DHA Throughout Life
Fat and the Good/Bad Conundrum
For years now, fat has been associated to obesity, weight gain, heart disease, type 2 diabetes and certain types of cancer. Consuming more than the recommended intake of dietary fats results in the said negative impacts on health. However, it is not just the quantity of fat consumed but the kind of fat consumed also effects the health.
- Olive Oil
- Canola Oil
- Butter, etc..
Poly-Unsaturated Fat (FUPA)
- Omega 3-fats
- Omega 6-fats
- Omega 9-fats
- Canola Oil
- Vegetable Oil
- Walnut, etc..
- Deep fried food
- Fried snacks
- Creamy frozen drinks
- Fast food
- Cakes, etc..
- Ice Cream
- Whole Milk
- Palm Oil
- Coconut Oil, etc..
Fatty acids are vital nutrients as proteins and carbohydrates for the human body. Fat is a rich source of energy; 1 gram provides 37 kJ (9 kcal). They are also essential for absorbing fat soluble vitamins such as vitamins A, D, E and K. Fat is also needed to build cell membranes and nerve sheaths. It is essential as protective cushion for major organs like brain, heart, nerves, and bones. Fats are also essential for blood clotting, immunity, muscle movement, inflammation and production of hormones. They are also important for cognitive development, vision, and cardiovascular health, maintain body temperature and weight control.
Molecular structure of different fats lead to differences in functions. Nutritionists and dieticians suggest on a low fat diet. This is mostly true as modern urban diet consists high concentrations of trans and saturated fat. Trans fat is supposed to be avoided and moderations is required in case of consuming food containing saturated fat. However, even with multitude of low fat options available now; obesity rates and risks associated with it is in the rise. This clearly suggests replacement of “bad fats” with “good fat” in the diet. Excess energy stored at fat leads to obesity which leads to cardiovascular diseases, type 2-diabetes and also might cause cancer. High intake of saturated fats and trans fat increase Low Density Lipoprotein (LDL) Cholesterol (Bad Cholesterol) but good fat reduces LDL Cholesterol and increases High Density Lipoprotein (HDL) Cholesterol (Good Cholesterol). However, Good fats such as omega 3-fatty acids promotes good cognitive and cardiovascular health; and also reduces risks of cancer.
It is thus generally recommended to:
- Avoid trans fat
- Moderate saturated fat intake to about 10% of calories per day
- Incorporate monounsaturated fat and poly unsaturated fat in diet
The UN FAO (Food and Agricultural Organisation) and WHO (World Health Organisation) recommend 10-30% of daily energy requirement to be met by fat intake.
What are Omega 3-Fatty Acids?
Omega 3 fatty acids are a group of long chain PUFA essential throughout human life also called n-fatty acids or ω-3 fatty acids. They are deemed essential because the human body cannot produce them on its own. Alpha Linolenic Acid (ALA; 18 carbon) cannot be made by the body. It is not active form and is thus converted to Eicosapentaenoic Acid (EPA; 20 carbon) and Docosahexaenoic Acid (DHA; 22 carbon). But, the conversion is very limiting where only about 5-10% gets converted to EPA and about 0.5-4% gets converted to DHA.
Mostly found in high fat plant source such as flaxseeds, chia seeds, soybeans, etc. benefits include neuroprotection, cardiovascular wellbeing, protection against autoimmune responses and counter to inflammation. However, ALA is not very active form but is precursor for EPA and DHA
Long chain ω-3 fatty acid critical for neurological & visual development, pregnancy cognitive and functional development of brain and optimal brain health. Also associated with cardiovascular health, inflammation prevention and immunity. Common sources are fish and dairy products with low levels in nuts, eggs and dairy products. Extremely limited in current human diet.
Another long chain ω-3 fatty acid mainly sourced via fatty fish, seafood and fish oil. It is important for heart, and cardiovascular health. It also prevents inflammation and used to form intracellular signalling molecules called eicosanoids which regulate inflammation, immunity and central nervous system.
Omega 3 fatty acids play an important role in:
- Fetal Development
- Cardiovascular System
- Body’s Defense
- CNS and Cognitive Development
- Cancer Prevention
- Inflammation Prevention
- Prevention of various diseases like Alzheimer’s disease, Arthritis, Autoimmune diseases, Crohn’s disease, etc.
Humans originally consumed a diet rich in omega 3 fatty acids. But due to changes in nutrition pattern due to modern food habits and dietary patterns has led to changes in omega 3-fatty acid:omega 6-fatty acids ratio from ideally 1:1/1:4 to 1:38-1:50 in Indian population; and 1:10-25 in western population (Europe/US). This skewed ratio increases the risk of cardiovascular diseases, obesity, osteoporosis and systemic inflammation.
Thus, it is recommended to intake omega 3-fatty acid supplements since human diet and cooking habits lead to an imbalance in uptake of necessary fatty acids. WHO (World Health Organisation) recommends omega 3 fatty acids should comprise 1-2% of energy intake per day for general adult population. Expert scientific organisations such as Academy of Nutrition and Dietetics (USA), National Heart Foundation of Australia (Australia), International Society for the Study of Fatty Acids and Lipids (ISSFAL), Swiss Society for Nutrition and Research (Switzerland), Cardiology Society of India (India), Israel Heart Society (Israel) etc. recommend daily intakes of 250 mg-1 g of EPA+DHA.
What is DHA?
Docosahexaenoic Acid (DHA; 22:6(n-3)) is the most abundant fatty acid present in brain and retina. Human body converts short chain ALA (Alpha Linolenic Acid) to DHA but the conversion is very limiting to about 0.5-4%. DHA was consumed in diet via fish, however; DHA is not synthesized in fish body but consumed from marine algae. DHA is naturally synthesized in photosynthetic and heterotrophic microalgae.
It is a well-recognized nutrient for brain, heart & visual health and infant development. DHA doesn’t act as a treatment for particular conditions but is essential throughout lifespan as a preventive measure and complementary medicine. DHA is naturally consumed primarily via fatty fish like salmon, tuna, sardines, etc. but also can be obtained from flaxseeds, olive oil, leafy green vegetables, etc. However, modern dietary habits leads to incorporating DHA from supplements or food products fortified with DHA. Currently algal oil is an excellent sustainable source of DHA as alternative to add fish oil to food products.
Benefits of DHA
Brain and Cognitive Development
DHA deficiency leads to structural and functional damages in the hippocampus, hypothalamus and cortex areas of brain. DHA comprises of 97% of omega 3-fatty acids in brain. It is linked to healthy functioning of brain and cognition. Many reviews link DHA an essential component affecting learning and behaviour. Neurophysiological assessment via brain activity indicates direct correlation and DHA concentration. DHA supplementation shows:
DHA rich supplementation is found to be more efficient at improving higher order cognitive tasks than EPA rich supplementation.
- Improvement in immediate and delayed memory
- Cognitive health with aging
- Improvement in reading and spelling skills among children
- Higher cognitive performance in middle aged adults
- Preserves visuo-spatial learning
- Improved reasoning
- Achieving higher levels of sustained attention
- Positive benefit to mood and behavioural disorders throughout life
- Improved psychomotor skills
DHA constitutes 93% t of all omega-3 fatty acids in the retina in the eye. DHA supplementation for eye is especially needed during 3rd trimester of pregnancy to infancy where DHA accumulation is needed for retinal development. DHA deficiency is often associated with weakened eyesight.
- Infants with DHA supplementation (through mothers) show better visual acuity
- Infants with DHA supplementation show improved vison
- May boost eyesight in healthy aging population
- DHA preserves healthy retinal functions
- DHA helps reduce risk from
- Macular Degeneration, age related eye diseases
- Dry Eye Syndrome
- High Eye Pressure
Many studies have indicated a strong correlation between DHA supplementation and its benefits to mother and the infant during pregnancy and nursing stage. It is not only shown to be beneficial to the foetus but also the mother. DHA accumulates both prenatally and postnatally in the brain, eye and central nervous system especially in the 3rd trimester. Since developing foetuses are not able to efficiently produce DHA on their own, they are dependent on maternal source (placenta during pregnancy and breast milk after birth). Babies accumulate DHA into the CNS up until about 18 months of age.
- Longer gestation period
- Increase mean birth weight
- Fewer preterm births
- Prevents potassium depression
- Better psychomotor skills for the babies
- Amount of DHA consumed directly correlates with the DHA accumulation in fetal tissue important for brain and eye development
DHA has been noted to benefit immunity in children. This helps especially in case of preterm infant when supplemented with DHA infant formula, have shown similar immunity when compared breastmilk fed infants. DHA supplementation has found to increase select few antibody production by enhancing B cell activation. Also, enhanced secretion of cytokines like Interleukin 6 (IL-6) and Tumor Necrosis Factor alpha (TNF-α). These cytokines are produced in response to infection, injury or exposure to foreign particle by the body.
- DHA supplementation delays onset on respiratory infection and allergic reactions
- Infants supplemented with DHA have fewer episodes of bronchitis and bronchiolitis
- Infants supplemented with DHA born to allergic mothers show improved response to antigen skin prick test
- DHA could also have favourable effects to patients suffering from lupus
DHA alters lymphocyte, monocyte and macrophages functions which reduces chronic inflammatory responses. DHA inhibits leukotriene synthesis by omega 6-fatty acids. This leads to vasoconstriction and mucus in asthma patients. More comprehensive studies are needed to assess the anti-inflammatory properties of DHA supplementation.
- DHA intake seem to benefit asthma patients
- DHA supplementation seems to reduce symptoms and inflammation in patients suffering from rheumatoid arthritis
The anti-inflammatory properties of DHA has been seen to affect oncogenic proteins especially in case of breast, colon and prostate cancer. Generally, the additive effect of EPA and DHA supplementation at higher doses is noted to reduce the risk of breast, colon and prostate cancer. Currently, there are studies underway examining possibilities and mechanisms for cancer prevention via omega 3 fatty acid supplementation.
- Omega 3 fatty acids seem to prevent bone metastasis preventing pain and bone fracture in breast cancer patients
- DHA is noted to improve inhibitory effect of chemotherapy drugs like doxorubicin in cancer proliferation
- DHA and EPA inhibits eicosanoids (intracellular signalling molecules) synthesis from ARA (Arachidonic Acid, omega 6-fatty acid) which maybe useful in adjuvant chemotherapy. Suppression of ARA derived eicosanoid biosynthesis; influences on transcription factor activity, gene expression, and signal transduction pathways; alteration of estrogen metabolism; increased or decreased production of free radicals and reactive oxygen species; and mechanisms involving insulin sensitivity and membrane fluidity
- DHA can inhibit tumour growth and development via decrease in proliferation and enhancing apoptosis of cancer cells
- DHA might help reduce toxicity during chemotherapy and radiotherapy
Cardiovascular benefits of DHA and EPA have been well documented. DHA effects the serum lipid composition by reducing triglycerides and LDL Cholesterol (Bad Cholesterol); and increasing HDL Cholesterol (Good Cholesterol). Sufficient DHA consumption has also been known to reduce blood pressure and heart rate. DHA inhibit the proliferation of vascular smooth muscle cells.
DHA and EPA share complimentary benefits for cardiovascular health. Combined supplementation would have advantage over little or no intake.
- Reduces risk of cardiac arrests
- Prevents cardiac arrhythmias
- Prevents hypertension
- Reduce risk of blood clots and improve arterial health
- Reduces risks of Cardio Vascular Diseases
DHA is essential for neurological development and function in infants. Studies suggest that DHA may prevent or reduce risk of many neuropsychiatric disorders. DHA supplementation to infant via infant formula or to mother (to infant via breastmilk enhances neuromotor development. It affects neurological function by modulating signal transduction pathways, neurotransmission, neurogenesis, myelination, membrane receptor function, synaptic plasticity, neuro-inflammation, and membrane integrity and membrane organization. DHA is rapidly accumulated in the brain during gestation and early infancy, and the availability of DHA via transfer from maternal stores impacts the degree of DHA incorporation into neural tissues. The consumption of DHA leads to many positive physiological and behavioural effects. Integrity and function of Central Nervous System can be irreversibly damaged due to DHA deficiency.
- DHA prevents the effect of ethanol on brain phospholipids; thereby preventing abnormal motor function, hyperactivity, impaired intelligence and low attention span in infants suffering from Foetal Alcohol Syndrome
- DHA has been shown to benefit patients suffering from attention deficit/hyperactivity disorder (AD/HD), autism, dyspraxia, dyslexia, aggression, major depressive disorder (MDD) and bipolar disorder, with promising results in schizophrenia and initial benefit for borderline personality disorder
- DHA with EPA supplementation has been shown to reduce the risks associated with Multiple Sclerosis and Bipolar Disorders
- DHA supplementation might be used as therapeutic agent for Alzheimer’s Disease and delay cognitive impairment in mild cases of Alzheimer’s Disease
- DHA with EPA supplementation has also shown to reduce depression
- Neuroprotection of Central Nervous System as a result of regular DHA intake allows for optimal development and aging where cognitive skills do not rapidly or abruptly decline. This impacts the general quality of life with no significant reduction in productivity.
DHA throughout Life
Pregnancy and Foetal Development
DHA has also been shown to play a part in maternal well-being. DHA increases gestation period of pregnancy increasing chances of healthier baby. DHA supplementation during pregnancy has shown to significantly improve cognition and problem solving skills in the children. Since foetuses cannot synthesize DHA on their own, they depend on DHA uptake from placenta during pregnancy and breastmilk during birth. DHA is needed for optimal infant brain and eye development. DHA also resulted in lower food allergy and IgE associated eczema. Recommendation for pregnant woman ranges from 300 mg/day to 600 mg/day by various experts. Neural integrity and function of Central Nervous System can be irreversibly damaged due to DHA deficiency during pregnancy.
Babies accumulate DHA into the CNS up until about 18 months of age. DHA plays a substantial role in foetal and infant brain development, increasing IQ scores, lengthening attention spans, and enhancing foetal and infant eye development. Maternity expert, Rebecca Matthias, president of Mothers Work, Inc., in her book, 51 Secrets of Motherhood; acknowledges DHA as "the new wonder supplement that actually increases your baby's growth". All infants, whether preterm or full term, seem to require dietary DHA for retinal development and normal visual function. Studies with human infants suggest supplementation with DHA in formula or by boosting maternal levels enhances neuromotor development. Studies also suggested that DHA alone can improve the infant’s performance on mental developmental tests. Thus, it can be inferred that DHA is an essential nutrient for optimal neural maturation during infancy. DHA also improves the visual acuity and reduces risks with cardiovascular diseases at later stages in life. DHA can also reduce symptoms of conditions like Foetal Alcohol Syndrome and Phenylketonuria.
Childhood and adolescence are phases of life where maximum brain DHA accumulation takes place via neuronal maturation, synaptogenesis and grey matter expansion. DHA supplementation benefits brain development, better focus and concentration, improvement in psychomotor skills, optimum behaviour patterns, visual health and cognitive development. Studies have associated DHA supplementation with betterment of verbal and nonverbal IQ, reasoning, impulsiveness and memory. Studies seem to support combined supplementation of EPA, DHA and few omega 6-fatty acids improved attention, learning and behavioural infirmities with children with Attention Deficit Hyperactivity Disorder (ADHD), Dyslexia and Dyspraxia.
Studies have associated higher level of DHA consumption by middle aged adults with improved non-verbal reasoning, mental flexibility and vocabulary. DHA supple mentation to adults leads to prevention of cardiovascular disorders, prevention of systemic/chronic inflammation and maintenance of optimal neural health. Extensive alcohol consumption depletes DHA concentration from membranes of neurons. This leads to secondary depression symptoms. DHA prevents sudden cardiac arrests and coronary heart disease. DHA prevents depletion in cognitive function induced by stress and long work hours. DHA also seems to reduce risk of dementia. DHA reduces LDL Cholesterol (Bad Cholesterol) and increases HDL Cholesterol (Good Cholesterol) reducing chances of cardiovascular disorders and benefits cardiovascular health. Some studies also show benefits of DHA with type 2 Diabetes.
Age leads to many problems bringing discomfort to the individual and people around him/her. Decrease in cognitive skills, memory loss, depression related symptoms, dementia, and also leading to conditions like Alzheimer’s disease (AD). However, DHA supplementation has be shown to benefit to healthy ageing. DHA seems to prevent cognitive impairment and also have positive impact on mood. It has been shown to improve immediate and delayed recognition and memory. It also reduces chances of Macular Degeneration which leads to temporary to permanent loss of vision. Studies also show that regular DHA uptake throughout life in combination with adequate intake of calcium prevents osteoporosis. DHA also seem to reduce symptoms associated with rheumatoid arthritis. DHA in combination with EPA shows enormous benefits considering cardiovascular health. It significantly reduces the risk of heart related death.
Dietary recommendations for DHA vary region to region via different expert scientific organisations and Authority.
The UN FAO (Food and Agriculture Organisation of the United Nations) recommends:
|Pregnant and Lactating Women|
|0.1-1.8% Energy||DHA 10-12 mg/Kg of Body Weight||100-150 mg/day EPA+DHA||150-200 mg/day EPA+DHA||200-250 mg/day EPA+DHA||0.3 g/day EPA+DHA with at the least 0.2g/day if DHA|
However, ISSFAL (the International Society for the Study of Fatty Acids and Lipids)
has established the following recommended minimum dosage chart:
|Pregnant and Lactating
|32 mg/lb EPA+DHA||15 mg/lb EPA+DHA||500 mg EPA+DHA
(with a minimum of 220 mg EPA and 220 mg DHA)
|300 mg DHA daily|