"To catch a fish, think like a fish." That's an aphorism repeated over and over in a New York Times opinion piece, YouTube videos and online seminars for entrepreneurs.

We'd add: To think (period), catch some fish oil (DHA omega-3).

A lab study in Scientific Reports found that taking supplements of DHA — the omega-3 fatty acid found in fish oil (and algal oil; algae is where the fish get it from) and synthesized from ALA (alpha-linolenic acid) found in foods such as walnuts and flaxseed — boosts production of estrogen in the brain.

It's essential. And because you convert only 2 percent of ALA into DHA, getting plenty is vital.

Estrogen is important for brain health. It helps reduce nerve damage from stroke, and protects the brain from environmental toxins such as methyl mercury.

And an estrogen imbalance in the brain is linked to changes that contribute to Alzheimer's disease, stroke, depression, and some autoimmune disorders.

Studies show that fish oil decreases tumor cell proliferation. We know that it reduces the effects of hypertension, arthritis, atherosclerosis, depression, diabetes, myocardial infarction, and the risk of blood clots.

Plus, in a randomized study, people who took 900 mg of DHA omega-3 daily for 28 weeks had improved learning and memory function. Their brain age was six years younger!

So take 900 mg DHA algal oil daily, unless you're on a blood thinner; then check with your doc and stick with salmon and ocean trout.