对19世纪的收获记录的分析来自一个孤立的瑞典社区，表明，如果父亲的祖母在童年时期粮食可用性发生了巨大变化，则女性孙子会增加患心脏病的死亡风险。

保持自由压力，保持健康，饮食良好 - 这些都是我们要做的一切，以保持我们的心脏健康。但是，您是否曾经想过您的父母和祖父母是否也会影响您的事情？New research已经建议，即使您的祖父母的饮食经历也可能影响您自己的健康。

食物短缺和饥荒显然对您不利。遭受饥荒或艰辛的成年人的心血管疾病风险较高，儿童众所周知，这些影响也可能降低到其未出生的后代健康状况。

对发展中的胎儿强调的强调似乎很直观，这很少是个好消息，但是除了第一代之外，这还呢？那你的格兰吃什么呢？找到这些问题的答案很棘手，因为饮食日记很少几代人保存。但是，数据集确实存在，科学家可以从何时从饮食中推断出饮食。

Retracing the records

One such unique cohort is from a remote community in Northern Sweden called Överkalix. Fortunately for researchers interested in studying “transgenerational effects” on health, diligent 19th century record keepers kept detailed accounts of harvests, births, deaths and family trees – just the kind of things that 21st century scientists need to figure out how much of what we are now reflects what our grandparents ate way back then when affects us now.

In the 19th century, the town of Överkalix was largely isolated from most of Sweden during the winter months, as it lacked a rail line linking it to the southern half of the country. Freezing of the Baltic sea during the same period meant that communities in this area were totally reliant on the success of the previous year’s food harvest, since there was no route for supplies to get through.

Detailed family histories kept by the parish registry have meant that family lives can be traced back to specific times in the community’s history, creating a high-quality pedigree in which the shock of moving from feast to famine, or vice versa, can be followed across generations.

在新的分析中今天出版inBMC遗传学这是来自瑞典三所大学和英国一所大学的研究人员的合作，这是在19世纪的五个单独的场合，当时收获质量在连续几年之间发生了巨大变化。

Tracing back individual family lines across two generations, they find a striking effect on the cardiovascular health of one subset of grandchildren in particular — daughters whose grandmother (on their father’s side) had experienced one or more episodes of drastic nutritional change before puberty were at a much greater risk of heart-related death compared to those whose grandmothers had not. In fact, no other groups of great-grandchildren among this cohort had a comparable risk to their cardiovascular health, regardless of whether their grandparents had experience the drastic change in food-supply or not.

Importantly, the researchers focused primarily on the magnitude of change in food availability, rather than the方向of change. That is, regardless of whether feast-followed-famine or famine-followed-feast, women on the paternal grandmothers’ side were affected most.

So what could be driving these effects, and why should they be so targeted to just one line of female grandchildren?

X marks the spot

作者推测，在生殖线X染色体上以表观遗传标记传播的代谢变化可能是负责的。在接受采访Biome magazine，这两位研究的作者拉斯·奥洛夫·拜格伦（Lars Olov Bygren）和马库斯·彭布里（Marcus Pembrey）解释了：

“Females have more routes than males through which exposure-induced physiological or metabolic changes can impact on the next generation.” However, they also caution that the picture looks likely to be complicated: “More than one mechanism is likely to be employed in the chain of events that make up a transgenerational response.”

That the effect seen in this study appears only on the paternal line could well be the result of epigenetic marks being erased when two X chromosomes recombine down the maternal line. In contrast, when the middle generation is male not all the X and Y chromosomes recombine, potentially maintaining an epigenetic signal.

尽管在没有分子分析的情况下，这些机制仍然是投机性的，但它们为复杂的图像增加了有价值的数据，这些数据对多代营养和压力的影响出现了。基于实验室和动物模型的实验实验正在深入研究这些反应的分子机制 - 在某些情况下，发现级联的效果一直降低到七代非暴露个人。

The Överkalix cohort also adds to a number of other valuable, ongoing datasets involving human populations, mostly arising out of great hardships from the recent past. The Second World War in particular has provided several harrowing, real-life experiments on the effects of malnutrition in humans. The three-year siege of Leningrad and the Dutch Hunger Winter of 1944-45 have both shed light on the inter-generational effects of stress, whilst more recent programs such as the Avon Longitudinal Cohort of Parent and Children (ALCPC) has been following individuals born in the 1990’s, and is already yielding valuable data on smoking-related transgenerational effects on childhood growth.

当然，将不同因素的相对效应与这些独特的自然体验的相对影响隔离，这通常会在基于实验室的实验中受到控制。Bygren和Pembrey解释了：

营养危机通常与个人，家庭和社会负担有关。对于即将到来的研究，辨别两个一般因素的归因将很重要。饥荒可能与压力有关，这至少在实验动物中会诱导转世反应。”

Results from Överkalix and other cohorts are beginning to build a complex picture of human health across the generational divide, in which there is still much to be resolved:

“This type of confounding can only be resolved with many more human transgenerational studies including studies of stressful events not associated with famine”.