The decreased risk achieved by adopting a healthy lifestyle is seen even in those with a high genetic risk.In addition to the above risk factors, meta-analyses indicate that there is robust evidence that other psychological traits, including personality (high neuroticism, and low conscientiousness), low purpose in life, and high loneliness, are risk factors for Alzheimers disease and related dementias. For example, based on the English Longitudinal Study of Ageing (ELSA), research found that loneliness in older people increased the risk of dementia by one-third. Not having a partner (being single, divorced, or widowed) doubled the risk of dementia. However, having two or three closer relationships reduced the risk by three-fifths.The two most modifiable risk factors for dementia are physical inactivity and lack of cognitive stimulation. Physical activity, in particular aerobic exercise, is associated with a reduction in age-related brain tissue loss, and neurotoxic factors thereby preserving brain volume and neuronal integrity. Cognitive activity strengthens neural plasticity and together they help to support cognitive reserve. The neglect of these risk factors diminishes this reserve.Studies suggest that sensory impairments of vision and hearing are modifiable risk factors for dementia. These impairments may precede the cognitive symptoms of Alzheimers disease for example, by many years. Hearing loss may lead to social isolation which negatively affects cognition. Social isolation is also identified as a modifiable risk factor. Age-related hearing loss in midlife is linked to cognitive impairment in late life, and is seen as a risk factor for the development of Alzheimers disease and dementia.
Hemoglobin binds to oxygen, enabling red blood cells to supply oxygenated blood throughout the body. Women of child-bearing age, children, and people with poor diet are most susceptible to the disease. Most cases of iron-deficiency anemia are mild, but if not treated can cause problems like an irregular heartbeat, pregnancy complications, and delayed growth in infants and children that could affect their cognitive development and their behavior. Signs and symptoms
Symptoms of iron deficiency can occur even before the condition has progressed to iron deficiency anemia. Symptoms of iron deficiency are not unique to iron deficiency (i.e. not pathognomonic). Iron is needed for many enzymes to function normally, so a wide range of symptoms may eventually emerge, either as the secondary result of the anemia, or as other primary results of iron deficiency. Symptoms of iron deficiency include:
fatigue
dizziness/lightheadedness
pallor
hair loss
twitches
irritability
weakness
pica
brittle or grooved nails
hair thinning
Plummer–Vinson syndrome: painful atrophy of the mucous membrane covering the tongue, the pharynx and the esophagus
impaired immune function
pagophagia
restless legs syndromeContinued iron deficiency may progress to anemia and worsening fatigue. Thrombocytosis, or an elevated platelet count, can also result. A lack of sufficient iron levels in the blood is one reason that some people cannot donate blood. Signs and symptoms in children
pale skin
fatigue
slowed growth and development
poor appetite
decrease in the size of testes
behavioral problems
abnormal rapid breathing
frequent infection

Iron requirements in young children to teenagers
Causes
blood loss (hemoglobin contains iron)
donation
excessive menstrual bleeding
non-menstrual bleeding
bleeding from the gastrointestinal tract (anus) (ulcers, hemorrhoids, ulcerative colitis, stomach or colon cancer, etc.)