By Dr. Mercola
Evidence is mounting that sugar is the primary factor causing not just obesity, but also many chronic and lethal diseases.
Dr. Robert Lustig, one of the leading experts on childhood obesity, and arguably the number one enemy of the sugar lobby, has published a well written article in the prestigious scientific journal Nature arguing that sugar is a poison.1
He believes that the negative health effects of sugar consumption can no longer be ignored, any more than the health effects of tobacco and alcohol could.
According to Dr. Lustig, via the website Diet Doctor2:
"The problem with sugar isn't just weight gain ... A growing body of scientific evidence is showing that fructose can trigger processes that lead to liver toxicity and a host of other chronic diseases.
A little is not a problem, but a lot kills -- slowly."
For the first time in history, "lifestyle" diseases -- diabetes, heart disease, and some cancers -- are killing more people than communicable diseases. And treating these entirely preventable illnesses costs more than one-seventh of the U.S. GDP. It stands to reason then that simply preventing these diseases could save the US health care system around one trillion dollars a year.
One of the primary, and likely most effective ways of preventing these diseases would be to curb the outrageous over-consumption of sugar.
Dr. Lustig rightfully argues that sugar used to be available to our ancestors only as fruit or honey—and then only for a few months of the year—compared to today, when sugar (primarily in the form of high fructose corn syrup) is added to virtually all processed foods and drinks; even items you normally would not think of as being high in sugar. Tragically, many infant formulas even contain more than 50 percent sugar! "Nature made sugar hard to get; man made it easy," Dr. Lustig says.
Fructose is NOT the Same as Glucose
Glucose is the form of energy you were designed to run on. Every cell in your body, every bacterium -- and in fact, every living thing on the Earth -- uses glucose for energy.
Fructose is not the same molecule. Glucose is a 6-member ring, but fructose is a 5-member ring. Sucrose (table sugar) is 50 percent glucose and 50 percent fructose, and HFCS is 42-55 percent fructose.
If you received your fructose only from vegetables and fruits (where it originates) as most people did a century ago, you'd consume about 15 grams per day. Today the average is 73 grams per day which is nearly 500 percent higher a dose and our bodies simply can't tolerate that type of biochemical abuse. Furthermore, in vegetables and fruits, the fructose is mixed in with fiber, vitamins, minerals, enzymes, and beneficial phytonutrients, all of which help moderate the negative metabolic effects. So it's not that fructose itself is "poisonous"—it's the biologically inappropriate doses you're exposed to that make it hazardous to your health and well-being.
How High Fructose Corn Syrup has Decimated Human Health
We now know, without a doubt, that it's the excessive sugar content in the modern diet that is taking such a devastating toll on people's health. According to GreenMedInfo.com, scientific studies have linked fructose to about 78 different diseases and health problems3. Select the hyperlinks provided to review how fructose may:
✓ Non-alcoholic fatty liver disease (NAFLD)
✓ Intracranial atherosclerosis (narrowing and hardening of the arteries in your skull)
✓ Have a genotoxic effect on the colon
✓ Cause tubulointerstitial injury (injury to the tubules and interstitial tissue of your kidney)
✓ Promotes obesity and related health problems and diseases
High fructose corn syrup (HFCS) was invented in Japan in 1966 and introduced to the American market in 1975. Food and beverage manufacturers quickly began switching their sweeteners from sucrose (table sugar) to corn syrup when they discovered that high fructose corn syrup (HFCS) could save them a lot of money. Sucrose costs about three times as much as HFCS. HFCS is also about 20 percent sweeter than table sugar, so you need less to achieve the same amount of sweetness.
In the mid 1970s, dietary fats were blamed for heart disease, giving rise to the "low-fat craze," which resulted in an explosion of processed nonfat and low fat convenience foods—most of which tasted like sawdust unless sugar was added. Fructose was then added to make all these fat-free products more palatable. Yet as the low-fat craze spread, rates of heart disease, diabetes, and obesity skyrocketed...
Clearly, there was a major flaw in the plan, and it's not difficult to see that trading fat for sugar is not a wise move.
The problem is that excessive fructose consumption leads to insulin resistance, and insulin resistance appears to be the root of many if not most of the diseases listed above. Insulin resistance has even been found to be an underlying factor of cancer.
How Fructose Increases Insulin Secretion and Worsens Your Insulin Sensitivity
Interestingly, recent research published in the Proceedings of the National Academy of Sciences shows that fructose can activate taste cells found on your pancreas, a reaction that can increase your body's secretion of insulin4. And, while this is of particular concern for people prone to diabetes, if statistics are any indication, this could include virtually everyone.
At present, one in four Americans already have either pre-diabetes or some form of diabetes, and type 2 diabetes is directly linked to your diet, so anyone on a high-fructose diet can be at risk.
In this study, the researchers were able to demonstrate that fructose activates the same proteins in your pancreatic cells that your tongue uses to taste sweets. And when these cells are exposed to both glucose and fructose, they secrete more insulin than they do when exposed to glucose alone. According to Science News5:
"Most sugars join the [metabolic assembly line] at a point where a supervisory enzyme can control the flow of goods. But fructose comes in farther down, where it can lead to an overproduction of fat. And because fructose ... doesn't stimulate the same insulin response that glucose does, the hormone isn't doing the other regulatory things it usually does, like moderating appetite."
Limiting Sugar is Also Vital for Longevity
By increasing your insulin and leptin levels (and subsequently decreasing receptor sensitivity for both of these vital hormones), excessive sugar/fructose consumption not only increases your risk of type 2 diabetes, it also accelerates aging in general. In fact, limiting sugar in your diet is a well-known key to longevity, because of all the molecules capable of inflicting damage in your body, sugar molecules are probably the most damaging.
Two years ago, the journal Nutrients published an excellent report on the impact of fructose on aging.6 Fructose is a particularly potent pro-inflammatory agent that creates advanced glycation end products, commonly known as "AGEs."
AGEs are a complex group of damaging compounds that form when sugar reacts with amino acids. Besides oxidation, glycation and the subsequent formation of AGEs is one of the major molecular mechanisms causing ongoing damage in your body, which leads to disease, (premature) aging and, eventually, death. According to the authors:
"[T]he data are supportive that endogenous AGEs are associated with declining organ functioning. It appears that dietary AGEs may also be related... As of today, restriction of dietary intake of AGEs and exercise has been shown to safely reduce circulating AGEs, with further reduction in oxidative stress and inflammatory markers."
In short, if you want to live a long healthy life, you need to restrict your consumption of sugar, particularly fructose. As a standard recommendation to limit glycation, I strongly advise keeping your TOTAL fructose consumption below 25 grams per day.
Most people would be wise to limit their fructose to 15 grams or less however, especially if you have elevated uric acid levels, which can be used as a predictor for fructose toxicity. This includes keeping track of your fructose intake from whole fruits. To evaluate the fructose content of many common fruits, please see this helpful fructose chart. I recommend this lower level of 15 grams a day simply because if you consume processed foods or sweet beverages at all, you're virtually guaranteed to consume "hidden" sources of fructose that can have a major impact on your health.
When I have mentioned this in the past many people have strongly disagreed with me as they believe fruit is fine because it is natural. And it may be ok for some people, especially those doing long and intense exercise sessions. However, there is an easy way for you to find out your risk. If your uric acid is above 5.0 would be wise to follow the rule. The higher above 5.0 your uric acid is, the worse your risk for damage. If your uric acid is between 3.5 and 5 you should be fine. I believe I must have a genetic polymorphism for uric acid as mine is always above 5.5 even with intense exercise and less than five grams of fructose a day, so I nearly always avoid fruit.
The authors of that paper offer an in-depth review of the many health hazards of fructose, due to its pro-inflammatory actions:
"Accumulation of AGEs has been found in healthy aging persons, and this accumulation is higher during high glucose concentrations. Microvascular and macrovascular damage, seen in diabetes, is attributed to the accumulation of AGEs in tissues, but it is also associated with atherosclerosis, Alzheimer's disease, end stage renal disease, rheumatoid arthritis, sarcopenia, cataracts, and other degenerative ophthalmic diseases, Parkinson's disease, vascular dementia and several other chronic diseases. For instance, Bar et al. have demonstrated differential increases of AGEs products in Alzheimer's dementia and vascular dementia compared to controls. It has also been suggested that AGEs are involved in the loss of bone density and muscular mass associated with aging."
How to Tame Your Sugar Cravings
If you're struggling with sugar addiction, I recommend trying an energy psychology technique called Turbo Tapping, which has helped many "soda addicts" kick their sweet habit. If you still want to use a sweetener occasionally, here's what I recommend in lieu of sugar:
- Use the sweet herb stevia.
- Use organic cane sugar in moderation.
- Use organic raw honey in moderation.
Avoid ALL artificial sweeteners, which can damage your health even more quickly than fructose. Agave syrup has been touted as a healthy alternative by many, but don't fall for it. It's a highly processed sap that is almost all fructose, and should therefore be avoided.