Walnuts: A worthy addition to your daily diet?

What can you add to a wide variety of foods, from cereals to salads, that’s crunchy, filling, and flavorful — and good for your heart? The answer is nuts. While all varieties of nuts are chock full of important nutrients, walnuts may be especially good for protecting cardiovascular health, according to a recent study in the journal Circulation that supports earlier research in this realm.

What is the study?

The Walnuts and Healthy Aging study is a randomized controlled trial supported by a grant from the California Walnut Commission that tracked healthy older adults living in two communities. For the study, researchers recruited 708 adults ages 63 to 79 living in Loma Linda, California, or Barcelona, Spain, and split them into two groups. One group added about a quarter-cup to a half-cup of walnuts to their daily diet for two years, while the other group ate no walnuts.

After two years, average levels of harmful low-density lipoprotein (LDL) cholesterol were modestly lower in the walnut group. Of note: nearly a third of the participants were taking cholesterol-lowering statins, so the average cholesterol levels of both groups were already in a normal range. The researchers speculate that the cholesterol-lowering benefits from walnuts might be more pronounced in people with elevated cholesterol levels. There is no way to know from the current data if this is true.

“This recent trial confirms what earlier studies have found, namely, that that adding walnuts to your diet appears to improve your cholesterol levels,” says Dr. Deirdre Tobias, an obesity and nutritional epidemiologist at Harvard-affiliated Brigham and Women’s Hospital. The new trial also lasted much longer than past walnut studies. However, it’s not clear what foods were being replaced by the walnuts in the participants’ diets, which might affect the magnitude of benefits the researchers saw. For example, replacing unhealthful, ultra-processed snacks with walnuts would presumably have a greater benefit than a lateral move from healthy options to walnuts, Dr. Tobias explains.

Lower levels of harmful blood fats, no additional weight

The researchers also analyzed the concentration and size of the LDL particles. Smaller, more dense LDL particles are more likely to trigger atherosclerosis, the buildup of fatty plaque inside arteries that’s the hallmark of most cardiovascular disease that results in heart attacks or strokes.

The walnut eaters had lower levels of these smaller particles. They also had decreased levels of intermediate-density lipoproteins (IDL), which are also linked to a rise in cardiovascular-related risks. And even though a quarter-cup of chopped walnuts is about 190 calories (and a half-cup is about 380 calories), the walnut eaters did not pack on any extra pounds.

Earlier research has found that people who eat nuts regularly are less likely to have heart disease, and many studies have focused specifically on walnuts. In 2018, Dr. Tobias and colleagues published a meta-analysis and systematic review of studies that examined how eating walnuts affects a person’s blood lipids and other heart-related risks. The review included 26 controlled trials involving a total of more than 1,000 people. It found that walnut-enriched diets led to lower total cholesterol, LDL cholesterol, and triglycerides, the most common form of fat in the bloodstream.

What’s special about walnuts?

Although all nuts are good sources of healthy unsaturated fats, walnuts are especially rich in alpha-linolenic acid (ALA). This is a precursor to the omega-3 fatty acids EPA and DHA found in fatty fish that are known for their heart-protecting powers. Our bodies convert ALA to EPA and DHA, although the efficiency of this varies from person to person.

What’s more, walnuts are usually eaten raw. So they have greater antioxidant abilities than nuts that are usually eaten roasted. (Antioxidants help prevent or reduce the artery-damaging oxidation that contributes to heart disease).

Adding walnuts to your diet

It’s worth noting that the FDA allows a qualified health claim on some nuts (including walnuts). Foods made with them are permitted to include the following statement: “Eating a diet that includes one ounce of nuts daily can reduce your risk of heart disease.” An ounce of walnuts is about a handful, or one-quarter cup.

You can sprinkle walnuts onto oatmeal or other hot or cold cereals; stir them into pancakes, muffins, or other quick breads; or toss them with vegetables or into salads. If high cholesterol is a health concern for you, there are other foods that may help lower your LDL cholesterol and boost your heart health.

Skin in the game: Two common skin problems and solutions for men

895ae13d-3d7c-473c-99b8-6add3931098a

When I was on the junior varsity basketball team in high school, I wasn't surprised when I developed a case of itchy, flaky athlete's foot. After all, I was an "athlete," so I assumed it was a sign of dedication and hard work.

I was shocked when my mother told me the truth: it was due to poor foot hygiene, not my dribbling skills.

Fast-forward almost four decades, and I’m much more diligent about skin care. Still, some skin issues plague me at times, like they do many men. Here is a look at two common problems and solutions.

Dry skin

Symptoms of dry skin include scaly patches (with or without redness), itching, and overall dryness. You can get dry skin year-round — from the heavy heat of summer to the bitter cold of winter. Sun exposure damages skin, leaving it thinner and less likely to hold in moisture over time. Also, aging skin produces less of the natural oils that keep skin lubricated.

Treatment. The first line of defense is a moisturizer that softens and smooths skin with water and lipids (fats). Some moisturizers attract water to the skin and seal it in. Others prevent moisture loss by coating skin with a thick, impermeable layer.

  • Petroleum jelly. This waxy, greasy substance stops water loss without clogging pores. It can be used by itself but is also an ingredient in many moisturizers and ointments. Because petroleum jelly doesn’t contain water, it’s best used while the skin is still damp after bathing to seal in moisture.
  • Mineral oil. Mineral oil has the same effect but without a greasy feeling. It also should be used while skin is damp.
  • Moisturizing lotions and creams. These products contain both water and oils. They’re less greasy and more cosmetically appealing than petroleum jelly or oils. Look for moisturizers with at least one of the following ingredients: glycerin, urea, pyroglutamic acid, sorbitol, lactic acid, lactate salts, or alpha hydroxy acids.

Prevention. Try a few changes to help prevent dry skin:

  • Add moisture to the air with a humidifier or a pan of water set atop the radiator.
  • In the shower or bath, use lukewarm water (hot water can dry the skin by stripping it of natural oils).
  • Choose nondrying soaps with no abrasives or irritants. Super-fatted soaps or cleansing bars are less drying than regular, liquid, or antibacterial soaps.
  • To retain the water your skin absorbs while showering or bathing, apply jelly, oil, or moisturizer immediately afterward.

Athlete’s foot

Athlete’s foot is caused by dermatophytes, a group of fungi on the surface of the skin. Tell-tale signs include intense itching; cracked, blistered, or peeling areas of skin, especially between the toes; and redness and scaling on the soles. Dermatophytes thrive in warm, moist environments like pools, showers, and locker rooms where people walk with bare feet. The warm, moist environment of sweaty socks and shoes encourages them to grow.

Treatment. First, try an over-the-counter antifungal ointment, cream, or powder, such as clotrimazole (Lotrimin AF, Mycelex, generic), terbinafine (Lamisil AT, Silka,), or miconazole (Lotrimin AF spray, Micatin). It can take weeks for an infection to improve, and recurrences are common. If symptoms don't improve after several weeks, consult a doctor, who may prescribe antifungal pills.

Prevention. Keeping feet clean and dry is the best way to ward off athlete’s foot. Also, do the following:

  • Wash your feet well every day, and wear a clean pair of socks after your bath or shower.
  • Take time to dry your feet thoroughly (including each toe and especially the web space between the toes) after you bathe, shower, or swim.
  • Wear flip-flops or sandals around public pools and in gym locker rooms and showers.
  • Wear moisture-wicking socks that absorb sweat.
  • Don’t wear the same shoes two days in a row. Give shoes a 24-hour break between wearings to air out and dry.

Naps: Make the most of them and know when to stop them

During the first year of life, naps are crucial for babies (who simply cannot stay awake for more than a couple of hours at a time), and crucial for parents and caregivers, who need breaks from the hard work of caring for an infant.

But as children become toddlers and preschoolers, naps aren’t always straightforward. Children often fight them (following the “you snooze you lose” philosophy), and they can conflict with daily tasks (such as school pick-up when there are older siblings) or lead to late bedtimes.

Here are some tips for making naps work for you and your child — and for knowing when they aren’t needed anymore.

Making naps work for your baby

Most infants will take at least two naps during the day, and early in toddlerhood most children will still take both a morning nap and an afternoon nap. Naps are important not just for physical rest and better moods, but also for learning: sleep allows us to consolidate new information. As children get older, they usually drop one of the naps, most commonly the morning nap.

Every child is different when it comes to napping. Some need long naps, some do fine with catnaps, some will give up naps earlier than others. Even within the same family, children can be different. A big part of making naps work is listening to and learning about your child’s temperament and needs. Otherwise, you can end up fighting losing battles.

The needs of a parent or caregiver are also important: everyone needs a break. Sometimes those breaks are particularly useful at specific times of the day (like meal prep time). While you can’t always make a child be sleepy at the most convenient time for you, it’s worth a try — which leads me to the first tip:

Schedule the naps. Instead of waiting for a child to literally drop and fall asleep, have a regular naptime. We all do better when our sleep routines are regular, even adults. If you can, put the child down awake (or partially awake). Learning to fall asleep without a bottle or a breast, or without being held, is a helpful skill for children to learn and can lead to better sleep habits as they grow.

A couple of scheduling notes:

  • If you need a child to fall asleep earlier or later than they seem to do naturally, try to adjust the previous sleep time. For example, if you need an earlier morning nap, wake the child up earlier in the morning. It may not work, but it’s worth a try.
  • Naps later in the afternoon often mean that a child won’t be sleepy until later in the evening. That may not be a problem, but for parents who get tired early or need to get up early, it can be. Try to move the nap earlier, or wake the child earlier. If the problematic afternoon nap is in daycare, talk to the daycare provider about moving or shortening it.

Create a space that’s conducive to sleep. Some children can sleep anywhere and through anything, but most do best with a space that is quiet and dark. A white noise machine (or even just a fan) can also be helpful.

Don’t use screens before naptime or bedtime. The blue light emitted by computers, tablets, and phones can wake up the brain and make it harder for children to fall asleep.

When is it time to give up naps?

Most children give up naps between the ages of 3 and 5. If a child can stay up and be pleasant and engaged throughout the afternoon, they are likely ready to stop. Some crankiness in the late afternoon and early evening is okay; you can always just get them to bed earlier.

One way to figure it out, and ease the transition, is to keep having “quiet time” in the afternoon. Have the child go to bed, but don’t insist on sleep; let them look at books or play quietly. If they stay awake, that’s a sign that they are ready to stop. If they fall asleep but then end up staying up very late, that’s another sign that the afternoon nap needs to go.

Whether or not your child naps, having some quiet time without screens every afternoon is a good habit to get into. It gives your child and everyone else a chance to relax and unwind, and sets a placeholder not just for homework but also for general downtime as children grow — and just like naps for babies, downtime for big kids is crucial.

Follow me on Twitter @drClaire

Saturated fat and low-carb diets: Still more to learn?

de5fba5f-287b-42a8-b6c0-5e4bb5427310

Various versions of low-carbohydrate diets have been popular for many years. The details of what is allowed and what is not vary quite a bit, and the amount of carbohydrates also differs. Too often these diets contain plates piled high with bacon, meat, eggs, and cheese. Due to the high saturated fat content in these diets, doctors and nutritionists worry about their potential adverse effect on cardiovascular disease.

The American Heart Association recommends aiming for about 13 grams of saturated fat, which is about 6% of 2,000 calorie diet. Recently, a new study published in the American Journal of Clinical Nutrition suggests that at least in the short term a low carb diet with a higher amount of saturated fat might still be heart-healthy. But is it that simple? Let’s take a look at what this randomized diet trial did and what the results really mean.

What did the study actually involve?

The 164 participants in this study were all considered overweight or obese, and had just finished a weight loss trial to lose 12% of their body weight. They were randomly assigned to one of three diets containing different proportions of carbohydrates and fat. Protein content was kept the same (at 20% calories) for everyone. They were not planning to lose any more weight.

The three diets were:

  • Low carbohydrates (20%), high fat (60%), saturated fat comprising 21% of calories: this resembles a typical low-carbohydrate diet and has much higher saturated fat than recommended.
  • Moderate carbohydrate (40%), moderate fat (40%), saturated fat comprising 14% of calories: this is not far from the typical American diet of 50% carbohydrates and 33% fat, and it is quite similar to a typical Mediterranean diet, which is slightly lower in carbohydrates and higher in fat than an American diet.
  • High carbohydrate (60%), low fat (20%), saturated fat comprising 7% of calories: this meets the recommendation of the Dietary Guidelines for Americans and is a typical high-carbohydrate diet, including a lot of grains, starchy vegetables, and fruits or juices.

The study participants received food prepared for them for 20 weeks. They had their blood measured for a number of risk factors of cardiovascular disease, and a lipoprotein insulin resistance (LPIR) score was calculated using a number of blood markers to reflect the risk for cardiovascular disease. (LPIR is a score that measures both insulin resistance and abnormal blood cholesterol all in one number, and it is used for research purposes.)

The researchers found that at the end of eating these diets for five months, the participants in each of the three groups had similar values of cardiovascular disease markers, such as the LIPR score an and cholesterol blood levels.

What were the participants actually eating?

Alas, those who were eating the low-carbohydrate diet were not piling up their plate with steak and bacon, and those eating the high-carbohydrate diets were not drinking unlimited soda. All three diets were high in plant foods and low in highly processed foods (it is easier to stick to a diet when all the food is prepared for you). Even the low-carbohydrate group was eating lentils, a good amount of vegetables, and quite a bit of nuts.

Even the two diets with higher than recommended amounts of saturated fats also were high in the healthy poly- and monounsaturated fats as well. For example, the diets contained a combination of higher amounts of healthy (salmon) and a small amount of unhealthy (sausage) choices. In addition, fiber intake (at about 22 grams/day) was slightly higher than the average American intake (18 grams/day). Overall, except for saturated fat being higher than recommended, the diet as a whole was quite healthy.

What is the take-home message?

Striving for a plant-based diet with saturated fat being limited to 7% of total calories remains an ideal goal. But for people who choose a low carb, high fat diet to jump start weight loss, keeping saturated fat this low even for a few months is challenging. This study at least provides some evidence that higher amounts of saturated fat in the context of a healthy diet do not seem to adversely affect certain cardiovascular risk markers in the short term. How it would affect actual disease — such as heart attack, stroke, and diabetes — in the long run is unknown. However, there is ample evidence showing that a diet that consists of healthy foods and has moderate amounts of carbohydrate and fat can lower the risk of these diseases.

Preventing diseases is a long-term process; a healthy diet must not only be effective, but it should also be flexible enough for people to stick to in the long run. Could a diet with lower amounts of healthy carbohydrates and ample healthy fats with a bit more saturated fat be healthy enough? As the researchers state, we need long-term testing to help answer the question.