• 
  The overconsumption of Sugar is increasingly being linked to
  brain-related health issues such as depression, learning disorders,
  memory problems and overeating
  


• 
  Research suggests consumption of Sugar and sweets can trigger
  reward and craving states in your brain similar to addictive drugs
  


• 
  Not all sugars have the identical effects. Fructose has been shown
  to activate brain pathways that increase your interest in food,
  whereas glucose triggers your brain’s satiation signal
  

By Dr. Mercola

While all cells in your body can use glucose for energy, when you burn
fat as your primary fuel your liver produces ketones that burn far
"cleaner" in that they generate fewer reactive oxygen species (ROS) and
secondary free radicals than sugars. The conventional view is that you
need Sugar or glucose to satisfy your energy needs, but only a very
small amount of sugar is actually required. Because sugar represents
calories, excessive consumption will negatively affect your health.

If you haven't given much thought to how much sugar you consume and
what it may be doing to your health, now is the time to get educated.
Overconsumption of sugar is increasingly being linked to brain-related
health issues such as depression, learning disorders, memory problems
and overeating.

Your Body Recognizes Sugar as a 'Drug'

Writing in The Atlantic, neuroendocrinologist Dr. Robert Lustig,
professor of pediatrics in the division of endocrinology at University
of California, San Francisco, states:

"… [T]he [U.S.] war on drugs has taken a back seat, but not
because it has been won. Rather, because a different war has
cluttered the headlines — the war on obesity. And a substance
even more insidious, I would argue, has supplanted cocaine and
heroin.

The object of our current affliction is sugar. Who could have
imagined something so innocent, so delicious, so irresistible …
could propel America toward … medical collapse?"

Previous research involving humans and laboratory rats suggests consumption of sugar and
sweets can trigger reward and craving states in your brain similar to
addictive drugs. Not only can sugar and sweets substitute for drugs
like cocaine, in terms of how your brain reacts to them, they can be
even more rewarding.

The dramatic effects of sugar on your brain may explain why you may
have difficultly controlling your consumption of sugary foods when
continuously exposed to them. Another study suggests a high degree of overlap exists between brain regions involved
in processing natural rewards, such as sugar and sweets, and drugs of
abuse.

"'Non-drug' or 'behavioral' addictions have become increasingly
documented … and pathologies include compulsive activities such
as shopping, eating, exercising, sexual behavior and gambling.
Like drug addiction, non-drug addictions manifest in symptoms
including craving, impaired control over the behavior,
tolerance, withdrawal and high rates of relapse."

The Biology of Your Brain: How Bad Habits Like Sugar Addiction Take
Root

An article published by CNN Health reminds us that the connection between your nucleus accumbens and
prefrontal cortex drives intentional actions, such as deciding whether
you will take another bite of chocolate cake, for example.

Your prefrontal cortex also activates hormones like dopamine,
triggering thoughts such as, "Hey, this cake is really good. And I'm
going to remember that for the future." Lustig explains the biological
process that takes place when you consume sugar or any addictive
substance:

"The brain's pleasure center, called the nucleus accumbens, is
essential for our survival as a species. … Turn off pleasure,
and you turn off the will to live. But long-term stimulation of
the pleasure center drives the process of addiction.

When you consume … sugar, your nucleus accumbens receives a
dopamine signal, from which you experience pleasure. And so you
consume more. The problem is with prolonged exposure, the
signal … gets weaker. So you have to consume more to get the
same effect — tolerance. And if you pull back on the substance,
you go into withdrawal. Tolerance and withdrawal constitute
addiction. And make no mistake, sugar is addictive."

Brain-injury survivor and author Debbie Hampton explains how habits are
formed around addictive behaviors:

"Every time you follow the same path, a specific pattern is
activated and becomes more defined … and it becomes easier to
activate the circuit the next time. … Pretty soon, the bad
habit neuronal pathway becomes the unconscious default, and
your brain, wanting to be efficient, just takes the easiest,
most familiar route. This is particularly true in the case of
depression.

In a depressed brain, there's less dopamine activity happening
in the nucleus accumbens, which means that things that used to
be enjoyable are not as pleasurable, and the only things that
motivate it have to have a big dopamine payoff, which are the
baddest of the bad habits, such as junk food, drugs, alcohol
[and] gambling."

Brain Imaging Shows Food Addiction Is Real

Research published in the American Journal of Clinical Nutrition examined the effects of high-glycemic index (GI) foods on brain
activity, using functional magnetic resonance imaging (fMRI). Twelve
overweight or obese men between the ages of 18 and 35 consumed one
high-GI and one low-GI meal.

Imaging was completed four hours after each test meal to assess the
cerebral blood flow as a measure of resting brain activity. The
researchers expected brain activity to be greater after the high-GI
meal in regions related to craving, eating behavior and reward.
According to the researchers:

"Compared with a … low-GI meal, a high-GI meal decreased plasma
glucose, increased hunger and selectively stimulated brain
regions associated with reward and craving in the late
postprandial period. … [T]he high-GI meal elicited greater
brain activity centered in the right nucleus accumbens."

The study demonstrates what you may experience when eating a high-GI
meal. After rapidly digesting net carbohydrates, your blood sugar
initially spikes, followed by a sharp crash later. As noted by
researchers, this crash in blood glucose stimulated greater brain
activity in the nucleus accumbens, the brain's pleasure center Lustig
mentioned above.

Can Too Much Sugar Contribute to Alzheimer's Disease?

While insulin is usually associated with its role in keeping your
blood-sugar levels in a healthy range, it also plays a role in brain
signaling. In one animal study, when researchers disrupted the proper
signaling of insulin in the brain, they were able to induce many of the
characteristic brain changes seen with
href="http://articles.mercola.com/sites/articles/archive/2015/08/13/sugar-alzheimers-disease-link.aspx"
>
Alzheimer's disease

, including confusion, disorientation and the inability to learn and
remember.

It's becoming increasingly clear that the same pathological process
that leads to insulin and
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>
leptin resistance

, as well as
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>
type 2 diabetes

, may also hold true for your brain. As you overindulge on sugar and
grains, your brain becomes overwhelmed by the consistently high levels
of insulin. Eventually insulin, leptin and signaling become profoundly
disrupted, leading to impairments in your memory and thinking
abilities.

A study published in Diabetes Care found that type 2 diabetes is
associated with a 60 percent increased risk of dementia in men and
women.

Research featured in the New England Journal of Medicine noted a mild
elevation of blood sugar, such as a level of 105 or 110, is also
associated with an elevated risk for dementia.

Dr. David Perlmutter, neurologist and author of the books "Brain Maker"
and "Grain Brain," believes Alzheimer's disease is primarily predicated
on lifestyle choices, including sugar consumption. He suggests anything
that promotes
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>
insulin resistance

will ultimately also raise your risk of Alzheimer's.

Glucose and Fructose: How Do They Affect Your Brain?

Increases in processed fructose consumption, typically in the form of
href="http://articles.mercola.com/sites/articles/archive/2015/01/21/corn-syrup-toxic.aspx"
>
high-fructose corn syrup (HFCS)

, seem to be running parallel to the spikes seen in
href="http://articles.mercola.com/sites/articles/archive/2016/04/20/overweight-diabetes-rates-global-crisis.aspx"
>
obesity

rates, so much so that diets high in it are thought to promote insulin
resistance and weight gain. The Journal of the American Medical
Association featured a study involving 20 adult volunteers who underwent magnetic resonance imaging
sessions at Yale University to identify neurophysiological factors
related to fructose versus glucose consumption.

The research suggests fructose — a type of sugar commonly extracted
from corn and found in sweetened products like soda — may activate
brain pathways that increase your interest in food, whereas glucose
ingestion appears to trigger your brain's satiation signal, effectively
telling you "you've had enough." When participants ingested glucose and
were then shown food pictures, their brains registered increased
measures of satiety and fullness. The researchers noted:

"Glucose … ingestion reduced the activation of the
hypothalamus, insula and striatum — brain regions that regulate
appetite, motivation and reward processing; glucose ingestion
also increased functional connections between the
hypothalamic-striatal network and increased satiety."

In contrast, when the participants consumed fructose and were presented
with images of food, more activity was noted in the orbitofrontal
cortex, an area linked to increased motivation to seek out rewards,
such as drugs or food.

Subsequent research, presented in the Proceedings of the National Academy of Sciences USA,
went a step further to investigate the effects of sugar on
food-approach behavior. After ingesting either fructose or glucose, 24
volunteers underwent two fMRI sessions while viewing pictures of
high-calorie foods and nonfood items in a block format.

After each block, participants were asked to rate their hunger and
desire for food, as well as perform a decision task. The decision task
involved choosing between an immediate food reward or a delayed
monetary bonus. Hormone levels were measured at baseline and 30 and 60
minutes after the sugars were consumed. The authors of the study noted:

"Parallel to the neuroimaging findings, fructose versus glucose
led to greater hunger and desire for food and a greater
willingness to give up long-term monetary rewards to obtain
immediate high-calorie foods. These findings suggest ingestion
of fructose relative to glucose results in greater activation
of brain regions involved in attention and reward processing,
and may promote feeding behavior."

Both of these studies underscore the importance of paying attention to
the type of sugars you consume. Clearly, fructose disrupts your brain's
signaling mechanism that is designed to tell you when you've had
enough. Because fructose fails to stimulate insulin, which in turn
fails to suppress ghrelin, or "your hunger hormone," which then fails
to stimulate leptin or "your satiety hormone," you are likely to eat
more and develop insulin resistance when consuming fructose.

The second body of research seems to indicate fructose intake can
influence you to act impulsively with respect to food, consuming more
and more of it even when your body should have told you it's had
enough. As you may imagine, continuing to consume large amounts of
fructose will become increasingly problematic if you've already
developed a bad habit of overeating.

Fructose Packs on the pounds Faster Than Any Other Nutrient

Because

fructose

is often consumed in liquid form, mostly as HFCS, its negative
metabolic effects are even further magnified. Energy drinks, fruit
juices, soda and sports drinks, as well as countless other sweetened
beverages, contain HFCS. Like all fructose, HFCS is metabolized as body
fat far more rapidly than any other sugar.

Similar to alcohol, the entire burden of metabolizing fructose falls to
your liver. This severely taxes and overloads it, introducing the
possibility of liver damage. Fructose also promotes a particularly
dangerous kind of body fat called adipose fat. This type of fat
collects in your abdominal region and is associated with a greater risk
of heart disease.

Although HFCS has about the same amount of fructose as cane sugar, it
is in a "free" form that is not attached to any other carbs. In
contrast, fructose in fruits and cane sugar is bonded to other sugars,
resulting in a decrease in metabolic toxicity. Consuming foods
containing high amounts of fructose — even if it's a natural product —
is the fastest way to trash your health. Among the health problems you
invite when you consume high amounts of fructose are:

• 
  Arthritis, cancer, gout and
  href="http://articles.mercola.com/sites/articles/archive/2015/03/16/added-sugar-heart-disease.aspx"
  >
  heart disease
  
  


• 
  Insulin resistance, metabolic syndrome, obesity and type 2 diabetes
  


• 
  Elevated blood pressure, LDL (bad) cholesterol, triglycerides and
  uric acid levels
  


• 
  href="http://articles.mercola.com/sites/articles/archive/2016/01/13/sugar-destroys-liver-brain.aspx"
  >
  Liver disease
  
  , especially non-alcoholic fatty liver disease
  

In addition, unbound fructose, found in large quantities in HFCS, can
interfere with your heart's use of minerals like chromium, copper and
magnesium. Furthermore, as you likely know, HFCS is most often made
from
href="http://articles.mercola.com/sites/articles/archive/2013/04/30/monsanto-gmo-corn.aspx"
>
genetically engineered corn

, which is fraught with its own well-documented health concerns and
side effects, many of which are linked to glyphosate or Roundup
residues.

How to Manage and/or Limit Your Sugar Consumption

Sugar, in its natural form, is not inherently bad when consumed in
amounts that allow you to burn fat as your primary fuel. However, you
should avoid all sources of processed fructose, particularly processed
foods and beverages like soda. According to SugarScience.org, 74
percent of processed foods purchased from the grocery store contain
added sugar.

Other sources have suggested it may be as high as 80 percent. I
recommend your diet be composed chiefly of naturally occurring whole
foods, with 10 percent or less coming from processed foods.

I also recommend severely limiting your consumption of refined
carbohydrates found in cereal, bread, pasta and other grain-based
foods, as they break down to sugar in your body, which increases your
insulin levels and causes insulin resistance. As a general
recommendation, I suggest you keep your total fructose consumption
below 25 grams per day, including whole fruit. Keep in mind while
fruits are rich in nutrients and antioxidants, they naturally contain
fructose.

If consumed in high amounts (especially if you are not burning fat as
your primary fuel), fructose from fruit worsens your insulin
sensitivity and raises your uric acid levels. Also, be sure to avoid
artificial sweeteners like

aspartame

and sucralose due to the health problems associated with them, which
are worse than those associated with corn syrup and sugar. Below are
some additional tips to help you manage and/or limit your sugar
consumption: