A Cold Shower A Day Keeps The Doctor Away?

This is Dutch extreme athlete Wim Hof, also known as “The Iceman”! He’s broken many world records mostly relating to the enduring the cold, for example:

• climbing Mount Kilimanjaro in shorts
• running a half-marathon above the Arctic Circle barefoot
• standing in a container completely covered with ice cubes for more than 112 minutes

You might not want to do yoga in your pyjamas on an iceberg, but you might like…

• better circulatory health
• reduced risk of stroke
• a boosted immune system
• healthier skin
• more energy and alertness

…and things like that. Wim Hof’s method is not just about extreme athletic achievements; most of what he does, the stuff that can benefit the rest of us, is much more prosaic.

The Wim Hof Method

For Wim Hof, three things are key:

• Breathing (See: Wim Hof Method Breathing Exercises)
• Commitment (See: How to Increase Willpower)
• Cold therapy (See: Benefits of Cold Therapy)

Today, we’re going to be focusing on the last one there.

What are the benefits of Cold Therapy?

Once upon a time, we didn’t have central heating, electric blankets, thermal underwear, and hot showers. In fact, once upon a time, we didn’t have houses or clothes. We used to be a lot more used to the elements! And while it’s all well and good to enjoy modern comforts, it has left our bodies lacking practice.

Practice at what? Most notably: vasodilation and vasoconstriction, in response to temperature changes. Either:

• vasodilation, because part of our body needs more blood to keep it warm and nourished, or
• vasoconstriction, because part of our body needs less blood running through it to get cooled down.

Switching between the two gives the blood vessels practice at doing it, and improves vascular muscle tone. If your body doesn’t get that practice, your blood vessels will be sluggish at making the change. This can cause circulation problems, which in turn have a big impact in many other areas of health, including:

• cardiovascular disease
• stroke risk
• mood instability
• nerve damage in extremities

On the flipside, if the blood vessels do get regular practice at dilating and constricting, you might enjoy lower risk of those things, and instead:

• improved immune response
• healthier skin
• better quality sleep
• more energy and alertness
• improved sexual performance/responsiveness

So, how to get that, without getting extreme?

As today’s title suggests, “a cold shower a day” is a great practice.

You don’t have to jump straight in, especially if you think your circulation and vascular responses might be a bit sluggish in the first instance. In fact, Wim Hof recommends:

• Week 1: Thirty seconds of cold water at the end of a warm shower each morning
• Week 2: One minute of cold water at the end of a warm shower each morning
• Week 3: A minute and a half of cold water at the end of a warm shower each morning
• Week 4: Two minutes of cold water at the end of a warm shower each morning

How cold is cold?

The benefits of cold exposure begin at around 16ºC / 60ºF, so in most places, water from the cold water mains is sufficiently cold.

As your body becomes more used to making the quick-change on a vascular level, the cold water will seem less shocking to your system. In other words, on day 30 it won’t hit you like it did on day one.

At that point, you can either continue with your two-minutes daily cold shower, and reap the benefits, or if you’re curious to push it further, that’s where ice baths come in!

Can anyone do it, or are any conditions contraindicated?

As ever, we’re a health and productivity newsletter, not doctors, let alone your doctors. Nothing here is medical advice. However, Wim Hof himself says:

❝Listen to your body, and never force the practices. We advise against doing Wim Hof Method if you are dealing with any of the following:

• Epilepsy
• High blood pressure
• Coronary heart disease
• A history of serious healthy issues like heart failure or stroke
• Pregnancy*
• Childhood*❞

*There is simply not enough science regarding the effects of cold exposure on people who are pregnant, or children. Obviously, we don’t expect this to be remedied anytime soon, because the study insitutions’ ethics boards would (rightly!) hold up the study.

As for the other conditions, and just generally if unsure, consult a doctor.

As you can see, this does mean that a limitation of Cold Therapy is that it appears to be far better as a preventative, since it helps guard against the very conditions that could otherwise become contraindications.

We haven’t peppered today’s main feature with study papers, partly because Wim Hof’s own website has kindly collated a collection of them (with links and summaries!) onto one page:

Further reading: The Science Behind The Wim Hof Method

Dr. Greger’s Anti-Aging Eight

This is Dr. Michael Greger. We’ve featured him before: Brain Food? The Eyes Have It!

This time, we’re working from his latest book, the excellent “How Not To Age”, which we reviewed all so recently. It is very information-dense, but we’re going to be focussing on one part, his “anti-aging eight”, that is to say, eight interventions he rates the most highly to slow aging in general (other parts of the book pertained to slowing eleven specific pathways of aging, or preserving specific bodily functions against aging, for example).

Without further ado, his “anti-aging eight” are…

1. Nuts
2. Greens
3. Berries
4. Xenohormesis & microRNA manipulation
5. Prebiotics & postbiotics
6. Caloric restriction / IF
7. Protein restriction
8. NAD⁺

As you may have noticed, some of these are things might appear already on your grocery shopping list; others don’t seem so “household”. Let’s break them down:

Nuts, greens, berries

These are amongst the most nutrient-dense and phytochemical-useful parts of the diet that Dr. Greger advocates for in his already-famous “Dr. Greger’s Daily Dozen”.

For brevity, we’ll not go into the science of these here, but will advise you: eat a daily portion of nuts, a daily portion of berries, and a couple of daily portions of greens.

Xenohormesis & microRNA manipulation

You might, actually, have these on your grocery shopping list too!

Hormesis, you may recall from previous editions of 10almonds, is about engaging in a small amount of eustress to trigger the body’s self-strengthening response, for example:

• The Stress Prescription (Against Aging!)
• A Cold Shower A Day Keeps The Doctor Away?

Xenohormesis is about getting similar benefits, second-hand.

For example, plants that have been grown to “organic” standards (i.e. without artificial pesticides, herbicides, fertilizers) have had to adapt to their relatively harsher environment by upping their levels of protective polyphenols and other phytochemicals that, as it turns out, are as beneficial to us as they are to the plants:

Hormetic Effects of Phytochemicals on Health and Longevity

Additionally, the flip side of xenohormesis is that some plant compounds can themselves act as a source of hormetic stress that end up bolstering us. For example:

Redox-linked effects of green tea on DNA damage and repair, and influence of microsatellite polymorphism in HMOX-1: results of a human intervention trial

In essence, it’s not just that it has anti-oxidant effect; it also provides a tiny oxidative-stress immunization against serious sources of oxidative stress—and thus, aging.

MicroRNA manipulation is, alas, too complex to truly summarize an entire chapter in a line or two, but it has to do with genetic information from the food that we eat having a beneficial or deleterious effect to our own health:

Diet-derived microRNAs: unicorn or silver bullet?

A couple of quick takeaways (out of very many) from Dr. Greger’s chapter on this is to spring for the better quality olive oil, and skip the cow’s milk:

• Impact of Phenol-Enriched Virgin Olive Oils on the Postprandial Levels of Circulating microRNAs Related to Cardiovascular Disease
• MicroRNA exosomes of pasteurized milk: potential pathogens of Western diseases

Prebiotics & Postbiotics

We’re short on space, so we’ll link you to a previous article, and tell you that it’s important against aging too:

Making Friends With Your Gut (You Can Thank Us Later)

An example of how one of Dr. Greger’s most-recommended postbiotics helps against aging, by the way:

• The mitophagy activator urolithin A is safe and induces a molecular signature of improved mitochondrial and cellular health in humans
• Urolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomized trial in middle-aged adults

(Urolithin can be found in many plants, and especially those containing tannins)

See also: How to Make Urolithin Postbiotics from Tannins

Caloric restriction / Intermittent fasting

This is about lowering metabolic load and promoting cellular apoptosis (programmed cell death; sounds bad; is good) and autophagy (self-consumption; again, sounds bad; is good).

For example, he cites the intermittent fasters’ 46% lower risk of dying in the subsequent years of follow-up in this longitudinal study:

Association of periodic fasting lifestyles with survival and incident major adverse cardiovascular events in patients undergoing cardiac catheterization

For brevity we’ll link to our previous IF article, but we’ll revisit caloric restriction in a main feature on of these days:

Fasting Without Crashing? We sort the science from the hype!

Dr. Greger favours caloric restriction over intermittent fasting, arguing that it is easier to adhere to and harder to get wrong if one has some confounding factor (e.g. diabetes, or a medication that requires food at certain times, etc). If adhered to healthily, the benefits appear to be comparable for each, though.

Protein restriction

In contrast to our recent main feature Protein vs Sarcopenia, in which that week’s featured expert argued for high protein consumption levels, protein restriction can, on the other hand, have anti-aging effects. A reminder that our body is a complex organism, and sometimes what’s good for one thing is bad for another!

Dr. Greger offers protein restriction as a way to get many of the benefits of caloric restriction, without caloric restriction. He further notes that caloric restriction without protein restriction doesn’t decrease IGF-1 levels (a marker of aging).

However, for FGF21 levels (these are good and we want them higher to stay younger), what matters more than lowering proteins in general is lowering levels of the amino acid methionine—found mostly in animal products, not plants—so the source of the protein matters:

Regulation of longevity and oxidative stress by nutritional interventions: role of methionine restriction

For example, legumes deliver only 5–10% of the methionine that meat does, for the same amount of protein, so that’s a factor to bear in mind.

NAD⁺

This is about nicotinamide adenine dinucleotide, or NAD⁺ to its friends.

NAD⁺ levels decline with age, and that decline is a causal factor in aging, and boosting the levels can slow aging:

Therapeutic Potential of NAD-Boosting Molecules: The In Vivo Evidence

Can we get NAD+ from food? We can, but not in useful quantities or with sufficient bioavailability.

Supplements, then? Dr. Greger finds the evidence for their usefulness lacking, in interventional trials.

How to boost NAD⁺, then? Dr. Greger prescribes…

Exercise! It boosts levels by 127% (i.e., it more than doubles the levels), based on a modest three-week exercise bike regimen:

Skeletal muscle NAMPT is induced by exercise in humans

Another study on resistance training found the same 127% boost:

Resistance training increases muscle NAD+ and NADH concentrations as well as NAMPT protein levels and global sirtuin activity in middle-aged, overweight, untrained individuals

Take care!