Environmental Exposures and the Global Obesity Epidemic –
The numbers of obese people worldwide have been steadily escalating revealing a complex picture among cultures and their populations. About 69% of adults in the United States are overweight, and of those, almost one-third are obese, according to data from the CDC. Obese people are prone to chronic diseases including type-2 diabetes, high blood pressure, heart disease, stroke, and cancers.
For adults, overweight and obesity classifications are determined by using weight and height to calculate a number called the “body mass index” (BMI). BMI is used because, for most people, it correlates with the amount of their body fat. According to the CDC, an adult who has a BMI between 25 and 29.9 is considered overweight. An adult who has a BMI of 30 or higher is considered obese.
The commonly held beliefs about obesity include overeating and inactivity but do not fully explain the current obesity epidemic. There is growing evidence that indicates that for many individuals, the body’s natural weight-control mechanisms are not functioning properly. Because the obesity epidemic has occurred relatively quickly, current research indicates that environmental causes instead of genetic factors may be largely responsible.
What had been overlooked in the study of obesity until recently is that the earth’s environment has changed significantly during the last few decades. Production and usage of synthetic chemicals has become exponential with over 100,000 chemicals being used in diverse industries today. Many of these chemicals have powerful weight-promoting actions that diminish our metabolic mechanisms, confuse cell signaling and disrupt our appetite-regulating systems. These chemicals are being classified as obesogens.
For example, livestock, including cows, pigs, and poultry headed for market are frequently injected with estrogen compounds to fatten them while being fed hormone disrupting pesticide-laden grains. When we ingest the meat from these animals, it similarly affects our metabolism and “fattens us up” as well. Human exposure to these chemicals may damage many of the body’s natural weight-control mechanisms. Furthermore, the synergistic effects of multiple environmental toxins, combined with foods that are highly processed and nutrient poor, appear to play a significant role in the worldwide obesity epidemic.
Common obesogens include BPA, phthalates, pesticides, PFOA, nicotine and arsenic.
Environmental Exposures on Metabolism
Environmental toxins interfere with metabolism and the signals for how we store and burn fat. Increases in sugar and refined carbohydrate consumption lead to increases in insulin production and ultimately insulin resistance. Eventually, this leads to the transformation of sugars into fats and accumulation of fat in the liver. When the liver is burdened with excess sugars there is an increase in oxidative stress. Oxidative stress impairs the function of the mitochondria, the powerhouse within every cell that is responsible for energy production and cell integrity. Damaged mitochondria cannot effectively burn fat or calories leading to a slower metabolism and more weight gain.
Chemicals and our Endocrine System
Cortisol, a hormone produced by the adrenal glands, is part of our daily hormonal cycle and plays a key role in the body’s response to stress. Impaired glucose metabolism and cortisol activation can disrupt sleep cycles and increase blood sugar levels contributing to weight gain.
The thyroid gland, which is responsible for metabolism and how quickly the body burns energy is also impacted by environmental exposures. For example, heavy metals including mercury, affect thyroid function as well as the halogen chemicals known as chlorides, bromides and fluorides. These exposures can interfere with thyroid function and cause hypothyroidism, a sluggish metabolism and consequently weight gain.
Fat cells produce the powerful hormone leptin, a primary force instructing metabolism, weight loss, and hormone balance. Leptin communicates directly to the brain, telling the brain how much fat is in storage. Leptin is another control mechanism of appetite, energy, and metabolic rate. Leptin problems are the primary reason for food cravings, overeating, faulty metabolism, and obsessions with food, As chemicals induce inflammation in the body, they also induce leptin resistance.
While research linking environmental toxins and impaired detoxification to obesity grows, billions of dollars are pouring into obesity drug research to find the magic molecule that will burn fat or reduce appetite. It is now clear that environmental chemicals can cause weight gain and play a major role in obesity.
Most researchers have largely ignored the effects of environmental chemicals on metabolism while some researchers have started connecting the dots linking toxins with the global obesity epidemic. While research linking environmental toxins and impaired detoxification to obesity remains in its infancy, these factors can no longer be overlooked. Avoiding exposures, limiting sugar and refined carbohydrate intake, and enhancing detoxification are all part of a long-term effective weight management strategy.
High Glycemic Foods: Obesity and Breast Cancer Connection
Recent research implicates increased risk of breast cancer with higher glycemic load. According to the authors of the study, “Glycemic index and glycemic load are measures that assess different aspects of dietary carbohydrates. Glycemic index is a measure of the overall quality of carbohydrates in the diet whereas glycemic load incorporates both quality and quantity of carbohydrates consumed. If breast cancer risk is related to the overall insulin demand of the diet, a stronger association would be expected for glycemic load, as was observed in the present study.”
Epidemiological studies have shown that obesity is a risk factor for postmenopausal breast cancer and breast cancer relapse. This may be in part, due to the fact that estrogen compounds, including environmental estrogen disruptors, are stored in adipose tissue. Studies also suggest that hyperinsulinemia (high insulin levels in the blood) is another independent risk factor for breast cancer and may also have a substantial role in explaining the obesity-breast cancer relationship. Interestingly, another paper documented the effects of both caloric restriction and exercise on lowering leptin, the hormone involved in fat metabolism we mentioned earlier. Additional research has demonstrated that both weight loss and exercise, offer protection from breast cancer and survival following diagnosis.
In summary, research supports the benefits on breast health of a diet high in healthy “low glycemic index” foods and cutting back on high glycemic foods.
Glycemic Index (GI)
The glycemic index, also called GI, is a list of foods that contain carbohydrates. What makes it different from your grocery list is that it ranks how those carbohydrates affect your blood sugar levels. Current research suggests that stable blood sugar levels benefit health, and that frequent irregularities in blood sugar levels may contribute to other maladies like diabetes and heart disease.
The GI was created by analyzing, over time, the blood of healthy volunteers after they had ingested a variety of carbohydrates. Then, using a scale from 0 to 100, with 100 representing simple sugar, those foods were listed in the index according to how they affected the blood sugar levels of the volunteers. Highly processed foods like white bread and starchy food like potatoes earned a high number while foods such as whole grains, unsweetened yogurt and apples earned a low number, thus the terms high-glycemic and low-glycemic. Foods that rank at 70 or higher are high GI, while foods ranked below 55 are low GI. There is also a mid-range from 56 to 69 that includes syrups, pomegranate juice, muesli and some breads.
The glycemic index of a certain food also takes into account its type of sugar or starch, the amount of protein, fiber and fat that it contains, how highly processed it is, the way it has been cooked, cooking time, its acid content and ripeness. There are several different GI scales and testing methodologies available, some with differing values for the same food. Simply put, high-glycemic foods cause “spikes”- a rapid rise and fall in blood sugar and insulin levels because the body digests and absorbs them too quickly. These episodes have been linked to greater sensations of hunger and higher stress hormone levels. Experts believe that diets filled with high GI foods may lead to overeating, obesity and adult onset diabetes, and cancer.
By contrast, low-glycemic foods take much longer to digest, providing the body with a slow, steady supply of energy that prolongs a feeling of fullness and helps prevent overeating. If used as part of a broader balanced diet, the glycemic index is a good general reference for choosing healthy food.Some of the benefits gleaned from eating low-glycemic foods and maintaining stable blood sugar levels include:
- Weight control
- An increase in insulin sensitivity
- A lower risk of heart disease
- Healthy blood cholesterol levels
- An increase in satiety
- Improved physical endurance
- Faster recovery from exercise
How to Use GI
Common sense use of the glycemic index is as simple as replacing highly processed grains and sugars with whole grains, vegetables and fruit – and avoiding high GI foods by themselves. Soft drinks and other sweetened beverages, including most fruit juices, are particularly notorious in this regard. Try substituting drinks with sparkling water or unsweetened tea to avoid those nasty spikes in blood sugar.
Low GI foods are the least processed foods. Here are some examples:
- All non-starchy vegetables including spinach, onions and broccoli
- Temperate fruits, such as all berries, cherries, apples and pears
- Nuts, seeds, and legumes
- Unsweetened yogurt
- Whole grains that are minimally processed, preferably with the whole kernel, such as steel cut oats, brown rice, quinoa, millet, dense whole grain breads with nuts, seeds or sprouted grains, lightly sweetened granola or muesli and al dente pasta
High GI Foods
High GI foods are the most highly processed foods. Here are some examples:
- Refined flours and grains, including crackers, rice cakes
- Refined sweeteners including corn syrup and fructose.
- Low-fiber commercial breakfast cereals
- Sweetened beverages, including soft drinks and juice
- Tropical and dried fruits
- Starchy vegetables such as white potatoes and corn
Beyond the GI
In the struggle to maintain healthy blood sugar levels, there are other tools in the health toolbox besides the glycemic index. Here are some other ways you can promote blood sugar stability:
- Cut hydrogenated or partially hydrogenated oils from your diet completely. Trans fats found in hydrogenated oils have been shown to interfere with insulin secretion and increase blood sugar levels.
- Be sure to eat enough fish (sardines,wild salmon).Take fish oil supplements.
- Chromium and magnesium are vital for the body to properly maintain healthy blood sugar levels. Consider supplementing if dietary levels are not sufficient.
- If you do snack, use the principles of the glycemic index to make good choices, such as a handful of raw nuts or some plain yogurt with fruit instead of potato chips or pretzels.
- Eat plenty of fiber, especially soluble fiber.
- Use Cinnamon to help regulate blood sugar.
- Use healthy sweeeteners including agave nectar, stevia, dark chocolate, 70% o
- nclude garlic, shallots and onions to help contain insulin peaks
- Exercise regularly.
- Portion control
- Restful and restorative sleep of at least 7 hours
- Practice stress reduction and relaxation techniques (yoga, breath work)