Essential fats are crucial for male reproductive health too. Omega-3 fats are a significant component of sperm, and in one particular trial of infertile men who received either EPA and DHA or a placebo for 32 weeks, in those receiving the fatty acids testing revealed a significant improvement in sperm quality — count, motility and form.
Omega-3 fatty acids are also a key component of the retina of the eye, and too little DHA may affect your vision. Eating fish at least twice a week is associated with reduced risk of developing age-related macular disease and can also help with dry eye syndrome.
Lack of omega-3 fatty acids is linked to coronary heart disease and high blood pressure. You can add, to that list, asthma, rheumatoid arthritis, and Crohn’s disease.
The key word when it comes to many of these physical ailments is inflammation. Interestingly, it is increasingly acknowledged that depression is an inflammatory disorder of the brain. Omega-3 fats are anti-inflammatory agents.
One inflammatory condition that Charles, a fifty-year old journalist, was all too familiar with was joint pain. He also lived with mood fluctuations and had done so for years. He described one bout of depression as “extreme”. Dry skin on his hands and feet was just a minor irritation by comparison.
I can’t say for sure that consuming oily fish and cutting out excessive omega-6 is what eliminated Charles’s joint pain and depression — he also cut out gluten, which in some cases can cause severe mental illness and numerous physical symptoms. But his dry skin cleared up well too. I suspect that it was the combination of eating oily fish and eliminating gluten that worked for him.
Mental signs and symptoms of omega-3 fatty acid deficiency include:
Bipolar disorder. DHA has been shown to be significantly lower in patients with bipolar disease and major depressive disorder compared to healthy controls.
“Several laboratories have provided evidence that depressed patients have, on average, lower plasma levels of n-3 PUFAs than non depressed controls; furthermore, there are relationships within these populations between severity of depressive symptoms and lower plasma levels of the n-3 PUFAs.” (Kiecolt-Glaser et al).
Attention deficit hyperactivity disorder. Children with ADHD also report symptoms that are typical of fatty acid deficiency, including thirst, dry skin, dry hair, dandruff, brittle nails.
Autism. Autistic children have been found to have levels of DHA that were “particularly decreased”, compared to non-autistic controls.
Schizophrenia. Post-mortem studies have revealed low DHA in the frontal lobes of schizophrenia patients.
What’s going on?
We once ate a lot of fish, the main dietary source of these incredibly important fatty acids.
“It is our contention that the movement in the 19th to 21st centuries away from traditional use of sea foods and increased emphasis on land based food supply is a likely cause in the rise in brain disorders including mental ill-health, stress, and other psychiatric disorders.”(Crawford et al 2014).
Fish consumption today, certainly in the UK, is alarmingly low. Without a regular intake of oily fish and seafood, or taking supplements, deficiency of DHA is virtually a given. We Brits love our fish and chips, but that is a far cry from the herring and salmon that were once a staple of the poor.
Food writer Colin Spencer describes in his book British Food: An Extraordinary Thousand Years of History how, after the Romans left Britain (in the early 5th century) and before the land enclosures, “The marshlands were crammed full of eels, the rivers had plenty of salmon and trout, and other fish such as perch, pike, tench, carp and bream.” Rivers, streams and lakes were also “stuffed” with freshwater fish, such as trout. The shoreline offered free and abundant treasures, including whelks, periwinkles, limpets and mussels.
During the Middle Ages, monks on their monastic diets did exceptionally well, consuming fish on average around 215 days a year, as part of their ‘fasting’ regime. Not so monastic after all.
In the 18th century, herring — and oysters — were cheap and plentiful.
“Just over a century ago, oysters were gathered and presented on the bar table in the East end of London free for those who bought beer.” (Crawford et al 2014).
The National Diet and Nutrition Survey provides information on the dietary habits of all four UK countries. In 2012/13 and 2013/14, oily fish consumption in all age groups remained “well below” the recommended weekly amount, at 13g-29g in children and 54–87g in adults.
In the US, the recommended consumption for fish is two 2.5oz servings weekly, preferably oily. However, the reality is that “a large percentage of the US adult population is not meeting recommendations for omega-3 fatty acid consumption”.
Without regular fish and seafood, it is difficult to obtain sufficient DHA (unless, like our grandparents, you eat a lot of offal, including brawn. Even I can’t envisage doing that).
Having said that, meat (and eggs) from animals that are pasture-fed contain much higher proportions of DHA than meat from intensively farmed animals. Better still, meat from wild animals (venison and buffalo) contains significantly more DHA than pasture-fed or organically reared animals.
Nuts and seeds and other plant foods are often suggested as a suitable vegetarian source of omega-3 fats. Although it is true that the body can make some limited DHA (and EPA, its precursor) from plant sources, its ability to do so is poor, and effectively meaningless. The liver converts less than 0.5% of the omega-3 fat in plant sources to DHA. That’s on a good day: in many studies, that conversion rate has been shown to be less than 0.1%, making it “negligible”.
Of course, there are many possible dietary causes of imbalances in the brain leading to mental health issues, some of which I cover in other articles in my publication Feed Your Brain. Neither is mental ill-health necessarily diet-related.
But it might be.