(June, 2017) Omega-3 fats make for better bodies in many ways. They contribute substantially to heart, brain, joint, skin, immune, mood and vision health. The most beneficial omega-3s are found in fatty fish (e.g., mackerel, salmon, tuna, herring, sardines, krill) and to a lesser extent in grass-fed animals. Omega-3 foods suitable for vegans (e.g., flax, walnuts, hemp, chia) are also beneficial, but not to the same extent. Polyunsaturated fats or PUFAs, including omega-3 and omega-6 fats, confer flexibility and liquidity to biological membranes, work as messengers to regulate inflammation, and improve flow of fatty substances in the blood. They are critical to optimum health.
As amazing as these fats are, they can be equally detrimental, if damaged. Once they become rancid (a.k.a., oxidized), they’re more harmful than helpful. We all know the smell of rotting fish. PUFAs protect us, but are chemically fragile and need their own protection. The best oils are fresh, unrefined, and loaded with antioxidants to keep them from spoiling.
Human aging also involves oxidation. Oxidized substances in the blood stick to vessels to promote atherosclerosis, macular degeneration, wrinkled skin, dementia and depression. Oxidation destroys fats, proteins, DNA, and cripples energy production in cells. This happens to all of us eventually, but there are ways to slow the process. The food and lifestyle choices we make not only affect our longevity, but also our quality of life.
Oxidation also fuels inflammation, which can become chronic and debilitating. Intact omega-3s are anti-inflammatory, help reduce blood triglycerides, enable blood fat to flow more freely, improve LDL-cholesterol quality, stabilize plaque to prevent heart attack and stroke, help relax arteries, and reduce blood pressure. The eyes, skin, brain and most other body organs and tissues rely on wholesome omega-3s to function properly. but they also rely on a bevy of antioxidants to keep them working in our favor.
Several antioxidants protect against PUFA oxidation, including carotenoids, vitamin E, curcumin, capsaicin, quercetin, olive leaf extract, green tea, and polyphenols from fruits and vegetables. Some of these antioxidants occur naturally in omega-3 foods. Astaxanthin is one example of a carotenoid found in salmon and krill oil. Indeed, astaxanthin imparts the salmon color to these foods. Cod liver oil is teeming with vitamin A. Flaxseeds are high in vitamin E. Walnuts are full of phenolic antioxidants in its skin. Pastured eggs and dairy contain carotenoids like beta-carotene, lutein and zeaxanthin to keep them from spoiling.
Lutein and Zeaxanthin (LZ)
These carotenoids are particularly protective of omega-3s in the eyes, brain and in the circulation. In mice fed high-fat diets, LZ lowered fat oxidation and arterial lesions dramatically. In humans, artery stiffness was 80 percent greater in people at the lowest versus highest blood LZ levels.
The brain is composed largely of omega-3s, and LZ is right there with them. LZ comprises roughly 75 percent of all brain carotenoids, and is concentrated in regions involved in memory and learning. Higher LZ in the brain means better cognitive function, and cognitive impairment is linked to low blood zeaxanthin in the elderly. In a recent clinical trial, learning and memory were improved by omega-3 or LZ, but especially in combination.
LZ are also the only carotenoids found in the retina and lens of the eye. They form the macular pigment, which–like a pair of internal sunglasses–protects omega-3s in the retina from oxidation to help prevent photo damage and macular degeneration.
Skin is also subject to sun damage. Solar radiation and environmental pollutants are destructive and lead to aging and cancer. Antioxidants (e.g., ascorbic acid, tocopherol, alpha-lipoic acid, melanin) are designed by nature to counteract oxidative stress and sun damage. Carotenoids are also deposited in skin to protect against sun exposure. Carotenoids like LZ, beta-carotene and lycopene work like internal sunscreen to help defend against sunburn. People with high intake of vitamin D, lutein and carotenoids show significantly reduced risk for melanoma. In clinical trials, subjects receiving LZ showed enhanced elasticity, skin hydration, and sunburn protection. Carotenoids also show anti-cancer potential, in part because they support omega-3 anti-inflammatory activity. Total carotenoid intake is strongly associated with anti-aging, likely by protecting omega-3s.
One important source of oxidized fats (and other damaged goods) is from cooking foods at high temperatures. Fats like extra virgin olive oil are susceptible, but PUFAs are the most easily destroyed by excessive heat. It’s wise to keep oils away from the stove, to freeze flax meal, and not to blacken fish and meat. During cooking, PUFAs can be protected to some degree by slow cooking, and adding antioxidant herbs (e.g., rosemary) and spices (turmeric) to the pan. Regarding supplements, if your fish oil has a bad smell, it’s time to toss it. Better to buy pharmaceutical-grade fish oil that has had the impurities removed. Generally speaking, buy it fresh, don’t overcook it, keep it cool, air tight, out of the light, and don’t let it sit too long unprotected. Toss the oil after 6 months. And stay clear of trans (partially hydrogenated) fats. These are damaged fats that can damage you.
It’s hard to overestimate the importance of fresh food, especially when it comes to PUFA. The best way to keep them fresh is to increase antioxidant intake, particularly with carotenoids and natural vitamin E. We are composed of several oils that can easily go rancid and contribute to aging. Protect your fats from damage by optimizing nutrition via healthy, wholesome, fresh food, a variety of antioxidants & anti-inflammatory nutrients, and high-quality dietary supplements.
Dr. Domenico, What is your stance on percentage of fat in the diet, especially in context to carbs? And how to proportion it through meals, ie. how many grams per meal? What about increased insulin sensitivity with some starch and more than 10-15 g of fat per meal? http://superhumanradio.com/high-saturated-fatty-acid-intake-induces-insulin-secretion-by-elevating-gastric-inhibitory-polypeptide-levels-in-healthy-individuals-2.html
I keep ratcheting down carbs and increasing healthy fats, non-starchy veggies, and high-quality protein. Don’t know exactly what the percentage of fat is, or the number of grams of this and that. I think it’s going to be different for each person. My wife eats a lot of complex carbs, yet stays slim and healthy. I can’t even look at them without having to loosen my belt. It would be nice to have some feedback mechanism to tell us what foods spike our insulin when overeaten. Or maybe they’ll be able to tell that from your DNA soon. You never know for sure if you are on the right track, but there are measurements available that give us some clue (e.g., blood pressure, waist circumference, aches & pains, mobility, energy level, poop quality). These are the things I focus on as I keep tweaking my routine for the better.