Gene Expression & Gut Health

This is Dr. Tim Spector. After training in medicine and becoming a consultant rheumatologist, he’s turned his attention to medical research, and is these days a specialist in twin studies, genetics, epigenetics, microbiome, and diet.

What does he want us to know?

For one thing: epigenetics are for more than just getting your grandparents’ trauma.

More usefully: there are things we can do to improve epigenetic factors in our body

DNA is often seen as the script by which our body does whatever it’s going to do, but it’s only part of the story. Thinking of DNA as some kind of “magical immutable law of reality” overlooks (to labor the metaphor) script revisions, notes made in the margins, directorial choices, and ad-lib improvizations, as well as the quality of the audience’s hearing and comprehension.

Hence the premise of one of Dr. Spector’s older books, “Identically Different: Why We Can Change Our Genes”

(*in fact, it was his first, from all the way back in 2013, when he’d only been a doctor for 34 years)

Gene expression will trump genes every time, and gene expression is something that can often be changed without getting in there with CRISPR / a big pair of scissors and some craft glue.

How this happens on the micro level is beyond the scope of today’s article; part of it has to do with enzymes that get involved in the DNA transcription process, and those enzymes in turn are despatched or not depending on hormonal messaging—in the broadest sense of “hormonal”; all the body’s hormonal chemical messengers, not just the ones people think of as hormones.

However, hormonal messaging (of many kinds) is strongly influenced by something we can control relatively easily with a little good (science-based) knowledge: the gut.

The gut, the SAD, and the easy

In broad strokes: we know what is good for the gut. We’ve written about it before at 10almonds:

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

This is very much in contrast with what in scientific literature is often abbreviated “SAD”, the Standard American Diet, which is very bad for the gut.

However, Dr. Spector (while fully encouraging everyone to enjoy an evidence-based gut-healthy diet) wanted to do one better than just a sweeping one-size-fits-all advice, so he set up a big study with 15,000 identical twins; you can read about it here: TwinsUK

The information that came out of that was about a lot more than just gene expression and gut health, but it did provide the foundation for Dr. Spector’s next project, ZOE.

ZOE crowdsources huge amounts of data including individual metabolic responses to standardized meals in order to predict personalized food responses based on individual biology and unique microbiome profile.

In other words, it takes the guesswork out of a) knowing what your genes mean for your food responses b) tailoring your food choices with your genetic expression in mind, and c) ultimately creating a positive feedback loop to much better health on all levels.

Now, this is not an ad for ZOE, but if you so wish, you can…

• Get the free ZOE gut health guide (this is good, but generic, gut health information)
• Take the ZOE home gut health test (quiz followed by offers of lab tests)
• Browse the ZOE Health Academy, its education wing

Want to know more?

Dr. Spector has a bunch of books out, including some that we’ve reviewed previously:

• Spoon-Fed: Why Almost Everything We’ve Been Told About Food Is Wrong
• The Diet Myth: The Real Science Behind What We Eat
• Food for Life: The New Science of Eating Well

You can also check out our own previous main feature, which wasn’t about Dr. Spector’s work but was very adjacent:

The Brain-Gut Highway: A Two-Way Street

Enjoy!

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!