Diet: Too much FRUCTOSE sends an ancient human instinct to forage for food into overdrive

Diet high in fructose sends an ancient human instinct to forage for food into OVERDRIVE and could lead to ‘hyperactive’ disorders like ADHD and manic depression

  • A little fructose triggers foraging and storage of energy as fat, US experts said
  • However, too much can lead instead to aggression, cravings and impulsivity
  • In turn, this raises the risk of certain manic and aggressive behavioural disorders
  • Humans today consume around 40 times the fructose we did back in the 1700s
  • The overall argument, however, was met with scepticism from some experts

‘Hyperactive’ disorders like ADHD and mania could be rooted in an ancient human foraging instinct triggered by eating a high fructose diet, a study has suggested.

University of Colorado researchers have argued that low levels of fructose trigger a pathway that promotes foraging and the storage of energy as fat.

However, in excessive amounts, the same pathway becomes hyperactive — leading to cravings, impulsivity and aggression that increases the risk of behavioural issues. 

Fructose — or fruit sugar — is found naturally in many plants and honey, but has become more common in modern diets through refined sugar and corn syrup.

Food and drinks containing high levels of fructose today include apples, grapes, fruit juices, peas, sugary beverages like cola, sweets, and fruit yoghurts.

In fact, it is estimated that our fructose intake has increased 40-fold since the 18th century — potentially also explaining modern incidences of diabetes and obesity. 

‘Hyperactive’ disorders like ADHD and mania could be rooted in an ancient human foraging instinct triggered by eating a high fructose diet, a study suggested. Foods containing high levels of fructose include apples, grapes, fruit juices, colas and sweets like liquorice (pictured)

‘Behavioral Disorders are common and are associated with obesity and western diet,’ wrote paper author Richard Johnson of the University of Colorado and colleagues.

‘We propose that excessive intake of fructose present in refined sugars and high fructose corn syrup may have a contributory role in the pathogenesis of these conditions,’ they added.

In their paper, the team reviewed previous studies into fructose and its impact on the human body to develop their case.

‘Fructose, by lowering energy in cells, triggers a foraging response similar to what occurs in starvation,’ the researchers explained.

‘This foraging response stimulates risk taking, impulsivity, novelty seeking, rapid decision making, and aggressiveness to aid the securing of food as a survival response,’ they added.

‘Unfortunately, overactivation of this process from excess sugar intake may cause impulsive behaviour that could range from attention deficit hyperactivity disorder, to bipolar disorder or even aggression.’

University of Colorado researchers from the have argued that low levels of fructose trigger a pathway that promotes foraging (illustrated, left) and the storage of energy as fat. However, in excessive amounts, the same pathway becomes hyperactive — leading to cravings, impulsivity and aggression that increases the risk of behavioural issues

University of Colorado researchers from the have argued that low levels of fructose trigger a pathway that promotes foraging (illustrated, left) and the storage of energy as fat. However, in excessive amounts, the same pathway becomes hyperactive — leading to cravings, impulsivity and aggression that increases the risk of behavioural issues

Some experts, however, have met the study’s findings with scepticism.

‘This is an elegant and biologically plausible model grounded in sophisticated bioecological thinking,’ developmental psychologist Edmund Sonuga-Barke of King’s College London told the Times.

‘Unfortunately, the notion that there is a consistent link between sugar consumption levels and ADHD in humans was largely debunked decades ago,’ he added.

The full findings of the study were published in the journal Evolution and Human Behavior. 

ATTENTION DEFICIT HYPERACTIVITY DISORDER 

Attention Deficit Hyperactivity Disorder (ADHD) is a behavioural condition defined by inattentiveness, hyperactivity and impulsiveness.

It affects around five per cent of children in the US. Some 3.6 per cent of boys and 0.85 per cent of girls suffer in the UK.

Symptoms typically appear at an early age and become more noticeable as a child grows. These can also include:

  • Constant fidgeting
  • Poor concentration
  • Excessive movement or talking
  • Acting without thinking
  • Little or no sense of danger
  • Careless mistakes
  • Forgetfulness
  • Difficulty organising tasks
  • Inability to listen or carry out instructions

Most cases are diagnosed between six and 12 years old. Adults can also suffer, but there is less research into this.

ADHD’s exact cause is unclear but is thought to involve genetic mutations that affect a person’s brain function and structure.

Premature babies and those with epilepsy or brain damage are more at risk.

ADHD is also linked to anxiety, depression, insomnia, Tourette’s and epilepsy.

There is no cure.

A combination of medication and therapy is usually recommended to relieve symptoms and make day-to-day life easier.

Source: NHS Choices