experiment. What’s more, total food intake (and total calorie intake) was higher in the two prohibition groups compared to the controls, proving that prohibition indeed results in higher intake, not only of tempting unhealthy food, but also of food kids usually don’t crave and fight over.

These studies support previous research showing that strict restrictions of foods lead to unintended consequences (many argue that The Prohibition in the twenties and early thirties increased drinking—or at least binge drinking—proving the same point).

What’s a parent to do? As with many other issues of effective parenting, I think what we’re all looking for is the middle ground between too much freedom, which isn’t a good thing for a kid, and to much control, which usually backfires, leads to rebellion, and I personally feel isn’t really fair!

A few suggestions I follow (none too strictly):

• Strive to make your home a sanctuary of nothing but healthy wholesome foods (by my definition that does include quality desserts in moderation).

• Try to provide as many of the meals your family eats.

• Don’t worry about imposing your rules out of home. I don’t dwell too much on what my kids eat at other people’s home or about the snacks they’re served at parties and sports events. Kids should know what their parents think, but then use their own judgment. I see with satisfaction that my kids often dismiss the typical after-soccer snacks and choose healthier options out of home, too.

• Provide an explanation for your objection to foods you think aren’t good to eat.

• Make healthy eating so pleasurable and tasty that it would be self-evident that anyone would prefer it over fast food and junk food. It actually isn’t that hard to do. If kids get accustomed to the great taste of quality real food, junk food will look more and more like the cheap imitation it really is.

And no, I definitely don’t think we should prohibit healthy foods so that kids will desire them more: I’m against tricking kids.

Kids will need to eventually build up their own self-control. Empowering them with the knowledge and tools to do so isn’t easy, but providing the control from the outside isn’t the solution either.

Please share your experience, opinion and advice.

Dr. Ayala

Reposted as part of Food Renegate's Fight Back Fridays--go join the food fight!