Gluten: what does the science say?

Wheat

What is gluten?

Gluten is a type of protein that’s found in wheat, rye, barley and foods made from these grains. It gives elasticity to baked goods, and provides that chewy texture. Gluten in made of two smaller proteins, called gliadin and glutenin. Gliadins and glutenins are the two main components of the gluten fraction in wheat.

Does present-day wheat have more protein (and gluten) than ancient wheat?

The grain composition of present day wheat varieties is very similar to ancestral wheat varieties. A 2014 study from the University of Saskatchewan examined the literature regarding changes in wheat protein concentrations produced by Western Canadian bread wheat lines developed during the last 85 years. They found no increased protein content in modern lines, and noted that normal protein variations (from 11-15% protein) are only attributed to yearly fluctuations in environmental conditions.

In a related study of 37 wheat varieties dating from 1860 to present, varieties showed an average 0.01% per year increase in grain protein concentration, which accounted to only 1% increase over a century (Hucl et al. unpublished). A preliminary examination of gluten in 10 wheat varieties introduced from years 1860 to 1994 also disproved a chronological change in subunit profiles.

Is gluten now somehow harmful to humans because wheat has changed over the years?

Gluten, a protein found in wheat, barley, rye and other grains, must be avoided by 1 percent of the population with celiac disease, and perhaps another 6 percent with gluten intolerance. There is no scientific evidence that either wheat or gluten are harmful to the health of anyone who does not have one of these conditions. In fact, whole grains like wheat are recommended as part of a balanced diet and associated with a reduced risk of heart disease, obesity, type-2 diabetes, dementia and other health conditions.

A recent study from the University of Saskatchewan looked at wheat seeds since 1860 and showed that they have not changed. Further, genetically modified wheat does not exist in the marketplace. Since no commercial wheat is genetically modified, and there have been no changes to wheat’s DNA or core protein content.

Is it true that the wheat’s gliadin protein acts like an opiate, causing wheat-based foods to be addictive?

No. This claim is based on a 1979 study that found many common foods such as wheat, milk, rice and even spinach produce the same effect on the human brain. The study focused on small fragments of proteins known as peptides believed to be responsible for this effect. It is an area that deserves more study as it remains unclear that peptides are absorbed when consumed intact in wheat-based food.

Is a gluten-free diet (if you aren’t celiac or gluten-sensitive), a good way to lose weight?

The gluten-free diet is meant for people who have an allergy or intolerance to wheat or gluten. There is no scientific evidence to link wheat or gluten to weight loss. Weight problems are not the fault of one food (or in this case one specific protein found in some foods); it’s total diet and lifestyle that matter.

Some people who eliminate gluten from their diet will lose weight, because they will no longer be eating cakes, cookies, pastries and baked goods, and their usual fast foods like pizza, burgers and pasta are no longer easily accessible. It’s not the gluten that helps with weight loss, it’s the reduction of total calories, sugar and fat. You can simply cut back on these foods to lose weight without totally eliminating gluten from the diet.

Gluten-containing whole grains, such as barley, rye and whole grain wheat, are part of a healthy diet, even when trying to lose weight. To date, 14 cross-sectional studies have found that ~3 daily servings of whole grains is associated with lower body mass index in adults. And a study on 74,000 women over a 12 year period shows women who consumed more whole grains and whole wheat consistently weigh less than those who ate less of these fiber-rich foods, and were 49% less likely to gain weight compared to those eating foods made from refined grains.

Why do so many people say they feel better after going gluten-free?

For 1 percent of people with celiac disease and about 6 percent of people with gluten sensitivity, eliminating gluten will help relieve uncomfortable symptoms such as gas, bloating, headaches and diarrhea. These people are feeling relief, because they have finally found an answer to their digestive problems. It’s great if people who have struggled with undiagnosed celiac or gluten intolerance for years finally find something that works for them – and that’s true of about 5-10 per cent of our population.

But, people who do not have these symptoms or these medical conditions do not need to remove gluten from their diet. About 25 percent of consumers report buying gluten free foods, many needlessly. They may not understand that GF is meant for people with certain health conditions – not for the entire population. And, GF foods are often more expensive, less healthy (more sugar, refined ingredients, fat and salt) and more processed than other staple foods.

 

High fructose corn syrup in detail: what does the science say?

What is high-fructose corn syrup?

High-fructose corn syrup, also called HCFS or glucose-fructose, is a corn-derived liquid sweetener that is chemically similar to table sugar. It was first introduced to the food and beverage industry in the 1970s. HFCS immediately became an attractive alternative to sucrose because it is stable in acidic foods and beverages, and it is not granular in form, so it’s easier to add to liquid foods (such as pop). It is not meaningfully different in composition or metabolism from other fructose-glucose sweeteners, such as sucrose, honey, and fruit juice concentrates. Both HFCS and table sugar are made of glucose and fructose, and deliver 4 kcal/g.

Why is high fructose corn syrup at the centre of controversy and confusion?

The controversy started with the publication of a commentary in the American Journal of Clinical Nutrition (AJCN) in 2004, which suggested that HFCS in beverages might play a unique role in the epidemic of obesity, since increased use of HFCS in the United States mirrored the rapid increase in obesity. Although the authors of this commentary clearly stated that they were only describing a unique association and not a cause-and-effect relationship, a media frenzy ensued. Even though the original authors of the AJCN commentary were clear that they were simply offering a hypothesis, other investigators, the media, food manufacturers, and the public at large have contributed to this controversy, often without distinguishing between an association and cause and effect, while frequently confusing the sugars used in research studies, or exaggerating the implications of animal studies.

Is high fructose corn syrup the cause of the obesity epidemic?

No single food is the cause of obesity. Rather, obesity is a multifactorial condition that takes diet, exercise, genetics and environment into account. The hypothesis that HFCS is a unique cause of obesity is not supported by science because:

  • HFCS has the same sugars composition as other “benign” fructose-glucose sweeteners such as sucrose, honey, and fruit juice concentrates. And they are all metabolized the same way.
  • Increased caloric intake since 1970 was not due to added sugars (including HFCS) but rather was due to increased consumption of all calories, especially fat, flour and cereals.
  • Although pure fructose can cause metabolic upsets at high concentrations and in the absence of glucose, such experiments are irrelevant for HFCS, which is not consumed at extreme high levels and is not pure fructose.
  • There is no longer an association between HFCS and obesity in the United States: per capita consumption of HFCS has declined in recent years, whereas obesity rates continue to rise.
  • There is absolutely no association between HFCS use and worldwide obesity; HFCS is really a minor sweetener in the global perspective. There are epidemics of obesity and diabetes in areas where little or no HFCS is available (e.g., Mexico, Australia, and Europe).

Is high fructose corn syrup worse for our health than table sugar?

At this time, there’s not enough scientific evidence to show that HCFS is any less healthy than any other type of sweetener. One notable study compared the effects of HFCS and sucrose at 30% of calories in two randomized 2-day visits in normal-weight women. Concluding that there is nothing uniquely quantifiable about HFCS, they reported no significant difference between the two sweeteners in fasting plasma glucose, insulin, leptin, or ghrelin or in energy or micronutrient intake.

Studies show that there are no metabolic or endocrine response differences between HFCS and sucrose related to obesity or any other adverse health outcome. This is not surprising given that both of these sugars have or are:

We do know, however, that too much of any type of added sugar — not just high-fructose corn syrup — can contribute unwanted calories that are linked to health problems, such as weight gain, type 2 diabetes, metabolic syndrome and high triglyceride levels. All of these boost your risk of heart disease. For health concerns, it’s advised to cut back on added sugar, regardless of the type.

Soy foods in detail: what does the science say?

Does soy affect thyroid hormones?

High-level studies (a review plus two randomized controlled trials) have found that isoflavones from soy do not appear to have adverse effects on the thyroid in people with normal thyroid functioning.

People with low thyroid function (hypothyroidism) need to be assessed by a doctor, since soy foods may slightly increase the amount of thyroid medication. To date, only animal studies and case studies have looked at answering this question. More research is needed to evaluate the potential impact of soy foods and supplements on individuals with subclinical hypothyroidism.

Does soy increase the risk of breast cancer in women?

No, in fact soy may help prevent breast cancer. Meta-analyses examining the relationship between soy intake and breast cancer incidence found that soy is associated with a reduced breast cancer risk. Soy contains several compounds that may help inhibit cancer, including protease inhibitors, phytates, and isoflavones, particularly genistein.

Average isoflavone intakes from soy foods range from 25-50 mg/day in Asia, but are closer to 1-2 mg/day in North America. And Asian women who consume more soy than North American women have a 3- to 5-fold lower breast cancer risk.

Can I eat soy foods if I have had breast cancer?

Research suggests that breast cancer survivors can also safely consume soy foods in the same range as in the typical Asian diet (25-50 mg/day in Asia (from 6 – 11 g soy protein).

These studies found that soy foods have no detrimental effect on risk of breast cancer recurrence, and may actually reduce the risk. Importantly, soy does not appear to interfere with tamoxifen or anastrozole therapy.

These studies looked at a range of soy products with different levels of isoflavone content and found that none of the products showed an increase in breast cancer risk, suggesting that enjoying either processed or traditional soy foods is acceptable for breast cancer survivors.

One study followed more than 9,500 women in the U.S. and China who had been diagnosed with breast cancer and found that those who consumed at least 10 milligrams of soy isoflavones per day (the amount in a half cup of soymilk) had a 25 percent lower chance of breast cancer recurrence than those who consumed less than 4 mg of isoflavones.

Whether a person has had breast cancer or not, the Canadian Cancer Society says that “up to 3 servings a day of soy foods, such as tofu or soy milk, may be included in the diet.”

Does soy cause fertility/reproductive problems in men?

No, the science clearly shows this is not the case. Studies have found no statistically significant effect of soy consumption from different soy sources (milk, flour, isolated protein, tofu, etc.) on:

  • levels of follicle-stimulating hormone
  • testosterone levels (low levels are associated with conditions causing infertility other reproductive indicators)
  • sperm or semen parameters
  • erectile dysfunction

It’s important to note that this myth largely stems from one human study that was popularized in the media. It focused on a 19-year old male who developed low testosterone after consuming upwards of 20 servings of soy foods daily. Ingesting that much soy represents an unbalanced diet with little variety or moderation, and is outside of the norm. It is not representative of the average male soy intake.

Recent studies indicate that soy consumption – in amounts of 2-4 servings of soy foods per day – will not affect fertility in males. A 2010 meta-analysis examined 15 studies to determine whether isoflavones exert estrogen-like effects in men. The results showed that neither soy foods nor isoflavone supplements lower testosterone levels or affect fertility in men.
A 2010 Medline literature review published in the journal Fertility and Sterility yielded similar results. The researcher found that soy does not alter testosterone or estrogen levels, and that isoflavones have no effect on sperm count and do not exert feminizing effects in men.

Whole grain pizzadillas and tofu ranch dipping saunce

Whole grain pizzadillas and tofu ranch dipping saunce

These easy lunchbox fold-overs are a cross between pizza and quesadillas, and a great replacement when your kids get bored of sandwiches. Paired with the creamy tofu ranch dip and assorted vegetables, they’ll be a huge hit at lunchtime.

Ingredients:

2 tbsp sodium-reduced tomato sauce

2 whole grain wheat tortillas (6 inch rounds)

1/3 cup shredded mozzarella or soy cheese

2 tbsp finely chopped sweet peppers

1 small mushroom, thinly sliced

Method:

Spread tomato sauce on one tortilla.

Sprinkle cheese, sweet peppers and mushrooms over sauce.

Top with second tortilla.

Cook in non-stick pan over medium heat turning over once until golden brown and cheese is melted, 4-5 minutes.

Let cool and cut into wedges.

Serve with tofu ranch dipping sauce.

Nutrition facts (per 1 pizzadilla): 285 calories, 7 g fat, 40 g carbohydrate, 16 g protein, 550 mg sodium, 6 g fibre
Convenience tip: If you have 10 minutes to spare, make the pizzadillas the night before for easy lunchbox packing in the a.m.

Tofu ranch dipping sauce

As a dip, dressing or sandwich spread, this wonderful condiment will soon become a staple in your fridge. With the piquant and savoury appeal of ranch dressing, kids will love to use it as a dip, and you’ll be confident knowing that unlike commercial dressings, it’s not high in calories, fat or sodium!

Ingredients:

12 oz. (350 grams) silken tofu

ÂĽ cup apple cider vinegar 3 tbsp lemon juice

1 tbsp olive oil 2 tbsp chopped fresh Italian parsley 2 tbsp chopped fresh dill ÂĽ tsp garlic powder ¼ tsp salt ¼ tsp pepper

Method:

In a food processor, add all ingredients and process until smooth.

Adjust salt and pepper to taste.

Serve with assorted vegetables for dipping.

Nutrition Facts (per 2 tbsp): 28 calories, 2 g fat, 1 g carbohydrate, 2 g protein, 40 mg sodium, 0 g fibre
Parent tip: try this dressing as a sauce for salmon – it’s divine!
Convenience tip: if you have a hand blender (also called an emulsion blender), skip the food processor and make this dip right in a bowl!

Whole grain pita crisps

Whole grain pita crisps

These crispy, whole grain, baked chips add super crunch to lunch and are perfect for dipping. Look for pitas made from whole grain whole wheat flour to boost the fibre and nutrient content of these crisps.

Ingredients:

1 whole grain pita (6 inch), cut into 2 halves

1 tsp mild-flavoured oil, such as corn or soy

1 tbsp grated Parmesan cheese

1/8 tsp garlic powder

Method:

Preheat oven to 350°F and line baking sheet with parchment paper.

Open the pita carefully so it does not tear.

Brush the inside of each half with oil. Sprinkle with Parmesan cheese and garlic.

Cut each half of pita into 8 triangles using a knife or pizza cutter.

Bake about 7 minutes, or until triangles are golden and crispy.

Nutrition facts (per 8 crisps): 120 calories, 4 g fat, 17 g carbohydrate, 5 g protein, 218 mg sodium, 2.5 g fibre.

Soy Hummus

In this unique version of hummus, traditional sesame seed tahini is replaced with the equally “nutty” taste of soy butter. Bonus: it’s now school-safe for classrooms where nuts and seeds are restricted.

Makes 8 servings (each serving is 1/3 cup)

Ingredients:

19 oz. can no-salt-added chickpeas, drained

1/4 cup silken tofu

1/4 cup fresh lemon juice

2 tbsp soy butter (such as Wowbutter)

1 tbsp extra virgin olive oil

2 tsp ground cumin

1 clove garlic, minced

1/2 tsp salt

1/4 tsp freshly ground black pepper

Method:

In a food processor, add chickpeas, tofu, lemon juice, soy butter, oil, cumin, and garlic.

Process until smooth.

Add salt and pepper, adjusting to taste.

Serve with whole grain pita crisps and vegetables for dipping.

Note: If you use canned beans that contain added salt, omit the ½ tsp of salt in the recipe.

Nutrition Facts (per 1/3 cup serving): 156 calories, 6 g fat, 20 g carbohydrate, 7 g protein, 150 mg sodium, 4 g fibre.