Q: Six months ago, I started exercising regularly. I am 52 and, though it might not have turned me into a hunk yet, it seems to be making me smarter - well, at least a bit sharper and less forgetful. Is that possible? - Marc W., Philadelphia
A: Good for you. Regular exercise at any age has enormous benefits for your whole body including the heart, liver, lungs, digestion and endocrine system (that's hormones such as cortisol, insulin, testosterone and neurotransmitters). But no benefit is more important than the connection between aerobic fitness and cognition.
Studies have shown that when you exercise regularly, you have better mental health (less depression), stronger decision-making skills (executive function), and are less prone to dementia. You also have better neural function and efficiency because exercise-increased blood flow ups "food delivery" of glucose and lipids to the brain and increases available oxygen. And the more you exercise, the more physical and cognitive reserves (that is, "backup") you build up.
Now a new study published in Medicine & Science in Sports & Exercise has demonstrated that the link between aerobics and protection of cognition happens to a large degree because of the brain neurotransmitter dopamine. It is produced when you exercise and plays a central role in brain function and cognition. One study shows an hour of yoga six days a week ups dopamine levels. Another study says that exercise reduces levels of hormones (cortisol) that are produced by emotional, brain-numbing stress, even as the workout stresses your body physically. Neat trick!
So aim for 300 minutes of physical activity weekly, including 20 minutes of aerobics/cardio three times weekly. And if you want to reinforce the brain benefits of exercise - up your nutrition. Deficiencies in iron, niacin, folate and vitamin B6 may reduce dopamine levels and affect your brain and emotions. Visit the National Institutes of Health's website at https://ods.od.nih.gov and research which foods contain those nutrients.
Q: I'm confused about whether or not eating eggs is risky for heart health. Do I really have to stick with egg whites? - Mary F., Oakland, California
A: We think whole eggs are a risk factor for heart disease, even though some nutritionists say otherwise. A 2019 study in JAMA found that each additional half-egg a day is associated with a 6% increased risk of cardiovascular disease and an 8% increased risk of premature death. And now a study in Plos that looked at 16 years' worth of data on more than half a million folks says every additional 300 mg of cholesterol you consume daily is associated with a 19% increase in your risk of death and each additional half a whole egg daily ups the risk of death by 7%. One egg contains 186 mg of cholesterol - all in the yolk - so an omelet will definitely take you over the top; the recommended daily intake is 300 mg.
But it isn't predominantly excess cholesterol that makes egg yolks a threat to your vigor. It's the choline they contain. Now, choline is essential to brain, liver and metabolism, and you need to get it from food (the liver makes a little, but not enough). But you don't want too much! In excess, and when combined with saturated fat (in an egg yolk, for example), it alters gut bacteria so they produce trimethylamine, which damages blood vessels and ups your risk for heart attack, stroke, many cancers and dementia.
The good news? The study found that egg whites/substitutes were beneficial. Every egg yolk you replace with an egg white/substitute reduces the risk of dying from cardiovascular diseases by 3%. That's because the white of one egg contains virtually no fat, 4 g protein and only 17 calories, along with folate, selenium, calcium magnesium, phosphorus and potassium - and no choline. Check out these recipes: All-Day Egg White Omelet at DoctorOz.com and the four-serving Egg-White Frittata in Dr. Mike's "What to Eat When Cookbook."
Mehmet Oz, M.D. is host of "The Dr. Oz Show," and Mike Roizen, M.D. is Chief Wellness Officer Emeritus at Cleveland Clinic. Email your health and wellness questions to Dr. Oz and Dr. Roizen at youdocsdaily(at sign)sharecare.com.
Distributed by King Features Syndicate, Inc.